Best Mags for 300BLK — both subs and supers?

[TheHorta]

Brand spankin’ new to the world of 300BO. Just snagged a Noveske factory 10.5” and a new SR-30 9.5” — both suppressed SBRs.

I have a variety of mags — Gen 2/3 Pmags, DD mags, USGI mags, and 20 new USGI “Enhanced Performance” Mags for the new 855A1 rounds, and some of the heavy steel Israeli Elanders.

What mag(s) work best with 300BLK? Does it matter with subs or supers? (i.e. is there a difference in feeding?)

 

[Docsherm]

Brand spankin’ new to the world of 300BO. Just snagged a Noveske factory 10.5” and a new SR-30 9.5” — both suppressed SBRs.

I have a variety of mags — Gen 2/3 Pmags, DD mags, USGI mags, and 20 new USGI “Enhanced Performance” Mags for the new 855A1 rounds, and some of the heavy steel Israeli Elanders.

What mag(s) work best with 300BLK? Does it matter with subs or supers? (i.e. is there a difference in feeding?)

I have had the best luck with the Brownell's Aluminium mags with the MagPul Followers. No feeding issues at all for Supers or Subs. That is all I use for 300BO.

 

[Dryan910]

I am a big fan of the Lancer 300 BLK mags. Never had any issues with either subs or supers.

 

[Zack_va248]

Brand spankin’ new to the world of 300BO. Just snagged a Noveske factory 10.5” and a new SR-30 9.5” — both suppressed SBRs.

I have a variety of mags — Gen 2/3 Pmags, DD mags, USGI mags, and 20 new USGI “Enhanced Performance” Mags for the new 855A1 rounds, and some of the heavy steel Israeli Elanders.

What mag(s) work best with 300BLK? Does it matter with subs or supers? (i.e. is there a difference in feeding?)

Mine fed flawlessly through the gen2 pmags but wouldn't feed through gen3's if I had more than 5-6 rds loaded up. YMMV

 

[hafejd30]

I purchased 3 of these. Work great with 200 SB subs

PMAG® 30 AR 300 B GEN M3™, 300 BLK

GEN M3 technology for your 300 BLK

magpul.com

 

[Landon4]

I’ve used the magpul 300 bo specific mags without issue for several years now

 

[Ronin_64]

I use Pmag gen 2 with both sub and super with no problems.

 

[Strykervet]

I got a few hundred various GI mags and as far as i know they all work... Probably another 100 pmags, the gen2's I think, they all work as far as I know. I just got some FN steel mags, not sure about those. But I can't see why not.

I never had to fuck with 'em to get 'em to work like say, Beowulf ammo.

Some CAN have feeding problems with the subs though, I can see how that'd be a thing. Just no problems so far with it.

Noveske makes really nice SBR's, they've been my goto for SBR barrels for a long time. Never got around to that KAC (I apparently had to get every fucking SCAR platform made) but I do have a built KAC lower waiting for the upper. The two Noveske factory rifles I have are super light and svelte.

 

[db2000]

My Seekins will eat from G2/3 Magpuls, MFT and Toolman Tac. Semi and FA

 

[bunsen27]

Lancer 300BLK mags are my first choice closely followed by D&H 300BLK mags.

Wilson Combat has some in stock and is accepting backorders, as is DSG Arms

300 Blackout, 300 HAM'R, and 762x40 Magazines

999-000-4280-05 Lancer L5AWM .300BLK 20rd Mag Opaque - Black

The Lancer Systems L5AWM 300BLK Magazine is based on the company's original design, which features a combination of steel and polymer, and tailors it for the dimensions of the .300 BLK cartridge, ensuring reliable, trouble-free feeding.

dsgarms.com

999-000-4280-04 Lancer L5AWM .300BLK 30rd Mag Opaque - Black

The Lancer Systems L5AWM 300 Blackout 30-Round Magazine is based on the company's original design, which features a combination of steel and polymer, and tailors it for the dimensions of the .300 BLK cartridge, ensuring reliable, trouble-free feeding.

