IMR 7977 and 7mm SAUM

[AKGuide]

I figured I would share my results with imr 7977 in my 24" Rem 700 BDL SS in 7mm RSAUM. I didn't know where to start using the 168 Berger VLD's and hopefully this will help some guys and give them a burn rate comparison to other powders. I figured I would use imr 7828 data that Berger sent me and started slightly higher than their starting load at 57.6 grains and moved up in .6 grain increments to 60.6 grains. Velocity was very low and the necks were very sooty all the way until 60.6 grains. I then tried 61.0 grains and went up in one grain steps to 66.0 grains and the results were better.
57.6-2474 61.0-2724
58.2-2548 62.0-2747
58.8-2572 63.0-2805
59.4-2597 64.0-2875
60.0-2638 65.0-2901
60.6-2642 66.0-2925

I stopped at 66 grains as I had a slightly stiff bolt lift, but no click and a slight swipe in my outer edge of my brass. The primer pocket was still very tight after this load. I want to test 65 and 65.5 grains for accuracy as the velocity is where I would like it with no pressure signs and the pockets are staying very tight. This is a stock rifle with a bed job in the recoil lug area and will shoot bugholes with 150 SMK's, .020" jump, and 60 grains H4831 at 3000fps.

The OAL for these loads were long at 2.970" this was so the Bergers were soft seated to the rifling. The boat tail sections are just above the neck shoulder junction at this length and with 66 grains of IMR 7977 the powder was right at the neck shoulder junctions also. With .010" jump I am sure 66 and 66.5 grains will show no signs of pressure as my gun seems to take another grain to get the pressure back up with a jump.

I picked up a 12 pack sampler and this is what I came up with. I look forward to testing this combination more as soon as I get more bullets. I shot mainly for velocity as the conditions weren't the best for grouping. The load workup averaged 2" for both sets with a couple pairs grouping well.

Hope this helps and I will add more to it as I get more data.

Reuben

 

[AKGuide]

I just finished testing to see where these HbN coated 168 VLD's like to be seated and it looks like 0.050" jump has some promise to it, first shot I pulled. I will next load sets of three with 64.0, 64.5, and 65.0 grains IMR7977. I am now using Norma brass instead of Rem brass as Rem brass is impossible to find at the moment. With the Norma brass, CCI BR-2, and 63.0 grains of powder I am averaging 50fps slower than rem brass and a GM215M primer. I am hoping to finish with a sub 0.5moa at 2900fps. I will use a bench I made for the upcoming tests instead of my mat and a harris bipod with a hard hold. More to come.

Reuben

 

[N2TRKYS]

I tried IMR7977 in my 270 Win and didn't like what I was getting.

I'm working on a RL26 load for my 7 SAUM. It's still a work in progress, but it's showing promise. I'm getting 2900fps with 160 grain Accubonds in a 22" barrel.