Trouble shooting an issue with my 30.06.... Need advice

[Rob]

Got a couple questions.  Picked up a used 30.06 a few weeks back.  Love it – nice old gun, and it shoots very well (Rem Model 1917 made in Enfield England in the spring of 1918 from what I can tell from the Serial #)

I have had it to the range a couple times and put about 80 rounds through it.  I am shooting 5 shot groups with an average spread of about 1.75 inches (pretty typical for me with larger calibers).

The issue is not so much the grouping size, but  the LOCATION of the groups relative to my point of aim.  Sometimes they are low, sometimes they are high, sometimes to the right, and sometimes to the left.  I did a lot of messing with the scope in an attempt to bring it to zero and never seemed to get it right.  The differences were not 1/2 an inch one way or another, it was as much as 4-6 inches between the groups – and this was after resting the barrel for at least 10-15 minutes between each 5 shot group.  See diagram below for an example of what I’m trying to describe.  The red dots are shots, and the green circles each outline a shot group.

General data (trying to predict questions that might come up):

Shells:
I was shooting re-loads, and had a chronograph on it.  Speeds with the chrony were very consistent and ranged between 2500 and 2900 depending on the load.  (Shooting 150 gr Hornady Interlocks, in 4 different powder configs Varget in 45 and 50 grain, and H4350 in 54 and 58 grain).  The chrony showed less than 1.25% speed variability within each shot group for the high and low velocities (i.e.(Highest Vel recorded for a group minus lowest velocity for a shot group divided by the average velocity for the group) -or-( 2796fps-2763fps)/2785fps = 1.19% for a 5 set shot with 50 grains of Varget)).  I was seeing shot groups move around the paper even within the same re-load formula.  (for example a 50 grain Varget load would move 6 inches to the right from where the last set of 50 grain Varget loads landed)

Other guns
I was shooting a 300 WM, .338 WM, and a .17 HMR that day and the groups with those guns were all as expected.  So this is the only gun with migrating groups.

Scope and rings
I put a new mount and ring set on the rifle and attached an older redfield 3x9.  It was on another gun and shot well while on that gun.  The screws are tight, and coated with lock tight.

Weather
Weather that day was in the 70’s, Winds were variable to 10 knots.  Usually a quartering headwind.

I was shooting from the bench with solid sandbags.

Possible issues:
1.  Scope.  It is possible I damaged the scope when re-mounting.  I would think however that I would end up with poor groups though and as stated above, the groups were consistent for my skill (or lack there of) level.

2.  Wind.  There was wind on the range.  However my other guns did not see the variability that the 30.06 did.

3.  Ammunition.  It could be the re-loads, however each load set shot similar FPS according to the chrony.  And I would not expect to see right/left movement from bad ammo.

4.  trigger.  The trigger has a LOT of play.  It is much different than my more modern rifles.  The trigger pulls back 1/3 to ½ of an inch before It gets to where the break is.  Then the trigger pulls pretty hard prior to breaking.  It actually feels OK when shooting, but significantly different than my other guns.  I don’t feel like I am flinching when shooting.  The shots feel solid.

5.  The rifle came to me with a recently replaced stock.  This is really the only unknown in my equation and I am wondering if it may need to be re-glassed/bedded.


So, based on the info above, does it sound as though I have a bedding issue with the stock?  Is what I am seeing symptomatic of that kind of issue?  Any other ideas?

If it does sound like a bedding issue, does anyone know of a good gunsmith between Seattle and Marysville who can re-bed a barrel?

[Huntbear]

Rob, first off is everything tight?  All the action screws, etc...  Second is this the original barrel?  You may have a problem there.  Make sure the barrel does not have a lead or copper build up.  After that, if it still is shooting groups all over the place, then take it to a gunsmith.

[littlebuf]

might want to have that barrel looked at with a bore scope. there not cheep but ive been thinking about buying one to be able to check riffling when buying a used gun. there was a guy at the range who was having a similar problem but with way more drastic ranges of grouping. turns out the riffling in the barrel was all screwed up, tool marks, gouging ext. there may be a little damage in that barrel from who knows what especially if your sure that scope is solid

[Bofire]

I am thinking scope, try a different one.
Carl

[Pat/Rick]

Action screws
Scope/mount screws
Does the scope move in the mounts
Scope
The puzzling thing is that even though your groups are scattered, the groups are consistent in size.
You could get the muzzle re-crowned. Could be the previous owners cleaned from muzzle to breach.
Just my starting points.Hope you find the trouble.

