Considering a .300 Blackout pistol. Cast worthy cartridge?

[Tallbald]

Palmetto State Armory has some very attractive AR pistol kits in the .300 Blackout cartridge. I believe they are 1 in 8 twist barrels.And I have an unused Aero lower receiver. Casting for 5.56 doesn't right now interest me, but the 30 caliber is quite attractive. And I read that the cartridge can use 110 to 220 grain slugs, for great versatility.
I'm sure it's been done and I've read several threads about it, but now that the cartridge is becoming mainstream and there are a number of different powders new to the market, I'm wondering what folks here think of casting for this new darling of the sport? Cast slugs in a gas operated platform is completely foreign to me. Lube clog gas ports? Gas checks give troubles near the gas port?
I prefer to stay close to subsonic. Not because I have a suppressor, but because that's my favorite way of shooting.
Thoughts on the latest findings and experiences sure appreciated.
Thanks as always. Don.

[fatelk]

I use the Lee 160gr bullet, powder coated, gas check, moderate charge of H110 or 4227. It works great, shoots around 2 moa @100 yards. I've had zero problems with leading. It's way beyond subsonic. I suppose if you want anything remotely close to subsonic that will still cycle, you'd need a much heavier bullet. I've never messed with those myself. I'm not much interested in suppressors; it's more of a plinking rifle for me.

[scotner]

No need for a gas check mold if you are shooting subsonic but powder coat is definitely the way to go. I have shot nothing but these boolits in my 10.5" suppressed SBR with no problem. For powder selection I am loading h110 behind a 240 grain bullet. My mold is the Accurate 31-240a. I PC'ed a few today.

By the way, you may not have a suppressor now but if you ever thought about getting one this will put you over the top.

[sutherpride59]

I don’t have a pistol but I bout one of PSA’s 16” rifle kits a year ago and it’s a very easy cartridge to cast for. I’m waiting on a group buy mold but I’ve been using the Lee 155grn pushing to normal copper velocities.

[tsubaki]

I'm powder coating Lee's c309-160-R (166gr actual) and pushing with 18.5gr of AA2230.
My 7 1/2" barrel is producing 1315fps. This translates to about 480 ftlbs at 100 yards making it barely acceptable for my hunting purposes.
I've had zero problems with this load cycling in it or my 16" barrel.

Another load, 11.5gr of AA1680 and a 220gr jacketed bullet cycles fine and gets 1195fps in my 16" barrel but will not cycle in my 7 1/2" barrel.
I upped the charge to 12.0gr and got 1116fps out of the 7 1/2" barrel, still will not cycle.
Others I have talked to with a 10 1/2" barrel do not have cycling problems with this same bullet/powder combination.
There "might be" a cut off point in performance with using certain low powder volumes below 10". I'm eventually going to get some software to compare this but right now it's just a guess.
I'd suggest getting a 10 1/2" barrel and change the flash hider to a forward throwing blast devise and cast/powder coat away!

[Tallbald]

This is wonderful information to have. I'm bookmarking it too. With .300 Blackout running at the best I've found so far, about 52 cents a round, it would absolutely have to be a "roll-my-own -ammo" handgun. i confess that I bought a PSA 5.56 kit over the Labor Day weekend. I've never owned or shot an AR prior to assembling this one. Daddy was a Korean Era vet and had no love for what was, in the 1960's, an obscure platform with a sketchy history (to Daddy). Odd that it's taken 40 years since my beloved shooting mentor and friend died, for me to jump into the now vintage AR platform arena.
I turned 60 a couple of days ago, and have decided to expand my experiences with something completely new to me. The .300 Blackout would let me explore the AR platform with a versatile and forgiving round. Whereas at this point with 5.56 it appears I'm limited to shooting tiny jacketed pills very fast, you folks have further opened my eyes to some real fun!
As to the alloy for this cartridge: I have clip on WW ingots right now (Thank you The Captain--You're great to buy from). Must I strive for a harder mix when casting for an auto-loading firearm? A rather "newbie" question, I've been unable to find here the answer so far. Can I tumble lube the slugs and have good results or must I plate or powder coat? The answer does affect my plans for financial reasons.
Thank you all for responding so much. And wishing good things to all. Don.

[roharmon]

I shoot the NOE .310 230gr bullet with good results.

[tsubaki]

As to the alloy for this cartridge: I have clip on WW ingots right now (Thank you The Captain--You're great to buy from). Must I strive for a harder mix when casting for an auto-loading firearm? A rather "newbie" question.
My unknown alloy is about a BHN11, no problems so far but I’m powder coating.

[popper]

My 10" works fine even for fast supers. Might want to look at one of the blade type tubes, easier to shoot. You probably need ACWW for alloy. I run a 185gr GC with soft but the 145 & 175 PB use H.T.d alloy (1400 -2100 fps). I PC and have no problem with the gas system. Mine is just over 5# loaded, heavy barrel. Cost increase over pistol cal is just the 4x powder use so I'm about $10/100.

