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possorry for the long t just trying to get it easy to read, got some of the info from

The Gun Zone -- .30 Caliber Ammo trying to do everything on the safe side hence the max proof pressures for the 308 stuff and the bolt head diameter instead of the true case head diameter

i got some good solid works 3D models of a romy trunnion today trying to run the force application on it as we speak (test how the lugs will hold up under different pressures applied from the bolt thrust)

not having much luck the software im using doesnt allow for heat treated steel so even the opperating pressures of the 7.62 x 39 arent giving safe results in the solid model stuff

ill keep trying and let you know what happens

Bolt thrust= area x psi

Area = 3.146 x ( (case head diameter / 2)^2)

Above is from

http://www.riflebarrels.com/articles...g_strength.htm
7.62 x 51 NATO

"Proof" pressure = 67,500 psi

Bolt head diameter = .475

3.146 x ((.475 / 2)^2) = .1772

67,500 x .1772 = +/- 12,000

7.62 x 51 NATO = +/- 12,000 lbs bolt thrust max

308 Winchester

"Proof" pressure = 83,000 psi

Bolt head diameter = .475

3.146 x ((.475 / 2)^2) = .1772

83,000 x .1772 = +/- 14,800

308 Winchester = +/- 14,800 lbs bolt thrust max

7.62 x 39

Max "reload" pressure = 45,000 psi

bolt head diameter = .458

3.146 x ((.458 / 2)^2) = .1647

45,000 x .1647 = +/- 7,420

7.62 x 39 = +/- 7,420 lbs bolt thrust

6.5 Grendel

Case head diameter = .445