Flash hole question- Diameter Vs. Pressure
I can tell right now that some of the old goats around here need to get their heads out of the gutter.[;)][:D]
What I'm talking about is:
quote:"Don't ream out or enlarge the flash hole in primer pockets. This can increase chamber pressure."
Now, I reload a LOT of .45ACP Winchester brass. The normal target stuff has small flash holes while the Win-Clean has a much larger hole. I've compared them side by side for accuracy, with no differance. I've also noted no differance in recoil. There are also no differences is the spent cases, at least none I've noted.
Is this because .45ACP isn't really a "high Pressure" load like, say, .44 Rem Mag or even .357Mag???
Does this rule apply to higher pressure loads?
Snuff- PLEASE, PLEASE ANSWER MY POST! I know you have the answer! Just don't embarrass yourself and start talking about the wrong subject like primers instead of flash holes.
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What I'm talking about is:
quote:"Don't ream out or enlarge the flash hole in primer pockets. This can increase chamber pressure."
Now, I reload a LOT of .45ACP Winchester brass. The normal target stuff has small flash holes while the Win-Clean has a much larger hole. I've compared them side by side for accuracy, with no differance. I've also noted no differance in recoil. There are also no differences is the spent cases, at least none I've noted.
Is this because .45ACP isn't really a "high Pressure" load like, say, .44 Rem Mag or even .357Mag???
Does this rule apply to higher pressure loads?
Snuff- PLEASE, PLEASE ANSWER MY POST! I know you have the answer! Just don't embarrass yourself and start talking about the wrong subject like primers instead of flash holes.
Reserving my Right to Arm Bears!!!!
People
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0
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Triton went with small rifle primers for their 450 smc case, with its considerably higher pressures. Maybe they knew what they were doing, maybe it's just sales hype. 0 -
X-ring for me.[}:)][:D]
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In black powder cartridge rifle, most shooters inlarge the flash hole in the case and use magnum large rifle primers in order to get more fire to the rather long powder column. I have never seen any signs of excessive prussure doing this, however, just like the .45 ACP you are dealing with relatively low pressure. What the result would be when useing a cartridge that develops 50-60,000 psi, I can't say. 0 -
It's not so much a rise in chamber pressure, but a rise in primer pocket pressure (which is where most visable "pressure signs" are at).
It takes time for pressure to build on the other side of a orafice (the larger the orafice the less time) so the powder burn rate will have a effect. Fast pistol powders won't show this as much because of the shorter peak pressure time, but a full load of slow rifle powder will due to the longer peak duration.
Some guys like a mag full of lead, I still prefer one round to the head.0 -
Right on Tailgunner1954.
PEACE THROUGH SUPERIOR FIRE POWER0 -
quote:It takes time for pressure to build on the other side of a orafice (the larger the orafice the less time) so the powder burn rate will have a effect.
So, in essance, as long as I maintain SAMMI specs on the flash hole in my rifle brass and pistol ammo such as .44's, .41's and .357's loaded with slower powders, I shouldn't have to worry.
I guess a second follow-up question is, "When and how will this give me a false positive reading of excessive case pressure. Or will it?"
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"When and how will this give me a false positive reading of excessive case pressure.
Load 1 large and 1 small flash hole case with a near max charge of fast powder, say Bullseye, in your 45 (everything else staying the same). The primer from the large hole case will (probably) appear as if it came from a overload.
Do the same thing with a powder that is at the slow end of the range, and the primers will appear to be (nearly) the same.
With the slow powder there was enough time for the pressures to equalize with both sizes of hole. With the fast powder, the small hole delayed the pressure build up in the pocket for a longer time, while the large hole allowed the pocket pressure to build in a shorter time.
As most rifle cases use the same size flash hole, the effect isn't seen as much there.
Some guys like a mag full of lead, I still prefer one round to the head.0
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