I have been looking at the primers to see if their is any cratering, or if the primer is starting to get flat. What other things do you guys look for?
Im shooting 45acp
Thanks
Im shooting 45acp
Thanks
pressure sings in semi-auto pistols
- Thread starter ubet
- Start date
Re: pressure sings in semi-auto pistols
What pistol? Barrel length?
Check the bottom of your chamber/ramp area. If there is an area that is open/unsupported when the slide is closed, that will probably be the first place you will see signs (this is known as an unsupported chamber and in some pistols is used to improve feeding as well as extraction). The case will bulge in that area. Be careful if you mix brass as well since some brands are not as strong as others. If you work up a load you should stick to the same components for safety sake.
Primers might are hard to use as an indicator in many semi-auto pistols since the firing pin swipes the primer anyway (scared me the first time I saw it!).
I personnaly do not try to "push the limits" in my pistols. I would also recommend using chronograph data instead of pressure signs as the indicator of an appropriate load in a semi auto pistol. You will probably get more reliable functioning that way as well.
my .02
tater
What pistol? Barrel length?
Check the bottom of your chamber/ramp area. If there is an area that is open/unsupported when the slide is closed, that will probably be the first place you will see signs (this is known as an unsupported chamber and in some pistols is used to improve feeding as well as extraction). The case will bulge in that area. Be careful if you mix brass as well since some brands are not as strong as others. If you work up a load you should stick to the same components for safety sake.
Primers might are hard to use as an indicator in many semi-auto pistols since the firing pin swipes the primer anyway (scared me the first time I saw it!).
I personnaly do not try to "push the limits" in my pistols. I would also recommend using chronograph data instead of pressure signs as the indicator of an appropriate load in a semi auto pistol. You will probably get more reliable functioning that way as well.
my .02
tater
Re: pressure sings in semi-auto pistols
Its a sig220 4.4" barrel. The chamber is supported. I dont push the limits any time I reload, damn firearms cost to much to take chances. I stay within boo
Its a sig220 4.4" barrel. The chamber is supported. I dont push the limits any time I reload, damn firearms cost to much to take chances. I stay within boo
Re: pressure sings in semi-auto pistols
1) If the case gets a bulge in the shape of the feed ramp intrusion into chamber support, stop the work up. Useful loads must be reduced by a safety margin from this threshold.
I have done this countless times in 25acp, 32acp, 7.62x25mm, .380., 9x19mm Luger, 9x23mm Win, 357 Sig, 40 S&W, 10mm, and 45acp.
There is an underlying principal, the thin case wall has chamber pressure on one side and one atmosphere on the other. It blows a bubble. Like blowing bubble gum, it does not take much more to pop the bubble.
If you pop the bubble, you will be sorry.
When the case bulge breaks:
a) gas shoots out into the gun and can do things like blow the magazine bottom plate off, dropping the magazine spring and follower and ammo onto the floor.
b) Things get even worse when the case head blows off, and the extractor pieces leave the gun at lethal velocities. I have only done this once in 7.62x25mm and once in 9x19mm.
2) Primer piercing only occurs before case bulge in pistols with poor firing pin to firing pin hole fit.
3) Failure to extract only occurs before case bulge in pistols with poor extraction.
4) Chamber splitting or chamber bulging only occurs before case bulge in pistols with good case support [to the web or close] and thin chamber walls, less than ~0.1" thick.
What does it all mean?
The case bulge is the warning. Stop the work up there, and back off on powder charges.
1) If the case gets a bulge in the shape of the feed ramp intrusion into chamber support, stop the work up. Useful loads must be reduced by a safety margin from this threshold.
I have done this countless times in 25acp, 32acp, 7.62x25mm, .380., 9x19mm Luger, 9x23mm Win, 357 Sig, 40 S&W, 10mm, and 45acp.
There is an underlying principal, the thin case wall has chamber pressure on one side and one atmosphere on the other. It blows a bubble. Like blowing bubble gum, it does not take much more to pop the bubble.
If you pop the bubble, you will be sorry.
When the case bulge breaks:
a) gas shoots out into the gun and can do things like blow the magazine bottom plate off, dropping the magazine spring and follower and ammo onto the floor.
b) Things get even worse when the case head blows off, and the extractor pieces leave the gun at lethal velocities. I have only done this once in 7.62x25mm and once in 9x19mm.
2) Primer piercing only occurs before case bulge in pistols with poor firing pin to firing pin hole fit.
3) Failure to extract only occurs before case bulge in pistols with poor extraction.
4) Chamber splitting or chamber bulging only occurs before case bulge in pistols with good case support [to the web or close] and thin chamber walls, less than ~0.1" thick.
What does it all mean?
The case bulge is the warning. Stop the work up there, and back off on powder charges.
