6.5 swede question

[elkhunter11]

Originally Posted by Sashi

I may have resolved my problem, The actual velocities verses the expected velocities were normal, But the soot covering the cases was from ruptured primers due to a nick in the firing pin. Hopefully the cause of the base expansions was caused by the hot gases flowing backwards and heating the base. This along with the pressures causing the bases to expand. My new firing pin should be in soon, and I will be able prove my assumptions.

The pressures required to produce over 3000fps are far higher than the 96 action is designed to handle. As for your explanation of the pierced primers causing the expanded case heads, I for one don't find it to be a reasonable explanation. The powder burning in the case would be producing those hot gases inside the case anyways, whether the primers leak or not. If anything, bleeding off some of the gases would reduce the chamber pressure very slightly. Regardless of the pierced primers, I would definitely not continue to fire that load in that rifle.

The primers are not even showing signs of flattening, a proven method of higher pressure signs,,,

The bevel/ rounded corners of your fired cases are identical to your un fired case

Then again, the primers being pierced and bleeding off some of the pressure, means that the primers may not be seeing the full chamber pressure.

[DevilsAdvocate]

Originally Posted by Sashi

Wellllllll..............I will take 31 grains of IMR4064........for 3193 ft/sec. ;-)

[elkhunter11]

Originally Posted by DevilsAdvocate

Wellllllll..............I will take 31 grains of IMR4064........for 3193 ft/sec. ;-)

I think that most of us would catch on to the misprint, when the maximum change only lists 2300fps.

Not to mention that the loads are listed with the highest velocities at the top, and the lowest at the bottom.

[Sashi]

Originally Posted by elkhunter11

The pressures required to produce over 3000fps are far higher than the 96 action is designed to handle. As for your explanation of the pierced primers causing the expanded case heads, I for one don't find it to be a reasonable explanation. The powder burning in the case would be producing those hot gases inside the case anyways, whether the primers leak or not. If anything, bleeding off some of the gases would reduce the chamber pressure very slightly. Regardless of the pierced primers, I would definitely not continue to fire that load in that rifle.



Then again, the primers being pierced and bleeding off some of the pressure, means that the primers may not be seeing the full chamber pressure.

I'll soon find out, a higher temperature should cause it to expand at a lower pressure, if my high school science is correct.

[elkhunter11]

Originally Posted by Sashi

I'll soon find out, a higher temperature should cause it to expand at a lower pressure, if my high school science is correct.

The heat of combustion would be transferred into the case with or without the primer leakage.

[Sashi]

Originally Posted by elkhunter11

The heat of combustion would be transferred into the case with or without the primer leakage.

Of Course,, How stupid of me.

[DevilsAdvocate]

Originally Posted by elkhunter11

I think that most of us would catch on to the misprint, when the maximum change only lists 2300fps.

Not to mention that the loads are listed with the highest velocities at the top, and the lowest at the bottom.

You must be crucial at parties.........to explain anybody's humorous antidote to everybody else,......and blurt out punchlines.

Start at the first post and you may finally get the humour. If not, then.........!!