7mm Rem Mag Advice Please

[Red_Beard]

The only real thing I have set in stone right now is that I will be using the 7mm Rem Mag with 180 gr vld's and IMR 4350 powder (I have 9 lbs of it and it has given me the best results in my 7mm sporter hunting rifle). I have ZERO experience with these heavy match bullets and am looking for a little experience and guidance to help me with starting my load developments. I guess my questions would be about seating depth, charge weight, and estimated velocity range out of a 28" pipe.

If you can think of other questions I should be asking, please let me know.

Thanks for the help!

 

[El Cid 92]

In my experience, the heavier 180gr VLD like a slower burn powder .... like H1000 or Retumbo. With a 28" barrel, I'd use a slower burn powder to get every bit of velocity out of it. With 67.5grains of Retumbo, I was getting 2830fps with very nice accuracy.

The VLDs tend to be "jump" sensitive. I have generally started at 0.005" jump and worked in till I found what worked. Generally, I work on powder charge to acheive accuracy and node identification. Then, I fine tune with bullet jump.

Review of Hogdon's web site shows starting load at 52gr and max at 56gr. These are using LR Magnum Primers.

Hope this helps.

Andrew

 

[Capt Academy]

I use Retumbo in my 7 mag with excellents results shooting the Berger 180 VLD's in my RBros rifle at 3056 fps

 

[30378]

IMR-4350 is WAY TOO fast for the heavys in a 7 Mag. For optimum performance Retumbo, H-1000, and RL-25 are your brews.

 

[Red_Beard]

Thanks for the help, now I just need to figure out where to get some of the Retumbo. Shame that I have so much 4350, but it is still a great powder for my 140gr hunting pills out of a 24 in barrel.

It seems like with the slow burners the powder charge is significantly higher. Will I still be able to seat the bullet deep enough to fit in the AI mags?

 

[Squid284]

Or... you could use IMR4350 and 162AMAX's or 168VLD's? Those should work alright I would think.

 

[P7id10t]

It seems like with the slow burners the powder charge is significantly higher. Will I still be able to seat the bullet deep enough to fit in the AI mags?

I think it's more powder optimal burn than a general slow vs. fast. I have VV recipes for N170 and N570 where the N570 uses 5 grains more and they're both slow powders.
Stay safe, start low and work it up.

 

[Red_Beard]

Thanks for the help guys. I now have 2 1lb tubs of h1000 and retumbo on back order to start figuring things out when they get here. As always, I really appreciate all your advice.