Velocity ladder with 165 gr. Sierra Gamechanger and the 7mm08

[Cornivorus]

From what I see H414 and (same as) W760 should also give you some pretty good velocities. You should be able to use 168 data for the 165's as well.

I thought about h414 but I've seen temp sense issues with h414 so I tend to steer clear of that one. I've been looking at 168 & 162 load data and kind of split the diff between them.

 

[Dell]

Yes I'm with you on this, I plan to run some more at the 40.9 and see how accuracy is. I was hoping for a little more velocity, but if that's where the accuracy is I'm good with that.

As for the recommended max, well I could not find any published load data with this bullet and powder combo so I'm winging this based on similar components.

Best of luck to you. Like I said before, your graph depicted a good flat spot. Be interested what you get for ES and SD when you test further.

 

[Cornivorus]

This has been kind of weird, I am not sure what's going on? When I ran the ladder test with incrementing the powder charge up 2/10 of a grain, my groups were better than they are now that I started testing for groups? I noticed some pressure signs were there at the top of the ladder, but at 40.9 things seemed pretty good. Then when I tested for a group size there it was all over the place, like a 4" group.

Early on in my testing I had a 1/2" group with this bullet, but the velocity was only around 2500 fps. That charge was 39.5 grains I believe.

So today I backed off to 40.5 gr. And tried adjusting the seating depth in 15/1000 increments for four different loads. This time I got some better Es & sd numbers but the groups are still bad, around 2 1/2". I'm going to have to ponder on this a bit and decide where to go from here?

 

[Rflshootr]

This has been kind of weird, I am not sure what's going on? When I ran the ladder test with incrementing the powder charge up 2/10 of a grain, my groups were better than they are now that I started testing for groups? I noticed some pressure signs were there at the top of the ladder, but at 40.9 things seemed pretty good. Then when I tested for a group size there it was all over the place, like a 4" group.

Early on in my testing I had a 1/2" group with this bullet, but the velocity was only around 2500 fps. That charge was 39.5 grains I believe.

So today I backed off to 40.5 gr. And tried adjusting the seating depth in 15/1000 increments for four different loads. This time I got some better Es & sd numbers but the groups are still bad, around 2 1/2". I'm going to have to ponder on this a bit and decide where to go from here?

What primer are you using?

 

[Cornivorus]

What primer are you using?

Winchester LR

 

[Dell]

This has been kind of weird, I am not sure what's going on? When I ran the ladder test with incrementing the powder charge up 2/10 of a grain, my groups were better than they are now that I started testing for groups? I noticed some pressure signs were there at the top of the ladder, but at 40.9 things seemed pretty good. Then when I tested for a group size there it was all over the place, like a 4" group.

Early on in my testing I had a 1/2" group with this bullet, but the velocity was only around 2500 fps. That charge was 39.5 grains I believe.

So today I backed off to 40.5 gr. And tried adjusting the seating depth in 15/1000 increments for four different loads. This time I got some better Es & sd numbers but the groups are still bad, around 2 1/2". I'm going to have to ponder on this a bit and decide where to go from here?

I can't remember early on what, or if, you said what the twist rate was in your rifle. That 7mm 165 GameChanger is a fairly high BC Bullet. I'd think it needs at least a
1/9 twist rate. I had a similar issue with a 25/06 several years ago. It shot .5 MOA at 100 all day long with a 100 grain bullet, RE-22 powder. I tried some 115 grain bullets, I think they were Nosler, and it wouldn't hold 4" at 100. Went back to the 100 grain bullets and .50 MOA returned. The twist rate(1/10) in that rifle just wouldn't handle the heavier bullets. Just thinking out loud here. Best of luck! It can be a frustrating search but once you find it....it will all be worthwhile!

 

[Cornivorus]

I can't remember early on what, or if, you said what the twist rate was in your rifle. That 7mm 165 GameChanger is a fairly high BC Bullet. I'd think it needs at least a
1/9 twist rate. I had a similar issue with a 25/06 several years ago. It shot .5 MOA at 100 all day long with a 100 grain bullet, RE-22 powder. I tried some 115 grain bullets, I think they were Nosler, and it wouldn't hold 4" at 100. Went back to the 100 grain bullets and .50 MOA returned. The twist rate(1/10) in that rifle just wouldn't handle the heavier bullets. Just thinking out loud here. Best of luck! It can be a frustrating search but once you find it....it will all be worthwhile!

It's a 9 1/2" twist. I'm starting to think my problem is likely the jerk behind the trigger. Today I loaded some more out to 2.980" , where 2.988" is just at the lands. I was getting frustrated again with the way it was shooting and I decided to change the way my trigger pull happens. Up to this point I have been setting up on target then slowly adding pressure until the surprise boom happens. But when I get on target and make a more deliberate pull of the trigger I put my last three into a 1/2" group. Thus rifle is new to me and the trigger is different than I'm used to. It has zero felt creep, and I mean zero! So I'm going to work on this some more and see what i can do with it.

Btw I had an ES of 21 and SD of 7 at 40.9 gr.

 

[Dell]

It's a 9 1/2" twist. I'm starting to think my problem is likely the jerk behind the trigger. Today I loaded some more out to 2.980" , where 2.988" is just at the lands. I was getting frustrated again with the way it was shooting and I decided to change the way my trigger pull happens. Up to this point I have been setting up on target then slowly adding pressure until the surprise boom happens. But when I get on target and make a more deliberate pull of the trigger I put my last three into a 1/2" group. Thus rifle is new to me and the trigger is different than I'm used to. It has zero felt creep, and I mean zero! So I'm going to work on this some more and see what i can do with it.

Btw I had an ES of 21 and SD of 7 at 40.9 gr.

Roger that

 

[Rflshootr]

Have you checked your action screws and scope screws to make sure nothing loosened up? 2" groups kind of tells me something else may be wrong.

 

[Cornivorus]

Have you checked your action screws and scope screws to make sure nothing loosened up? 2" groups kind of tells me something else may be wrong.

I did check that as well, in fact I took the stock off and inspected everything with the recoil lug. All looked good and then I torqued it down to Tikka specs.