dsgarms.com

300BLK-AL-20-BT-RD D&H Tactical .300 Blackout 20rd Aluminum Black Magazine w/ Red Follower

The D&H Tactical .300 Blackout 20rd Aluminum Magazine with Red Follower (300BLK-AL-20-BT-RD) has optimized ribs and feed lips for the 300BLKOUT round.

dsgarms.com

300BLK-AL-30-BT-RD D&H Tactical .300 Blackout 30rd Aluminum Black Magazine w/ Red Follower

The D&H Tactical .300 Blackout 30rd Aluminum Magazine with Red Follower (300BLK-AL-30-BT-RD) has optimized ribs and feed lips for the 300BLKOUT round.

dsgarms.com

 

[texag0842]

I'm shooting both a Noveske Ghetto Blaster and a SR-30.

Dedicated Lancer 300 mags but I believe Noveske shipped with a Pmag that's also been okay.

Lancers seem to be slightly better and I prefer the smoke color so I can glance and see what round is loaded. Lancer is also marked with a easier to read "300" splitting hairs but it's the little things that make the Lancer slightly better.

I also use these on the Pmag just so I know which are subs and which aren't

httpss://www.amazon.com/Sighthound-Ballistics-Blackout-Magazine-Gray-Black/dp/B07MVDZYG2/ref=mp_s_a_1_18?dchild=1&keywords=300+blk+mag&qid=1616092191&sr=8-18

 

[101stinfantry]

I've used both the Magpul and Lancer purpose built 300BO mags without issue. I like the Lancers better, but that's more of a "How it looks" thing, rather than a functionality thing. I only run subs though.

 

[TheHorta]

Lancers are all sold out everywhere, so I ordered some Pmag M3 300BLK mags.

It’ll be interesting to compare them to the regular M3 Pmags to see if there is a difference.

 

[Snuby642]

The 300blk pmags work better than 223 mags for my sbr.

I have not bothered trying others and shoot mostly subs suppressed.

 

[Strykervet]

10.5" .300 Johnny Rifle:

Came with that "flaming pig" magpul mag. I'm gay though so I sourced one in the matching puke green to go with it. This particular rifle was the ex's and I took it during the divorce --it's still never been fired. But I've got a couple 8.5" Noveske barrels in other rifles that have never had so much as a hiccup and mags were never an issue, well, until you brought it up I guess.

There was no such thing as a .300 mag when these came out, the whole point of BLK is that it can use all 5.56 shit with the exception of the barrel. That's not to say you can't optimize one, mostly with subs in mind, I just think it's unnecessary.

It was designed with GI mags in mind.

I think the big design change with the M3 mags was so they could wear the "STANAG" stamp and fit shit like the Mk16 rifle better. Apparently some of the older ones don't fit right.

 

[WillHugh]

I've always run GI mags (Surefeed, Colt, and D&H) and all have run fine, even with 220 grain round nose subs. One thing to consider is you may want to go with a mag that's completely different than what you run for 5.56, just to minimize the chance of a mistake - especially when running night vision. I use the same ones, but I like to live dangerously.

 

[TheHorta]

I have factory Hornady Black 208g subs. 500 rounds of Sig 220g Black arrives Monday, according to UPS.

I ran a few rounds through a cheap metal mag sent to me from a political candidate (Jay Atkins) for making a donation to his campaign last year stamped with his name on it. It doesn’t cycle reliably, so I just pulled an M3 Pmag to go try to sight in my new blaster.

 

[nutation]

Do you handload? If so, you can seat the bullet so that the point on the ogive of the 300 BLK bullet which is 0.25" in diameter is the same distance from the cartridge base as the point on the shoulder of the 5.56 case which is 0.25" in diameter; a .25 caliber CBTO gauge is helpful for measuring. This is the location where the ribs in most 5.56 magazines are. This seating method is necessary, in particular, for the D60 drum.

