7 saum info

[whiter02]

I just got my 7 saum build complete and now I am ready to start working on a load. It is a shilen dgr la with a 28 in barrel 220 fb. I am trying the 180 hybrids out. I could only get my hands on remington 300 saum brass so that is what i will be using for now. I made it to the range the other day to find max charge with h1000. From what I have seen most people are running about 64-64.5 gr. I had pressure sighns at 63.5 gr. I havent chronographed it yet to check my velocity but I was wondering what most people are using? I can probably get a hold of some h4350 and retumbo. I was also wondering about primers. Should I use standard or mag?

 

[Milo 2.0]

I've been around a lot of 7 saums. First you have a lot of freebore, no biggie but it's a lot.
I'm linking a burn rate chart, I've seen from N 560 to N 570 work in this caliber, mostly between h1000 and 570, 24N41 is way too slow, and you can't find the two in between. 4350 will be too fast. I'd also go with a standard primer.
I do find it best to chrono at the same time as finding pressure points, when the data is side by side, it makes it easier to pick a powder. It doesn't make sense to settle on 62.1 grains of H1000 when it's only going 2675 fps.

http://hodgdon.com/burn-rate.html

 

[buster2765]

I also have two 7 saums, & they love h4831sc

 

[gme]

I have two 7 RSAUM's with .220 freebore chambers, different barrels on each (both 28") I'm running 63.0 H1000, 180 hybrids jumping .030 in both, could go higher but they both shoot well there, in my experience the H1000 is much easier on the barrel than 4350 or 4831

 

[dzelenka]

My 7 SAUM hammers with Retumbo and RL25. The load I have been using is 180 VLD over 64.5 Retumbo in a Nosler case with a WLR primer. 2875 in a 26" Krieger. Chamber has .188 FB.

 

[whiter02]

Thanks for the info. I will continue with h1000 and see how it does. If I am not happy I will try retumbo. Hopefully I will make it out again with the chronograph next week.

 

[thomasholbrook43]

I shoot two saums. 168vlds 60.5 H-4831sc 2950fps low es hammers out to one thousand.
180 hybrids with 58 grs H-4831sc 2850fps great one thousand load.That one's slow but hits in the same spot consistently.

 

[dzelenka]

I shoot two saums. 168vlds 60.5 H-4831sc 2950fps low es hammers out to one thousand.
180 hybrids with 58 grs H-4831sc 2850fps great one thousand load.That one's slow but hits in the same spot consistently.

what is the freebore on your chamber? What is your OAL for these loads?

 

[brxbrad]

Mine likes 61 Grains of H1000, 180 VLD's pushed in the lands .005, and Tula LRM Primers......

 

[thomasholbrook43]

Sami spec chamber. 12Thousand in. You will find very little difference between 168vld an 180 hybrid. The 168 vld's you gain 100fps and at 600 they out preform the 180hybrids in wind dfift.

 

[whiter02]

Have any of you had your barrels to pick up speed after about 100 rounds? If so around what round count and about how much did it speed up? I am getting about 2920 out of mine with the 180 hybrids at 64.5 and have a light mark on the brass at 64.9 with h1000. I think I need to go a bit higher with the load but dont want to be that close to pressure. I have about 65 rounds through my barrel right now. I have heard of some barrels speeding up around 100 rounds so I dont want to give up on h1000 to soon.

 

[thomasholbrook43]

yes most barrels will speed up around the 250 round count. Mine did by 75fps some where around there. You will love the saum. Its much longer barrel life than the 6.5x284. So far barrel count at 1400 rounds still going strong.

 

[lvgolfer962]

My first barrel (30") loved 63.3 h1000 in rem brass, 62.3 in nosler brass with 180 bergers.

The new barrel is a bit shorter(28") and is liking 63.9 h1000 in rem brass with 180's

3050 to 3100 fps seems to be the speed mine really shoot well at.