Cast bullets in 300BO for AR

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Looking at casting some 230gr 309 projectiles for 300 BlackOut. Was planning on running them through a supressed SBR AR. The AR gas system is pretty simple and easy to clean if needed should I encounter leading, but running these subsonic I don't know that it will be an issue, or is it? Thats my question.

Anyone shoot cast bullets through an AR? Any problems or concerns encountered?
 
Looking at casting some 230gr 309 projectiles for 300 BlackOut. Was planning on running them through a supressed SBR AR. The AR gas system is pretty simple and easy to clean if needed should I encounter leading, but running these subsonic I don't know that it will be an issue, or is it? Thats my question.

Anyone shoot cast bullets through an AR? Any problems or concerns encountered?
No issues. I ran subs and supers without issues. Coated cast works better (less mess) I borrowed a buddies bump fire stick at the range years ago to pop on my blackout upper. 200 grain spire points ran through that gun like green corn through the new maid.



i would ask quite provocatively - why would anyone use non-jacketed bullets in a modern rifle? what is the imperative of that? bullets can be found at 20c apiece, and with no compromises.

First reason would be cost. I can make a 200 grain bullet for almost free. Even if I paid for my lead it would be about 2.5 cents a pop. This makes for more trigger time and overall better quality of life 😁

Second is because we like to reload and like to mess with things to see how they work and if they work. There’s a sense of satisfaction in that.

Third and possibly last would be not having to rely on the few vendors that ship to MA to hope for a deal on bullets. Grabbing some while you have the funds vs taking pliers to Walmart at night and clipping all the free wheel weight you can handle. They actually like when you do it to the people that park there overnight. It deters them from doing it again.
 
First reason would be cost. I can make a 200 grain bullet for almost free. Even if I paid for my lead it would be about 2.5 cents a pop. This makes for more trigger time and overall better quality of life 😁

Second is because we like to reload and like to mess with things to see how they work and if they work. There’s a sense of satisfaction in that.

Third and possibly last would be not having to rely on the few vendors that ship to MA to hope for a deal on bullets. Grabbing some while you have the funds vs taking pliers to Walmart at night and clipping all the free wheel weight you can handle. They actually like when you do it to the people that park there overnight. It deters them from doing it again.
i get all those reasons and respect them totally, but i am afraid that the outcome of this idea for an AR gas platform will be quite same (only faster) that shooting a 22lr does to an AR15 - a lead blocked gas port, that will require disassembly and melting out that build-up.
old rifles is a one thing, a modern load spitting out projectile at 3000fps - an another thing. unless there is some magic coating on the cast bullets that is as strong as a copper jacket.
 
i get all those reasons and respect them totally, but i am afraid that the outcome of this idea for an AR gas platform will be quite same (only faster) that shooting a 22lr does to an AR15 - a lead blocked gas port, that will require disassembly and melting out that build-up.
old rifles is a one thing, a modern load spitting out projectile at 3000fps - an another thing. unless there is some magic coating on the cast bullets that is as strong as a copper jacket.
The OP specifically asked about running a 230g bullet through a suppressor.
A coated cast bullet isn't going to plug the gas port running under 1100fps.
 
That was my thought, though I don't coat my bullets, so I am concerned about straight cast harball alloy. These are just cost effective plinkers for me.
Then it's all about fit and lube choice.
A harder lube will help keep you from filling up the gas port with lube but might not throw sufficiently to not lead at the muzzle.
Most people size to .309 but that might not be correct for your barrel so you'll need to slug it to find the optimum size for your gun
 
Then it's all about fit and lube choice.
A harder lube will help keep you from filling up the gas port with lube but might not throw sufficiently to not lead at the muzzle.
Most people size to .309 but that might not be correct for your barrel so you'll need to slug it to find the optimum size for your gun

The bullets im looking at are a Lee tumble lube design, lubed with liquid allox. I cast quite a few different TL designs and have been happy with them but havent casted a TL bullet for a semi auto yet.
 
i get all those reasons and respect them totally, but i am afraid that the outcome of this idea for an AR gas platform will be quite same (only faster) that shooting a 22lr does to an AR15 - a lead blocked gas port, that will require disassembly and melting out that build-up.
old rifles is a one thing, a modern load spitting out projectile at 3000fps - an another thing. unless there is some magic coating on the cast bullets that is as strong as a copper jacket.
Nah no big worry really. If you dig in on CastBoolits there are guys doing it on the regular. The lube get vaporized and makes a mess but you don’t really get much lead buildup. Usually guys run coated and or gas checks to help but it’s a different animal really.

When you can get 55 grain FMJ for 6 cents a pop it’s not as much of a savings vs running a 200+ grain in a blackout. Those are expensive.

Also trying to push super fast with lead is more of the issue. You run into the RMP threshold which is the big issue.

Any of the 30 cal or larger cartridges in an AR are fine with cast. I have tons through my blackout upper and a fair amount through my 305 legend upper. Accuracy is good enough to hunt with and I don’t try to squeeze anymore out of it.
 