If you're loading very long subsonic bullets (like the Berry's 220 grain spire points), they'll be seated pretty deep, so you will probably want to decrease the load somewhat.

 

[freedom71]

I use both Lancer and PMAG .300 BO specific mags and have never had problems with either. If you also shoot .223/5.56, I strongly urge you to use .300 Blackout magazine bands, duct tape, or some other way to readily identify your .300 BO magazines from your .223/5.56 mags. You DON'T want to load a .300 BO mag in your .223/5.56 AR-15.

 

[bantaman2]

Lancers are all sold out everywhere, so I ordered some Pmag M3 300BLK mags.

It’ll be interesting to compare them to the regular M3 Pmags to see if there is a difference.

we use the magpul 300blk mags at work. they do the job pretty well

 

[TheHorta]

Well, supers cycle fine, but subs are hit and miss. It could be the buffer (?) since the lower is from an N4 Infidel and the upper is a 2014 vintage factory 300BLK. I bought it new from a well regarded Hider.

My suppressor is a home-brew Form-1 — my first-ever, in fact. It has quite a bit of backpressure and quickly fouls every chamber (even on piston guns). I figured, if anything, that would help cycling, but maybe I have that backward?

I’m going to try sticking a TBAC Ultra 9 on it (which kinda defeats having a 10.5” barrel, but for “science...”). I just hate removing a perfectly installed ASR hider.

 

[TheHorta]

Do you handload? If so, you can seat the bullet so that the point on the ogive of the 300 BLK bullet which is 0.25" in diameter is the same distance from the cartridge base as the point on the shoulder of the 5.56 case which is 0.25" in diameter; a .25 caliber CBTO gauge is helpful for measuring. This is the location where the ribs in most 5.56 magazines are. This seating method is necessary, in particular, for the D60 drum.

If you're loading very long subsonic bullets (like the Berry's 220 grain spire points), they'll be seated pretty deep, so you will probably want to decrease the load somewhat.

I don’t reload. Never got into it. My dad is into it bigtime, like 250K rounds insane bigtime.

 

[Strykervet]

I don’t reload. Never got into it. My dad is into it bigtime, like 250K rounds insane bigtime.

Well then please save all that brass for me, I could use it and I'm not up to 250k yet. If I don't load it, I don't shoot. I'm dead serious too, just PM me with details and I'll make it happen. Flat rate boxes full of Blackout, Grendel, 5.56, 7.62, .338LM would make my day. I mean, if you don't use and all...

I put a 9" 30CB9 (what became the Ultra9) on an 8.5 and an Ultra5 on another... Both have their advantages.

 

[TheHorta]

Well then please save all that brass for me, I could use it and I'm not up to 250k yet. If I don't load it, I don't shoot. I'm dead serious too, just PM me with details and I'll make it happen. Flat rate boxes full of Blackout, Grendel, 5.56, 7.62, .338LM would make my day. I mean, if you don't use and all...

I put a 9" 30CB9 (what became the Ultra9) on an 8.5 and an Ultra5 on another... Both have their advantages.

Sadly, I can’t tell you how many 1000’s of brass casings have been crushed into the dirt on my range. I don’t police my brass and neither do most guys who come here. I could probably pave a small highway with brass from what the earth has reclaimed over the years.

I may start collecting it, just for you SV.

 

[hafejd30]

Well, supers cycle fine, but subs are hit and miss. It could be the buffer (?) since the lower is from an N4 Infidel and the upper is a 2014 vintage factory 300BLK. I bought it new from a well regarded Hider.

My suppressor is a home-brew Form-1 — my first-ever, in fact. It has quite a bit of backpressure and quickly fouls every chamber (even on piston guns). I figured, if anything, that would help cycling, but maybe I have that backward?

I’m going to try sticking a TBAC Ultra 9 on it (which kinda defeats having a 10.5” barrel, but for “science...”). I just hate removing a perfectly installed ASR hider.

