Low es/sd load that won’t shoot?

[SageRatShooter]

First off congratulations on getting the low es/sd most of the time I struggle getting anything close to what you've accomplished. I think your results indicate you have a proven load in that your component choices are working well together and your reloading technique, shoulder bump, neck tension, etc. is all good. You've got the bullet exiting the barrel at very similar velocities every time, well done. Now you have to dial in the separation of the bullet and barrel at the same harmonic timing, especially true if your groups have a lot of vertical. Most of us go back and repeat ladders looking for a different node with acceptable velocities or try different powders.

 

[26Reload]

I was shooting a week or two ago with same load i had really good numbers on just a few days before...
Over a chrony......i had such variations shot to shot....firet i had seen of that...bewildered me.....thought maybe the chrony died....but was out doing a tall test and shot through the chrony....very tight numbers til the chrony starting tipping....
Got to watch every aspect of every test to come up with correct data......

 

[JustMe2]

Jake, what Canhunter and Sage are trying to explain is ES and barrel harmonics are 2 entirely different things to tune. ES/SD only tells you how consistent your bullet velocity is. ES/SD does NOT tell you when the bullet is optimally timed with your barrel whipping up and down which will spread out your groups. Your bullet with the lowest ES/SD may be exiting your barrel during the fastest pendulum movement (whip) of your barrel which is bad. You want the bullet to exit when the barrel is stopped at the end of its highest pendulum movement, when the barrel is stopped and starting to move in the opposite direction like the pendulum on a clock stopping momentarily to change direction. Hopefully, that explains why ES/SD is not always the most accurate load. The bullet has to also be timed with your barrel whip by tuning velocity (changing powder charges) and may not necessarily be the lowest ES/SD.

 

[DJ Fergus]

I actually do not recall, but it would have had to be in the high 30's.
At the time I just thought it was a misnomer with the chrony, but several tests with the same load proved it to have a ES of 100fps.
I still remember the load, RE22 @ 56gr with 100gr BT's @ 3356fps average over 10 shots, my notes haven't got the SD in them, just the ES.

Cheers.

I load for a buddy who has a 25-06. It likes 85gr ballistic tips @ 3350 with 43.5 gr RL17. I can't exa remember ES but it was low teens. But even if it was in the 20s it wouldn't have made much difference on a 600 yard target at those velocities.

 

[LongBomber]

How many shots was that es/sd for? From what I have seen it is hard to get a es that is stellar from a load that is out of tune. If it is only 3 to 5 shots sometimes you just get lucky on the numbers, just like printing a group in the .1's when the rifle is truely a .5" gun.

 

[Plinker147]

ES and SD only tell you that your load is consistent and your not going to have vertical stringing at distance. So if you have a good shooting load at 100yds with low ES and SD that tell you the load will work at distance. But to get the good load you need to establish your seating depth, then node, then accurate group. If your using a consistent powder and good reloading techniques( neck tension) your ES should be there with minor tweaking

 

[redneckdan]

I have had a few loads with good statistics but poor grouping. Like others have said, seems to be due to barrel harmonics not matching bullet exit timing. Two recent examples are 6.5 staball with 115 dtacs and a standard federal primer in 6creed. 100yds group showed random impacts and couldn't get it below about an inch and a half. Started again with ramshot hunter, dtacs and wincheter magnums. Found a good load at about the same velocity in the high node that is grouping under 3/4" with SD of 6 for 10rds.

 

[RD57]

Had a few that didn't print well but had excellent numbers on the chrono. I had to tweak the bullet seating depth by .050 to get it to group great, but it only changed the ES/SD by 9/4 fps respectively. Another rifle didn't like the bullet as much as I wanted to and nothing I did changed group size much, good thing I had another rifle that liked those bullets!

 

[rsmithsr]

very simply
you have put the cart before the horse.
get a good load,
THEN LOOK AT ES/SD
....not before

 

[Blackhawk]

anybody ever have a load with amazing ES/SD but just can't get it to shoot? I've got a load that's getting an ES of 5 and SD of 2 but can't get a group under 1.5 MOA. I've got other loads around .5 now but really wanted to get this working. I've tried seating depths twice and no fix yet? This is a 6.5 creedmoor with Peterson brass cci 450s and rl26.

Your ES & SD numbers are amazing. ( Are you Shure that these posted figures are correct ?)
Perhaps you may want to look at the following nine items.

1) Bullet jump dimension. ( work in. 002 increments) (I know that this is time consuming ) '
2) Bullet TIR or runout. (strive for .001" or under)
3) Turning of case necks..
4 Annealing of case necks.
5) bullet neck tension itself.
6) Finally Change of brass , as well as change in brand of primers..
7 ) Perhaps invest in a quality set of dies depending on the brand you are currently using.
8) Examine your press itself for any undue wiggle room in the ram.
9) Check the wear on the shell plate / holder and replace if needed.

The above areas perhaps you may want to examine !
Hope this may point you in the right direction!

 

[Kerryt38]

Have you checked your bases and rings to make sure that they are still tight?

 

[Lenwood901]

Just had this same problem ended up being my front action screw was loose

 

[DJ Fergus]

Your ES & SD numbers are great
Perhaps you may want to look at the following nine items.

1) Bullet jump dimension. ( work in. 002 increments) ( i know that this is time consuming) '
2) Bullet TIR or runout. (strive for .001" or under)
3) Turning of case necks..
4 Annealing of case necks.
5) bullet neck tension itself.
6) Finally Change of brass , as well as change in brand of primers..
7 ) Perhaps invest in a quality set of dies depending on the brand you are currently using.
8) Examine your press itself for any undue wiggle room in the ram.
9) Check the wear on the shell plate / holder and replace if needed.

The above areas perhaps you may want to examine !
Hope this may point you in the right direction!

I have saw .003 in seating depth make a significant difference in group size, even with jump tolerant hybrid ogive bullets.

 

[MLN1963]

I have had the same, numbers should never be the deciding factor. I once had a 6 creed load that produced ES of 1 for 10 shots, it shot all of 12" at 500 yards.

That sounds like the perfect excuse to buy a barrel tuner and see if you can tighten up that group. I've never heard of an ES of 1 for 10 shots. You have your brass prep and reloading figured out!