7 Saum Load Development

[Utpikahtr]

I working through load development with a new 7 Saum proof 20” 1-8 twist. I’m struggling to find a combo that hold 3 shot groups under 1moa. Best combo so far is 175 eldx with 57.5 grs of 4831sc .020 off the lands 2700 muzzle fps. Wondering if anyone else has had trouble dialing in their 20” proofs and what the solutions were? Thanks
Lone peak Fusion TI
Hawkins rings
Leupold Mark 5
Proof Carbon 20” 1-8

 

[ManBun]

is your chamber sammi?

 

[Mag_7s]

Have you tried H1000? Mine (26" proof) appears to like H-1000, with sub 20 es, ~2970 fps.
CCI 250
ADG brass
175 berger eol.

 

[Utpikahtr]

Have you tried H1000? Mine (26" proof) appears to like H-1000, with sub 20 es, ~2970 fps.
CCI 250
ADG brass
175 berger eol.

Yes sir, I started out with H1000 it has been my go to powder for me with my 300 ultra, 300 prc and 7mag. All of which have 23” - 26” barrels. I had high hopes for H1000 in the Saum but the burn rate is just a tad to slow in the 20” proof. That said I think the 4831sc is just a tad to quick I’d like to try n565. Also, I feel like I’m hitting pressure way sooner than what I see a lot of others are seeing on here.
What seating depth did you find the best node with?

 

[Mag_7s]

This thread might help you in finding a powder your barrel might like. https://rokslide.com/forums/threads/7-saum-powder-selection.286468/

I'm sitting at 20k off the lands. I follow the Erik Cortina method of load dev.

 

[codym]

Is that the only bullet you have tried? I’ve had luck with the 180 elm and the 180 hybrids h1000 and n565 are my go to powders rl23 is probably really good too

 

[Brucebarker024]

My 24inch proof likes the 180 hybrid targets and 162 eldm with both 4831sc and h1000.

 

[Utpikahtr]

Is that the only bullet you have tried? I’ve had luck with the 180 elm and the 180 hybrids h1000 and n565 are my go to powders rl23 is probably really good too

I’ve also been trying the 180 eldm with very similar results. I do have some vld 168’s I’m tempted to try. Thanks for the info.

 

[Utpikahtr]

My 24inch proof likes the 180 hybrid targets and 162 eldm with both 4831sc and h1000.

Thanks for the info sir.

 

[codym]

One thing to be sure of is if your barrel is actually an 8 twist.. wouldn’t be the first time I’ve seen a barrel marked something it wasn’t

 

[lineslayer]

I had a hard time with pressure even with the book loads for my 18in Tikka. Ended up with the best velocity with H1000 at 2760fps. 62.6gr, 3.02 COAL, 40thou off jamb, 168 ABLR, ADG brass. Groups are 1/2 MOA

 

[Hunter14]

My 24” proof carbon likes the Barnes 145LRX and H 4831sc. Getting 3100fps out of it.

 

[sdupontjr]

If you have H4831sc, try the 160 accubonds.
60g 4831sc, CCI-200, Norma brass, 2.866" COAL or 2.291" CBTO, gives .007" off lands of a custom Mack Brothers setup. 2860 on the velo that shoots 5 shot groups under .75 moa. Got better velo with RL26 and more 4831sc, but this 20" barrel seems to like the velocity node at or around 2857 - 2880. Anything pass that, things start to really open up.