I coat with Hi-Tek so not sure how well allox does in 300AAC
As silly as this sounds, I've never coated anything because of the way they look lol. I don't want no skittles lookin boo-lits. That, and i don't have any complaints thus far so I think it'd be looking to fix a problem that doesn't exist. For me anyways.
 
i would ask quite provocatively - why would anyone use non-jacketed bullets in a modern rifle? what is the imperative of that? bullets can be found at 20c apiece, and with no compromises.

The answer to your question is if there are no drawbacks to using cast, then why spend twice as much money for jacketed bullets? In the case of subsonic loads for this cartridge, it is safe to use cast bullets. There are no compromises. And it is the most cost effective solution.

Yes, it is safe to shoot all of the cast bullets you want in subsonic loadings for this cartridge in a gas gun.
 
i get all those reasons and respect them totally, but i am afraid that the outcome of this idea for an AR gas platform will be quite same (only faster) that shooting a 22lr does to an AR15 - a lead blocked gas port, that will require disassembly and melting out that build-up.
old rifles is a one thing, a modern load spitting out projectile at 3000fps - an another thing. unless there is some magic coating on the cast bullets that is as strong as a copper jacket.

The OP asked about subsonic loads, not 3000 fps. You would be correct to avoid shooting cast bullets at 3,000 fps through an AR 15. Subsonic cast is fine, however.
 
The OP asked about subsonic loads, not 3000 fps. You would be correct to avoid shooting cast bullets at 3,000 fps through an AR 15. Subsonic cast is fine, however.
kinda skeptical still, as 22lr subsonic clogs ar15 just fine, but, may be it is not as bad indeed. cannot argue about something i have never done.
 
kinda skeptical still, as 22lr subsonic clogs ar15 just fine, but, may be it is not as bad indeed. cannot argue about something i have never done.
Can't blame you. I haven't experienced the issue with 22lr, although its talked about a lot on the webs. But I've put about two thousand supersonic lead bullets through a suppressed 300 without issue so far.
 
Can't blame you. I haven't experienced the issue with 22lr, although its talked about a lot on the webs. But I've put about two thousand supersonic lead bullets through a suppressed 300 without issue so far.
just to speculate on that - there may be enough pressure in the 300blk load to sneeze any lead remnants out of the gas system as well, something the weaker 22lr just cannot do.
 
just to speculate on that - there may be enough pressure in the 300blk load to sneeze any lead remnants out of the gas system as well, something the weaker 22lr just cannot do.
I think that is a good speculation. Could be hot enough and with enough pressure that at the point its reaching the gas tube it is blowing it all out. Not sure. For what it is worth, the shooting I've done with lead bullets has been through an adjustable gas block, bleed off style, with the gas turned down to the bare minimum to cycle the action. So, not a lot of pressure. But must be quite a bit more than 22lr.
 
alright. Whats this coating process.....cost....time........
Hi-Tek

Mix 20 grams of powder with 120 ml of acetone. Shake it up and store in a bottle with a snap lid or cork. Something acetone safe of course.

Use 1ml of liquid per 1# of bullets. Shake your mixture. Measure. Apply to bullets in an acetone safe container. Swirl around a bit to coat evenly.

Dump onto so metal mesh. Let it dry for a bit.
Bake in the oven at 400* for about 10 minutes.
Let them cool to room temp.
Do it again

That’s over simplified but basically it.

Tons of info on YouTube if you dig in for it.
 
With my short stint in the 300blk I found the 200 gn cast bullet was just fine. I dumped about 600 rounds through that upper. Just a water dropped wheel weight alloy 2400 lube and 2400 powder. No signs of leading except a touch on the feed ramps.

223 cast in the AR was fine also. 100% cycle about 3 moa with out trying to hard. 1/9 twist barrel 60 grain bullet
 
i would ask quite provocatively - why would anyone use non-jacketed bullets in a modern rifle? what is the imperative of that? bullets can be found at 20c apiece, and with no compromises.
agree to the point where .20 each is to expensive for range blasting. Casting them is getting down to under 5 cents each....well if you been casting a while. Most of my equipment was close to free and the stuff I did buy has long paid for itself.
I had a short stint with cast in the AR enough to know I can and it will.... lost interest in 300 and sold that upper. Cant be bothered with cast in 223 anymore.
 
i get all those reasons and respect them totally, but i am afraid that the outcome of this idea for an AR gas platform will be quite same (only faster) that shooting a 22lr does to an AR15 - a lead blocked gas port, that will require disassembly and melting out that build-up.
old rifles is a one thing, a modern load spitting out projectile at 3000fps - an another thing. unless there is some magic coating on the cast bullets that is as strong as a copper jacket.
I did not experience any leading in my ARs even with the 22lr conversion kit. Although I seem to be one of few that have very few issues with 22lr. I shot 10s of thousands of 22lr every summer for years. Even the Model 60 would go several 1000s of rounds before having any problems. The 10/22s would only get cleaned when they actually started to jam...that could be a few summers!
I just crested 2500 rounds through the Kidd Build and other than rust preventive wipe down still functioning 100%
 
The OP asked about subsonic loads, not 3000 fps. You would be correct to avoid shooting cast bullets at 3,000 fps through an AR 15. Subsonic cast is fine, however.
you can push caast to 3000 fps just need like a 1/28 twist barrel. For your common lead alloys you need to keep the rpms around 120,000 and max out around 140,000
 
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