Same load - 2 diff POI

[murphdog]

What makes a gun to this?  Same load shoots to 2 different points of impact (see pic below).  This was a 9-shot string.  3-4 shots landed in the upper "group", and 5-6 landed in the lower "group".  It varied (2 below, 1 up, 1 below, 2 up, etc).  Gun is H&R 223 ultra with factory fitted barrel.  Ammo is hand-loaded 40gr VMAX, but same thing occured with 55gr factory ammo.  Shooting from solid bench with front and rear bags.  What would be the first thing to evaluate?  Forend fit (o-ring did not help)?  Scope mount (seems solid)?  Bad scope (Banner 4-12x40 AO)?  Inconsistent cheek weld (I really tried to control this)?  Something else I'm not thinking of?  Would really appreciate it if someone could save me some time by pointing me in the right direction. 

[jabey9210]

I have a 243 that  had similar issues and it turned out to be the fore end I tried putting a washer in it and it also did nothing I did a full length bedding on it lightened up the trigger and it now shoots under 1 inch at 100yrds.  It seems to me that your forestock may be putting pressure and messing with the harmonics I know that was the issue with mine.

[Dinny]

I would also consider doing more with the forend. Sometimes when the barrel warms, it expands and touches a part of the forend and that affects POI. Another thought that comes to mind is the scope mountings. Be sure to check the base and rings. Sometimes bedding the scope rail to the receiver and lapping the rings will help.

As an afterthought....I had a similar problem recently and I corrected the problem by stoning the latch shelf allowing for better engagement. Keeping the latch shelf clean and dry helped too.

When all else fails, swap the scope to see if the problem persists.

Good luck and let us know what works best for your rifle.

Thanks, Dinny

[mechanic]

Start with the simple stuff.  Remove the fore end and bag under the receiver.  Snap the barrel shut with authority every time.  Make sure the latch is dry, no oil or lube. 

From there check the list in the FAQ's.  The gun is obviously capable of good accuracy as it has some tight groups with the stringing.

Ben

[jabey9210]

Another thing that comes to mind that I learned the hard way is check and make sure the scope rail screws are tight cause most all of my handi's  have not been very tight when I got them.  And I also take the scope rail off make sure none of the threads from when the factory drilled and  tapped them are sticking up and locktite the screws back in. 

[Jimbo47]

Personally I would have to rule out anything wrong with the scope because the groups are tight.

You said they alternated so I'm thinking your hold and rest may have been different on your shots.

On a bolt gun or semi it's easy to hold the same way every shot, but with the Handi you have to break the barrel to unload and reload so your hold can be different unless you are totally aware of it.

Try to shoot it again and this time make sure you repeat your same hold every shot.

[necchi]

I've seen that with my 223, it was simple barrel heating.
I can get 3 shots then the 4th goes high, let'er cool a bit and it will repeat the same string

[murphdog]

Thanks for sharing your thoughts on this.  Something in this gun (or in this shooter ) is clearly shifting back and forth between two consistent but different positions.  While this shooter is certainly capable of inconsistency, my inconsistencies tend to be more random.  Too much coffee, and I've got a nice round group thats just wider than usual, not two different tight groups.  I doubt that its barrel heat, as it did not climb up to the higher group, it bounced back and forth between the groups.  I actually shot this in three 3-shot strings, with a cool-off time of ~5 min between strings.  In each string, some went to the low group and some went high.  I was worrying about rest/hold inconsistency, and I was deliberately placing the front bag just in front of the hinge pin.  I don't know if the rear bag was placed as consistently, but I tried to make sure every shot "felt" the same.  I'll recheck the latch shelf also.  I'm usually anal about swabbing the latch shelf with a Q-tip, but I may not have done so before this target.  My first inclination is a forend problem, and if weather is good tomorrow I'll try shooting with forend off.  If removing the forend doesn't help, I'll pull the scope and check the rail screws.  I've got a 44 mag barrel for this frame that is always loosening its rail screws, but when that happens, I can usually grab the scope in one hand and the barrel in tthe other and detect a little wiggle.  So far, I haven't detected that with this scope and barrel.  I shouldn't need to lap the rings, as these are burris Zee rings with the plastic inserts.  If I get a chance to shoot tomorrow I'll let you know how it goes.  I really appreciate all your ideas.  Please feel free to share any other thoughts you might have.  I'm always amazed at the wealth of knowledge on this site. 

[gcrank1]

Retorque the buttstock.
When you get behind it on the bench make sure you put you chest to to bench the same, that your elbows hit the same spots and that the butt pad is on the exact same place on you shoulder.

[murphdog]

Thanks, everyone, for your thoughts on this.  Seems like the majority opinions were forend problems or bench technique.  Sunday was a little windy, but I went on out and shot it with the forend off, and paying closer attention to consistent technique.  (Oh yeah, gcrank, I did recheck stock bolt also. It was tight, but that was a good thought.  I've had it loosen on me before, and should have thought of that myself.)

