What is causing my groups to do this?

[Smoak352]

3 shot group has first two shots in one hole, third shot opens group up to .75"

I went to the range yesterday and shot 5 different loads, all producing .75" groups at 100 yards. I noticed the first two shots would be touching or very close and the third shot would open the group to .75". The rifle is a 25-06 hunting rifle in a non-magnum contour, free floated barrel, 1.25lb trigger.

Any ideas?

 

[brentc]

I've see this many times. Your load isn't far off. There are a couple things you can do. First is powder charge. Of all your different loads, pick either the one with the best extreme spread, or if you don't have a chrono, pick the tightest grouping load. From that load, try shaping your group a little by bumping your load up and down .4 grains in .2 grain increments. When you're comfortable with a powder charge, work your seating depth with small increment changes. Most of the time I can get rid of it with seating depth changes in .005 increments in and out around where you're currently at. Do only one thing at a time. Get your powder charge first, then work out you're seating depth. Make sure you let your barrel cool between shots to ensure barrel heat is not affecting your group.

Edit* There is a third thing you can try to that I thought of after I posted this. Changing your primer may be enough to pull that third shot in as well. I've seen primer changes shrink loads quite a bit. Try this with your chosen powder charge prior to seating depth adjustments.

 

[Smoak352]

OK, all 5 of my loads were the same powder and charge. I guess I can try that. I appreciate the advice!

 

[gohring3006]

I've see this many times. Your load isn't far off. There are a couple things you can do. First is powder charge. Of all your different loads, pick either the one with the best extreme spread, or if you don't have a chrono, pick the tightest grouping load. From that load, try shaping your group a little by bumping your load up and down .4 grains in .2 grain increments. When you're comfortable with a powder charge, work your seating depth with small increment changes. Most of the time I can get rid of it with seating depth changes in .005 increments in and out around where you're currently at. Do only one thing at a time. Get your powder charge first, then work out you're seating depth. Make sure you let your barrel cool between shots to ensure barrel heat is not affecting your group.

Edit* There is a third thing you can try to that I thought of after I posted this. Changing your primer may be enough to pull that third shot in as well. I've seen primer changes shrink loads quite a bit. Try this with your chosen powder charge prior to seating depth adjustments.

+1
especially the primer change up..

 

[oldfamily]

Try waiting more between shots?

 

[Smoak352]

Try waiting more between shots?

I think this may be a possible issue as well because I would shoot 3 consecutive shots and then wait, but after the 3rd shot, the barrel was pretty warm. The barrel contour is just a non-magnum contour, although fluted, is not thick at all.

I just made some loads going up .2 & .4 grains and down .2 & .4 grains. I will also wait a few minutes between each shot.

Thanks guys.

 

[meatyrem]

Usually when I go I'll take several at a time. Therefore by the time I am done with the others, I will get the first one out and it will be cool to the touch allowing several minutes between shots. I especially do this with big magnums

 

[LoneTraveler]

If your first 2 bullets holes touch and then the 3 rd. bullet opens the group. Where does the third shot go? Does it hit in the same place every group? Do you clean the barrel between groups. I have dealt with guns that will shoot a couple shots in near one hole group then go wondering with the 3 rd 4th and 5th shots leaving the group, Stop and clean the barrel and it will go back in the group after the first fowling shot. I have fire lapped and pour lapped barrels to get them to hold group. A place catching fowling can make a gun shoot this way. Good Luck.

 

[LONGSHOOTER]

I think this may be a possible issue as well because I would shoot 3 consecutive shots and then wait, but after the 3rd shot, the barrel was pretty warm. The barrel contour is just a non-magnum contour, although fluted, is not thick at all.

I just made some loads going up .2 & .4 grains and down .2 & .4 grains. I will also wait a few minutes between each shot.

Thanks guys.

Might be the barrel is warping as it heats up.

 

[Smoak352]

If your first 2 bullets holes touch and then the 3 rd. bullet opens the group. Where does the third shot go? Does it hit in the same place every group? Do you clean the barrel between groups. I have dealt with guns that will shoot a couple shots in near one hole group then go wondering with the 3 rd 4th and 5th shots leaving the group, Stop and clean the barrel and it will go back in the group after the first fowling shot. I have fire lapped and pour lapped barrels to get them to hold group. A place catching fowling can make a gun shoot this way. Good Luck.

It seems the first 2 shots are touching and the 3rd shot is randomly .75" away. I measured all 5 groups with calipers.

 

[meatyrem]

Do you load one at a time or load the magazine full then shoot?
Do you crimp or not?
It is possible under recoil, if the magazine has rounds in it the seating depth could change if there is no crimp. Just a slight possibility. May be primer is close to being not enough or too much. Try switching primers.
What is you set up? Round? Powder? Primers?

 

[LoneTraveler]

Thanks for the answers, With the 3rd shot jumping around, Clean barrel and then coming back to the first 2 shots touching, Then shot 3 going astray. Is there any jacket material showing up when barrel is cleaned? May be a small place in the barrel catching jacket metal and making the 3rd go astray. I have cured guns throwing the 3rd or 4th fourth bullet by fire lapping the barrel. Which just slick up any small flaws in the barrel. Good Luck in finding a cure.

 

[jsthntn247]

What kind of barrel. A good cut riled barrel on a true action can get firecracker hot and point of impact won't shift.

 

[elkaholic]

If you can't make it shoot with the above suggestions, your barrel may be a good candidate for cryo! It is my understanding that barrels that need stress relieving will often perform as you described...........Rich