300 Sherman Shortmag (SS)

the 300 WSM is a great cartridge with 150- 180 gr bullets in short action form, does well with 210- 230's in a long action, the SAUM case is already lacking in powder capacity and shrinking it more is not going to make it faster than the 300 WSM, plus you can always "improve" the WSM case, gain 2.5 gr, throat it for zero bullet into case and gain an additional 2.5 gr of powder use, total of 5 gr over the original 300 WSM, kind of makes the 300 SAUM pointless even more so by shortening it and reducing capacity even more ...... the neat magical trick I would like it to perform is 3000 fps with 215's in a "real short action length" at 2.830", an unmodified Rem700 short action ........ if you start altering actions to run longer 2.990" coal boxes or building it on long actions then it is no longer a "true" short action and you are better off with the 300 WSM ..... may as well run the 30 Nosler then
 
Made it out yesterday and ran a pressure test with RL 22 which was getting closer to what I'm looking for.
61 2797
62 2841
63 2897
64 2925
65 2961
66 3009
Looking like this is going to be one heck of a shooter. I was able to put 5 shots into .75" at 100 yards just with a 14x scope.
Still looking for some n560 to try. I'll try to get out next week and try a couple other powders.
 
The 66 grains had a slightly shiny extractor mark and slightly stiff bolt lift but primer looked good. 66 is compressed and was the max I could fit in the case. This was with the 215. Forgot to mention that. Looks like I need a powder just slightly faster but 22 is the best I have tried so far. Also considering trying some H and IMR 4831 and superformance since I have them on hand. Kinda curious about the newer IMR 4955 since the newest burn rate chart in the 2016 hodgdon magazine puts it between RL 22 and H4831.
 
That is lookin' way more about what I expected! Looks like like maybe shortening the saum case isn't such a bad idea. It is still holding true even with a .308 bore. You just can't beat efficiency! By the way, Ryan didn't mention that those 5 shots into .75" were 5 different charges (5 grain spread) That is a REALLY good sign for tack driver in the works. I can see this cartridge being REALLY easy on barrels with 300 WM velocity. I am pretty sure that a full dose of N560 might be a little better yet. Nice job Ryan and Rhian......Rich
 
The 66 grains had a slightly shiny extractor mark and slightly stiff bolt lift but primer looked good. 66 is compressed and was the max I could fit in the case. This was with the 215. Forgot to mention that. Looks like I need a powder just slightly faster but 22 is the best I have tried so far. Also considering trying some H and IMR 4831 and superformance since I have them on hand. Kinda curious about the newer IMR 4955 since the newest burn rate chart in the 2016 hodgdon magazine puts it between RL 22 and H4831.

I'm not sure it needs to be faster burning but a little more dense. I THINK maybe N560 is more dense than RL22? Does anyone know?...Rich
 
64gr of h4831sc was just compressed and at 2800 with pressure. 63gr n560 im over 2900 with less pressure and room to spare.

If that helps.

And this is with a straight 300 saum
 
64gr of h4831sc was just compressed and at 2800 with pressure. 63gr n560 im over 2900 with less pressure and room to spare.

If that helps.

And this is with a straight 300 saum

That helps a lot! Thanks Shawn. I think it may be the one that will produce the best results......Rich
Do you happen to know what your throat length is? That is if you don't mind sharing that? You can PM if you like. I just checked the burn rates and was a little surprised to see N570 being a fair amount faster than RL22.
 
Made it out yesterday and ran a pressure test with RL 22 which was getting closer to what I'm looking for.
61 2797
62 2841
63 2897
64 2925
65 2961
66 3009
Looking like this is going to be one heck of a shooter. I was able to put 5 shots into .75" at 100 yards just with a 14x scope.
Still looking for some n560 to try. I'll try to get out next week and try a couple other powders.

Looking very encouraging. That's about the velocity I get with Berger 210 VLDs in a 25.5" Lilja barreled 300 Win Mag using IMR 7828. I've not worked up a load with the 215 Hybrids. They would likely leave the muzzle a bit faster than the 210, based on what's been posted by others.
 
Nothing yet... between weddings, work, lack of powder, and other life I havent had a chance to get anymore loads done. I'm hoping this weekend to get somewhere that may have some n560 in stock.
 
Made a quick trip down to sportsmans yesterday and got a pound of N560 and IMR 4955. I loaded up 61 to 66 grains of N560 under the 215 Berger and went out tonight to see what I could make happen.

Unfortunately this powder which we thought had so much promise didnt work very well in this case. I stopped shooting at 63 grains due to pressure and a bolt that was very very stiff. Here's what I got...

(cleaned barrel of copper and carbon before shooting)

61 2697
62 2785
63 2847
Even with the clean cold barrel all 3 shots went less than 3/4" with the first shot doubling the size it could have been.

All else aside this rife is a shooter!!!

Not what I was hoping for but now I know. Also not holding out much hope for the IMR 4955.

I may pick up some Magpro and give a shot next time.

For now RL 22 is still the winner.
 
Very interested in the results. In my saum h4350 was to fast. And 4831sc reached pressure before a full case as well. Im using n560 right now and can get 64grs in my case as a max charge and the 208eldm was moving at 2940. Seems fast but thats where it was verified. Ive lowered the charge to 63 as a safe max.

Its throated for the 215s so the 208s could see a little more room for powder if the throat was set up for them....

Food for thought i guess

What chronograph you are using? Have you validated these numbers at distance with drops?
 
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