Brass vs Steel 7.62x39mm Ammo: Reliability, Performance & Accuracy Compared

Brass vs Steel 7.62x39mm Ammo: Reliability, Performance & Accuracy Compared

Choosing between brass-cased and steel-cased 7.62x39mm ammunition is a common dilemma for AK-47 and AR-15 enthusiasts. Each type of casing has its own impact on reliability, performance, and the long-term health of your firearm. In this guide, we provide an objective comparison of brass vs. steel 7.62x39 ammo – covering cost, extraction, chamber cleanliness, barrel wear, and more. We’ll dispel myths (especially about using steel ammo in AK-47s vs. AR-15s) and explain why brass-cased 7.62x39mm (such as MARK-1’s 124GR FMJ Brass) is often the superior choice for consistency and longevity.

Understanding Steel vs. Brass Casings in 7.62x39 Ammo

Before diving into specifics, it’s important to understand what “steel-cased” vs “brass-cased” means:

• Brass-Cased Ammo: Uses a brass alloy cartridge case. Brass is softer and more malleable, which allows it to expand and seal the chamber when fired, then contract for easy extraction . Brass is also corrosion-resistant and reloadable.

• Steel-Cased Ammo: Uses mild steel for the cartridge case (often with a protective coating). Steel is harder and less ductile than brass, making it cheaper to produce but less adaptive in the chamber. Steel cases usually aren’t reloadable and can be prone to rust if not coated .

Quick Comparison – Steel vs. Brass 7.62x39:

• Cost: Steel is generally ~20% (or more) cheaper per round than brass , making it popular for high-volume shooting.

• Reliability: Brass expands and seals better for dependable extraction, while steel’s rigidity can lead to more carbon build-up (though AK-type rifles are built to handle it) .

• Cleanliness: Brass ammo burns cleaner with less residue and smoke; steel allows more fouling in the chamber due to a poorer seal .

• Barrel Wear: Many steel-case rounds use bi-metal (steel) jacketed bullets that accelerate barrel wear compared to the copper-jacketed bullets typically loaded in brass ammo .

• Reloadability: Brass cases are boxer-primed and reloadable, whereas steel cases are often Berdan-primed and not practical to reload .

• Corrosion: Brass is naturally corrosion-resistant (slower to oxidize), whereas steel will rust without protective coatings .

• Use Case: Steel-cased ammo is great for budget practice and AKs built for it; brass-cased ammo is optimal for maximum reliability, accuracy, and long-term firearm care.

Next, let’s break down each of these factors in detail.

Cost and Value: Brass vs. Steel 7.62x39 Ammo

One of the biggest draws of steel-cased 7.62x39 is its low cost. Steel ammo is “dirt cheap” to manufacture, often running at least 20% less expensive than equivalent brass rounds . For example, a case of steel 7.62x39 (e.g. Wolf or TulAmmo) might save you a significant amount if you’re planning to burn through hundreds of rounds in your AK-47 during a range session.

Brass-cased ammo, on the other hand, commands a premium price. The materials and manufacturing are costlier, and you’re paying for that quality. For shooters on a tight budget or those who plink in high volume, steel can be an enticing way to stretch your dollars. However, it’s worth considering the value beyond the price per round:

• Reloading Value: If you or someone you know handloads, each brass case can be reused multiple times. That offsets cost in the long run because you can reload brass 7.62x39mm cases (with new primers, powder, and bullets) instead of buying new ammo . Steel cases are not reloadable in practice, so every steel round is one-and-done.

• Wear & Tear Costs: We’ll discuss barrel and parts wear more below, but note that cheap ammo isn’t truly cheap if it causes you to replace barrels or parts more often. Some studies found that thousands of rounds of steel ammo can wear out a rifle barrel roughly twice as fast as brass ammo would . Thus, the money saved on ammo might be spent on a new barrel or extractor sooner.

• Performance for Price: Brass-cased 7.62x39 (like MARK-1’s 124GR FMJ Brass) typically offers more consistent performance, which is crucial in competitions or serious training. If each shot is more accurate (and we’ll see that it often is), you might get more value out of a pricier brass round than a cheap steel one that doesn’t hit where you aim.

