Howdy all. Just wondering if anyone has much experience with IMR 7828 in the .7mm Rem mag? I have worked up a load of 69.3 grains behind the 140 gr Sierra GameKing BTSP, that is printing 1/2 MOA @100 yds. According to my chrony it clocks an average 3050 fps, from a 24 inch barrel, and I just wanted to see if someone may have any comparable loads with this powder. According to Lyman's manual, this load is not close to maximum with this powder, but I really like the grouping!
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Imr 7828
- Thread starter gun44
- Start date
Linear Thinker
New member
I tried 7828 in 300WinMag with heavy bullets, was not pleased. The powder does not meter well with either Jones, Harrell or Ohaus measures. My loads were inconsistent, with velocity SDs higher than I like.
RL22 is my choice for Magnums with heavy bullets, RL19 with lighter ones.
LT
RL22 is my choice for Magnums with heavy bullets, RL19 with lighter ones.
LT
Linear Thinker
New member
Shoney - I shoot 208gr A-Maxes in 300WM at 600-1000yds, switching from 200gr Sierra MKs a few years back. I consider those to be heavy bullets, as I shoot 155gr Palmas and 168gr MKs in other 30 calibers.
I tried the 240gr MKs as well, with so-so results - probably due to my 1-10 twist barrel not stabilizing them properly.
Many years ago, I weighted every powder charge (rifle only, not pistol), in the never-ending search for best accuracy. I used an Oehler 33 to check my velocities, and did the statistics on a notepad with a calculator. When Oehler 35Ps came out, I finally had an easy way to run Stat Process Control on my handloads. In comparing the weighted vs. by-volume charges, I found no benefit to weighing each charge, when using a high quality powder measure, for both stick and ball powders.
If you are interested in my methodology, drop me a PM.
I "might" have done better by weighing each 7828 load. I did weigh every 10th charge, and never saw more than 1% deviation from the 74gr max load. When throwing the Reloder powders, the deviation is ~ .25%.
I do measure the group sizes, not just the stats, to evaluate my loads. Oddly enough, some of my pistol loads are very accurate even though the velocity SDs suggest otherwise.
But by and large, lowest velocity's SD = best accuracy.
LT
I tried the 240gr MKs as well, with so-so results - probably due to my 1-10 twist barrel not stabilizing them properly.
Many years ago, I weighted every powder charge (rifle only, not pistol), in the never-ending search for best accuracy. I used an Oehler 33 to check my velocities, and did the statistics on a notepad with a calculator. When Oehler 35Ps came out, I finally had an easy way to run Stat Process Control on my handloads. In comparing the weighted vs. by-volume charges, I found no benefit to weighing each charge, when using a high quality powder measure, for both stick and ball powders.
If you are interested in my methodology, drop me a PM.
I "might" have done better by weighing each 7828 load. I did weigh every 10th charge, and never saw more than 1% deviation from the 74gr max load. When throwing the Reloder powders, the deviation is ~ .25%.
I do measure the group sizes, not just the stats, to evaluate my loads. Oddly enough, some of my pistol loads are very accurate even though the velocity SDs suggest otherwise.
But by and large, lowest velocity's SD = best accuracy.
LT
Last edited:
crowbeaner
New member
I use IMR 7828 in the 243 and 25/06 for the heavy bullet weights and it really shoots well in both guns. I don't have any belted big boomers in my battery right now so I'll have to read what's posted about them also.