Reloader 17 and my 7mm SAUM

[dougm]

I have been looking at powders for my 7 SAUM using 168 Bergers.
My pistol is a rear grip xp with a 17 inch barrel. The gun was built by Kirby and is an awsome shooter!
I have been using 140 and 150 AB's and was fortunate to take an Antelope at 588 yrds using the 140's last year. This year I want to try and stretch it to 800 yards. That's why I am looking at using the 168 Bergers.

Anyway, I tried 100V but started to hit pressure at around 2675 fps.
I was hoping to get the 168's up to 2800 fps if possible.
Last weekend I was able to try R17. I'm glad I did. I was able to go up to 58 grains and had a measured velocity of 2850 fps!!! That was with the bullet touching the lands too.

This weekend I'm following the instructions for finding the optimum bullet seating depth that Berger Bullets wrote. I will be trying 57.5 and 58 grain loads. Hopefully one of these will shine in the accuracy department. 57.5 grains gave me a velocity reading of 2818 fps which if it proves to be more accurate is fine.

I'm using Fed. 210 primers and Remington brass.
I'll post how the accuracy turns out when I get the results.

Doug

 

[JARHEAD1371]

That's great news. I'm looking at using R17 in my 7mm SAUM custom rifle, but I can't find any data. The company doesn't have any and I don't know enough about load development with an untried powder. How did you come up with a starting load? I'm shooting 168 Bergers through a 28" barrel.

 

[zuba]

awesome doug! r17 is awesome with these short barrels! I've got to re-read the berger article, but I'm pushing the 168 smk's @ 2900. ever try it in your dakota? I'm planning to try the 180 berger's and mabey some wildcat's this fall

 

[winmagman]

Doug,

That's great info. I've got 5 lbs of Re 17 and a 7 SAUM. I was in the same boat as JARHEAD, no idea where to start , now I'll have to give it a try.

Chris

 

[dougm]

I searched around the Internet and found some loads, then looked at load data for IMR 4350 since according to Alliant the two powders have a similar burn rate.
Using all the info I just started at a mid level load (for imr 4350) and worked up .5 grain at a time shooting through the chrony until I began to notice a drop in speed or the usual case signs, or a tight bolt lift etc.

When I got to 58 grains, I sensed the bolt lift to just begin to be ever so slightly stiffer (not hard by any means) than the 57.5 grain load. Everything else still looked great but I stopped there since I had already passed the speed I was looking for (2800 fpls).

I had the bullets heavy into the lands, and temp was 84 degrees so it was rather worse case conditions. I feel confident that in my gun the 58 grain load is safe.

This weekend I'll try the different seating depths with both loads (57.5 and 58). Hopefully one of them will shine.

Zuba,
Not thought about it in the Dakota. Not sure I can get a good case fill due to the volume of the Dakota, I still have a bit of room in the SAUM. I'd say I'm between 85-90% full though.
Now that I'm getting the Dakota rebarreled to 25 inches I think Retumbo, H1000, should work well.

 

[JARHEAD1371]

Dougm,
Thanks for the info, you have put my mind at ease regarding which powder I will try in my soon to be delivered custom 7mm SAUM. I'm glad I'm not the only one that saw the promise in that cartridge. Thanks again.

 

[zuba]

Not thought about it in the Dakota. Not sure I can get a good case fill due to the volume of the Dakota, I still have a bit of room in the SAUM. I'd say I'm between 85-90% full though.
Now that I'm getting the Dakota rebarreled to 25 inches I think Retumbo, H1000, should work well.

I figured you probably wouldn't be able to fill that case... thats gonna be a crazy pistol! what kind of stock are you going to use? you might want to move the bi-pod further forward so it balances better...

 

[dougm]

Matt, you're right about the stock and bipod placement.
I think I will eventually go with another another McRee using the longer forend.
Right now, I'm trying to limit my spending so will use the McMillan midgrip stock I already have for it. I know it will look funny and not balance the best, but it will have to do for now.


Depending on my velocities, I may eventually get the barrel cut back to 22-23 inches, just depends on wheather that length will provide the speed I want for the 180's. Everything I'm reading points to them working best between 2950 - 3050 fps.



Doug

 

[zuba]

You might be able to get Joel to make a lee-six style stock with a longer forend... that should be cool either way!

 

[JARHEAD1371]

I picked up a pound of RL 17 yesterday. All I'm waiting on is my rifle to get finished.

 

[Buttermilk]

Interesting regarding the RL17 with the 7 SAUM. Some good velocity with it as well.

I currently shooting some RL17 in my 284 Win. The gun is a 15" T/C Encore. So far, I've been able to push the Berger 168 VLD's to ~2547 fps (chrono'd at ~ 15 ft from muzzle) using RL17. My accuracy has been good, but next range session, will be using Berger's recommendations regarding COAL to find the sweet spot.

Good luck with your 7 SAUM.

Rog

 

[Left Hand Dave]

Doug,
I have a new centergrip XP in 7 SAUM with a 17" barrel that I am just starting load development on. I plan on using 140-150 grain bullets. Could you share your 140 and 150 grain loads?

Thanks
Dave

 

[Buttermilk]

In my XP-100 7mm RSAUM, I've had really good results using H1000, H4831sc, and IMR4451. Barrel is a Bartlein 5R, 17.5" long, with a FB of 0.140", 1:9" twist.

Nosler 150 gr ABLR was used with the IMR4451. I hit pressure at 58.0 grains. Accuracy initially was stellar at 0.25 MOA, but wasn't repeatable. Velocity was 2850 fps.

I used H4831cs with the Berger 168 VLDH with exceptional accuracy as well. 60.0 grains is the max I've loaded to. Gives sub 1/2 MOA (best has been 0.24 MOA) at 2700 fps.

H1000 has given me the best combination of accuracy and speed with the Berger 168 VLDH. I've went up to 67.0 grains, but have slightly better accuracy at 65.0 grains. I've still got some more load development to do with H1000, but so far, it's been 1/2 MOA or slightly better.

I've also used 65.0 gr H1000 with the Hornady 162 ELDX with 1/2 MOA as well. It's been a consistant 1/2 MOA load so far.

I also play some with IMR7977 since it is supposed to be similar burn speed to H1000. In my gun, I hit pressure at 63.0 grains of powder, which is where I started at. I stopped working with it after the 63.0 grain charge. I had better results with H1000.

Hard to go wrong with H1000 and H4831cs in the 7 SAUM.

In my 7mm RSAUM, I've pretty much settled on H1000 for the bullets I plan to shoot.

 

[Left Hand Dave]

Roger,
Do you think H1000 would work with 143 grain Hammers or do you think I will run out of case capacity?
Thanks
Dave