In short, steel ammo wins on upfront cost, but brass ammo can pay dividends in reloadability, better performance, and less wear. Your choice may depend on whether immediate savings or long-term value is the priority.

Extraction and Reliability in the Chamber

Reliable feeding and extraction are critical for any semi-auto rifle. Here’s how brass and steel cases affect these functions:

• Sealing the Chamber: Upon firing, the case obturates (expands) to seal off the chamber and prevent gases from blowing back. Brass excels here – its malleability lets it expand fully and then spring back, which prevents gas leakage and eases extraction . Mild steel is less elastic, so it may not form as perfect a seal. This can allow hot carbon-laden gases to leak around the case and dirty up the chamber (more on fouling later) . The slight gap with steel can also mean the case doesn’t shrink back as much, potentially making extraction a bit stickier in some firearms.

• Smooth Extraction: Brass’s “springiness” contributes to smoother extraction and less strain on the extractor claw . A brass case that has expanded and then contracted will slide out easily, whereas a steel case, being stiffer, might remain expanded and require more force to pull out. This is one reason some shooters report occasional stuck cases or failures to extract with steel, particularly in rifles with tight chambers or weaker extraction systems.

• Extractor Wear: Because steel is harder than brass, there is a concern that it can wear down the extractor (the hook that yanks the spent casing out) faster. Brass causes very little extractor wear due to its softness . Steel casings are still made of relatively soft mild steel, but over many thousands of rounds the extra hardness can take a toll on the extractor’s edge . In one test, AR-15s shooting steel showed more extractor wear by 10,000 rounds (not always visible to the naked eye, but measurable) and could benefit from a mid-test extractor spring replacement . The good news is extractors are cheap and easy to replace, so this isn’t a major fear point – just part of normal maintenance if you run a lot of steel.

• AK vs AR Extraction Dynamics: Here’s an interesting twist – the AK-47 (and SKS) were designed around steel-cased ammo and have very robust extraction. These rifles feature a long-stroke piston and a big chunky extractor claw, with a violent pull on the case to rip it out of the chamber. They’ll run steel ammo all day. In fact, some sources note that in these Soviet-designed guns with “violent extraction,” a brass case could be more likely to suffer a case-head separation (tearing in half) under extreme conditions . Steel’s extra rigidity might actually help it hold together during the aggressive extraction cycle of an AK . Such failures are rare, but it’s a reminder that AKs happily chew through steel by design – and why many AK owners have never even seen a brass case in their guns. AR-15s, by contrast, have a shorter, faster extraction cycle that’s not as overpowered as an AK’s. They rely more on the case contracting for easy removal. So, ARs tend to be a bit more sensitive to steel vs. brass differences, which we’ll explore more in the AR vs AK section.

In summary, brass-cased ammo generally offers more reliable extraction and less stress on your gun, especially in firearms with tighter tolerances. Steel can work reliably too (and does in millions of AKs), but you might see a few more hiccups. For critical uses where you need absolute reliability (home defense or competition), brass has the edge in giving you confidence that each round will feed and eject smoothly.

Chamber Cleanliness and Fouling

Another major difference between brass and steel 7.62x39 ammo is how clean or dirty they run your gun’s chamber and action:

• Brass Seals Better = Less Fouling: As mentioned, a brass case expands to seal the chamber completely. This means most of the soot and powder gas goes out the barrel behind the bullet, rather than leaking back. Steel cases, not sealing as perfectly, allow more carbon and soot to blow back into the chamber . The result? After firing a bunch of steel rounds, you’ll typically find your chamber and bolt face dirtier than if you had fired the same number of brass rounds. More fouling can eventually lead to sticking or malfunctions if not cleaned, especially in a tighter AR-style action.

• Coatings on Steel Ammo: To aid feeding and prevent corrosion, steel cases are often coated with polymer or lacquer by the manufacturer . (For example, TulAmmo and Wolf use gray polymer, Barnaul’s Brown Bear uses green lacquer.) There’s a longstanding misconception that “lacquer coatings will melt in a hot chamber and gum up the works.” However, extensive testing has debunked this myth – even after firing thousands of rounds to heat up the chamber, no evidence of melted lacquer causing stuck cases was found . In fact, one test showed polymer-coated steel ammo had more extraction failures than lacquer-coated ammo, indicating lacquer was not the culprit for issues . The truth is the carbon build-up from gas blow-by is a more likely cause of any sticking with steel – not the coating. Regardless, both polymer and lacquer perform similarly in normal use; just focus on cleaning the gun periodically.

