Need 7mm RUM load data!

[bigngreen]

So I picked up a 7mmRUM barrel from another member and I'm looking for some data. I stopped and picked up some brass and dies also picked up some 175 Sierra Gamekings. Any do's or don't tips would be good also.

 

[sledder1]

This seems to be a very finicky caliber. I recently built a 7 RUM and after alot of trial and error I settled on the 190 matrix bullet, 86 grains of Retumbo, nosler custom 300 RUM brass necked down and federal 215 primers. I started with Remington brass but found that after 2-3 loadings, I had difficulty getting the bolt to open. This was remedied with the nosler brass. I also tried cci 250 primers however I ended up with alot of hang fires! Bad deal. Remedied with federal 215s. I tried h1000, rl25 and 50 bmg powder but found my most consistent and most accurate loads with Retumbo. I also loaded the 180 bergers with 88 grains of Retumbo to about 3250 fps and very accurate but settled with the 190 matrix at 3150. I want to try some h 869 powder next. I hope this helps you a little bit

 

[jrw1976]

Uh oh, BnG must be getting bored waiting for your barrel to get back if you are playing with a "7mm". I dont have anything intelligent to add I just wanted to jab you a little. Im in the same boat I have found myself a little bored as of late so I am in the infant stages of designing my own wildcat with the help of sin arms. I would really bet that you are going to find your best all around performance with the 160-168 grain class bullets. Atleast that is what I have found playing with all my 7mm's.

Good luck, Jason

 

[bigngreen]

Jason,

Ya, waiting for a barrel is much easier on us Savage guys since we can have a back up to run while waiting ever so patiently! I feel like I've done all kinds of evil getting a 7mm, I'll have to sneak out to the range so no one see's me with it, you wouldn't believe the ration of crap I've gotten from my shooting buddy I plan on using it to play with the heavier bullets and piles of Retumbo to see if I want to get a tweaked up reamer made, I have an idea brewing lightbulb Tweaking stuff is so addictive I hope I never recover from it but winning the lottery would help!!!
Good luck with your wildcat!!

 

[bigngreen]

This seems to be a very finicky caliber. I recently built a 7 RUM and after alot of trial and error I settled on the 190 matrix bullet, 86 grains of Retumbo, nosler custom 300 RUM brass necked down and federal 215 primers. I started with Remington brass but found that after 2-3 loadings, I had difficulty getting the bolt to open. This was remedied with the nosler brass. I also tried cci 250 primers however I ended up with alot of hang fires! Bad deal. Remedied with federal 215s. I tried h1000, rl25 and 50 bmg powder but found my most consistent and most accurate loads with Retumbo. I also loaded the 180 bergers with 88 grains of Retumbo to about 3250 fps and very accurate but settled with the 190 matrix at 3150. I want to try some h 869 powder next. I hope this helps you a little bit

Thanks, that helps. All the feed back I've gotten on the 7RUM seems to point to Retumbo and Fed 215's which I load a lot of anyway so that's good.

 

[bigngreen]

Lit it up this evening and results were encouraging, loaded 3 of 88gr of Retumbo and then 89, 90, 91, 91.5 and 92gr of one each to get a feel for the top end with a 175 GameKing. The velocities ran from 3012 to 3204. Shot 1 didn't land on target so got it lined up better and shots 2-5 went under 1/2 inch at 100 then it moved around a little but still OK, really need to get a Muscle Brake installed to take some of the push out of it as my shoulder didn't like moving that much Over all I'm finding it interesting!

 

[jrw1976]

So what are the specs on this rig. What is the length ect...?

Jason

 

[bigngreen]

It's my Savage model 12 in a Bell and Carlson Varmint stock, action trued up a bit and bedded. Got the barrel from another LRH member, factory Savage 7mmRUM barrel 26in long, figured what the heck I have like a 150 bucks into it and all the new reloading stuff not a bad way to try it out. The chamber has a long throat, touching the lands barley has the bullet in the case so I seated them at 3.800 COAL.

 

[jrw1976]

Sweet, you are right you didn't get hurt on that deal. For 150 bones you can do all kinds of experimenting and shoot the snot out of it and not feel bad about it not even a little bit.

I like it!!!!