7RM Load Development Results – Advice Moving Forward

[Full Curl]

Looking for some advice. I'm not new to reloading but I don't have as much knowledge and experience as many on here do. I had a new carry hunting rifle built chambered in 7RM. Bartlein #3 24" 1:8. I recently started load development for 160 Accubonds pushed by H1000. After a couple OCW tests I have 2 good accuracy nodes… a lower one at 65.3 grains (2,869 fps) and an upper one at 69.0 grains (3,015 fps). At 69.0 the primers start showing the slightest sign of flattening but not much. In the photo, the 69.0 case is on the right and the 65.3 case is on the left. I don't notice any other signs of pressure… although I had the bolt cerekoted and its brand new so still not worn in silky smooth yet and I'm not sure I would notice a little sticky bolt lift?? It certainly shows no signs of noticeable heavy lift.

I have not gone beyond 69.0. Both loads are sub MOA with the 65.3 load having a slight advantage at a solid 1/2 MOA. I was really hoping to find a good node in the 67.5 to 68.5 range like I have with previous 7RM's but it's not there with this one. Looking for advice on what load to move forward with. My goal is to focus on a specific load and that's the one for this rifle. It will be used 80% for hunting and 20% for occasionally banging steel, rarely over 800yds. The rifle should easily outlast me. I'm not sure how "hot" the 69.0 load is, but barrel life, case life, and rifle wear and tear is a consideration. At the same time, I feel I'm sacrificing a lot of the advantages of the 7RM to move forward with an under 2,900 fps load.

Anyway, please talk me through this and what load to move forward with and not look back. Thanks!!

 

[cajun]

Hogdon lists 66 grains of h1000 with the 160 partition at 2839 fps from a 24" as max. They do pressure test their loads. Nosler doesnt list h1000 with the 160 but with the 168 ablr ( different bullet profile ) they show 70 grains with 2993 fps. Trying to read brass and primers is kinda voodoo. By the time you start seeing ejec marks and bolt lift your usually over max. In some rifles that are hard cocking uncocking like a savage bolt lift can be hard to see until it's really hard. I have not used h1000 but with R 26 and the 160 ab we can get close to 3000 but are running it 2950 in my sons rifle.

 

[Full Curl]

Hogdon lists 66 grains of h1000 with the 160 partition at 2839 fps from a 24" as max. They do pressure test their loads. Nosler doesnt list h1000 with the 160 but with the 168 ablr ( different bullet profile ) they show 70 grains with 2993 fps. Trying to read brass and primers is kinda voodoo. By the time you start seeing ejec marks and bolt lift your usually over max. In some rifles that are hard cocking uncocking like a savage bolt lift can be hard to see until it's really hard. I have not used h1000 but with R 26 and the 160 ab we can get close to 3000 but are running it 2950 in my sons rifle.

I looked at both of those and some other bullet brand manuals and max is all over the place. That 66.0 max is listed with a 160NP. Then they list 70.0 as the max for a 162 H-BTSP and 68.0 for a 150NP. I'm not sure how the AB fits in there?? I've always tried to let the rifle tell me but like you said that's voodoo at best sometimes. I wish I had a good accuracy node right there around 2950 or even 2900+ but at 2869 I just feel like I'm shortchanging the caliber's potential. BUT I'm also one who has never loaded at the far leading edge of the pressure cliff just to squeeze another 30fps+ out. I have another stock 700 Rem 7RM that likes 68.5 of H1000 pushing the 160AB and that rifle has 700+ firings of that round on it and still shoots great. I notice bolt lift pressure signs at 69.5 with that rig.

 

[Quintus]

Are these loads on virgin brass?

 

[Bob Wright]

There aren't any pressure signs on your brass. However, it sounds like your rifle is new with low round count. It should speed up over time. If we still had access to Reloder powders, RE23 would get you the speed you're looking for.
So, while you are still loading for that 2950 type speed, changing powders and doing some ladders would show you more potential even as the barrel speeds up over time.
But the other question is, does your bullet's terminal performance at the distance you want to shoot require significantly higher speeds?

 

[Full Curl]

Are these loads on virgin brass?

Yes.