• “Dirty” Powder and Primers: Many steel-cased rounds (especially imported ones) use powder that isn’t as clean-burning, and some use primers that can leave residues. Shooters often notice that steel ammo is smokier and smellier – a common remark is that some steel rounds have a harsh odor (ammonia or “cat urine” smell) when fired . By contrast, quality brass ammo tends to use cleaner-burning propellants. In a hands-on comparison, a shooter found that Fiocchi brass-cased 7.62x39 produced far less smoke and didn’t have the acrid smell of typical steel ammo, and the gun “shot much cleaner than steel cased ammo” – with barely any clean-up needed after 40 rounds, whereas 40 rounds of steel left a noticeable mess . Less smoke and residue also mean your internals stay cleaner longer.

• Cleaning Intervals: Because of the above factors, if you shoot a lot of steel, you’ll need to clean your rifle more frequently for optimal function. An AK-47 will chug along even when filthy (that’s its claim to fame), but an AR-style rifle running steel may start to choke if the chamber gets grimy. If you switch from brass to steel in one session, be mindful: the brass might leave a thin carbon layer, and the steel case won’t expand enough to scrape it out, potentially causing a sticky chamber. It’s a good practice to either shoot steel first or clean the chamber before switching to steel ammo during extended shooting.

Bottom line: Brass-cased ammo tends to keep your gun cleaner – a benefit for both reliability and maintenance time. Steel-cased ammo isn’t “bad” or inherently corrosive (modern steel rounds are usually non-corrosive), but they do run dirtier. Keep that bore brush handy, and your firearm will be fine with either type, as long as you give it a cleaning when due.

Barrel Wear: Bi-Metal vs. Copper Jackets

One of the most important long-term considerations is barrel wear. Many people have heard that shooting a lot of steel ammo will wear out a barrel faster. Is this true, and if so, why? The answer lies not in the case material, but in the bullet jacket material.

Most brass-cased 7.62x39 ammo (especially Western or commercial ammo) uses bullets with a traditional copper jacket over a lead core – often a gilding metal jacket (copper alloy) that engages the rifling. Copper is relatively soft. Steel-cased ammo from Russia and similar sources often uses “bi-metal” jackets, which are mild steel jackets plated with copper or tombac. The bullet looks like a normal FMJ, but underneath the thin copper wash is a layer of steel. When you fire these, you are effectively putting a soft steel object down your barrel at high speed.

Tests have confirmed that bi-metal jackets greatly increase barrel wear compared to pure copper jackets. In one epic torture test involving 10,000 rounds through AR-15 barrels, the rifles firing bi-metal jacket steel ammo lost accuracy much sooner. The barrels shooting steel-case/bi-metal ammo were “shot out” (accuracy dropped off a cliff) after about 4-5,000 rounds, whereas the barrel shooting brass-case copper-jacketed ammo was still holding acceptable accuracy at 10,000 rounds with no replacement needed . That’s a dramatic difference – roughly double the barrel life with copper jackets.

Why the big disparity? Simply put, steel on steel causes more friction and erosion. A barrel’s rifling is steel; a copper jacket glides over it with minimal abrasion, but a steel jacket (even a soft steel) scrapes more material with each shot. Over thousands of rounds, the rifling wears down faster. Think of it like sandpaper: copper is like a very fine grit, steel is like a coarse grit. The effect isn’t immediate – you won’t see wear from just a few magazines of ammo – but it accumulates.

It’s worth noting that not all steel-cased ammo has bi-metal jackets, but the common budget brands (Tulammo, Wolf, Barnaul, etc.) typically do. Some labels will say “Magnetic” if the bullet sticks to a magnet, that indicates steel content in the jacket or core. There have been exceptions: for instance, TulAmmo made a “range friendly” 7.62x39 with a non-steel (lead/copper) bullet, and Hornady produced a match-grade 7.62x39 with a steel case but a premium V-MAX or SST bullet. Those won’t harm your barrel like the bi-metal FMJs do. But most shooters buying steel ammo are getting the cheap stuff, and that usually means bi-metal FMJ. So, the rule of thumb stands: steel cased ammo itself doesn’t wear your barrel – but the steel jacketed bullets in it do.

