Gew88 Max Loads?
I've been handloading my Gewehr 88. It is "S" marked but I still prefer 0.318" bullets, and they actually seem to give superior accuracy. I'm going to slug it again, but it appears the bore is pretty tight. Came out to 0.3165" last time, but I've shot fouling out since.
Anyway, I'm using Varget. It has become my go-to powder for milsurps, especially the 7.62x54R and 7.9x57J.
Now, as I understand it, the max operating pressure for a Gewehr 88 is 45,000 CUP. According to Hodgdon, 45.5 grains, the starting load, produces around 37,500 CUP with the max load producing 49,000 CUP. This is with a 150grn bullet.
Now, I'm running 46.5 grains of Varget. I was thinking I had low pressure signs in my Remington cases. After making some cases from Winchester .30-06, I found that the tolerances in the Remington cases were not in spec, so I trashed them.
Any guesses as to the pressure I'm running?
I'd like to keep below max pressure, or, in other words, I'd like to have a new minimum and maximum to work with, maximum being maybe 44,900 CUP or thereabouts.
Data listed by Hornady has their minimum as 43.5 grains but no pressure listing.
This sounds like a good starting load for the 7,9x57J, though. What do you think?
Should I just start again at 43.5 grains and work my way up? When should I stop?
My only goal is to find maximum precision in a given range. For example, if I use 43.5 grains to start and consider 47 grains to be max, then I won't go past 47 grains.
For comparison, the original J load was a 0.318" bullet pushed by Poudre B (can't find a burn rate on that; a burn rate for this powder would help a LOT). The bullet was cupro-nickel jacketed, 227 grains, and pushed to 2100fps.
Opinions would be appreciated!