7mm SAUM Starting loads

[Singo85]

Hoping to speed up the development of my SAUM. So after some ball park loads to get to 2950.

Barrel is a Bartlin 32 in 8.5. Will be using BR2 primers and have both 2209 and 2213sc and Berger Hybrids.

Any help with a ball park number so I can look for a node instead of a velocity on Saturday.

[Tim N]

My current bartlein saums use about 56.5 of 09 to reach 2950 with hybrids

[DenisA]

Is everyone running 8.5 twist SAUMS? For the 183 SMK's and in anticipation of 195 Bergers?

[ajvanwyk]

I run a 1 in 9 and same as Tim, 56.5 of 09 to achieve 2950. The node that have worked for me sat between 2870 and 2890...

[shooter mcreid]

Dennis, I have a 1:9, 2 x 1:9.5, a gain twist 10 to 9.25 and finally a 1:8.25.
The 9.5s seem to be working great for 180s and the 8.25 is well suited to the sierra 183s.
My 30" saums required around 55.9gr of 2209 to be around the 2950 mark, my 28" saums require 56.4 to get close to 2950.
Michael, I would think you would require somewhere in the high 55s to get 2950, then again I was suprised by tims load.

[Matt P]

Hi All
I have 3 SAUM's and 2 of the 3 run 56.2 of 09, one with VLD's and the other with Hybrids, the Bartlien with VLD's runs at 2950 and the Brux with Hybrids runs at 2915. The other I'm still playing with, down loaded to 284 speeds.
Matt P

[ajvanwyk]

Shooter, what brand of barrel are you running ? 55.9 of 09 gives me no more than 2890/2900 in a 32" Bartlein. Given that you are 2" shorter I am surprised with your velocities. The other variable could also be the batch of 09, not that I have much experience on which lot numbers run hotter than others.

Albert

[shooter mcreid]

Albert, all barrels are Bartleins. maybe it is the powder? the two 9.5s are still young so possibly will slow down after a 200 or so rounds. The plan is to tune them very soon so ill report back with what they show for a bit of confirmation.

[macguru]

Singo you probably needed more powder today for 2950 because its a new barrel. I bet it speeds up after another 100 rounds....

[macguru]

Screen Shot 2017-05-06 at 11.53.39 pm.png

Another tuning question .... What primers are people using BR2s , federal match ?? ..... I am using BR2s.

I get the odd high 6 - low 6 with the rest x ring elevation. This generates the odd 5 when mis-handled . Can it be the primer flash ? And some BR2s are 5.1, most 5.2 and some 5.3gr ... Is it the amount of chemical in the cup ? If so the shape of the energy curve would be a little different.....

I mean the other barrel is a 6 and it behaves alot better. (BR4s in that case...). I said i would never batch primers but .... I am definitely going to try some federals and see if i get the same group shape. see above. I am using 54.3 gr 2209, i think low 2900s. 8 twist pacnor super match.

[shooter mcreid]

Did some load testing on one of the 30" 9.5s this morning and found a good spot to be at 55.3gr, 180 vlds jumped 30 thou. Lab radar gave the average velocity of 2930fps.

[Singo85]

I did some testing yesterday.
Load and avg velocity below 180hyb touching lands with 2209 powder br2 primers
55.5 2890
55.8 2910
56.1 2925 bolt lift becoming firmer
56.4 2930 hard bolt lift
56.7 2955 hard bolt lift

[DenisA]

Tighter twists should produce slightly less velocity.

[Brad Y]

How many firings per case are you getting from that 56 odd grains of 2209 at 2920?

[ajvanwyk]

How many firings per case are you getting from that 56 odd grains of 2209 at 2920?

Brad, I've been running 55.8 (so pretty close to your question) and after about 5-6 firings per case, still do not have any primer pocket issues. That said, 55.8gn of 2209 was only about 2880 ftp in my barrel. Hope this helps.

Albert