AR-10 max pressure same as AR-15?

[fatelvis]

I'm working up loads for my new AR-10 in 6Creed, and am wondering if the loads should be kept to the same 52K psi ceiling as the AR-15 loads are. Or is it a different figure? THanks!

 

[Park ranger]

That’s very low pressure. Why that low? That’s what sammi hold to a 6 arc in an AR, but that’s because the big case in a small bolt. Not much meat on the bolt. I run mine much higher.

 

[fatelvis]

That’s very low pressure. Why that low? That’s what sammi hold to a 6 arc in an AR, but that’s because the big case in a small bolt. Not much meat on the bolt. I run mine much higher.

Actually, I was referring to the 6ARC max pressure with the 52k. I figure the max pressure would be cartridge specific, taking the bolt face into consideration for strength. I was just wondering what I should use as my figure when working up 6.5 Creedmoor loads.

 

[Adam in WI]

Since the 6.5 is available in factory produced AR rifles, I'd have no problem loading to factory ammo pressures. 7.62/.308 pressure is 60k/62k. Like park ranger, I think the big concern is on the smaller platform loading cartridges with cases larger than the original 5.56.

 

[Rocketvapor]

Pressure limits for AR-15 cartridges are limited by a safe BOLT THRUST, which is calculated on INTERNAL case diameter (cross sectional area X Pressure).
A 5.56 case has a pressure limit of 62,000 PSI with an AR-15 bolt.
A larger diameter 22 Nosler case has a limit of 55,000 PSI with an AR-15 Bolt,
Even larger case body diameters, like Grendel size cases have a limit of 52,000 PSI due to bolt thrust and Case Head Diameter reducing lug strength.
For an AR-15, large diameter case bodies, and thin bolt lugs with larger BASE diameters create reduced safety margins in bolt design.
These larger cases can have a 62,000 PSI limit in a suitable BOLT gun.

The larger bolt of the AR-10 allows a max pressure of 62,000 PSI for cases up to .308.
Your 6 Creed should be good to 62,000 PSI.

 

[fatelvis]

Pressure limits for AR-15 cartridges are limited by a safe BOLT THRUST, which is calculated on INTERNAL case diameter (cross sectional area X Pressure).
A 5.56 case has a pressure limit of 62,000 PSI with an AR-15 bolt.
A larger diameter 22 Nosler case has a limit of 55,000 PSI with an AR-15 Bolt,
Even larger case body diameters, like Grendel size cases have a limit of 52,000 PSI due to bolt thrust and Case Head Diameter reducing lug strength.
For an AR-15, large diameter case bodies, and thin bolt lugs with larger BASE diameters create reduced safety margins in bolt design.
These larger cases can have a 62,000 PSI limit in a suitable BOLT gun.

The larger bolt of the AR-10 allows a max pressure of 62,000 PSI for cases up to .308.
Your 6 Creed should be good to 62,000 PSI.

that’s what I was hoping to hear!