[scotner]

I am using COWW plus 10% lino for mine. Regarding powder charge, you will just need to see where the gun shoots best. Looking at my test target you can see that more is not necessarily better as the group closed up with less powder (minus one flyer). Also, regarding reliable cycling, be sure to get an upper with the pistol gas system if getting a short barrel. Google that for more info.

[Tallbald]

Thank you all. The PSA kits are pistol length gas tubes all I believe. The Saint from Springfield has an adjustable gas block in pistol length, but truly and unashamedly, I share that The Saint's a gun outside my financial grasp. For me this will be a range gun and dare I say a "toy" rather than something carried into a serious situation. Mercy forbid that change, but were it so, I would load heavy and hope for the best.
Thanks to those here I have what I need to know for my exciting plan. Thanks again.
Oh. $10/100 is quite affordable even for a man of my means. Don.

[KenH]

The trick to 300BO in subs is for pistol gas system. I've got a 7-1/2" setup which will cycle 170 grain cast bullets just fine when subsonic. With a 16" barrel and pistol gas system I had to use 230+ grain for reliable cycling when subsonic. I've shot very few jacket bullets, 99% have been cast, both gas checked and plain base. All subs are plain base.

[Tallbald]

The information shared here with me has made my decision easier. Thanks folks. I am currently following PSA ads for sales. Holidays are coming, and from my understanding, PSA sometimes runs great Black Friday Sales. But too, the elections are coming. Concerned about pre-election panic buying like back in 2016. These may be "the good old days" we remember in a couple of years. I'm like many others in my "get while the gettin' is good" thoughts. Thank goodness for recent powder and primer availability.
Don.

[Moonie]

We have an 10.5" SBR, a 16" Carbine and I have a 7.5" Encore Pistol barrel, we use a suppressor on all 3 of them, they are seriously fun to shoot. My 7.5" is a full bull custom MGM barrel, enough weight to feel like a 22LR when shooting subs with the suppressor on it.

[Tallbald]

A suppressor would be exciting to have. But I'd need to hit the lottery to comfortably afford one. And the closest to entering the lottery for me is driving on the interstate. Thanks. Don.

[popper]

It is not a toy, fine for close hunting and SD. I've been playing with cfe pistol and 110 to 175 gr cast with reasonable results.

[Tallbald]

I need to read about powder coating. I understand the benefits, but I'm used to tumble lubing and would like to learn if TL would be sufficient for .300 Blackout. Thoughts please folks? Don.

[scotner]

I need to read about powder coating. I understand the benefits, but I'm used to tumble lubing and would like to learn if TL would be sufficient for .300 Blackout. Thoughts please folks? Don.

I don't know that I would want to use TL with a gas system. At subsonic velocities the round is just a big pistol boolit but I would not think that alox would be good for the gas system. If you have the sizer die the only other investment would be the powder and a toaster oven. Most of us started with whatever oven was available at the local Goodwill or other thrift shop. There are also usually some available on Craigslist or FB Marketplace. $5 to $15 will put you in business there. Check the coatings and alternative section for tips on how to get into PC on a budget.

[tsubaki]

I need to read about powder coating. I understand the benefits, but I'm used to tumble lubing and would like to learn if TL would be sufficient for .300 Blackout. Thoughts please folks? Don.

You are already on your way toward powder coating and don't know it yet. The same type plastic bowl you probably use to tumble lube will be used in conjunction with air soft pellets to help the powder adhere to the cast bullets. Now all you need is a cheap toaster oven.

[Tallbald]

I didn't know it was that low tech or that you tumbled the powder onto the slugs. I expected the slugs needed to be static electrically charged and a powder gun used to apply even coats, like done industrially. And I remembered seeing a fellow neatly stand the slugs upright on a tray for coating, and thought "wow that's getting detailed". I did watch a video of a man powder coating last night. He said he was using Harbor Freight powder, and as you all have shared, tumbled them to coat, sifted out the excess powder, then poured them into a tray in a pile and heated them about 20 minutes. He went on to pour them again in a pile to cool, then separated them. Made me wonder if they stick together like melting then cooling Raisenets in a clump.
As said, I need to read and study this process here. I'm guessing the powder is the lube(?), since I've seen powder coaters size the slug after coating (understandable). I thought though the powder would be sized off in the process.
I appreciate you all sharing. TIme for more searched here on the forum. Don.

[popper]

LLA will work but is more trouble actually. Alloy needs to be harder and fit is more important. LLA works with GC bases OK but that is extra cost. Even with subs you're in the 30-40K psi range. PC is cheap, easy and works. There are a few tricks to learn but if I can do it you can too.

