I have a new Rock River lar-8. I know how to tell if the pressure is to great from the point of view of the cartridge, but how would I know if I were beating the gun up unnecessarily.?
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How do I know ?
- Thread starter rocky_creek
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Re: How do I know ?
Try a chronograph. If your velocities are a lot higher than what reloading manuals suggest you should be seeing; you're probably exceeding SAMMI pressure maximums.
Try a chronograph. If your velocities are a lot higher than what reloading manuals suggest you should be seeing; you're probably exceeding SAMMI pressure maximums.
Re: How do I know ?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rocky creek</div><div class="ubbcode-body">I have a new Rock River lar-8. I know how to tell if the pressure is to great from the point of view of the cartridge, but how would I know if I were beating the gun up unnecessarily.?</div></div>
are you talking reloading or commercial ammunition? Have you ever fired an over pressured/over gassed gun. You will know the difference by the feel. It feels odd and gets your attention.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rocky creek</div><div class="ubbcode-body">I have a new Rock River lar-8. I know how to tell if the pressure is to great from the point of view of the cartridge, but how would I know if I were beating the gun up unnecessarily.?</div></div>
are you talking reloading or commercial ammunition? Have you ever fired an over pressured/over gassed gun. You will know the difference by the feel. It feels odd and gets your attention.
Re: How do I know ?
Hand loaded. There are very few manuals that give loads specifically for gas guns. Those that do seem way conservative.
Hand loaded. There are very few manuals that give loads specifically for gas guns. Those that do seem way conservative.
Re: How do I know ?
This is one reason it's important to test incrementally hotter loads when you're doing load development. You'll start seeing pressure signs long before they become excessive, and it's easier to follow their growth and expansion and recognize the limit. However, just where that limit lies is a matter of judgment and experience. There's a number of tutorials online dealing with reading pressure signs ( here and here, for two).
Experience is the best teacher and if you're not comfortable with your own judgment, IMHO, the best thing you can do is consult with an experienced reloader any time you're uncertain.
This is one reason it's important to test incrementally hotter loads when you're doing load development. You'll start seeing pressure signs long before they become excessive, and it's easier to follow their growth and expansion and recognize the limit. However, just where that limit lies is a matter of judgment and experience. There's a number of tutorials online dealing with reading pressure signs ( here and here, for two).
Experience is the best teacher and if you're not comfortable with your own judgment, IMHO, the best thing you can do is consult with an experienced reloader any time you're uncertain.
Re: How do I know ?
Some semi's, (Garand, and the M1A/M14 to a somewhat lesser extent) impose a powder burn rate and upper bullet weight limitation for handloading. This is because heavier bullets and slower burn rates can deliver excessive port pressures to the gas system.
Opinions on this vary for other systems, and I can't say with certainty how this concept extends to them. But I also wouldn't be surprised if there's at least some application.
Conventional post firing case pressure signs may not tell much about port pressures, but indications of damage or rim deformation from the extractor or major dents from ejection can suggest excessive port pressures.
For the Garand/M1A, I prefer not to go slower than IMR-4064, and heavier than 175gr.
Greg
Some semi's, (Garand, and the M1A/M14 to a somewhat lesser extent) impose a powder burn rate and upper bullet weight limitation for handloading. This is because heavier bullets and slower burn rates can deliver excessive port pressures to the gas system.
Opinions on this vary for other systems, and I can't say with certainty how this concept extends to them. But I also wouldn't be surprised if there's at least some application.
Conventional post firing case pressure signs may not tell much about port pressures, but indications of damage or rim deformation from the extractor or major dents from ejection can suggest excessive port pressures.
For the Garand/M1A, I prefer not to go slower than IMR-4064, and heavier than 175gr.
Greg
Re: How do I know ?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rocky creek</div><div class="ubbcode-body">Hand loaded. There are very few manuals that give loads specifically for gas guns. Those that do seem way conservative.</div></div>
one of the most important items I have purchased for reloading is the Chronograph. I know many people who reload without it but I personally believe that it enhances your understanding of loads at different charges and outside temperatures.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rocky creek</div><div class="ubbcode-body">Hand loaded. There are very few manuals that give loads specifically for gas guns. Those that do seem way conservative.</div></div>
one of the most important items I have purchased for reloading is the Chronograph. I know many people who reload without it but I personally believe that it enhances your understanding of loads at different charges and outside temperatures.
Re: How do I know ?
I used to load without the chronograph and was always worried about stuff like this. Once I got the chrono, using that and pressure signs from an incrimental load regimen I would never go back. i push it to a reasonable velocity and or pressure signs whichever comes first. If pressure signs come first then i back off and maybe look for reasons in my brass or powder. If the velocity comes first I stick with it and go no further.
If i can get out to the distance i want with my velocity and energy i see no need to push the velocity to maximum just to get a couple inches ....but thats just me.
P.S. I take average velocities from loads developed on the hide here for my "reasonable".
I used to load without the chronograph and was always worried about stuff like this. Once I got the chrono, using that and pressure signs from an incrimental load regimen I would never go back. i push it to a reasonable velocity and or pressure signs whichever comes first. If pressure signs come first then i back off and maybe look for reasons in my brass or powder. If the velocity comes first I stick with it and go no further.
If i can get out to the distance i want with my velocity and energy i see no need to push the velocity to maximum just to get a couple inches ....but thats just me.
P.S. I take average velocities from loads developed on the hide here for my "reasonable".
Re: How do I know ?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">There are very few manuals that give loads specifically for gas guns.</div></div>
Lyman 48 for .223 and Speer 13 .308.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">There are very few manuals that give loads specifically for gas guns.</div></div>
Lyman 48 for .223 and Speer 13 .308.
