My 338 Sherman Shortmag

mgood said:

I've seen comparisons of the SS cartridges to this cartridge or that cartridge, but I haven't seen the 6.5 SS compared to 264 Win Mag. It's probably been discussed and I've missed it because I'm not on here that often, but from what I have read here about the SS and what I can look up on the WM, they do look to be very close in velocity.

Anyway, I've become an 8mm junkie and I'm reading this thread with the mindset that if it works for .338, it'll work for .323.

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So my 2cents is as follows. The whole essence of the Sherman shorts is the fact that it is based on a short action while maintaining the same performance as its same caliber belted magnum. This makes the cartridge more efficient while not losing on ballistic performance. So if you looked up the 264WM and seen similar or identical performance then there's the proof. I'm doing trials on the 338 and am completely tickled that such a little round could have such down range authority. Hope this helps "realign" the perspective.

mgood said:

Anyway, I've become an 8mm junkie and I'm reading this thread with the mindset that if it works for .338, it'll work for .323.

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It should line up very closely I would think.

On the 338 front:
IMO Hrdy .338 ELD-X 230gr looks good and would have been really awesome IF they had not basically just added a long bt to the SST in terms of dimensions. That **** long bearing surface not like the other caliber ELDs. On the plus side: ITS ALSO HALF THE COST OF THE 285 ELD!!

Winmag load data for the 230 eld-x is 2810 from 24" and those loading a bit longer hit 2900. 2900 fps should be achievable with a few different powders I would think with a 25-26" barrel int the SS. With a .310 G7 with energy cap of 1800fps/1500ftlb for Elk and 1600fps/1200ftlb for deer that gives you max range of 800yd and 1000yd respectively @ 2900 MV . I have taken deer consistently with good broadside presentation down to 1400fps/700 ftlb but wouldn't at that kind of range with that bullet.

The cuttting edge 225 MHT bullet looks like they may work well also.

What do you guys think of the 265 ABLRs if they shoot well in the gun? You would have room in the TIKKA and WIn 70s for its longer COAL. Load data for the Winmag holding at SAAMI COAL was mid 2700s 24". For the SS 2800 should work 25"-26" I would think?

Range report, Superformance and the 250's.

61 - 2588
62 - 2608
63 - 2674
64 - 2699
65 - 2733

Even with my crappy RP brass there was no extractor marks or stiff bolt lift all the way to 65 grains. I'll load higher and see where capacity tops out and/or I get any pressure signs.

ruby76 said:

Range report, Superformance and the 250's.

61 - 2588
62 - 2608
63 - 2674
64 - 2699
65 - 2733

Even with my crappy RP brass there was no extractor marks or stiff bolt lift all the way to 65 grains. I'll load higher and see where capacity tops out and/or I get any pressure signs.

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That's what we found in the long action. You'll probably get up to 68-69 grs. Jace ran his over 2900' in the long action with Norma brass

elkaholic said:

That's what we found in the long action. You'll probably get up to 68-69 grs. Jace ran his over 2900' in the long action with Norma brass

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I'll stay with it for testing but I'm not confident using it long term if there is temp stability issues. Where I live its super hot in the summer and I can be hunting in -20 or colder. What about RL16? Supposed to be very temp stable but slightly faster burning than RL17.

You're right on the super stability. I don't plan on using it either!
RL16 may work for you. Doc had some pretty good results with it and it is stable.N550 and 560 would be worth a try too.

The temp effect on powder can change based on the bore to powder ratio so while Rl17 is known for moving as temps get hot it maybe not severe like it is in the smaller calibers or it could be worse. Still I would not run a hot load developed in the winter in the heat of the summer unless it was tested and known to be very temp stable.

If rl16 works you might want to try Norma URP as I think its very close and may very well be first run version of Rl16. There is a long history of Alliant Powders from Bofo being seconds of Norma powder runs if Norma has the powders produced. This is not true of the high energy powders from Nitrochemie in Switz Rel17, 25,33. They are made specifically for Alliant.

But Norma and Bofos are all part of the same parent corp group so... Rl16 works well in the 6.5 creedmoor and their are a few threads on the Norma URP being the equal or **** close likely difference is the tighter tolerances of the Norma.

It seems as the Winmag has very close to the same bore to case volume ratio of the SS its a good way to find good powders. The URP seems to do well in the Norma Data as well MRP. Unfortunately Alliant is the worst at load data and only lists Rl17 which is just being lazy/cost cutting IMO.

If you look at the make up for the two powders here you can see URP is faster but less bulk density but more energy per grain so there is trade offs. If you look at their load data for the 338Winmag you can see how the two seem to flip flop for top spot. N204 also seems to be in hunt as well. URP should be the most temp stable of the group. This is mentioned under the Norma 217 description

"Like the URP it contains a lot of energy and is less sensitive to temperature and moisture than most other powders."

What I really like about Norma powders like VV is they give you hard data and from lot to lot its almost always very close to the same. Alliant you get nothing unless you call or with Quickload and the lot to lot variance of their Bofos produced powders can vary wildly which is understandable if its Norma powder that did not quite make spec.

Thanks for the powder tip Tim, I havent seen Norma powder locally but will look around. I'm on the lookout for RL16 as well.

Anyways, finished off the Superformance max test.

66 - 2742
67 - 2800
68 - 2835

With my RP brass I started seeing a faint ejector mark at the 66 grain load, got a little worse and slightly resistant bolt lift at 68. I don't think there is any more room left with 68 grains, it was likely a little compressed as is.

Yep I think its clear that Rl17 will get the best vel if temp stability is not critical. The question is what single base stable powder will get the best vel with low es.

I wouldn't count out N560 or even 550.

Yep I was thinking of adding that caveat. Its wierd and I guess from availability and cost you never really see the VV mentioned as much but I love their powders. One the most accurate 45 auto loads I have ever made uses VV powder.

N560 has always burned faster for me than the charts say! It has a lot of energy and is pretty dense. I think you just might be able to squeeze enough behind a 250.

If that fits then yes that could be cool. Might take a drop tube

elkaholic said:

N560 has always burned faster for me than the charts say! It has a lot of energy and is pretty dense. I think you just might be able to squeeze enough behind a 250.

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How is it for temp stability? I'd really like to narrow down powder choices based on good temp stability. So between RL16, N560, and H100V which would likely be the best compromise of getting enough in the case to get good velocity but has good temp stability?