In contrast, high-quality brass-cased ammo will have non-magnetic bullets (copper jacket, sometimes with a lead core or a specialty expanding tip). These are much gentler on rifling. That’s a key reason we say brass ammo is better for long-term firearm health. If you’re primarily shooting brass ammo, your barrel will maintain its accuracy for more rounds down the line.

Also related to wear is the throat erosion and gas port erosion from hotter-burning powders. Some steel ammo might use faster powder that increases flame temperature, potentially eroding the throat faster. However, the big factor is still the bullet jacket hardness. If maximizing barrel longevity is important to you – for example, you have a match-grade AR-15 in 7.62x39 or a cherished rifle you want to keep accurate – investing in brass ammo with copper-jacketed bullets is the wise choice.

“The bi-metal jacket greatly increases barrel wear, meaning that you will need to purchase a new barrel… a lot sooner than if you shot copper jacketed bullets.” This statement from an ammunition guide succinctly captures why many experienced shooters avoid running excessive steel through their guns. In practical terms, maybe your AK’s barrel lasts 15,000 rounds with brass ammo vs 10,000 with steel – if the cost savings of steel are enough to buy a new barrel, some will accept that trade-off. Others would rather not hassle with a barrel change and stick to brass.

Accuracy and Performance Differences

When it comes to downrange performance – i.e. how consistent and accurate the rounds are – brass vs steel can make a noticeable difference. However, it’s not an intrinsic magic of the metal; it’s largely due to manufacturing quality and consistency:

• Muzzle Velocity Consistency: Brass-cased ammo is usually loaded to tighter tolerances, yielding more consistent muzzle velocities shot-to-shot . Consistent velocity is key for consistent impact points. Many steel-cased commercial ammo brands have a reputation for wider velocity variation and often slightly lower power. In fact, a reviewer shooting Fiocchi brass 7.62x39 noted that it felt “hotter” than typical steel ammo – and indeed the point of impact was higher, indicating higher velocity, whereas “much of the steel cased ammo on the market is under-loaded.” . Brass ammo from quality manufacturers (e.g., Fiocchi, Sellier & Bellot, Prvi Partizan, or MARK-1’s 124gr FMJ) is usually loaded closer to the original spec for 7.62x39, giving you the full power the cartridge can offer.

• Group Accuracy: Beyond velocity, accuracy is affected by bullet consistency (weight, uniformity) and how well the bullet engages the rifling. Cheap steel-case ammo is often considered “plinking ammo” – it might get 4-6 inch groups at 100 yards in an AK, which is fine for fun but not precision. In contrast, brass-case ammo, especially if it’s marketed as “match” or just made with better QC, can shrink those groups. In the Fiocchi example, the shooter observed the brass ammo was “noticeably more accurate” than the steel ammo he usually used . The groups were tighter and more consistent, turning a decent AK into an actually pretty precise shooter. This isn’t surprising, as Fiocchi (and similar ammo) uses better-made bullets and charges. Some users report similar improvements with other brass brands or premium loads – the rifle just shoots better when fed better ammo.

• Quality Control: Brass ammo is often made by companies aiming at markets that demand reliability and accuracy (military contracts, hunters, etc.), so there’s typically a higher level of quality control in powder charge uniformity, primer seating, case dimensions, etc. Steel ammo from former Eastern bloc factories is mass-produced for affordability and assumes the end platform (AK rifle) doesn’t require pinpoint precision. As a result, there can be more variability round to round (occasional flier shots, etc.). This doesn’t mean all steel-case ammo is inaccurate – you can certainly hit targets with it out to a few hundred yards – but if you’re looking for tight MOA-level groups or maximum consistency, you’ll likely favor brass.

• Recoil and Shootability: There is a minor difference in felt recoil or “smoothness” as well. Brass-cased rounds that are loaded a bit hotter will kick more, but also cycle the firearm more reliably (especially in something like an AR). Underpowered steel rounds sometimes cause marginal cycling (short-stroking) in AR-15s, though it’s less of an issue in AKs which are over-gassed by design. If you ever experience an AR failing to lock back or cycling sluggishly with steel ammo, switching to brass ammo often fixes it because of the slight bump in pressure and cleaner burn.

