123 SST verses the ELDM

[spladi]

I think I panic bought some 123 SST's so that come shooting season I wouldn't be high and dry. My old brass is about done and is showing small pin holes/splits near the Nk./ shoulder junction, time to FF some new stuff, right.
Loaded up 15 or so SST's and 5 123 x .264 ELDM's (same powder charge and primer) and put a target up at 330 yds. I expected the SST's to perform about the same as the ELDM's but the target proved my thinking quite wrong. At least in my factory target rifle they were moved a lot by the wind and wouldn't group, just left to right and up and down, basically not responding to any adjustments I made in hold etc. Now the five ELDM's were another story......they grouped and one shot responded to a let up just like it should. Bottom line in my gun the SST's are not for match shooting or can you recommend an upper or lower powder charge or a change in seating to make the SST shoot better ?....Thanks

 

[Roughrice]

I think I panic bought some 123 SST's so that come shooting season I wouldn't be high and dry. My old brass is about done and is showing small pin holes/splits near the Nk./ shoulder junction, time to FF some new stuff, right.
Loaded up 15 or so SST's and 5 123 x .264 ELDM's (same powder charge and primer) and put a target up at 330 yds. I expected the SST's to perform about the same as the ELDM's but the target proved my thinking quite wrong. At least in my factory target rifle they were moved a lot by the wind and wouldn't group, just left to right and up and down, basically not responding to any adjustments I made in hold etc. Now the five ELDM's were another story......they grouped and one shot responded to a let up just like it should. Bottom line in my gun the SST's are not for match shooting or can you recommend an upper or lower powder charge or a change in seating to make the SST shoot better ?....Thanks

FWIW- I've never shot 123's but shot other SST's in 6.5, 7mm and 30 cal.
I've always had luck @ .020-.030 OFF and usually easy to tune and shot very well.
Only use the remaining stock on paper now after the explosive effect on a few whitetail.

 

[Roughrice]

Also.. if you are loading both to same COAL... you will have lots of difference in base to ogive measurement because the ELD have longer distance from tip to ogive which could be as much as .030 difference from the lands if ELD and SST are loaded to the same COAL.
My 7mm 162's touch at .031 difference in length when measuring B to O with comparator.
You could be jumping ELD and jamming SST @ same COAL

 

[spladi]

Also.. if you are loading both to same COAL... you will have lots of difference in base to ogive measurement because the ELD have longer distance from tip to ogive which could be as much as .030 difference from the lands if ELD and SST are loaded to the same COAL.
My 7mm 162's touch at .031 difference in length when measuring B to O with comparator.
You could be jumping ELD and jamming SST @ same COAL

I'm loading both to .010" from the lands......which is my starting and most often my ending setting for many bullets.

 

[Roughrice]

Ok. I understand.
Have you tried farther off?
All my rifles do better with hunting bullets off at least .020.
Some Nosler bullets .050 or more.
Just a thought...

 

[Agent82]

I just loaded some 123 SST for my son. We have the bullet on the Lands. Obviously, ever rifle is different but this is our load:

Sig Brass
123 SST
Hodgon 4350 with 43grains. It shot well with 41 grains as well but it did not give us the velocity we were looking for.
Federal 210M
2715 FPS

Rifle:
Mossberg Bantam 6.5 Creedmoor with 20" barrel.

Have you tried different charges going up with .5 grain increments? Maybe try the same seating depth but different powder charges.

 

[spladi]

I just loaded some 123 SST for my son. We have the bullet on the Lands. Obviously, ever rifle is different but this is our load:

Sig Brass
123 SST
Hodgon 4350 with 43grains. It shot well with 41 grains as well but it did not give us the velocity we were looking for.
Federal 210M
2715 FPS

Rifle:
Mossberg Bantam 6.5 Creedmoor with 20" barrel.

Have you tried different charges going up with .5 grain increments? Maybe try the same seating depth but different powder charges.

View attachment 366928

I'm at 39.5 grns. of Varget = 2750 FPS. with a 26" brl. My go to load uses 40.3 grns. of Varget with the Lapua 123 Scenar and a WW primer, I will give 4350 a try, although I save my 4350 for the 147's and my Feds. usually. Nice target!