I run a TBAC ultra 9 on my 8” SBR 300 BO. Works excellent and is the one of the cleanest shooting gun I own with the factory SB ammo.

 

[WillHugh]

The infidel lower probably has an h2 in it. Assuming you're getting weak cycling, switch er up to a regular carbine buffer and you should be good to go. The TBAC ultra cans are high back pressure, but silly quiet with subs.

Knights has been releasing batches of their dsr blackout cans if you decide you want the ultimate cool build.

 

[tacops1]

Lancer or Magpul mags

Buffer help here

Which buffer for 300Blk SBR? » 300BlkTalk

 

[tacops1]

The infidel lower probably has an h2 in it. Assuming you're getting weak cycling, switch er up to a regular carbine buffer and you should be good to go. The TBAC ultra cans are high back pressure, but silly quiet with subs.

Knights has been releasing batches of their dsr blackout cans if you decide you want the ultimate cool build.

Also what he said on H2 Carbine buffer

 

[tacops1]

Also check out the spikes I run the ST-T2

The 3 is nice and heavy for smooth suppressed shooting works well

Do the lancer or p mag with the 2 or 3 buffer and your set

Make sure the bolt and charging handles wet

And rock n roll

Never been much into form 1 cans but to each their own

Spikes Tactical Tungsten Buffer

Spike's Tactical T1/T2 buffers reduce cycling noise, allowing your AR-15 to cycle smoother with Low Density Tungsten Powder technology. Upgrade today!

www.wingtactical.com

 

[tacops1]

Last but not least if you can find them
The best way is to go with a Vltor A5 stock kit and buy their buffers to tune her up for what ya need they work awesome

VLTOR A5 Buffer System Overview – AR-15 News, Reviews and Expert...

VLTOR A5 Buffer System has been called by some the single most legitimate upgrades the AR-15 has ever seen. We reached out to VLTOR to learn more.

www.arbuildjunkie.com

 

[Darkside-Six]

Just pick one. They all work fine. I have a 9.5” BCM and it runs both regular and subs perfectly fine in PMags, GI mags, lancers.

 

[TheHorta]

I run a TBAC ultra 9 on my 8” SBR 300 BO. Works excellent and is the one of the cleanest shooting gun I own with the factory SB ammo.

SB subs?

 

[hafejd30]

SB subs?

Sellier & Bellot 300 Blackout Ammo 200 Grain Full Metal Jacket Box of

Sellier and Bellot has been producing cartridge ammunition since 1825. The year 2009 saw one of the milestones in the history of the company, the...

www.midwayusa.com

 

[Yondering]

I’ve been using Pmags for 300 Blk since it was first released; back then we had to file the ribs out to make them work right with some of the heavy sub rounds. With supers it mostly doesn’t matter because the bullets are shorter, but many long subsonic bullets will go pigeon toed in a 5.56 mag and feed poorly, especially heavy cast bullets. (In a way those early days were better times for the 300 Blk, before it got popular with the magazine writers and all the mouth breathers started filing the internet with bad info.)

Now that Lancer and Magpul both make 300 Blk specific mags it’s easier, but Lancer makes them in 20 rd flavor and Magpul only does 30rd, so I prefer the Lancer. It’s nice being able to count your rounds in the mag too, but more importantly the Lancer 300 Blk specific mags are easy to tell apart from the others, with the smoke body and FDE base plate.

I highly recommend using separate mags for 5.56 and 300 Blk and never mixing them; using the Lancer 300 Blk mag makes that easy.

These are not to be confused with Lancer’s other mags that are listed for both 5.56 and 300 Blk; the 300 Blk specific mag is only the one color, has different internal ribs, and does not list 5.56 on it.

 

[sparky702]

way back when the 300 blackout was the new kid on the block I tried a p-mag with 220 grain sub's and it sucked . I had a couple of lancer mags I used for my 458 socom and 50 beowulf so I gave them a try with the 300 blackout and they work great . Now thats all I use . I think I have around 40 mags . tan for 300 blackout , 458 socom and green for 50 beowulf and 5.56 .