In a nutshell, brass-cased 7.62x39 ammo generally delivers better accuracy and more consistent performance than the typical steel-cased varieties. This is why serious shooters – whether it’s for competition, hunting, or defense – will opt for brass. For casual blasting of cans or hitting torso-sized steel plates, steel ammo is usually “good enough.” Just set your expectations: you might get a 2-3″ tighter group with something like MARK-1’s 124gr FMJ brass ammo or another premium load, compared to the bargain steel stuff.

Reloadability and Reusability

If you’re a reloader (handloader) or even thinking about getting into it, the choice between brass and steel is a no-brainer. Brass cases are reusable; steel cases are not (at least not easily or economically).

Brass-cased 7.62x39 ammo is almost always Boxer-primed, which means it has a single central flash hole and uses a Boxer primer that is easy to punch out and replace. Steel-cased ammo from Russia/Europe is typically Berdan-primed, with two off-center flash holes and a primer that is extremely difficult to remove. Berdan primers make conventional reloading impractical . Moreover, the steel material doesn’t handle the stresses of resizing well – it lacks the elasticity of brass, so it won’t reform to original dimensions without cracking or getting stuck in reloading dies . In short, steel cases are meant to be used once and discarded .

Brass cases, by contrast, can be collected, cleaned, and run through reloading dies to load again. Even if you personally don’t reload, save your brass or give it to someone who does. Many shooters even collect spent brass at ranges (another reason some ranges don’t allow steel – they resell the spent brass scrap). Some popular brass 7.62x39 options (like Prvi Partizan or Winchester “white box”) are valued because you get reloadable cases for your stockpile.

From a storage/preparedness perspective, reloadable brass gives you more flexibility. In ammo shortages, reloaders were able to replenish their 7.62x39 supply by component handloading when factory ammo (especially imports) was scarce or expensive. With steel, you’re out of luck once your stash is shot.

Another angle to reloadability is “stripper clips” and magazine ease: Many surplus ammo cans of steel 7.62x39 come on stripper clips (for SKS rifles) or loose. Brass ammo from Western sources often comes in 20-round boxes. This is a minor point, but some find brass ammo easier to handle for loading magazines (depending on packaging) since it’s not covered in as much grime or factory sealant compound.

Finally, spent steel cases have little salvage value – you can’t get cash for them at the recycler (and they aren’t picked up by range brass scavengers). They are magnetic, so one clever trick is using a magnet to quickly collect them from your shooting area (as one forum member noted, it’s handy to clean up a pasture by picking up steel cases with a magnet) . With brass, you might actually profit a bit by selling the scrap or once-fired brass.

In summary, brass = reloadable and reusable; steel = shoot it and sweep it. If you never plan to reload and don’t care about picking up cases, this may not matter – but it’s always nice to have the option.

Corrosion and Long-Term Storage

When storing ammo for the long term (months to years), the casing material becomes important for keeping your rounds in good condition:

• Brass Resists Corrosion: Brass is an alloy of copper and zinc and does not rust like iron/steel. It can tarnish (turn brownish), but that’s usually superficial. As long as you keep it dry, brass ammo can last decades. Military surplus brass rounds from the mid-20th century often still fire just fine if they were stored well. Brass “endures harsher conditions” and doesn’t succumb to rust and decay as quickly as steel .

• Steel Needs Protection: Steel will start to oxidize (rust) if exposed to moisture over time. That’s why steel-case ammo is usually coated. The common polymer coatings do help a lot with rust prevention – you can find old tins of Soviet ammo where the rounds are still shootable thanks to sealant and coatings. However, if that coating is scratched or if humidity is constant, you might see rust spots on steel cases in storage. It’s cosmetic until it’s severe, but if a steel case gets too corroded it could become unusable or unsafe to fire. Always inspect older steel ammo for any serious rust.

