300 BO lead cast in AR

I have been using 220 gr bullets both Berry's plated lead and Makers REX all copper bullet. I have had good luck with IMR 4227 and Accurate 1680 respectively. I am using my ammunition in two different 300 BO firearms, a 16-inch carbine and a 9-inch pistol. I am enjoying sub-sonic 300 BO quite a bit. I have not tried cast bullet yet but I have seen a fair number of people using various polymer coated lead bullets successfully in 300 BO subsonics loads. It is definitely the most cost effective way for plinking ammo.

If you are going subs only, and just for plinking, I would shoot HiTek coated 200+ grain bullets.

They are going to be over sized projectiles - .310'' or so. I like to utilize a 7.62x39 expander and give the brass a good chamfer when loading cast - it'll prevent shaving of the projectiles upon seating... can't go wrong with A1680, very gassy and meters well.

Could you elaborate on why you have 'tried to avoid this cartridge'? Was it the uber cool-name, out of curiosity?

I've only ever shot jacketed or coated bullets in my AR, out of a concern that lead shaving on the gas port would cause issue (lead buildup in places that I don't want it). Is this not really a concern?

sevt_chevelle said:

300 BO ... running subsonic ammo ONLY with lead cast bullets.

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Consider powder coating your bullets as bare lead bullets will coat/clog your gas system with lead/fouling deposit - https://www.thehighroad.org/index.p...-for-powdercoating.753510/page-3#post-9502898

bds said:

Consider powder coating your bullets as bare lead bullets will coat/clog your gas system with lead/fouling deposit - https://www.thehighroad.org/index.p...-for-powdercoating.753510/page-3#post-9502898

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Roger - thanks!

bds said:

Consider powder coating your bullets as bare lead bullets will coat/clog your gas system with lead/fouling deposit - https://www.thehighroad.org/index.p...-for-powdercoating.753510/page-3#post-9502898

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Do you know this from experience or are you repeating something you have heard from someone else?

I have one 300 Blackout upper with at least 10K conventionally lubed cast lead bullets through it and the gas system shows no sign of fouling yet. I suppose if in another 25K or so it starts to slow down then I guess I could spend $15 and buy a new gas tube.

OP: do you cast your own or will you be buying your bullets? As far as powders go it depends a bit. In an 8” gun with a pistol length gas system having a silencer attached gives you more pressure for cycling. Without a silencer you will need generate more gas volume. 2400, H-110, 300-MP or 4227 are where I would start. People also rave about AA1680 but I find it a bit dirty.

Elkins45 said:

Do you know this from experience or are you repeating something you have heard from someone else?

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THR member blarby sent me some cast lead bullets as trade (Quite generous on his part) during the "Great Component Shortage" (He is now co-owner of a gun store in Oregon). I ended up PIF two Texan 12/20 ga shotsell reloaders and several sleeves of primers and a box of powders to him during the shortage and later Dillon 450 for more of his cast lead bullets (They shot great in my Sig 1911) - https://www.thehighroad.org/index.php?threads/pay-it-forward-in-reloading.698208/page-2#post-8683592

He experimented quite a bit with cast bullets and part of reason why I decided to cast lead bullets into retirement. To maximize cost savings, I thought of casting .300 BO bullets but he advised shooting higher velocity lead bullets, if led to leading, would coat the gas system. It was this that led to our joint venture into powder coating thread by combing our finances to reduce cost of testing - https://www.thehighroad.org/index.php?threads/a-partnership-for-powdercoating.753510/

In the end, I abandoned my pursuit of higher velocity .300 BLK lead cast bullets to lower subsonic heavier powder coated .300 BO bullets and plan to cast after retirement this year (I have several hundred pounds of lead alloy saved up).

rbernie said:

I've only ever shot jacketed or coated bullets in my AR, out of a concern that lead shaving on the gas port would cause issue (lead buildup in places that I don't want it). Is this not really a concern?

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Between two different uppers I have shot 15K conventional lead bullets. 5K have been supersonic out of a 16” and 10K subsonic out of a 10”. My gas system in both is still working fine.

Elkins45 said:

Between two different uppers I have shot 15K conventional lead bullets. 5K have been supersonic out of a 16” and 10K subsonic out of a 10”. My gas system in both is still working fine.

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So no leading in the barrel and no coating of lead on gas system? What alloy mix and lube are you using?

I have wheel weight alloy and 16" pistol length gas tube upper. I was thinking about 150 gr bullet weight but due to leading concern decided to go with 230 gr powder coated bullet out of Lee mold.

bds said:

So no leading in the barrel and no coating of lead on gas system? What alloy mix and lube are you using?

I have wheel weight alloy and 16" pistol length gas tube upper. I was thinking about 150 gr bullet weight but due to leading concern decided to go with 230 gr powder coated bullet out of Lee mold.

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The only place lead has built up has been in my silencer, but it’s user serviceable so I scrape it out occasionally.

