Chamber pressures and bullet seating

[Ganderite]

The muzzle gasses can ignite and make a big fireball and a load bang. Most noticeable if it happens only some of the time. This is why a flash suppressor is useful. it breaks up the gasses.

 

[Pathfinder]

On a less intense and pressing subject: The 6mm Remington being a well balanced cartridge I think based on (necked down alone?) the very fine 257 Roberts. Has someone already necked these medium length cartridges up to 6.5 mm (264 thousandths of an inch) to take advantage of the myriad of bullets available for that caliber?

Additional consideration for why someone might conceive of such a wildcat: It seems logical to have a cartridge with case capacity somewhere between the 6.5-06(long case for that caliber) and the short actions in 6.5/260 derived from 308 cases? The 257 case length measures between the long and short mentioned, however the 30-06 parent would have some inefficiencies due to all the empty case space, and the short cases would suffer a lack of capacity, and of course resulting chamber pressure would increase +/- 20% over the former. Beating a pointlessly killed horse?

Ived necked down 7x57 mauser to 6.5mm which is the same. Nice cartridge.

That being said I dont' think the 260 rem really lacks capacity for what it's designed to. My opinion is the 6.5x257 Roberts (or 6.5x57) (or 6.5 spence) is so damned close to 6.5x55 in capacity that it's completely redundant. It was more popular in the 50's when War souvenir Japanese Arisaka's were being rechambered (presumably because there was no brass or ammo for them) .

 

[mmattockx]

That having been said, accuracy seems to be best "just off the lands", not into them,

That depends on the bullets being used. Many of the secant ogive bullets seem to perform best if jammed, whereas the tangent ogive ones do seem to prefer a bit of a jump.


Mark

 

[Ganderite]

How did this thread get into 6.5 wildcats?

I use a 260 Rem Ackley. It has about the same case capacity as a 6.5x55 in a short action. It get about 2900 fps with a Sierra 142 (32" barrel.)

 

[Pathfinder]

How did this thread get into 6.5 wildcats?

I use a 260 Rem Ackley. It has about the same case capacity as a 6.5x55 in a short action. It get about 2900 fps with a Sierra 142 (32" barrel.)

The original post asks a question about them (second part).

 

[JDForBrkFst]

What prevents the gun from becoming a pipe bomb is

I know its irrational, but this line will be going on loop in my mind next time I'm shooting.