Author Topic: magpro for .270 win (Read 1475 times)

dcnewyork · « **on:** January 19, 2006, 12:29:09 PM »

I was wondering if anyone has tried magpro in a .270 win. 2234fps has me pretty interested, but wonder how the accuracy is. is this powder temp sensitive? what difference does temp really make ? I will never shoot when its over 100 degrees, nor will I ever shoot when its super cold, so will it really matter to me? This being a spherical powder is good for guaranteeing charge weight from what i understand.

Siskiyou · « **Reply #1 on:** January 19, 2006, 04:15:25 PM »

I am glad that you have asked the question. I have been thinking about Magpro for my .270 Win. It's burning rate puts it next to the old WW785 which is slower then H4831. I had excellent results with WW785 ball powder. Did they come out with Magpro to fill the void? Anyway I will be tracking this post.

It should be a good powder for the 6.5-284 and the 6.5-06.

Graybeard · « **Reply #2 on:** January 20, 2006, 03:22:28 AM »

The biggest problem with Magpro is the lack of tested reloading data. I've used it in .30-06 and .243 for which data is available. I hope to try it in 6MM Remington and .270 but am unsure if I can find pressure tested data or not. In those two it worked great. It gives the highest available velocity usually and good accuracy.

dcnewyork · « **Reply #3 on:** January 20, 2006, 08:51:06 AM »

the accurate reloading site has preasure tested data.

lilabner · « **Reply #4 on:** January 21, 2006, 11:29:36 AM »

The Accurate Powder website shows 63200 PSI for the 130 gr. loading at 3234 fps. That is below the SAAMI of 65000 PSI for the .270, but no by much. Magpro is also shown getting 3000 fps for the 150 gr. at 63600PSI. I would approach these loads from below with caution. They have an interesting load for the .243 100 gr. also - 47.5 gr. Magpro for 3107 fps at 59800 PSI

Lou270 · « **Reply #5 on:** January 24, 2006, 05:31:35 PM »

I have tried magpro in 2 separate .270s. 1 is a custom with 24" barrel. With the max load of Magpro (65 gr), I was just over 3200 fps. 2 grains less averaged right at 3100 fps and groups were in the 3/4" range. In a 22" barrel Remington 700 Ti, 2 grains under max was at 3070 fps and ~1". For some reason, when I hit the max load, velocity jumped to 3250 fps, which was higher than I expected given the 22" barrel, so I pulled the rest and decided 3070 fps is good enough. It should be noted in the second case, I substituted 130 Rem Corelockts for the Nosler Ballistic tips used in the data, so maybe this had something to do with it (not sure why as Nos Btips generally give me higher velocity at same powder charge as standard cup & core bullets).

In summary, Magpro looks really promising in the .270. Velocity is way up there and accuracy was great. Magpro is not temp insensitive (I sent them an email and asked). For my own loads, I tend to stay with H-4831sc, which is temp stable, but in reality it's probably more out of habit and long successful use than anything. I'm not so worried about velocity loss, but more so the change of impact that it might incur (as reported by others). That being said, I have hunted for years with powders in other calibers that are not temperature insenstive such as IMR-4350 and IMR-4831 and never had issues.

-Lou

dcnewyork · « **Reply #6 on:** January 25, 2006, 11:47:01 AM »

How was the accuracy with the max load?
Did you see any signs of preasure? What kind of accuracy problems can come about with temp. sensitivity, how drastic would the temp. deviations have to be?
What velocity do you get when useing H-4831sc out of the 24 and 22 inch barrels. I have a 22'' barrel so am courious as to what you get from that.
Why would that max load give 2250fps with a 22''? Does the powder burn more efficently in a 22'' v. a 24'' ? I wonder what a 26'' or a 20'' would do

Lou270 · « **Reply #7 on:** January 26, 2006, 02:15:06 PM »

