Reloading q

[wooltie]

Any reasons why a load that grouped well one day, refuses to group next time at the range?

I started reloading 30-06 recently--I'm new to reloading.  I found a load that grouped will using the round robin approach to identify a stable charge, meaning--all three rounds were touching.  So I loaded another 12 rounds at this charge/seating depth.  Returned to the range today to adjust/chrono and get my drops--but this load would not group.

Shots were 1" left, 1" high, 1" right.  Some shots were touching.

Only difference between when the load grouped well and today was the temperature outside was about 20 degrees cooler.  I've followed the same cleaning routine after each range session. 

Also, I have a ctrl group of ammo that groups consistently, so I always verify my poi and shoot two fouler shots before shooting my handloads.

Any help is appreciated.  Thanks.

55.9g IMR4350, 165g SST, seated .010" off the lands grouped the best during the round robin approach, though I think I will try 57g next.

[h20hunter]

Check the gun? Nothing loose?

[wooltie]

Check the gun? Nothing loose?

Oh yea -- I go through a checklist of items to ensure consistency.  Same bench, same target height, same stool, same positions on the front and rear rests, action screws tight, barrel floated.

I always shoot two foulers with factory ammo that I know shoots well, and also shoot 1 shot of this ammo at the end just to ensure that the rifle and setup are still under control.

[Bill W]

some days I shot good and some days I didn't.  Could be the shooter.

[Hilltop123]

Check the gun? Nothing loose?

Oh yea -- I go through a checklist of items to ensure consistency.  Same bench, same target height, same stool, same positions on the front and rear rests, action screws tight, barrel floated.

I always shoot two foulers with factory ammo that I know shoots well, and also shoot 1 shot of this ammo at the end just to ensure that the rifle and setup are still under control.

Nice you have a checklist, but you mentioned everything but, scope bases and rings. When I have a drastic or erratic change with bullet impact, the culprit is usually found with those two pieces of equipment. JMTCW

[lokidog]

I use about the same load, but use 56.5 grains of 4350.  This has been absolutely fantastic behind every 165 - 168 grain bullet I have tried and in three different rifles.

If I recall, I am slightly compressed so have not tried the longer Cu bullets.

[hunterofelk]

The companies like Speer that put out loading data use a larger sample set and than an average is calculated.  They also try to remove all variables like having the firearm in a vise and indoor range.  Consistent is the key.  I have tried weighing the bullets and cases.  Kept the five closest weights together and mark the cases and shoot them in a group.  Also used a neck sizer die.  I think it helps a little.

[Curly]

Check that you have the same COAL as you had the first time when the groups were good.  Maybe the die got inadvertently adjusted and now your OAL has changed.   

[jmscon]

Any wind could change the grouping as well

[wooltie]

The round robin approach yielded this grouping (white target), but yesterday's shots were all over the place (black target).  The 7 shots around the bulleye were my handloads.

[hogslayer]

How many rounds down the tube?  I have had this happen before.  Ended up the barrel broke in at about 120 rounds. Loads speed up about 75 fps and groups were not good.  I would also check to make sure all that cleaning didn't mess up your crown depending on cleaning methods.  And see if your bullets are still .010 off the lands. If you checked this measurement on a dirty barrel.  It could of given a false reading.  When I load things close to the lands they can get off the sweet spot very easily. The second node back is usually more forgiving.

[wooltie]

How many rounds down the tube?  I have had this happen before.  Ended up the barrel broke in at about 120 rounds. Loads speed up about 75 fps and groups were not good.  I would also check to make sure all that cleaning didn't mess up your crown depending on cleaning methods.  And see if your bullets are still .010 off the lands. If you checked this measurement on a dirty barrel.  It could of given a false reading.  When I load things close to the lands they can get off the sweet spot very easily. The second node back is usually more forgiving.

thanks.  I'm going to move to .020".  Bore is clean but may not be all the way broken in.  I estimate about 100-120 rounds shot through it.

[Wazukie]

Weather conditions? 

[wooltie]

Weather conditions?

No wind, but the temps were about 45-50f.  I think the temps were around 60-65f when I shot that good group, and no wind.

[Blacklab]

How your brass? times reloaded, trimmed, shoulder bump and COAL.