Home Forums Reloading Big Game Rifles .270 win. velocity / load questions

Yeah Bob, I've seen them come reasonably close in shorter bbls such as my Sako Finnlight.

You are dead on about the wall with H4831, it will flatten primers in most rigs with close to max, to max, and sometimes slightly over max where R22 will sometimes keep getting faster after book maxes w/o showing tale-tale signs of pressure.

I find my best uses for H4831 in rigs where I don't care about velocity such as the 30-06 with 180s or the 300WM with 180-200s. Accuracy trumps in most of my rigs, but a combination of both never hurts. H4831 will shine(in terms of both acc/MV) with lighter pills in some carts as well, such as the 25-06 with 100s or the 7rm with 140s etc....

Ya'll have a good one,

loder

That's my experience too...........I just don't really see much need for 4831 anymore as RL22 does as well or better in every round that could also use 4831.

If I want something different, I'll go to Norma MRP which I find to be interchangeable, performance & load wise with '22, but it is definitely not the same powder, as some think.

I think the temperature sensitivity of '22 & the temp stability of H4831 is much overstated in both cases, at least in the +20 - 70 degree range.

MM

Ditto MM, Summer heat in La to 10-20 deg in CO several times hasn't effected my POI with R22. The 75yd 6x6 mulie wasn't much of a test, but the 325yd 6x6 bull didn't have any luck with the "temp sensitivity" of R22 when I put two through the boiler

Have a Good One,

loder

A few other powders to try to get top velocity with 130s is Magpro, IMR-4831, and Ramshot Hunter. H4831 is still a great .270 powder and is my go to. In one rifle, I get 3150 fps with 59 gr and 130 Hornady (24" barrel). In a second .270 with 22" barrel, I get 3000 fps with 60 gr and 130 Hornady, and 3100 fps with 130 Scirocco. I have had mixed results with RL22 in the .270 from velocity standpoint. I had one lot that gave me 3200 fps with 58 gr and another that gave me 3000 fps with 60gr, both with Speer 130s and others inbetween. The only place that still shows 62gr H4831 is Hornady at 3100 fps. Most others are in the 58-60 gr as tops with 130s. Possibly the Hornady has a bit less bearing surface and requires a bit more powder to get 3100 fps compared to different shaped bullets.

Lou

My absolute favorite .270 powder for my gun is H1000. It is the most accurate poder in my rifle. 61.0 H1000 and a 140g accubond is scarry accurate for 3,000fps, could probably get more out of it but it gives me what I want. I do use a drop tube but it is not that long and not very compressed when the tube is used. I also get 3,000fps with a book max charge of Magpro with a speer 150 hot core with excellent accuacy. My .270 is a M70 24inch and it likes IMR 4831, H4831, H1000, Magpro, R22, not picky at all.

Both of my 270s will easily exceed 3100 fps with a max load of IMR 4831. But I hunt with H4831 and just shy of 3000. The critters don't seem to notice any difference.

True, that, in most cases.

MM

I did chrony the same loads in the same rifle on different days that had a temp difference of about 30 degrees (80 vs 50). IIRC, the average velocity difference was so small, it was insignificant. I'm not at my house or I could look up what the actual figures were. I want to wait til it drops below 30 and chrony some more just out of curiousity and because I too have seen a few claim it's fairly sensitive.