jeffe,

I have my bolt apart. I'm having a little trouble seeing how the gas is routed to the shooter's eye more so than other centerfires. Could you elaborate some?

Thanks,

TBP

Here's a blunder done by my nephew. A .308 loaded in a rem .280, a 7400. Believe it or not, no damage to the gun or shooter! The rifle has been carefully inspected, cleaned and returned to reliable service.

The bolt was stuck shut, but gentle persuasion from a solid brass cleaning rod got it open. This was NOT a full power .308 however. The Nephew has a then 12 year old son and his wife shooting a m100 winny. I loaded some 130 grain spire points with a minimum powder level of WC 844.



The soft thin jacket of the 130 spire Hornady must have swaged quite easily, and .284 is closer to .308 than .277 is.


Still,,, the pressure must have been extremely high!

The big bullet in a small bore making no pressure increase is counter intuitive.

The way I reconcile it is to think in the time domain.
If the peak pressure of powder burn is not concurrent with the increase pressure to swage, the peak pressure does not change.


This phenomena of large bullets working in a small bore without pressure spikes is documented in P.O. Ackley 1966 "Handbook for Shooters and Reloaders Vol 2" chapter 7 "additional pressure tests":

"..30 cal barrel pressure barrel was fitted to the test gun, but the
neck and throat was enlarged to accept the 8mm bullet, with the bore remaining the standard 30 caliber. A Remington factory 30-06 cartridge with the 150 gr bullet had been tested and previously gave 57,300 psi, for a velocity of 3030 fps. The the bullets were pulled from two more Remington 150 grain cartridges and were replaced with 8mm 150 grain
bullets. To everyone's surprise, although the velocity was rather erratic, these loads averaged 2901 fps, with a pressure of 40,700 psi."

The rerason that a 8x57 will "blow" a 30/06 isn't due to the larger bullet. The neck of the 8x57 will be compressed
to the point that the bullet cannot release. Most 06's will not accept a 8x57. The Springfield 03, and the
Win 95 had oversized necks in the chamber and will usually chamber one.
As Ackley pointed out it is not the oversize bullet that causes trouble. The bullet only has to travel a short distance before it is
swaged to size.
Good luck!