07-04-2017, 04:17 PM (This post was last modified: 07-04-2017, 04:39 PM by DJudge.)
The other day at the range I shot the 2 groups in the picture below and have never seen this much variation between 2 types of ammo especially the same brand and same weight bullets. Both are Hornady 6.5 Grendel 123gr Factory Loads AMAX and SST shot at 100 yards. Thinking that it might have been me I reshot several time with similar results. Really would like input on possible cause as this has me scratching my head...
Hornady 123gr AMAXs (<1"group) on the left and Hornady 123gr SSTs (>2 1/2"group) on the right
Likewise in my 16" Grendel. Eld-m shoots anywhere from .5-.75, SST thus far with limited development are anywhere from 1 moa to 1.5. Haven't given up on them yet though!
Kilco Wrote:Likewise in my 16" Grendel. Eld-m shoots anywhere from .5-.75, SST thus far with limited development are anywhere from 1 moa to 1.5. Haven't given up on them yet though!
In general I wouldn't expect the SST(hunting bullet) to shoot as well as the amax(target bullet)
Rifles are funny things. I've seen similar results as you got from some, and have others that shoot about everything between .75 and 1.25 ish. No idea why.
I could throw out cold bore vs hot bore possibly but total of ten rounds isn't much.
I can say that my rifles shoot amax around .80" and ssts around 1.25" both consitantly at that those numbers as long as my barrels are warm.
In all the years of shooting both factory loads across several different lots, I have not been able to see a difference in how they group for me over many different barrels.
Doesn't matter if it's a lightweight 18" or 16" barrel, or 24" bull barrel. They have both always shot really well for me.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
LRRPF52 Wrote:In all the years of shooting both factory loads across several different lots, I have not been able to see a difference in how they group for me over many different barrels.
Doesn't matter if it's a lightweight 18" or 16" barrel, or 24" bull barrel. They have both always shot really well for me.
What he said.
Never walk away from home ahead of your axe and sword. You can't feel a battle in your bones or foresee a fight. -The Havamal
LRRPF52 Wrote:In all the years of shooting both factory loads across several different lots, I have not been able to see a difference in how they group for me over many different barrels.
Doesn't matter if it's a lightweight 18" or 16" barrel, or 24" bull barrel. They have both always shot really well for me.
Regarding handloads, do you find that load data is interchangeable between these two bullets? Or typicaly do they require a separate work up?
Kilco Wrote:Regarding handloads, do you find that load data is interchangeable between these two bullets? Or typicaly do they require a separate work up?
In all of the chambers I have tried them both in (mostly SAAMI), as well as poring over hundreds of different loads using other 120-123gr cup and core bullets, I have interchanged the data after seeing how both clock over a chronograph or magnetospeed.
Same with the 120gr Nosler Ballistic Tip, 120gr Scenar, etc.
Where things will really change on you is when you switch to a monolithic solid bullet. They build pressure much faster, and resist being driven into the lands more, while taking more case capacity for the same bullet weight due to their lengths.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
DJudge Wrote:The other day at the range I shot the 2 groups in the picture below and have never seen this much variation between 2 types of ammo especially the same brand and same weight bullets. Both are Hornady 6.5 Grendel 123gr Factory Loads AMAX and SST shot at 100 yards. Thinking that it might have been me I reshot several time with similar results. Really would like input on possible cause as this has me scratching my head...
Hornady 123gr AMAXs (<1"group) on the left and Hornady 123gr SSTs (>2 1/2"group) on the right
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Also forgot to mention that the SSTs are .010" longer than Amaxs and that the ogive on the SST appears to be about that same distance farther forward than the Amax. For that reason you could adjust seating depth 0.010" and note results. Was going to try myself once but it just wasnt high priority since my groups were still "acceptable" with the SSTs