• Storage Tips: If you’re storing steel-cased ammo, it’s wise to keep it in a climate-controlled environment or at least a dry ammo can with desiccant. Many surplus steel 7.62x39 rounds came in “spam cans” – hermetically sealed metal cans – which preserves them nicely. Once that seal is broken, though, the rounds inside will be exposed to air. Brass ammo also likes to be kept dry and cool, but it’s a bit more forgiving. For example, brass-cased hunting rounds often come in just a cardboard box and can sit on a shelf for years without issue. Steel-cased rounds left loose in a damp basement might surprise you with some orange fuzz (rust) next time you check.

• Temperature Extremes: Both brass and steel can handle a range of temperatures, but brass might have an edge in that it’s less brittle in extreme cold. Steel can lose some ductility when very cold, theoretically increasing the chance of case cracks or failures, though in practice most will still work in typical winter conditions. In extreme heat, coatings on steel could stick or leave residues, whereas brass might tarnish but not impair function. These are edge cases, but relevant for those who keep ammo in vehicles or sheds.

In general, for long-term caching of ammo, brass-cased is the “safer” choice simply because you have one less thing to worry about (rust). If you rotate through your ammo stash regularly, steel is fine to keep around. Just store it properly. MARK-1’s 124GR FMJ Brass, for instance, would be an excellent candidate for storage – being brass cased and non-corrosive, you could sock away a case of it and be confident it’ll be good to go years down the line.

Steel Ammo in AK-47s vs. AR-15s: Misconceptions and Realities

There are a lot of myths and assumptions floating around when it comes to using steel-cased ammo in different rifles – especially comparing the AK-47 and AR-15 platforms. Let’s address a few:

• “AK-47s were made for steel ammo, so you should only shoot steel in them.” – It’s true that the AK-47 was literally designed around steel-cased 7.62x39 from the beginning . The Soviet military used steel cases to save cost, and the AK’s loose tolerances and robust mechanism reflect that. AKs will run steel ammo reliably, even in harsh conditions, and the vast majority of ammo available for AKs has been steel-cased. However, this doesn’t mean AKs can’t shoot brass or that steel is inherently better in an AK. In fact, many modern brass-cased loads (like Yugoslav M67 or commercial brass ammo) shoot excellently in AKs, often giving better accuracy and cleaner performance (as we saw with the Fiocchi test) . The AK doesn’t “need” the case to be steel – it was just built tough enough to handle the cheaper steel. You won’t hurt your AK by feeding it brass; if anything, you’re pampering it with nicer food!

• “AR-15s will jam or break if you use steel ammo.” – Early AR-15/M16 rifles in Vietnam had issues due to poor powder, and that stigma has oddly carried over to people suspecting steel ammo as problematic. The reality: a well-made AR-15 can run steel 5.56 or even steel 7.62x39 with decent reliability, but it may not be as trouble-free as brass. In the LuckyGunner 10k round test with AR-15s, the brass ammo gun had zero malfunctions in 10,000 rounds, whereas the steel ammo guns had a handful (Wolf: 15 stoppages, Brown Bear: 9 stoppages over 10,000rds) . That’s over 99.9% reliability with steel, but brass was effectively 100%. So yes, steel showed a slightly higher failure rate in ARs during extreme testing. Additionally, as discussed, the AR barrels wore out faster with steel/bi-metal. Extractor wear was also higher, though replacing the extractor at 5,000 rounds kept things running . None of this means your AR will choke immediately on steel – many people run thousands of rounds of cheap steel through their AR-15s. But be aware: you must keep it cleaner (especially the chamber) and expect perhaps a shorter parts life. Many AR users find that if they do shoot steel, they’ll schedule more frequent maintenance (such as cleaning every few hundred rounds and swapping extractor springs at intervals) to ensure reliability .

• Differences in Caliber/Design: Note that most AR-15s are .223/5.56, and that’s where tons of anecdotal evidence comes from about steel vs. brass. If we’re talking AR-15s chambered in 7.62x39, there’s an added layer: the AR was not originally designed for this fat, tapered cartridge. Feeding 7.62x39 in an AR mag is tricky, and bolts can be weaker due to the larger case head. These rifles can be ammo-sensitive. Often, using good brass ammo (with properly sized cases and consistent pressure) can make an AR-7.62x39 run more smoothly than cheap steel ammo, simply because the AR’s tolerances are tighter than an AK’s. So in this niche case, brass may not only preserve your AR-15’s parts but also reduce the chances of feeding/extraction issues that an AK wouldn’t blink at.