Quote from: dcnewyork

How was the accuracy with the max load?
Did you see any signs of preasure? What kind of accuracy problems can come about with temp. sensitivity, how drastic would the temp. deviations have to be?
What velocity do you get when useing H-4831sc out of the 24 and 22 inch barrels. I have a 22'' barrel so am courious as to what you get from that.
Why would that max load give 2250fps with a 22''? Does the powder burn more efficently in a 22'' v. a 24'' ? I wonder what a 26'' or a 20'' would do

Accuracy was ~1.25" for 3 shots in the .270 w/ 24" barrel. The 2 grain less load was slightly more accurate in both .270s. I'm not sure how temperature senstivity affects hunting loads as I have not really noticed it. I've only been keeping steady records for the last 4 years (loaded for alot longer than that) and I've lived in TX, so don't see the extreme colds. I never really noticed it in the NE where I moved from, but like I said, don't have the records to prove it. I have read articles by John Barsness in Handloader/Rifle that he has experience point of impact changes with temperature sensitive powders, but the groups were still good. One thing to note is that if temperature affects velocity (and it can by 100+ fps), then trajectory can change.

With H4831, I have seen anywhere from 2950-3200 fps in different .270s. I would say average is just over 3000 fps in 22" barrels, and right at 3100 fps in 24" barrels. I have seen reports from other guys that say they get 3100+ fps out of a 22" barrel with H4831, so I guess it depends on your gun & other components.

I'm not sure why velocity jumped so high with the max load in the 22" barrel. It could have been a chrony blip or something. The 2 grain under load gave me 3070 fps or so and 1" moa, which I was happy with so didn't worry too much about it. TX gets pretty hot, so I tend to stay a couple grains under max anyway.

In general, I think as you increase barrel length, speed will go up regardless of powder. There may be exceptions when using really short barrels (i.e. Encore hand cannon types), but typically powders that give best velocities in long rifle length tubes will do the same in short tubes. I routinely see guys reporting higher velocities than I get in guns with shorter tubes than I use with the same loads and vice versa - again it seems a lot has to do with your individual gun.

Hope this helps!

-Lou

Lou270 · « **Reply #8 on:** January 26, 2006, 02:17:33 PM »

Quote from: dcnewyork

How was the accuracy with the max load?
Did you see any signs of preasure? What kind of accuracy problems can come about with temp. sensitivity, how drastic would the temp. deviations have to be?
What velocity do you get when useing H-4831sc out of the 24 and 22 inch barrels. I have a 22'' barrel so am courious as to what you get from that.
Why would that max load give 2250fps with a 22''? Does the powder burn more efficently in a 22'' v. a 24'' ? I wonder what a 26'' or a 20'' would do

Accuracy was ~1.25" for 3 shots in the .270 w/ 24" barrel. The 2 grain less load was slightly more accurate in both .270s. I'm not sure how temperature senstivity affects hunting loads as I have not really noticed it. I've only been keeping steady records for the last 4 years (loaded for alot longer than that) and I've lived in TX, so don't see the extreme colds. I never really noticed it in the NE where I moved from, but like I said, don't have the records to prove it. I have read articles by John Barsness in Handloader/Rifle that he has experience point of impact changes with temperature sensitive powders, but the groups were still good. One thing to note is that if temperature affects velocity (and it can by 100+ fps), then trajectory can change.

With H4831, I have seen anywhere from 2950-3200 fps in different .270s. I would say average is just over 3000 fps in 22" barrels, and right at 3100 fps in 24" barrels. I have seen reports from other guys that say they get 3100+ fps out of a 22" barrel with H4831, so I guess it depends on your gun & other components.

I'm not sure why velocity jumped so high with the max load in the 22" barrel. It could have been a chrony blip or something. The 2 grain under load gave me 3070 fps or so and 1" moa, which I was happy with so didn't worry too much about it. TX gets pretty hot, so I tend to stay a couple grains under max anyway.

In general, I think as you increase barrel length, speed will go up regardless of powder. There may be exceptions when using really short barrels (i.e. Encore hand cannon types), but typically powders that give best velocities in long rifle length tubes will do the same in short tubes. I routinely see guys reporting higher velocities than I get in guns with shorter tubes than I use with the same loads and vice versa - again it seems a lot has to do with your individual gun.

Hope this helps!

-Lou