It seemed to make a difference.  All shots except one clustered around the same point of impact, and the one that went high I'm pretty sure was my fault.  The group was a little looser this time, but there was more wind and I'd enjoyed way too much coffee at church (sights seemed to jump all over when my heart beat).  So, I think it probably was a forend problem.  Now what to do?  Taking a cue from jabey that it might be barrel harmonics, and looking for the easiest fix, I used Quick's trick of using refrigerator magnets to make a pressure pad at the front end of the forestock.  Took 6 more shots, and I think that may have fixed the problem. 

One shot did go off to the right, but a gust of wind came just as I released the shot and I blame that on the wind.  I'll have to do some more shooting to see if it really is fixed, but I am hopeful that I may have this licked.  Appreciate everyone's help. 

[gcrank1]

Looking good!

[jabey9210]

I drill a 1/2 inch hole and put a brass bushing in where the forend bolt goes but you don't have to do that if you don't want to I just preffer it the hardware store in my town just happens to have some that are flanged and work perfect. Use a bunch of white lithium grease for release agent and then I drill a bunch of 1/8" holes in the forend where the barrel sits so the Devcon or Jb weld have something to bite on then I tape off the sides of the forend so when it oozes it doesn't get all over the outside of the forend then i simply lay some JB weld or Devcon down stopping about 2" from the front and the back of the stock then put the barrel on and tighten it down but not very tight if you over tighten then when it sets up there is no pressure between the stock and barrel and that is what you are trying to accomplish so it always has constant contact all the time in the same spots. Clean up what oozes out and it will ooze out for quite a while, make sure the gun is setting level then let it sit for a few hours then when it stiffens up I pull the forend off so it doesn't become a permanent fixture then reattach it and let is set up fully an Wah La you now have a bedded stock.  It sure improved accuracy on all of my handi's dramatically.  Other than my ultra varmint all of them needed help. Plus I can now shoot off bipod's and still hold sub moa groups.

[wwjmbd]

I am having the exact same problem with my 30 30 handi rifle, shooting 10 shot groupings at 100 yards there would be a couple diffeerent 1" groups at different poi's a couple inches apart or shots very tight horizontally but stung out vertically. Thanks for the info, I think ill try the refigerator magnet trick.

[Sourdough]

Just looking at the first target it looks like you shot three shot groups.  Two shots went right where they were supposed to, third went high due to barrel heating.   Set it aside let it cool and repeat.  Same results, two good and one high.  I can usually get three good shots ou6t, but on warm days mine will do that.  When hunting the first one is the only one that counts anyway.   

[gcrank1]

Ive shot enough competition to know that I, even with a consistently grouping rifle, will shoot two groups about that far apart from a bench. I have a BSA Martini International MkIII with a 20x that will shoot flies at 50yd. It is amazing to pull the trigger and watch a hole appear right where the crosshairs are when it goes bang. It is also amazing to see how very subtle changes in hold or placement of the butt plate upon the shoulder will result in a pulled from the group shot.
I am confident that my two distinct groups, after eliminating the barrel heating issue, is due to heartbeat when the hammer falls.
I need more practice or less coffee........

[Sourdough]

When sitting at the bench preparing to make a long 800 yrd shot I have the scope cranked up.  Every time my heart beats the scope will jump to the right about 10 ft, then back past the target to the left about 5 ft, then settle on the target.  Slow steady breathing, concentration on the period between beats when the cross hairs are on the target, and your heart beat will slow down.  Just after a beat you nudge that hair trigger and the gun goes off.  Bullet strikes target right where you willed it to be.  If your shot goes off during a heart beat, it will mean a miss by several feet, or a wounded animal.

Several years ago my Dad came to Alaska to go hunting with me.  He borrowed my wife's Remington 1400.  We changed out the stock with one of my rifles, since my wife's stock was cut down to a 12" pull.  After leaving my wife switched it back.  Just before leaving on a hunting trip the wife and I went to the range.  Her first shot was 2" high at 12 o-clock, second shot was 2" at 3 o-clock level with bulls eye.  Third shot touched the first one at 12 o-clock, 4th shot touched the second at 3 o-clock.  So on for the 5th 6th 7th and 8th shots.  She was really getting frustrated, saying Dad had ruined her gun.  I went to my truck and got a big screw driver and a crescent wrench.  I removed her recoil pad and using the screw driver with the crescent wrench on the flats under the handle, I got another quarter turn out of the screw.  Next four shots were 2" high at 12 o-clock.  Her stock was shifting after each shot, causing the change in POI. 

[ratdog]

your groups don't really look that bad try a heavier bullet and i always j.b. weld all my scope rails on.good luck.