Temp stable .270 wsm powder

skipglo

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I'm looking for powders to start load development on a short barreled .270 wsm with 140 berger classic hunters. (I don't know how short the barrel is gunna be yet, I plan to chronograph it at 26 inches and decide how much I am willing to lose from there). I can find some load data that should work for h1000 which will be a good starting place being as it shoots well from my 7 mag but H1000 is in short supply right now. I have lists of load data I just don't know adam from eve when it comes to powders. I am looking for temp stability first and velocity second. Im seeing re 26, aa magpro, ramshot, n560, 7828 ssc. Any ideas which powders I should be looking for?
H4350, H414
 

bigngreen

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I load Retumbo in all 270 WSMs from 140 gr up from there down I consider them varmint loads so I run. R17 which is not stable enough for long range work but works excellent under 110 gr TTSX for varmints.
R22 has about 80 fps swing on a typical Mt winter day.
 

Starlite

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The table gives an estimate of how much MV changes over temperature (temperature stability). For example: If you shoot H1000 @ 32˚ at a given velocity and then shoot it at 82˚ the MV will change by 0.21 X (82-32) = 10.5 FPS. If you shoot IMR4320 under the same conditions the MV changes by 1.32 X (82-32) = 66 fps.

I hope that helps.
Still have no idea why some powders appear twice On this chart yet the numbers stay the same. Curious at to the publis of this article. I’m intrigued.
 

Starlite

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I see, I saw two columns that had the same powders in them and thought they were different but didn't look close. The left column is sorted in order of least to most affected, the right is sorted alphabetically. I thought at a glance the 50* comment was detonating that the two columns were different parameters.
I thought the same. Little confused at first but makes sense now.
 

Wapity hunter

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Ive been using a SAKO 85 270WSM for 12 years now.
Barrell 23 inches dpt suppressor
I originally tried most of the poweders mentioned except for RL 26 .
IMR 7828 ssc is what u want.
Im not sllowed to publish my charge weight as its well over the recomened load. With 145grain eldx im getting 3330fps
150 grain BST 3280 fps.
Same charge weight for both projectiles.
Accuracy is outstanding.
At 200metres bullets overlapping on target. Ive nailed chamios at 725metres . Bullet 2 inches from aiming point.
Temperature doesn't seem to noticibly effect impact point when hunting.
I would say from what ive read similar velocity can be obtained with 26.
I may try it one day but you cannot go past IMR 7828ssc. I seat the bullet just off the lands .
Hope this helps.
 

new2mud

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Still have no idea why some powders appear twice On this chart yet the numbers stay the same. Curious at to the publis of this article. I’m intrigued.
Consider charts like this not statistically proven data, and certainly not manufacturers’ claims. Rather it is a fellow reloader who has taken the time to collect either from their own experience or from others anecdotal results they have experienced or heard of.

If you are looking for “prove it to me data or reporting”, this isn’t it. If you are wanting relative anecdotal comparisons between powders from collective experience, this is a tremendously helpful compilation that a fellow enthusiast has put together so that you don’t have to go out and buy a bunch of powders.
 

bigngreen

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The 7828ssc is an excellent powder BUT in the weather swings in Mt it's unusable for a long range load because of temp swings, we run it and H1000 in 270's and they run very close in velocity but at ling range you'll see a difference.

Really H4831, H1000 and Retumbo are the go to for something rock solid, I'd throw R26 and R23 in there next as n xt choices.
 

Huntz

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A max load of Ramshot Magnum and a 140 grain Berger Hunter gets me about 3250 out of a 24" Tikka barrel and a one hole 3 shot group at 100 yards.
 

Wapity hunter

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For hunting out to 700metres i dont see enough different variation on an animal . Its still an instant kill.
Bull thar minus 10c at 479m
Buck chamios 725m at 17 deg c.
Imr 7828ssc
 

Wapity hunter

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Could be . I got 4250 with 145 grain eldx . But the load was exssive so only fired one round. Bolt hard to open. Backed off 2 grains from that, is were i load to now..3330 fps.
 

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