7mm build

[CMRHG]

If looking for more speed, I would try a slower powder like IMR 7828 SSC, 7977, or H1000.

Ive got a buddy that uses 73.1gr of Retumbo and pushes the 180 gr Berger Hybrid match at 3040fps.

 

[Bob Wright]

If looking for more speed, I would try a slower powder like IMR 7828 SSC, 7977, or H1000.

I had tried 7828 ssc but not the latter 2 powders. I had called Nosler and they hadn't worked up a 175 LR load using the more temp stable RE 23. So, I experimented slowly and ended up here. Ok, but not great. I have 330 rounds through this tube. Should have room for more tests but will check my jump to see if it is moving forward a bit. I keep it clean always so its not being tortured....figure I'll have 500 min. rounds to go before I worry. Thats a lot of game hunts left, lol.
What's weird is at 2600 fps it shoots 180 Burger bug holes when I was breaking it in. Too slow for hunting, but fun!

 

[MudRunner2005]

Ive got a buddy that uses 73.1gr of Retumbo and pushes the 180 gr Berger Hybrid match at 3040fps.

I tried Retumbo in several different cartridges, but never could get it to settle in with any good groups. So after a couple lbs. I decided to shelve it. Still got over 1/2 lb. of the last canister I bought...

 

[MudRunner2005]

I had tried 7828 ssc but not the latter 2 powders. I had called Nosler and they hadn't worked up a 175 LR load using the more temp stable RE 23. So, I experimented slowly and ended up here. Ok, but not great. I have 330 rounds through this tube. Should have room for more tests but will check my jump to see if it is moving forward a bit. I keep it clean always so its not being tortured....figure I'll have 500 min. rounds to go before I worry. Thats a lot of game hunts left, lol.
What's weird is at 2600 fps it shoots 180 Burger bug holes when I was breaking it in. Too slow for hunting, but fun!

I would try the new Berger 175 Elite Hunters (seated .015" off the lands) with 7977 and Fed 215M or CCI 250's in Nosler brass. Nosler brass is weight-sorted before it gets packaged, and since going to it years back for all my belted mags, my SD's and ES's have dropped drastically. Groups tightened up, too.

 

[WildRose]

Yes, that's what it looks like. My buddy sold it to me complaining it wouldnt shoot. He was right to a point. The berger worked but I bet this was "shot hot" and dirty many times and just may be tired now.

MR has a good point. With the Length of the STW case it would be even easier to get past the damaged part of the barrel with minimum reduction in length.

 

[WildRose]

I tried Retumbo in several different cartridges, but never could get it to settle in with any good groups. So after a couple lbs. I decided to shelve it. Still got over 1/2 lb. of the last canister I bought...

I've never been a Retumbo fan, it's the dirtiest powder I have ever shot and got better velocity and/or es with quite a few other powders.

 

[highdrum]

I've never been a Retumbo fan, it's the dirtiest powder I have ever shot and got better velocity and/or es with quite a few other powders.

IMR 8133 is a viable option.

 

[highdrum]

Retumbo 73.6 grains. New Norma Brass, Federal 215M Primer. Ive built 4 7RM that shoot this same bullet between 2930-2960 fps. I just built a 300-7 shooting the 195. 85.5gr RL33, necked down new Norma Brass, 215M primer, between 3110-3115FPS. In 25 shots thru it, got it down to a 1/4"moa. I work hard to find a simple load that is accurate but easy to put together for my clients. My 270 win builds push the 170 gr berger eol at 2950 as well and are low recoil tack drivers. Simple load as well...

Barrel lengths on these fire breathing loads? Your velocities are very high for bullet weight and case capacity.

 

[MudRunner2005]

IMR 8133 is a viable option.

I keep forgetting about this one, as I haven't bought any to try yet... Hopefully soon.

 

[Bob Wright]

MR has a good point. With the Length of the STW case it would be even easier to get past the damaged part of the barrel with minimum reduction in length.

