300 blk, need some schoolin!

[1903Collector]

I'm looking for an entry level 300 blk upper assembly and have noticed they come in pistol and carbine length gas systems, I don't know much about this caliber but I have read that subsonic ammo may not function in all uppers? I would want something that will function with all ammo So what gas system should I get with a 16" barrel? Also what would be a good MD for this round?

I'll be happy with standard handguards and FSB, can anyone recommend a good upper that won't break the bank? Say $500-$700 range, I really don't want to build this time.

Thanks,

 

[ChevyGuy91]

I just saw somewhere that had 300blk barrels on blowout for 100 bucks, I will dig through my history and see if I can find it.

 

[MAD Geary]

I just saw somewhere that had 300blk barrels on blowout for 100 bucks, I will dig through my history and see if I can find it.

Radical firearms, they make good stuff. $70

http://www.radicalfirearms.com/category-s/2086.htm

 

[dcmdon]

Jobob outfitters had radical uppers with Seekins handguards for $20 more than on Radical's web site. I like the Seekins handguards more than the Radical ones on their own site.

Either way, its another option.

To the OP. No upper will work with everything. If you have subsonic ammo with anything less than a 230 ish grain bullet, its not going to cycle a upper unless it has a silencer. The silencer lengthens the amount of time that the pressure remains in the barrel (called dwell time) so the bolt carrier gets sufficient speed to cycle.

If you modified it to work with weak subsonics, and no silencer, then it would have TOO MUCH gas when fired with supersonic ammo and reliability and longevity would suffer.

Bottom line is that in order for subsonics to cycle well in a .300 blk gun, they need to be very heavy, or kindof heavy and run through a can.

Don

 

[Coyote33]

Here you go:

1) ?? .300 AAC / 7.62 x 35 ??

2) 300 AAC Blackout, why not?

3) 300 Blackout

4) Need ideas/convincing

5) Does anyone have experience with ARs chambered in WSSM calibers?


I'd second taking a strong look at the Joebob stuff.

 

[crazymjb]

I have a 9" rainier arms barrel, so far has been flawless, but I admittedly only have a few hundred rounds through it.

Mike

Sent from my cell phone with a tiny keyboard and large thumbs...

 

[ChevyGuy91]

To the OP. No upper will work with everything.

Perhaps this is true for 16" guns, but the cartridge was designed to run out of a 9" barrel, and out of my 8.5" I have not found a loading that has not worked, suppressed or unsuppressed. To add to this, I have not shot thousands of rounds through it like a 5.56 gun.

I am looking for a light weight 16" barrel myself for a light weight brush gun for the fall, but that rig will only see supersonic, lighter bullets and not subsonics.

 

[1903Collector]

Lots of good info here, many thanks! My question remains though what gas system would you all recommend.....carbine or pistol length? Unless magic happens I won't be getting a suppressor or a barrel under 16".

Maybe I'll just skip the whole thing and get a bolt gun instead

 

[ChevyGuy91]

Lots of good info here, many thanks! My question remains though what gas system would you all recommend.....carbine or pistol length? Unless magic happens I won't be getting a suppressor or a barrel under 16".

Maybe I'll just skip the whole thing and get a bolt gun instead

If you are looking to run supersonic ammo only, I would go with a carbine length gas system, I would think that would get you a slightly softer recoil impulse. IIRC, there are some places offering pistol length gas systems on 16" barrels in hopes of making both run, but I don't have any experience with 16" barrels yet.

 

[warwickben]

+1 on radical.
My gf built a ar with one of there uppers and stock bcg .

 

[Bt74]

Hoping to get a chance to shoot the 10.5 I just received from Joebobs a couple of days ago. Paid $299 shipped, and it came with a $180 Seekins full float handguard. Picked up a Kak flash can, just have to get the A2 flash hider off (torqued on pretty tight and don't want to damage the free float). Looks pretty good, no markings on the receiver and appears to be test fired. Pistol length tube.

 

[dcmdon]

I'm torn over whether to get the Joe-bobs or to build one myself.

I'll have about $450 into an all AeroPrecision upper. (based on the assumption that I already own an adjustable gas block for it)
The benefit is that I can do a 7.5" barrel and a 9" handguard so the silencer slips into the handguard.

I just received a demo Thunderbeast Ultra-7, 7" .30 cal can that weighs 9 oz. It should work great.

Don

p.s. If anyone wants a complete silenced upper from Aeroprecision, complete with Silencerco Omega can, let me know. I'm putting together an order. I'd do it for my cost for Green members with proof of a $100 donation to Comm2A. Proof of green-ness and donation required (all state and fed laws followed)

http://aeroprecisionusa.com/m4e1-sd.html

 

[1903Collector]

So I am in the 300 Blackout game, After looking around I found a 16" flat top upper with standard handguards from Double Star. I have used their parts before on builds and have been satisfied with the quality so I'll see how the upper goes, fit and finish look very good. I cobbled together a lower from parts I had hanging around. I have always used Magpul MIAD's on my builds but I had a BCM gunfighter pistol grip in the parts box......I really like this grip!! Finished off with an ACE entry stock and swiped an Aimpoint off one of my other ARs. Very much looking forward to getting this to the range this weekend.