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  #11  
Old 06-24-2019, 04:25 PM
HighpowerRifleBrony HighpowerRifleBrony is offline
 
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If the rim is bent forward, it's likely from the extractor snapping over. Not uncommon for me to see.
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  #12  
Old 06-24-2019, 07:35 PM
mushka mushka is offline
 
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If I'm not mistaken, wc872 was used for loading 20mm cannon ammunition. I've not been successful loading it in small cased ammo. .30 cal and such. I believe in it might only marginally work well heavy bullets in .30 call. 200 or 220 grainers, but then in your Garand you might be wrecking op rods.
I do load 50 BMG with wc872 and it is a good functional powder in this caliber. Heavy bullets and long barrel.
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  #13  
Old 06-25-2019, 03:51 PM
Unclenick Unclenick is offline
 
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As a general rule, the slower burning a powder is, the higher the peak pressure needed to get it to burn reasonably completely. If Jeff Bartlett is correct that it burns similarly to H870, then you are running in the 20-27 kpsi range with your loads, which can't burn a slow powder very well. If you did get it up to a peak pressure that the powder liked, the greater progressivity would give you higher muzzle pressure, so don't be surprised to see the op-rod starting to get slammed around if you find a way to do it. Your starter charge is getting a little more of it lit up a little sooner but isn't changing the overall progressivity of the main powder mass any.

Even with a 220-grain bullet, QuickLOAD says a 110% load of H870 would only get to 32,000 psi. Still low for good burning. But assuming the two are really that much alike is assuming a lot.
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  #14  
Old 06-25-2019, 11:54 PM
s11033 s11033 is offline
 
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Quote:
Originally Posted by HighpowerRifleBrony View Post
If the rim is bent forward, it's likely from the extractor snapping over. Not uncommon for me to see.
Got it, thank you. I also removed the plug because I didn't have my adjustable gas plug with me, and I wasn't sure what would happen. Anyway, good to know that's not a concern. It may well have been on the case before I fired it. I'll have to check more carefully next time.

Quote:
Originally Posted by mushka View Post
If I'm not mistaken, wc872 was used for loading 20mm cannon ammunition. I've not been successful loading it in small cased ammo. .30 cal and such. I believe in it might only marginally work well heavy bullets in .30 call. 200 or 220 grainers, but then in your Garand you might be wrecking op rods.
I do load 50 BMG with wc872 and it is a good functional powder in this caliber. Heavy bullets and long barrel.
You're correct, it's made for 20mm Vulcan.

Quote:
Originally Posted by Unclenick View Post
As a general rule, the slower burning a powder is, the higher the peak pressure needed to get it to burn reasonably completely. If Jeff Bartlett is correct that it burns similarly to H870, then you are running in the 20-27 kpsi range with your loads, which can't burn a slow powder very well. If you did get it up to a peak pressure that the powder liked, the greater progressivity would give you higher muzzle pressure, so don't be surprised to see the op-rod starting to get slammed around if you find a way to do it. Your starter charge is getting a little more of it lit up a little sooner but isn't changing the overall progressivity of the main powder mass any.

Even with a 220-grain bullet, QuickLOAD says a 110% load of H870 would only get to 32,000 psi. Still low for good burning. But assuming the two are really that much alike is assuming a lot.
Thank you for the additional information. I should probably get myself QuickLOAD. I guess the question really becomes how much of an effect do the unburned grains have on the bore over time. I may still use the WC872 with cast boolits just because it puts them in a sufficiently low velocity range, so long as the unburned kernels don't have some crazy negative effect on the bore.

Steve
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  #15  
Old 06-26-2019, 10:47 AM
Unclenick Unclenick is offline
 
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Watch out for them packing the gas port or accumulating in the gas cylinder. As long as they don't do that sort of thing, you should be OK. I would pull the gas cylinder plug and check for accumulation before firing a normal load, just to be sure its space hasn't been reduced any.
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