Alloy has been a whole bunch of stuff ranging from range scrap to clip-on wheel weights to my now standard alloy of 96-2-2. For supersonic I generally drop directly from the mold into water so they are significantly harder than the alloy would suggest.

Lube has been a gazillion different things: I’m a bit of a home brew lube alchemist. My experience with different lubes hasn’t been to control leading but to control accuracy. Generally if you get leading in the bore it’s because your bullet isn’t fat enough. The problem with cleaning has been lube residue, not lead. After about 500 rounds the inside of the rifle is pretty filthy, including the fire control parts. I use a lot of carb cleaner these days.

I recently started experimenting with the HiTek coating. I have some powder from Eastwood as well but haven’t gotten around to trying it. If the HiTek can stop the leading inside my silencer I will probably stick with it.

I run 150grn powder coated bullets in my blackout. first a 16" barrel and now a 9 inch. I push them about 1500fps using h110. they work pretty well. I use a lee mold designed for a 30/30.

sevt_chevelle said:

Any experience with the newer CFE black powder?

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I have W296/H110 to A1680 to H4198 for .300 BLK loads with preference for A1680 for subsonic loads (May try IMR 4227 and CFE BLK once I run out of A1680). Hodgdon puts CFE BLK right next to A1680 and should be comparable with A1680 - https://www.hodgdon.com/wp-content/uploads/2017/09/burn-rate-color.pdf

FYI, A1680 is made in Israel and CFE BLK is made in USA - https://www.thehighroad.org/index.p...g-components-made.577067/page-4#post-10297475

Here's a A1680 vs CFE BLK subsonic comparison showing smaller SD for CFE BLK.

bds said:

I have W296/H110 to A1680 to H4198 for .300 BLK loads with preference for A1680 for subsonic loads (May try IMR 4227 and CFE BLK once I run out of A1680). Hodgdon puts CFE BLK right next to A1680 and should be comparable with A1680 - https://www.hodgdon.com/wp-content/uploads/2017/09/burn-rate-color.pdf

FYI, A1680 is made in Israel and CFE BLK is made in USA - https://www.thehighroad.org/index.p...g-components-made.577067/page-4#post-10297475

Here's a A1680 vs CFE BLK subsonic comparison showing smaller SD for CFE BLK.

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Both of those SD seem rather lacking to me for sub-sonic loads. A SD 41.9 fps with 1680 seems really bad. I got a SD of 8.83 fps using 1680 under a Maker REX 220 gr bullet.

I got the PCC (Pistol Caliber Carbine) bug and have been mainly focused on 9mm load development and accuracy comparison testing recently so haven't done much .300 BLK testing and wanted to give OP something to compare CFE BLK to.

Now that I am retiring, should have more time for load testing of other calibers (Looking at .45ACP conversion barrel/bolt/magwell kit for Just Right carbine).

I am using 225 gr Cast and coated from my NOE mold. http://noebulletmolds.com/NV/produc...cts_id=5546&osCsid=77e34sdb4ngj2g3uo1lge2l5h3 . Mine is a 5 cavity mold though. I run both subsonic and supersonic with these. I have ran about 350 of them through my 300 BLK. Then I have a Lee 230gr 2 cavity mold. Similar nose profile but it has a boat tail and lube grooves. Not fond of it because you can't adjust the Seating as much and still maintain neck tension like you can the NOE bullet.

Honestly, a1 and h4 series powders for gas volume seem to do the trick for 30 cal rifle loads in cast.

It's been years for me to unload everything I pressed, and here's my results :

sevt_chevelle said:

Ive tried to avoid this cartridge but I have several as in many AR lowers laying around, thinking of trying out a AR pistol build in 300.

My plan is going with something in the 8in barrel length, running subsonic ammo ONLY with lead cast bullets. My question is, how possible is this, what powder and bullets are you guys using?

Thanks...Eric

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Here are my initial results with Missouri's 245 gr. Hi-Tek coating using Reloder 7. I have only shot 50 loads so far. No feed issues as of yet.

https://www.thehighroad.org/index.php?threads/reloder-7-and-sub-sonic-300-bo.855224/

Here is the link for the bullets I'm using.
http://missouribullet.com/details.php?prodId=204&category=6&secondary=36

Here is a link to a guy logging some results from different combinations of powders, bullets, and rifles/pistol.

http://www.dayattherange.com/?page_id=3817

LiveLife said:

I have W296/H110 to A1680 to H4198 for .300 BLK loads with preference for A1680 for subsonic loads (May try IMR 4227 and CFE BLK once I run out of A1680). Hodgdon puts CFE BLK right next to A1680 and should be comparable with A1680 - https://www.hodgdon.com/wp-content/uploads/2017/09/burn-rate-color.pdf

FYI, A1680 is made in Israel and CFE BLK is made in USA - https://www.thehighroad.org/index.p...g-components-made.577067/page-4#post-10297475

Here's a A1680 vs CFE BLK subsonic comparison showing smaller SD for CFE BLK.

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Thanks for the video. Accurate (Western) powders are rare on the shelves around here. But Hodgdon is plentiful.