Going from .308 to 6.5 Creedmoor- Do I need a HP bolt too?

[PDXGS]

Hi all, I'm an experienced long-range bolt gun shooter in the process of converting a .308 AR10 to a 6.5 Creedmoor. Assuming that the bolt is a good match/fit, is it necessary to also swap it for a JP high pressure bolt?
I await the wisdom of the forum....

 

[knuckleballz]

What bolt and barrel do you have now in your 308? What barrel are you switching to?

 

[PDXGS]

Currently running a DPMS "precision" stainless barrel with an Aero BCG and switching to an Aero stainless barrel.

 

[padom]

I would most certainly switch to a JP HP bolt if going 6.5cm.

 

[Red_SC]

The Aero BCG is HP. A standard firing pin hole is .080, the Aero is .070. Some companies make them down to .062, I don't know the JP size offhand.

I use JP bolts in my builds for non-.308 applications, but since you already have it I'd try the Aero to see if there's a problem before replacing it. I do use Aero bolts sometimes in .308 builds including my own .308, they're well made.

 

[SFree]

Doing same conversion, but with an Armalite rifle, so possibly no need for the JP hp bolt? I believe the AR-10 bolt firing pin hole is .062...

 

[padom]

The smaller firing pin hole is not the only design change of JP's HP bolt. There's a reason JP's HP bolt is the go to standard for people building 6mm/6.5mm semis and is the reason many factory barrel makers headspace to JP bolts like Rainier. Check out JP's site if you want the list of things you get with their HP bolt. RCA HP bolt is the only other bolt I would use in a 6.5cm semi.

 

[SFree]

JP doesn't make anything for Armalite/RockRiver pattern rifles,so the bcg/bolt needs to be changed to DPMS type?

 

[SFree]

Don’t understand the necessity for a different bolt when chamber pressures should be close and other operating pressures could be controlled by adjustable gas blocks or gas keys. Seems some problems in other systems were solved by switching to an Armalite bolt. Why has the AMU used Armalite almost exclusively if advantages were with other systems besides the magazine issue. This is from searching and reading from the internet so it MUST be true
My apologies if I’m dense, I’m here to learn.

 

[mazelaska]

Can anyone say whether FailZero AR10 bolt is sufficient for 6.5 Creedmoor AR10?

 

[bfoosh006]

IMHO, it is just as important to make sure the bolt remains locked long enough... IE, make sure to run an adjustable GB and heavy buffer weight and recoil spring.

Any pressure signs I saw went away , promptly, after allowing the bolt to remain locked just milliseconds longer.

I also believe... Armalite BCG's have a slightly different cam pin path that aids in a millisecond longer locked action... ( and the gas tube is different )

Ejector smear marks went away... the whole 9 yds.


I am not negating the value of the JP bolt at all.... just saying that there more factors to help mitigate pressure issues then just the bolt