[mazama]

It is probably your different loads, mine does the same thing with different loads will shoot to a different poi, shoot a group with 1load. Adjust scope after you have found favorite.  good luck

[GEARHEAD]

sounds like your chasing rounds. let it cool further.don't be to quick to adjust the scope, those groups are tight.  i shoot one round maybe every 5 minutes. a 3 round group takes me the whole 15 minutes if i'm at a range. i then let the gun sit at least 30 minutes before i do it again.
consistency is important, same temp each shot, same shoulder and cheek placement.

[Bigshooter]

I'd bet a left nut its the scope if everything is tight.

Shoot a group then move the up and down nob 8 clicks up and the left to right nob 8 clicks to the left.  Then shoot another group.  Then move the nobs 8 clicks back down and 8 clicks back to the right.  Then shoot another group.  If you shoot a group in the same spot you shot your first group (your first and third group should be in the same spot) your scope is fine.  If not you need a new scope.  Hope this makes since.

[BLKBEARKLR]

I would have to agree sure sounds like a scope issue with me. I had the same thing happen sent the scope in to have it repaired and the issue was the reticle was broken not to the extent that it could be seen. I was doing the same thing a good shot group but just wandering all over the paper.

[ICEMAN]

100yards?

Groups seem good and snug.

I usually shoot just one load configuration in order to remove all the variables....

I also prefer to sight in a new gun/scope combo at maybe 50 yards, to also remove as many other variables as possible, until I can confirm that the gun keeps putting lead in the same spot, and that I can control that with scope adjustment....then I move further and further out in distance until I am happy....

I would try again with only one bullet/powder configuration, even over the counter ammo.....and confirm that it is not simply migrating around due to load differences....

[Pat/Rick]

Just read the "shells" part again. Different loads will group different like mazama said. Get a box of factory rounds and compare to that even further. Each of your loadings seem to shoot a good group. Looks like it is time to stick with one.

[Rob]

Thanks all.  This is going to be a fun project.

Good advice.  It sounds like the scope is the likely suspect.  I still find it kinda funny to see that the groups are tight, but wandering.  I would expect a bad scope to place shots somewhat randomly.

What are the symptoms seen when stock bedding needs to be re-glassed?

Let me clarify on my loads a bit:
-I had four sets of shells
-I shot 6 groups with them, and recorded data on 5 of the groups (The one I struck was a 6 shot group where I was moving the scope every 2 shots - invalidating the data)
-I only moved the scope twice over the sets - including the set I scratched.

Below is a pivot table I took from my data.  It does not tell the whole story though.  What is missing is horizontal drift (Right/Left).  I did not record that.  You can see that the drop from Point of aim is consistent with the load and velocity though.

Based on the advice in this thread, here is what I think I'll do.

1.  Load up a set of 40 rounds with 58 Grains of H4350 and 150 Gr Hornady interlocks
2.  Triple check all screws on the gun (scope screws are good - checked those twice already, but I did not check any of the action screws)
3.  Go back to the range and set up on the 50 yard bench, shoot 4 sets of 5 and record the results.
4.  Set up on the 100 yard range and shoot 4 more sets of 5 and record the results.

Probably be a week before I can get back out there.  I'll report back, and in the mean time, any other ideas are welcome. 


Who knows, I might need to buy a really cool scope for my 22.250 and move that scope to the 30.06....  wouldn't that be a shame!

[BLKBEARKLR]

Rob,

After reading this more in depth I am withdrawing my scope issue. I think it is more that you were shooting different powders and grain weight.

You need to shoot one load and see what that does for you, adjust the scope to the grouping and see if you can get it dialed in.

Usually that is the problem when shooting different weights

[Rob]

I plan on giving that a try.  but like I said a couple times, the patterns are wandering WITHIN the same powder loads.

Also, I can see the powders causing up and down issues - and you can see  that play out predictably in the data table.  However I am surprised to see right/left variance.  After typing all this up and looking at the data I believe left/right variance is really the problem I am trying to solve for.

[Sporting_Man]

This sounds like a stock problem, or support - how is the stock supported (bench rest, sandbags, etc..)
I would not blame the scope, since it groups nicely. It is the group incosistency... therefore more likely to have some treacherous part not working for you, like stock. I would do some action bedding if not performed (given that stock is worth it).