7mm mag powder choice

kaseyfied

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Update

Shot 68-72 grain powder string at 200 yards. Shot a couple at 68 to make sure i was on paper since the rifle only had 6 rounds on it.. left group was all the 68 grain loads up to 69.5.. right side was 70-72 no ajustments made

All shots were pretty close to touching lol.. with 70-72 being pretty good. 72 was 2884 and no pressure at all do im going to inclrease the charge to 74 see if i get thag upper node around 73-74.. 24 inch carbon barrel too BTW
Kasey
 

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Lefty7mmstw

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Imr 7828ssc is my go to powder for the 7mm rem mag.

I keep the imr4350 for the 7mm08
I've had a couple 7rem rifles that love 7828, and one that puked every time the temp went down... You have to test I guess... Also, that 7rem loved 4064 with 140's, which is a decent amount faster than 4350... The current 7rem is eating 140 sierra's with rl22 or 175 hdy with aa 8700 pushing...
 

Lefty7mmstw

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My 7RM, 26" 1:8.5" Bartlein:
180 Hyb over H1000 in a moderate load @ 2996
184 Hyb over RL26 @ 3045fps
I don't even run my 8" twist Brux bbl'd 7rum that hard... it's just below 2900 fps with a 175 eld-x... I suppose I could run her up, but why?? She popped a mule deer at 500 yards for me last year in a nasty crosswind- had to be over 40mph...
 

lancetkenyon

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I don't even run my 8" twist Brux bbl'd 7rum that hard... it's just below 2900 fps with a 175 eld-x... I suppose I could run her up, but why?? She popped a mule deer at 500 yards for me last year in a nasty crosswind- had to be over 40mph...
You have to be running a REALLY light load.
I run a 195 in my 26" 1:8" 28 Nosler at a moderate 3084 (had up to 3161fps).

Starting load development on a long throated 7RUM tomorrow with the 195, wondering is 3200 will be attainable.
 

kaseyfied

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UPDATE

Another range session this morning.. loaded the following charges. I had 24rounds on the barrel before this session

72 grains n568
.020 off lands 180 hybrid 200yds
2864...2864...2863 1.1inches center to center

72.5
2880..3870...2884
1.4 inches center to center

73.0
2910....2915...2909 1.4 inches center to center

73.3
2920..2934..2918
0.4 at 200 center to center..

I think 73.5 or 73.7 goiing to be the money spot. Not sure where people are saying they get no velocity. I run retumbo with this reamer at like 73-73.5 and get 2975-3k with a 24inch barrel. Seems to be on par with slower than retumbo faster than 570..
Pic is of 73.3 grain group.. 200 yards off bipod and no rear bag

Kasey
 

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Veteran

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Yes, you should by burn rate get something equal to or faster than retumbo and not as much velocity as for N570. Just correlating burn rate to pressure and velocity, N568 ought to be in the middle in theory.
Doesnt mean its so, but should be.
Thats if the slower powder lets you get to more pressure and velocity
as you work up.
 

kaseyfied

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Yeah i really just wanted a reason to try it. Anything over 2900 in this light of a rifle is going to be awesome.. 7lbs..9punces complete with optics..

Kasey
 

KurtB

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Feb 11, 2004
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675
Location
Colorado
UPDATE

Another range session this morning.. loaded the following charges. I had 24rounds on the barrel before this session

72 grains n568
.020 off lands 180 hybrid 200yds
2864...2864...2863 1.1inches center to center

72.5
2880..3870...2884
1.4 inches center to center

73.0
2910....2915...2909 1.4 inches center to center

73.3
2920..2934..2918
0.4 at 200 center to center..

I think 73.5 or 73.7 goiing to be the money spot. Not sure where people are saying they get no velocity. I run retumbo with this reamer at like 73-73.5 and get 2975-3k with a 24inch barrel. Seems to be on par with slower than retumbo faster than 570..
Pic is of 73.3 grain group.. 200 yards off bipod and no rear bag

Kasey
Dang, almost makes me want another 7 mag. Nice shooting.
 
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