.300 Questions

[CJ]

Good info. Interesting about the gas ports not being standardized; good to know but I am planning on going DI so I wasn't concerned about that so much. However, I am interested in the shorter barrel length since eventually I want to get a suppressor for it. At 6", suppressed and non suppressed, do you get much muzzle flash? Also what about the longer barrel and suppressor combo make it potentially less accurate?

Barrel harmonics. I posted an article a few months back that was an excellent test. They took a barrel, tested it at each length from 28" down to 6" i believe, and found 6" was the most accurate.

[matts5.0]

Im wanting to build a hog/deer gun, so 18" barrel or there abouts, is 300 out of the question? My next options are 6.8, or step up to 450 bushmaster, or one of the big bore rounds.

[svauto-erotic855]

Im wanting to build a hog/deer gun, so 18" barrel or there abouts, is 300 out of the question? My next options are 6.8, or step up to 450 bushmaster, or one of the big bore rounds.

Been down this road. The big bore (.45 cal) ARs are a waste of time in my opinion and the brass is very expensive. Why try to reinvent something that was perfected more than 100 years ago in the form of a lever action 45/70?

[dee]

Been down this road. The big bore (.45 cal) ARs are a waste of time in my opinion and the brass is very expensive. Why try to reinvent something that was perfected more than 100 years ago in the form of a lever action 45/70?

While I agree for the most part. The 458 Socom is pretty effective with a can. Plus I've never seen a semi auto 45-70.

[Danny46]

First thing before you buy a .300blk. Do you reload?

If there answer is no, don't buy a .300blk.


1) The shortest barrel length possible with a standard pistol length gas system is 6". I have a 6" barrel on mine, it was a 9.5". Barrel length is irrelevant if you're shooting suppressed and it can even hurt accuracy the longer you make it. Remember, most .30 cal suppressors are 9" long, so 9+9.5"=18.5" barrel. The shorter you go the better in nearly every area. It's more accurate, smaller, and lighter.

2) If you drop below a 9.5" barrel you need to go to a 1:7 twist. At 9.5" and longer 1:8 is fine.

3) Brands don't matter because 90% of all manufacturers use the same blanks. Just make sure they know how to machine it. Pistol length gas systems are non-standard. Meaning there is no predefined exact specifications for where and how to cut the gas port, and the shelf. I ran into this problem when trying to do a piston setup on my M16. For DI it really doesn't matter.

4) get a pistol length gas system only.

5) I prefer light profile barrels, especially if you're shooting it as subsonic only. There is substantially less harmonics subsonic, especially if you have a titanium suppressor. There is an opportunity to save a lot of weight.

I haven't started reloading yet but definitely intend to for the .300. Been keeping an eye for a used single stage setup.

I do intend to shoot this suppressed....eventually.... I want to get it SBR'd first and the suppressor will come down the road. @CJ, you stated that barrel length isnt relevant if shooting suppressed, whats your thinking for unsuppressed?

I am hoping to have this built soon as I would like to hunt with this before the season is over, I will certainly take photos and such once its all complete!

[CJ]

If your intent is to suppress it, get the barrel you want the first time. If you're not going to suppress it then you're going to shoot supersonic and you want more barrel length to squeeze out velocity.

[matts5.0]

Been down this road. The big bore (.45 cal) ARs are a waste of time in my opinion and the brass is very expensive. Why try to reinvent something that was perfected more than 100 years ago in the form of a lever action 45/70?

My thoughts are if I did go big bore, or any other exotic route, are that im not going to be putting a 1000 rounds a year through it, maybe a few hundred, so im not super concerned with that. Im just trying to figure out what would work best so I can formulate a plan of attack.

[svauto-erotic855]

My thoughts are if I did go big bore, or any other exotic route, are that im not going to be putting a 1000 rounds a year through it, maybe a few hundred, so im not super concerned with that. Im just trying to figure out what would work best so I can formulate a plan of attack.

My point was that it just is not worth the headache. You are asking too much of a mediocre design just because you have an attachment to the design. Just because you can do something doesn't mean that it is a useful allocation of funds to do so. Just get yourself a 45/70 lever action if you reload and you will have something that works the first time, every time, and you will not have to fuck around with it.

[Danny46]

If your intent is to suppress it, get the barrel you want the first time. If you're not going to suppress it then you're going to shoot supersonic and you want more barrel length to squeeze out velocity.

Thats the route I went, the suppressor is just not going to be coming any time soon so I'll just have to deal with the velocity and such. Any reason why I shouldnt shoot the subsonic without the suppressor?

[Danny46]

http://www.cabelas.com/catalog/product.jsp?productId=1379113&categoryId=0&parentCategoryId=0&subCategoryId=0&indexId=0&itemGUID=5881b076b72d6302fac3e72a879ab5dd&WTz_l=Header%3BSearch-All+Products

This seem like a good deal/good ammo? Also it doesnt indicate whether subsonic or not, are the heavier grains generally subsonic?

[CJ]

Thats the route I went, the suppressor is just not going to be coming any time soon so I'll just have to deal with the velocity and such. Any reason why I shouldnt shoot the subsonic without the suppressor?

No reason, it's just kinda pointless, like burning race gas in a moped.

[lilvega]

http://www.cabelas.com/catalog/produ...h-All+Products

This seem like a good deal/good ammo? Also it doesnt indicate whether subsonic or not, are the heavier grains generally subsonic?

That should be subsonic.

Try AmmoBiz.

http://ammobiz.com/inc/sdetail/300_aac_black_out_150_fmj/375/378

$40 for 50 rounds isn't bad.

They are here in Texas and will sell direct. I have had zero problems shooting their stuff. I load my own but I bought a few boxes from them and Jameson to test my loads against. No issues with either.

Also for deals check out www.gunbot.net

[Danny46]

That should be subsonic.

Try AmmoBiz.

http://ammobiz.com/inc/sdetail/300_aac_black_out_150_fmj/375/378

$40 for 50 rounds isn't bad.

They are here in Texas and will sell direct. I have had zero problems shooting their stuff. I load my own but I bought a few boxes from them and Jameson to test my loads against. No issues with either.

Also for deals check out www.gunbot.net

Thanks man I'll definitely check that out! Last few pieces on order, hopefully will start building over Christmas.

[01yz2nv]

Good deal on ammo?

http://www.midwayusa.com/product/643120/fiocchi-shooting-dynamics-ammunition-300-aac-blackout-150-grain-full-metal-jacket-boat-tail?cm_mmc=pe_weekly-_-clearance-_-clearance_20141212_1-_-producttitle

[CJ]

It's unbelievable what they charge for that stuff