 

[tacops1]

way back when the 300 blackout was the new kid on the block I tried a p-mag with 220 grain sub's and it sucked . I had a couple of lancer mags I used for my 458 socom and 50 beowulf so I gave them a try with the 300 blackout and they work great . Now thats all I use . I think I have around 40 mags . tan for 300 blackout , 458 socom and green for 50 beowulf and 5.56 .

Lancer is the best mag I ever used

 

[PJ65C]

Normally i just run G2 or G3 223/556 PMAGS without issue. Only had a couple feed problems, nothing out of the ordinary. Going to try the 300 BLK specific mag from magpul this weekend and see what thats all about.

 

[rustyinbend]

Brand spankin’ new to the world of 300BO. Just snagged a Noveske factory 10.5” and a new SR-30 9.5” — both suppressed SBRs.

I have a variety of mags — Gen 2/3 Pmags, DD mags, USGI mags, and 20 new USGI “Enhanced Performance” Mags for the new 855A1 rounds, and some of the heavy steel Israeli Elanders.

What mag(s) work best with 300BLK? Does it matter with subs or supers? (i.e. is there a difference in feeding?)

Lancer 300-BLK mags have always been terrific in my rifles and pistols. The differences are subtle, but shooting 300 from a 223 magazine is asking for issues ... IMHO.

L5AWM® 300BLK 30 Magazine – Lancer Systems

lancer-systems.com

 

[TheHorta]

Sadly, I’ve scoured the interwebs and cannot find a single vendor with the Lancers in stock.

On a positive note, I ordered a half dozen M3 300BLK PMags from Weapon Outfitters yesterday afternoon and they just arrived!

WTG WO!!!

 

[rustyinbend]

Sadly, I’ve scoured the interwebs and cannot find a single vendor with the Lancers in stock.

On a positive note, I ordered a half dozen M3 300BLK PMags from Weapon Outfitters yesterday afternoon and they just arrived!

WTG WO!!!

No worries ... those should be fine. Any of the mags engineered with the 300-BLK mods should be A-OK ...

 

[alamo5000]

Lancer 300-BLK mags have always been terrific in my rifles and pistols. The differences are subtle, but shooting 300 from a 223 magazine is asking for issues ... IMHO.

I won't hold myself out as an expert but I have seen a lot of information put out over time Re: 300 BLK specific mags. Apparently the only major differences is there are some ribs inside that have different thickness and/or placement to prevent bigger heavier bullets from dragging and binding up.

I have always heard others say that with regular ammo under 200 grains it won't make a difference but when you move up in weight it does prevent binding to have a specific 300 BLK mag.

That said I have PMags and some Lancers for both 300BLK and 5.56. Both are awesome. I ran 5.56 mags for quite some time and I personally never ran into an issue but that's not saying it won't happen.

 

[TurboTrout]

I don’t have any experience in 300, that said, when a question has “ar” and “mags” in it, normally the answer is lancer

 

[rustyinbend]

I won't hold myself out as an expert but I have seen a lot of information put out over time Re: 300 BLK specific mags. Apparently the only major differences is there are some ribs inside that have different thickness and/or placement to prevent bigger heavier bullets from dragging and binding up.

I have always heard others say that with regular ammo under 200 grains it won't make a difference but when you move up in weight it does prevent binding to have a specific 300 BLK mag.

That said I have PMags and some Lancers for both 300BLK and 5.56. Both are awesome. I ran 5.56 mags for quite some time and I personally never ran into an issue but that's not saying it won't happen.

No arguments with that assessment. The place where I got some "Failure to Feed" issues on standard .223 PMags was using the heavier sub-sonic bullets ... which is almost exclusively what I shoot. Never had that happen since I switched to the Lancer mags.

 

[strikeeagle1]

I have a few .300 BO SBR's and have been confident in the PMAG .300 's and B&H steel magazines.
This one is a 9.5" KAC SR30 E3 Mod2.