Cooper Backcountry 7mm Rem Mag load ?

[rharfo]

i know all barrels are different but I am hoping someone has a load for a Cooper Backcountry in 7 rem mag they can share. I have tried the load Cooper allegedly shot the one hole group on the supplied test target but it was over a inch @ 100 yards. So far I've tried IMR 4831,4350 and H1000 with Barnes 145LRX and the 162 Eldx. All have shoot over 1 inch at 100 off the bench (3 shot) groups. Since they chambers should be similar and the barrels the same brand maybe you can help me out and get me close. Thanks

 

[WeiserBucks]

What's the twist?

 

[rharfo]

What's the twist?

1 in 9 do you have a Backcountry in 7 Mag?

 

[WeiserBucks]

No but I've got a fair amount of experience loading 7 RM. I would recommend staying with H1000 and try heavier bullets.

 

[Lab rat]

I'm shooting 154 interbond with 68 gr of RL 26 all elk in the picture was shot with154
Interbonds

 

[Gary in MD]

Are you sure that your scope, rings and mounts are good?
RL22 and H4831 worked well in the last 7mmRM that I had.

 

[rharfo]

The scope rings look good. Using Talley with a Swarovski z5. Both bought brand new for the gun. I don't have any RL26 or H4831 but do have a lil R22.
I have lots of H1000 and IMR 4350...
I also have some 175 and 180 hornady but really think the 162 would make a great all around bullet for deer and black bear. I also have 150 eldx and 145 Lrx.

 

[pdogger]

haven't got a load for you, but your test target was shot at 60 yrds.....because that's all the longer there building is..

 

[Jud96]

I would get some H1000 or try to find RL26. Start at 66gr with both and work your way up. My Dad shoots 68.8gr of RL26 in his 7mm Mag with 162s @ 3070fps with low ES. We haven't done a ton of testing with H1000 though.

 

[naja302]

My dad has the same gun and I was too lazy to reload for it, so I tried about a dozen different factory loads and most shot terribly (like 2" at 100 yards)...then I found one it likes. Barnes ammo with 139g LRX shoots consistently 1/2 MOA. I think it's just such a lightweight gun with a tiny pencil barrel that you really gotta find the magic spot with barrel harmonics to get accuracy. FWIW this load does get 3300 FPS out of Dad's gun which is surprisingly fast

 

[howco]

Magpro powder can be a real sleeper in 7mag. As others have said, rl22,rl26. Retumbo shot well with 162amax for years with several 7s for me. Honestly give your z5 a target test, their erector springs are known for issues, I unfortunately have experience working with swarovski in that department

 

[Gary in MD]

Take a couple of the best loads that you have come up with and change your seating depths both ways.

I just noticed your "partner ".
Here is my little bad boy, only about a 1 1/2 years old.
Good luck with your rifle , it will come around or Cooper will make it right.
Gary

 

[Rifleslut]

haven't got a load for you, but your test target was shot at 60 yrds.....because that's all the longer there building is..

I heard 47 yards. Lol. Although they do have a 1/2 MOA guarantee. I wish I had a cooper back country. I do have a Tikka Superlight 7 mag. 180 Berger Hybrids and Retumbo was the ticket for that gun. 5 shot groups were 3/4" with no flyers ever. Not bad in my opinion for a 6lb factory gun. I'd still trade it to have a cooper back country

 

[Jud96]

Take a couple of the best loads that you have come up with and change your seating depths both ways.

This right here. This past week I was developing a load for my .284 and my Dad's 7mm Rem Mag. I typically find accuracy from 0.005-0.020 off the lands. Both of these rifles shot inconsistent and bad with those seat lengths. Surprisingly, we found the best accuracy at 0.050 off in both rifles with different bullets. It pays to try seating depths at all ranges to see what your rifle likes. Sometimes certain things surprise you in reloading haha.