Piston or no Piston?

Discussion about rifles in 300 AAC BLACKOUT (7.62x35mm), hosted by the creator of the cartridge.

Moderators: gds, bakerjw, renegade

Post Reply
Rolex 2012
New Member
Posts: 2
Joined: Fri Jul 20, 2012 4:47 pm

Piston or no Piston?

Post by Rolex 2012 »

I was looking into a Core15 16" BO barrel.
They have a disclaimer that reads something
like this: you will need a piston set up to
make this barrel run properly!

So who has a 16" BO barrel and does NOT
run a piston system in it? And is it reliable?
And I misreading their ads?

I want to buy one, but not if the only way
it will run properly is with a piston- Why because
it's just that much more money spent!

Thanks
Recoil737
Senior Silent Operator
Posts: 125
Joined: Wed Oct 10, 2007 2:17 am
Location: Texas

Re: Piston or no Piston?

Post by Recoil737 »

No manufacture has gotten a piston to run better than DI in a 300BLK. The 300BLK runs more reliable with DI than with a piston.
User avatar
AR-300
Silent But Deadly
Posts: 1351
Joined: Mon Jan 09, 2012 10:26 pm
Location: Foothills NC

Re: Piston or no Piston?

Post by AR-300 »

PSA 10.5" & 16'' FN CHF CL 300 AAC Blackout
User avatar
velo555
Silent But Deadly
Posts: 391
Joined: Wed Mar 28, 2012 9:14 am
Location: Upstate SC

Re: Piston or no Piston?

Post by velo555 »

Actually the quote for the 16" 4150 barrel says to use an adjustable gas block since there gas ports are optimized to run subsonic suppressed or unsuppressed. Maybe they went overboard and opened up the gas port to avoid customer service issue due to subs without a can.

http://www.core15.com/products/parts/up ... gory_id=14
Victor Lopez
User avatar
300Blk
Site Admin
Posts: 7331
Joined: Mon Apr 25, 2005 9:31 am
Location: USA

Re: Piston or no Piston?

Post by 300Blk »

There is never a situation where a 16 inch carbine gas system barrel benefits from an adjustable gas block. Never. No matter how large you make the gas port, it will never be too large for supersonic suppressed. (for example, the cyclic rate will never exceed Colt M4 specs).
robrob
Silent But Deadly
Posts: 302
Joined: Wed Nov 25, 2009 9:53 am
Location: West Virginia

Re: Piston or no Piston?

Post by robrob »

300Blk wrote:There is never a situation where a 16 inch carbine gas system barrel benefits from an adjustable gas block. Never. No matter how large you make the gas port, it will never be too large for supersonic suppressed. (for example, the cyclic rate will never exceed Colt M4 specs).
That sure takes the mystery out of the gas port size for 16 inch barreled 300BLKs with carbine gas--just make it the same size as the inside diameter of the gas tube, .125 inch.

The one exception to your comment is it's nice to be able to turn off the gas completely for single shot quietness.
nolwark76
Silent But Deadly
Posts: 1148
Joined: Tue Nov 27, 2007 9:56 pm
Location: Oregon!!!

Re: Piston or no Piston?

Post by nolwark76 »

+1 for the DI system. I like the piston cleanliness unsuppressed but since I have a can, I like to shoot with it. That negates the cleanliness as the piston system is barely cleaner suppressed. Then there's the fact that LWRC, who's at the top of the piston game and til now only made piston rifles, made their 300 BLK a DI gun. Hmmmm.....
Rolex 2012
New Member
Posts: 2
Joined: Fri Jul 20, 2012 4:47 pm

Re: Piston or no Piston?

Post by Rolex 2012 »

OK- so if I buy a 16" 300 barrel- what about the twist? Some say 1/7"
is the NEW 1/8". I do intend to shoot WO a can and use 125gr bullets,
and if necessary- some say I will need one- adj. gas block?

Again thanks-
User avatar
velo555
Silent But Deadly
Posts: 391
Joined: Wed Mar 28, 2012 9:14 am
Location: Upstate SC

Re: Piston or no Piston?

Post by velo555 »

1/7 and 1/8 will work fine with 125g bullets. 1/7 may be needed for heavy bullets (more than 220g I believe). Cor-Bon says there 240g shots fine out of a 1/8. I think Robert Silvers has said that 1/7 is better for the heavies. I would trust his word on pretty much anything on a 300BLK AR. He is a engineer in the firearms industry not a net ninja like me and others.
Victor Lopez
User avatar
300Blk
Site Admin
Posts: 7331
Joined: Mon Apr 25, 2005 9:31 am
Location: USA

Re: Piston or no Piston?

Post by 300Blk »

I have not been able to make 1/7 be less accurate with supersonic and I am sure 1/7 is better for subsonic.
Post Reply

Who is online

Users browsing this forum: Semrush [Bot] and 129 guests