6.5 SAUM 150gr SMK (update) 3175fps

[whiskeysierra762]

I thought I would share my load development so far for my 6.5 SAUM with the 150 SMK.
The rifle has a 26" Proof Research with 1-7.5" twist that was throated for the 150 SMK.
Norma 7mm SAUM brass necked down to 6.5, Neck turned to 0.015", trimmed to 2.030"
Fed 210M primers, H1000 powder.
150gr SMK seated to 2.355" off the Ogive.
My final ladder test showed a node at 64.8gr to 65.2gr.
65.2gr was a little warm, light ejector swipe on the brass and light bolt thrust and Im going to consider this my max charge.
There was another node at 62.4gr to 63.0gr, which showed no high pressure at all that I might play with if 65grs is too hard on brass.
I will post further load development later.

 

[Gilly]

Wow those are some hot loads! I’m running just under 61 with a nearly identical setup rifle and components to you and over 3000 fps. What is your velocity at 65???

My old saum was maxed out about 60.5 best accuracy was 59.2

 

[whiskeysierra762]

I don't know the velocity. I don't bother with a chronograph.
I ladder test, do my load development, then I will reverse calculate my muzzle velocity when I true my drop with my Kestrel.
I will post my estimated MV later when I settle on a load.

 

[Seandradamus]

I’ve never heard of anyone shooting 65 grains of h1000 in a Saum for any bullet let alone the 150s
In mine that would be over 3300 FPS
I shoot 57.5 g of h1000 or rl26 for velocity around 3065 in a 26” 7.8 twist .... must be an incredibly slow lot

 

[whiskeysierra762]

I was surprised as well. I ended up shooting 3 ladder tests looking for high pressure because I started below what everyone else is loading the 140's at.
This is the same lot of H1000 I have been loading in my other rifles with expected velocity.
Hopefully Friday I can get some group tests done, and might be able to zero with some sighters loaded at 65.0 and shoot them to 600 for a rough drop truing for a MV.

 

[whiskeysierra762]

Update:
Today I went out and zeroed with the 65.0gr H1000 load, then shot out to 580yds on a steel gong, then used the truing function in my Kestrel for an approximate muzzle velocity of 3175fps.
The speed is impressive but the grouping was not. I will be playing with the node below this later, which was 62.8gr-63.2gr.

 

[gamewarden]

Any further updates...? Thanks.

 

[elmerdeer]

tag

 

[whiskeysierra762]

Im planning on doing a seating depth test on Sunday. I loaded up test loads of 62.5gr of H1000 and 3rds of different depths.
I will test jammed 0.010", touching 0.000", (all load testing so far has been with a 0.010" jump), 0.020" jump, 0.040" jump, 0.060" jump, and 0.080" jump.

 

[whiskeysierra762]

Got to shoot the seating depth test today.
Best so far is jammed into the lands 0.010" and jumping to the lands 0.080". However, I loaded 3 round test groups, both of those put 2rounds on top of each other and then threw the third round.
I was reading a thread over on 6mmbr and a guy shooting a 6.5WSSM was jumping 0.120" with the 150smk's. So, I might try a deeper depth still and see what happens.
But, I need to order more bullets so I won't be testing anymore for a few weeks.

 

[Bradu]

I’ve never heard of anyone shooting 65 grains of h1000 in a Saum for any bullet let alone the 150s
In mine that would be over 3300 FPS
I shoot 57.5 g of h1000 or rl26 for velocity around 3065 in a 26” 7.8 twist .... must be an incredibly slow lot

I was thinking the same thing.

 

[whiskeysierra762]

New update. Seating depth with a 0.100" jump has shown best accuracy so far in my seating depth testing.
62.5gr of H100 with the 0.100" jump is right at a 0.35" group. I might try a little more jump and then a new ladder test with the new seating depth.

 

[gamewarden]

Keep the info coming. Thanks

 

[whiskeysierra762]

I did my final seating depth test this morning.
0.110" jump produced a 0.183" three round group at 100yds.
Next is a new powder charge ladder test from 61.0-63.0gr of H100 to narrow down the barrel node.

 

[whiskeysierra762]

Today I shot a 300yd ladder test with the 0.110" jump seating depth.
There was a clear node at 62.2gr to 62.8gr, placing 3 rounds on the exact same line. The next round at 63.1 was within 0.5" of the other 3, but I think I will be playing with the lower powder charges to save my brass some.
I now have all my brass fire formed. Im waiting on my annealing machine and my Fx-120i with powder trickle before I do any further testing.

 

[Seymour Fish]

Today I shot a 300yd ladder test with the 0.110" jump seating depth.
There was a clear node at 62.2gr to 62.8gr, placing 3 rounds on the exact same line. The next round at 63.1 was within 0.5" of the other 3, but I think I will be playing with the lower powder charges to save my brass some.
I now have all my brass fire formed. Im waiting on my annealing machine and my Fx-120i with powder trickle before I do any further testing.

That FX-120 is a jewel

 

[steve123]

Today I shot a 300yd ladder test with the 0.110" jump seating depth.
There was a clear node at 62.2gr to 62.8gr, placing 3 rounds on the exact same line. The next round at 63.1 was within 0.5" of the other 3, but I think I will be playing with the lower powder charges to save my brass some.
I now have all my brass fire formed. Im waiting on my annealing machine and my Fx-120i with powder trickle before I do any further testing.

Did you have any mid air blow ups yet, also did the brass start failing with the higher charges?

 

[whiskeysierra762]

No disintegrating bullets. And the brass is only on its second loading, but primer pockets are still tight.

 

[30cal user]

I thought I would share my load development so far for my 6.5 SAUM with the 150 SMK.
The rifle has a 26" Proof Research with 1-7.5" twist that was throated for the 150 SMK.
Norma 7mm SAUM brass necked down to 6.5, Neck turned to 0.015", trimmed to 2.030"
Fed 210M primers, H1000 powder.
150gr SMK seated to 2.355" off the Ogive.
My final ladder test showed a node at 64.8gr to 65.2gr.
65.2gr was a little warm, light ejector swipe on the brass and light bolt thrust and Im going to consider this my max charge.
There was another node at 62.4gr to 63.0gr, which showed no high pressure at all that I might play with if 65grs is too hard on brass.
I will post further load development later.

Which reamer/freebore on this bbl? the fb must way out there to allow 65gr h1000...

 

[whiskeysierra762]

This rifle was cut with a standard 6.5saum reamer, but throated with a uni-throater for a base to ogive/lands length of 2.320".
And now that I found out these 150's like to jump so much Im thinking about having the throat cut another 0.100" longer so that I can stretch them back out to my original seating depth and up the powder charge again.

 

[Rootshot]

Interesting thread. Given the cost / prep time of SAUM brass, I invested in a primer pocket go/no-go gauge from Ballistic Tools. This way I can work up loads at the bench, use a decapping rod to pop the primer and check the pocket for different loads. If the pocket shows enlargement, I stop firing and dump powder of loaded rounds.

 

[30cal user]

Bertram says brass will in stock mid December