• “Steel ammo will damage your AR-15’s chamber or void your warranty.” – Some firearm manufacturers or ranges discourage steel ammo. This is partly because of the bi-metal jacket issue (indoor ranges don’t want sparks or damage to backstops from steel in bullets ). From a chamber perspective, steel cases can be a bit harsher. If an AR has a rough or match-grade chamber, a steel case might scratch or wear it microscopically more than brass. But it’s not usually a significant worry. As long as you clean out the extra fouling, a quality barrel’s chamber will be fine. That said, always check your rifle’s manual – a few high-end manufacturers do recommend against steel-case ammo, likely to ensure users get the best function and longevity (or to steer them away from super cheap ammo in a premium gun).

In summary: AK-47 owners love steel ammo for its cost and history, and rightly so – it works and has proved itself in those guns. AR-15 owners are more split: steel ammo can be a great cost-saver for training, but you have to accept a bit more grime and wear. Neither platform “explodes” with the wrong ammo type, contrary to internet lore. It comes down to how much you value ease of use vs. cost. If you want the absolute utmost reliability and longevity from either an AK or AR, brass-cased ammo is the champ. If you’re okay doing more upkeep and possibly changing a barrel or extractor down the line, steel can serve you well for casual shooting.

To quote an ammo expert’s conclusion: “If you plan to shoot a rifle descended from the fine comrades of Eastern Europe (AK-47/AKM), steel should be what you feed your beast. However, if you like reloading or just enjoy the added reliability and barrel life but don’t mind the added cost, it’s brass all day long.” . And indeed, many shooters compromise by using steel for practice and brass for “serious” use.

Steel-cased 7.62x39mm FMJ cartridges (here, polymer-coated cases with copper-plated steel bullets). Steel ammo is affordable and made for AKs, but it tends to produce more chamber fouling and barrel wear than brass-cased ammo .

Conclusion: Which Should You Choose?

After weighing all the factors – cost, reliability, cleanliness, wear, accuracy, and more – we can draw some clear conclusions about brass vs. steel 7.62x39mm ammo:

• Steel-cased ammo is best suited for budget-conscious shooting and rugged firearms. If you’re just plinking at the range, training drills, or enjoying your AK-47 for what it was built for, steel ammo works fine. It will save you money and still go “bang” every time in a well-maintained gun (especially AKs or SKS rifles). Just be prepared to clean your weapon more often and accept a bit less pinpoint accuracy. For many AK enthusiasts, blasting through cheap steel ammo is half the fun of owning the rifle. In an AR-15 (or any rifle) where you want to shoot steel ammo, just monitor your parts for wear. Replacing an extractor or even a barrel after a high round count of steel is a manageable maintenance cost, often offset by the money saved per round .

• Brass-cased ammo is the better long-term choice for performance, consistency, and firearm health. If you value reliability above all (say for home defense or SHTF scenarios), go with quality brass – you want the ammo to be one less worry. If you treasure your rifle and want it to last tens of thousands of rounds, brass and its gentler bullets will help extend its life. For accuracy, there’s simply no contest: brass ammo loads are the way to go when tight groups matter. And if you reload, brass is your only real option. The upfront cost is higher, but you’re investing in your firearm’s performance. MARK-1’s 124gr FMJ brass-cased 7.62x39, for example, offers that top-tier reliability and consistency; round after round will feed smoothly, shoot accurately, and come out without beating up your gun the way cheap ammo might. Over years of shooting, that consistency builds trust in your equipment.

In practical terms, many shooters adopt a hybrid strategy: keep a stock of steel ammo for general practice or plinking, and reserve brass ammo for serious use – whether that’s dialing in optics, hunting, competition, or emergency purposes. This way you get the best of both worlds: savings when you need it, and performance when it counts. There’s no one-size-fits-all answer, but armed with the facts from this guide, you can make an informed decision.

Ultimately, our recommendation for most shooters: Use steel-cased 7.62x39 for fun and high-volume range days (especially in your AK platforms), but use brass-cased 7.62x39 whenever you want the utmost reliability and care for your firearm’s longevity. Your rifle will thank you in the long run with smoother operation and a longer life. And when in doubt, remember – brass is class! It may cost a bit more, but it delivers performance you can count on.