First custom rifle 28 Sherman mag

Lenwood901

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Joined
Oct 18, 2018
Messages
260
Location
Tucson az
5EE8383B-5B69-4F4C-B23C-7F897B8DAF41.jpeg

Ag composite alpine hunter
Muller 26 in barrel
Defiance anti action
Hawkins bottom metal
Ti- pro 3 muzzle brake
Trigger tech trigger

Very happy how this rifle came out going to start with the 195s and retumbo
 

highdrum

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Nov 30, 2008
Messages
2,843
Location
Montana
A 28SM has 4-5gr less powder cap than a 28N, so they're both quite overbore. Getting the same velocity as a 28N with less capacity requires more pressure, so will likely have same throat erosion. N570 will exhibit the worst. Retumbo in a 28N will have around 8k per 100 rounds, N570 is close to 10k. It's just a lot of powder burning in a small bore. I shoot a 7/300prc with N570 and I'm seeing 7-8k erosion per 100 rounds at 79.4 gr charge weight. Ballistically speaking, while balancing recoil, big 7mms pushing 190+ gr bullets is as good as it gets on paper. They don't have the energy of big fast 30s and 338s, but they're flatter and with proper shot placement, just as effective in 90% of hunting scenarios.
 

Chamberman

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Mar 23, 2012
Messages
318
Location
Caldwell, Idaho
Thank you guys If anybody has load data for this round please post here and I’ll keep everybody updated with what I come up with
I have the ShermanMag line up on a switch barrel system- 6.5 Max, 28SM, 30SM & 33SM

For the 28 SM I am using 80 grains of N570, GM215M primers, 315 neck bushing. I would start your seating depth at 60 off and work forward.
 
Joined
Aug 14, 2018
Messages
12
Location
Corpus Christi, Tx
I have a new build 28 Sherman Mag shooting 195s w N570 pressure (click) at 83.0 gr @ 3200-‘/s dropped off 1.0gr and no pressure 3150’/s have nor shot the brass enough to
know about primer pocket and reloading times for the brass which is head stamped by Sherman (ADG)
Also loading 175 LR AB w H1000 79.0 gr easy bolt lift at3250’/s
if you get retumbo information I’d really like to have it
IM SHOOTING AT 1000’ MSL, 85 DEG
AS ALWAYS WORK UP YOUR LOADS CAREFULLY AS RIFLES ARE DIFFERENT
 

Lenwood901

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Joined
Oct 18, 2018
Messages
260
Location
Tucson az
I’ve been using the .314 bushing but loaded Lapua round is .316.5 going to order the .315 bushing. I loaded up 195s with retumbo to fire form brass also have h 1000 but thinking it will be too slow also have 180 vlds if the 195s don’t work out
 
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