My 338 Sherman Shortmag
- Thread starter ruby76
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elkaholic
Well-Known Member
Aaaah, so more capacity and more pressure left to discover!
ruby76
Well-Known Member
Now your just rubbing it in, ha ha
elkaholic
Well-Known Member
We just need a border invasion from the north like we have from the sourh so you can join the party and get some
ruby76
Well-Known Member
In time for sure, I'm still having a blast testing and shooting. Started stretching its legs a bit to 600, felt too easy. I can go to 900 at that range and at my other spot as far as I want.
trackhoehunter
Well-Known Member
- Joined
- Nov 8, 2009
- Messages
- 118
I'm must Stop reading this thread!! But I can't! It's like a person with a giant booger in their nose that you're talkin to face to face you can't stop staring at that booger!
elkaholic
Well-Known Member
Nice! Kinda thought N560 would work with the heavies!
ruby76
Well-Known Member
Max test coming with N560 and H4350. Made up my dummy round for the 250 Barnes LRX, length comparison with the 250 berger and 200 accubond:
elkaholic
Well-Known Member
I went out today with my long action Sherman to compare powder/velocity, etc. to the SS. Mine is a 24' barrel. I was primarily looking at the 285 ELDM but did fire a proof round with my hunting load of 65 grains H100v behind a 250 Berger. It clocked 2821, which was up about 14' from my hunting clock in at 46 degrees of 2810'. Todays temp was about 25 degrees warmer at 71, so that is about right for H100V.
I then tried 70 grains Magpro, which was all I could stuff in behind the 285. It clocked at 2582'. Pressure was low but that is all there is room for. I then shot 68 grains N560 for 2609' and 69 grains at 2644'. Both loads were under max but I think the 69 grain load was getting close. I might be able to squeeze another 1/2 grain in, but not sure? Unless Superformance or RL26 are used, it looks like N560 is king. I did get 2679 with RL26 with a compressed load and Superformance will reach a little higher but the temp instability is not worth it in my opinion, at least with the Superformance. So Doc, I think you can scratch Magpro from your SS list as it would not pressure up in that case.
I then tried 70 grains Magpro, which was all I could stuff in behind the 285. It clocked at 2582'. Pressure was low but that is all there is room for. I then shot 68 grains N560 for 2609' and 69 grains at 2644'. Both loads were under max but I think the 69 grain load was getting close. I might be able to squeeze another 1/2 grain in, but not sure? Unless Superformance or RL26 are used, it looks like N560 is king. I did get 2679 with RL26 with a compressed load and Superformance will reach a little higher but the temp instability is not worth it in my opinion, at least with the Superformance. So Doc, I think you can scratch Magpro from your SS list as it would not pressure up in that case.
elkaholic
Well-Known Member
Nice! My guess is your RP brass will go south around 65 grains of N560 behind a 250, if it was a Berger. The Barnes may be different?
ruby76
Well-Known Member
More baseline data with the 250 Bergers.
H4350 powder - 60 gr. - 2663
61 - 2690
62 - 2715
63 - 2759
I started seeing slight extractor marks at 61 grains, at 63 had a slight heavy bolt lift. I think there is some more room in the case beyond 63 grains so worth exploring at a later date with better brass.
N560 powder - 60 gr - 2481
61 - 2562
62 - 2587
63 - 2669
64 - 2699
I got slight extractor mark starting at 62, and the 64 grain was slight heavy bolt lift. I think there's a bit more room left in the case.
I'm sounding like a broken record about my brass but its crap. Period. It's a limiting factor to what this cartridge is capable of. I'm going to circle back to RL17 and reduce the charge a bit to save my brass and see what sort of accuracy I can get. The velocity was good down below 61 grains (just over 2800) so I loaded a few at 60.5, 60.7, and 60.9. I really want to reach my 2800 goal with an accurate load for hunting season. I'm still on the hunt for RL 16 as well so I hope to do some testing with it too.
H4350 powder - 60 gr. - 2663
61 - 2690
62 - 2715
63 - 2759
I started seeing slight extractor marks at 61 grains, at 63 had a slight heavy bolt lift. I think there is some more room in the case beyond 63 grains so worth exploring at a later date with better brass.
N560 powder - 60 gr - 2481
61 - 2562
62 - 2587
63 - 2669
64 - 2699
I got slight extractor mark starting at 62, and the 64 grain was slight heavy bolt lift. I think there's a bit more room left in the case.
I'm sounding like a broken record about my brass but its crap. Period. It's a limiting factor to what this cartridge is capable of. I'm going to circle back to RL17 and reduce the charge a bit to save my brass and see what sort of accuracy I can get. The velocity was good down below 61 grains (just over 2800) so I loaded a few at 60.5, 60.7, and 60.9. I really want to reach my 2800 goal with an accurate load for hunting season. I'm still on the hunt for RL 16 as well so I hope to do some testing with it too.