[Tallbald]

Searched again here on the forum. One poster referred to a long thread with lots of information that's in the alternative coatings section. Still trying to locate that one. hate rehashing old topics if there's existing threads. Thanks folks. Keeping up the hunt, and keeping an eye on PSA Daily Deals. Don.

[fatelk]

Speaking for myself only, powder coating is the best thing since sliced bread. I’m not one to jump on the bandwagon for new things very quick, and I was really hesitant about trying PC, but now I’ll never go back to lube, for a variety of reasons.

It’s funny, I never considered my reloads smoky before, but now I’ve gotten used to shooting PC ammo. I had a partial box of older lubed loads that I brought along to shoot, and was surprised at how smoky they are by comparison.

[tsubaki]

This is me.
In a Cool Whip bowl place enough BLACK Air Soft Pellets to cover bottom of bowl. The type of material the bowl is made of makes a difference. #5 inside a triangle on the bottom of the bowl is the recycle type you want. The black colored Air Soft Pellets also makes a difference.
Add 4 tablespoons paint powder, more or less. Too much or too little will not coat bullets evenly. Black pigment is the hardest to get decent coverage. Add 50 to 100 bullets to the bowl, depending on size.
Place lid on bowl and shake or swirl around for several minutes to create a static charge. The correct ratio of bullets and powder will shorten the shaking time needed. All is trial and error. Coat enough to not see the lead of the bullets.
With large tweezers or chop sticks remove bullets from bowl and place on a parchment paper lined tray from the toaster oven. Standing up is preferred. Smaller bullets may need 1/4" hardware cloth to lay bullets on side.
In the 400° preheated oven place tray of bullets in it for 15 minutes.
Remove from oven, let cool, resize bullets if you feel the need.
Check your work by mashing one of the bullets with a sledge hammer. Hit as hard as you can and inspect how well the paint adhered.

[tsubaki]

227803
These are some of the bullets retrieved from a sand pile.
Muzzle velocity 1492fps, impact velocity 1274fps, approx.

[David2011]

Properly applied powder coat will not come off. To test there is the "smash test." Smash a coated boolit with a hammer until it has been pounded flat. I smash 170 grain .40 boolits until they are larger than a nickel. The powder should remain adhered to the boolit. If it comes off then either the boolit was contaminated or it did not get hot enough for long enough when baked. It isn't hard to get the powder to stick, though. Many people here use powder from Smoke4320. It will save you the aggravation that goes with Harbor Freight PC powder. http://castboolits.gunloads.com/showthread.php?252509-VS-Hi-Quality-Powdercoating-Powder-For-sale Lots of application info there as well. There are endless hours of reading here: http://castboolits.gunloads.com/forumdisplay.php?184-Coatings-and-Alternatives

Another thing you will notice when sizing is that the boolits go through the sizing die with much less resistance than they do with conventional lubes. Your firearms will look the same after shooting powder coated boolits as they do after shooting jacket bullets.

[KenH]

When you decide to try PC'ing be sure NOT to use Harbor Freight powder. Get some from Smoke - his is for sure to work with tumbling. There are other good powders, but Smoke's powder is tested to be sure it will cover with tumbling, or he will tell you it doesn't tumble.

[Iowa Fox]

I've been seriously looking at a 300 blkout barrel (barrel only) for the AR. Am I correct in my assumption that regardless of barrel length it take a pistol length gas system to run subsonic reliably?

[Moonie]

I've been seriously looking at a 300 blkout barrel (barrel only) for the AR. Am I correct in my assumption that regardless of barrel length it take a pistol length gas system to run subsonic reliably?

My 16" carbine has a carbine length gas and runs subs with most appropriate powders, it will not run with W296/H110 however. My son had a 16" carbine that ran fine with subs and W296/H110, he now has a pistol gassed SBR.

[sutherpride59]

I am using COWW plus 10% lino for mine. Regarding powder charge, you will just need to see where the gun shoots best. Looking at my test target you can see that more is not necessarily better as the group closed up with less powder (minus one flyer). Also, regarding reliable cycling, be sure to get an upper with the pistol gas system if getting a short barrel. Google that for more info.

I’m a little late on this but most all of the ballistic advantage barrels are pistol length gas system.

[Handloader109]

Two things. Buy some CFE blackout powder. Trust me, it works. I futzed with my 9 inch pistol for a long while trying to make it cycle with h110, and other powder. Cfe worked the first time and every time. 155 to 230 grain bullets subsonic thru suppressor. Perfect

Sent from my SM-G892A using Tapatalk

[popper]

CFEblack seems to like full book loads for best performance. H110 shouldn't be down loaded below min. Pistol or carbine port is determined by length of barrel after the port so short barrels need the pistol port. Maybe even an H2 buffer.

[mattw]

Keep in mind the 300 bo is a little different animal. Many barrels up to 16 inches use a pistol length gas system for best function .