That's a great point. It is a long cartrtridge that would clean up well and add some life into the barrel. I'll look at the drawings for the cartridge. I believe this cartridge really shined with lighter bullets for that 9.25 twist. It's been a while since I read the original designers article, noting its ability to drive faster/flatter and a simple reaming job to get it to the STW. Layne Simpson was the developer? I'm happy with a lighter bullet for this rifle since its a backup gun and figuring a ~600 yard max effective range for my Leopold 6.5-20 with varmint reticle. Terminal performance of the Bergers on 3 animals pushed me to Accubonds on the other rifle. Sounds like Hornady has some great options today too. This could be fun....

 

[WildRose]

Yes Mudrunner, saw a lot of discussion on the merits of STW and the 28. My custom is a 7mm RM Krieger barrel at 8.5 twist. It makes a fine hunting rifle using the 175 Nosler LR. still tweaking slowly to improve but nowhere near the speeds I see in this thread. Those are impressive speeds and groups. I settled for 2935 fps at .75 groups using RE 23. Good for hunting, not for records LOL.

Give RL26 a try. You won't be disappointed.

 

[WildRose]

That's a great point. It is a long cartrtridge that would clean up well and add some life into the barrel. I'll look at the drawings for the cartridge. I believe this cartridge really shined with lighter bullets for that 9.25 twist. It's been a while since I read the original designers article, noting its ability to drive faster/flatter and a simple reaming job to get it to the STW. Layne Simpson was the developer? I'm happy with a lighter bullet for this rifle since its a backup gun and figuring a ~600 yard max effective range for my Leopold 6.5-20 with varmint reticle. Terminal performance of the Bergers on 3 animals pushed me to Accubonds on the other rifle. Sounds like Hornady has some great options today too. This could be fun....

I'm shooting 150gr mono's and up to 175s in lead core bullets in my 1:9's and it's devastating.

With your 1:8.5 you should be able to stabilize the 161gr Peregrine VLR 5's with no problem, the straight 9tw is a bit slow. I could send you some to try if you like.

 

[Bob Wright]

I would try the new Berger 175 Elite Hunters (seated .015" off the lands) with 7977 and Fed 215M or CCI 250's in Nosler brass. Nosler brass is weight-sorted before it gets packaged, and since going to it years back for all my belted mags, my SD's and ES's have dropped drastically. Groups tightened up, too.

Yep, Nosler brass, Fed 215s is my basic starting point unless specified differently on primers.
For the 82 vintage Rem I don't neck turn the Nosler brass. The new, custom Krieger, I had to neck turn due to pressure signs and SD'S. I ruined a lot of brass (pockets) until I got some helpful advice to cast the chamber and measure (is .3164 dia.). I allow .004 clearance on the diameter of loaded neck now. Slower burn rates, of course, helped. No more brass problems. Annealing brass also was a plus on the Krieger barrel rifle. Neck sealing and headspace is spot on/uniform now. Documented brass growth in 5 areas, over 40 rounds, and arrested it, finally. Never have to bump the shoulders, yet. It was a long process for me....my first magnums anyway.

 

[WildRose]

Yep, Nosler brass, Fed 215s is my basic starting point unless specified differently on primers.
For the 82 vintage Rem I don't neck turn the Nosler brass. The new, custom Krieger, I had to neck turn due to pressure signs and SD'S. I ruined a lot of brass (pockets) until I got some helpful advice to cast the chamber and measure (is .3164 dia.). I allow .004 clearance on the diameter of loaded neck now. Slower burn rates, of course, helped. No more brass problems. Annealing brass also was a plus on the Krieger barrel rifle. Neck sealing and headspace is spot on/uniform now. Documented brass growth in 5 areas, over 40 rounds, and arrested it, finally. Never have to bump the shoulders, yet. It was a long process for me....my first magnums anyway.

I've been reloading since the 70's and I'm still learning.

My first adventure in neck turning came with the 6.5LRM I bought off of another member here. It has most certainly reduced chamber pressure but I'm wondering what it will do for brass life. In the past the first signs of failure I usually see are necks cracking and splitting as they got too thin.

We shall see what the future holds. I have five different loads worked up for it now to try with the brass I've turned and the results will be interesting I'm sure.