Calvin45
Well-Known Member
I went fast.
Got to test my load workup out at my dads place in the country (good to catch up with dad over a few cups of coffee, a good day all around).
Having fiddled around with rl 17, h380, h4350, h4831sc, imr 7828 ssc, and hodgdon SUPERFORMANCE, im settling on rl17 as the best powder I have for the 75 grain hammer hunter in my 24 inch stainless barrelled .257 weatherby magnum, vanguard. H4350 did almost as well but not quite the velocity before pressure AND I have less of it on hand and my .358 Norma has dibs on the rest of it
I fired only two shots at each charge weight as all these components are very expensive
For me AND .257 wby barrels and needlessly high round counts during load development is just a foolish combo haha.
Also included some bullets I pulled out of the snowbank I shot into (yes, there are still big snowbanks here but they're melting finally) - 75 hammers and a picture perfect "Barnes flower" as well from a 100 tsx and as well a 75 x out of a 243. No conclusions about how performance from these, it's JUST A PICTURE
. A snowbank isn't a ballistic proxy for, well, anything else.
Weatherby brass, hammer 75 grain hunter treated with hex boron nitride (as is the bore of my rifle), rl17, "dominion" brand standard rifle primers (not magnum), lee factory crimped on the top groove.
68 grains
3879 and 3871 fps. Mild. Sooty on neck.
69 grains.
3937 and 3941 fps. Still zero signs and necks a bit dirty
70 grains
4016 and 4018 fps - only two shots, but holy smokes that's the same thing. No pressure signs AND squeaky clean necks, full obturation. Much promise at this node.
71 grains 
4055 and 4048 fps - still moving up in velocity nice and predictably though it's notable now that the increases are getting a tad less
72 grains
4110 and 4093 - VERY slight cratering around firing pin indent, no pancaking of primer edges, no ejector swipe, no stiff bolt or anything else
72.7 grains
4172 and 4169 - again a sampling of two but that's still very promising and worth looking into when it comes time to test for accuracy
73.4 grains
4217 and 4166 fps. Crazy big difference between those. Slightly stiff bolt, pancaking, cratering, shiny spot on case head. Along with that velocity erratic behaviour that's all clearly saying "pressure" - went up one more like a bone head anyway
74.1 grains
4271 and 4277 fps. Stiff bolt. Very flat primer. Very pronounced ejector swipe. Back off man!!!!
Didn't really test accuracy out, my process is to find the points in the workup that look promising and then develop further. Though these all did kind of shoot to the same point of impact anyways so that's nice. Intrigued about 70 and 72.7 (probably split between that and 72, so 72.4 grains). Both North of 4000 fps so I'm a happy camper.
Just sharing my experienc and some data points for referencing. Everyone is responsible for their own safety and equipment, this is not advice haha.
Got to test my load workup out at my dads place in the country (good to catch up with dad over a few cups of coffee, a good day all around).
Having fiddled around with rl 17, h380, h4350, h4831sc, imr 7828 ssc, and hodgdon SUPERFORMANCE, im settling on rl17 as the best powder I have for the 75 grain hammer hunter in my 24 inch stainless barrelled .257 weatherby magnum, vanguard. H4350 did almost as well but not quite the velocity before pressure AND I have less of it on hand and my .358 Norma has dibs on the rest of it
I fired only two shots at each charge weight as all these components are very expensive
For me AND .257 wby barrels and needlessly high round counts during load development is just a foolish combo haha.
Also included some bullets I pulled out of the snowbank I shot into (yes, there are still big snowbanks here but they're melting finally) - 75 hammers and a picture perfect "Barnes flower" as well from a 100 tsx and as well a 75 x out of a 243. No conclusions about how performance from these, it's JUST A PICTURE
. A snowbank isn't a ballistic proxy for, well, anything else. Weatherby brass, hammer 75 grain hunter treated with hex boron nitride (as is the bore of my rifle), rl17, "dominion" brand standard rifle primers (not magnum), lee factory crimped on the top groove.
68 grains
3879 and 3871 fps. Mild. Sooty on neck.
69 grains.
3937 and 3941 fps. Still zero signs and necks a bit dirty
70 grains
4016 and 4018 fps - only two shots, but holy smokes that's the same thing. No pressure signs AND squeaky clean necks, full obturation. Much promise at this node.
71 grains 
4055 and 4048 fps - still moving up in velocity nice and predictably though it's notable now that the increases are getting a tad less
72 grains
4110 and 4093 - VERY slight cratering around firing pin indent, no pancaking of primer edges, no ejector swipe, no stiff bolt or anything else
72.7 grains
4172 and 4169 - again a sampling of two but that's still very promising and worth looking into when it comes time to test for accuracy
73.4 grains
4217 and 4166 fps. Crazy big difference between those. Slightly stiff bolt, pancaking, cratering, shiny spot on case head. Along with that velocity erratic behaviour that's all clearly saying "pressure" - went up one more like a bone head anyway
74.1 grains
4271 and 4277 fps. Stiff bolt. Very flat primer. Very pronounced ejector swipe. Back off man!!!!
Didn't really test accuracy out, my process is to find the points in the workup that look promising and then develop further. Though these all did kind of shoot to the same point of impact anyways so that's nice. Intrigued about 70 and 72.7 (probably split between that and 72, so 72.4 grains). Both North of 4000 fps so I'm a happy camper.
Just sharing my experienc and some data points for referencing. Everyone is responsible for their own safety and equipment, this is not advice haha.
). What is OCW theory again?
