6BR not consistent

[STOMP442]

I built this rifle a couple months ago. The intended purpose was something to punch paper with while I waited for other guns to cool. This was something to challenge myself with and practice my fundamentals. No serious competition just my enjoyment. Turns out this thing has been the most aggravating and discouraging rifle I have ever messed with. Rifle specs are as follows.

Tikka T3x Action
Krieger HV 12 twist finished at 24"
Richards Wolverine target stock pillar and glass bedded.
Jard 12oz trigger
Leupold one piece rail
Burris Signature Zee rings
Sightron SII Target 36x42
ADG Brass
CCI 450 Primers.

I have tried 64gr Bergers, 70gr Sierras and 85gr Sierras all with Varget, N133, N135, Benchmark and H4895. All bullets seem to shoot about the same. Best 5 shot groups I have been able to get, are high twos to mid threes which I would be extremely happy with if I could do it consistently. This rifle will not repeat, ever. I can work up a load with any given combo find one that shoots really well, go home and load enough for three or four five shot groups and never shoot a group under a half inch on my next outing. I am an experienced shooter and don't feel that I am the cause. I have had my wife shoot it (she is a better shooter than I am) with the same result so I am fairly positive that it is not shooter induced error. I have pulled the bedding and re-bedded the rifle, changed scopes, checked all action and base screws and done the cotton swab around the crown. Everything checks out fine. The 70gr Sierra seems to be the most consistent bullet out of this rifle and has give me most of the better groups this rifle has shot. I purchased a bore scope to look at the barrel and I did find a concerning area about an inch from the muzzle and these marks go 360 degrees at this spot. I guess my question is, this the cause of all my inconsistency? I am also attaching a target photo from my last outing. All groups were shot at 100 yards from a bench rest and rear bag. 29.0gr of N133 and the Sierra 70gr Match King. I spent the day prior working up a load with that bullet and powder combo and shot a group in the high twos. Took it back out to confirm and shot these three groups. Chrony data showed a velocity of 3208fps and SD of 5 over the course of fire, using a buddies new Garmin Unit. Barrel probably has 400 rounds on it at this point and I have been giving it a good cleaning every 50 rounds or so generally before switching powders to try.

 

[Idaho-Lefty]

Frustrating, for Sure !! Your Powder choices, Look, Fine !
Might Try some, 6 MM Berger, 80 Grain, Flat Base,. Varmint / Target, Bullets.
IF it doesn't shoot, THESE,.. you've got, other,.. Problem's.
Also, you might Try, some JB's, in the Barrel, a FEW strokes, to "Smooth" it, out ! Good Luck !

 

[Bill Norris]

Would be interesting to know how far you are bumping the shoulders back when re-sizing as tight-chambering will cause vertical in your groups? Also, have you tried a neck tension test with different sized bushings? Alex Wheeler will attest to neck tension issues.

 

[gme]

If it were mine I'd cut the barrel off to remove those pitted areas

 

[AlNyhus]

Two questions:
-What are you using for flags?
-Have you tried another scope? -Al

 

[STOMP442]

Frustrating, for Sure !! Your Powder choices, Look, Fine !
Might Try some, 6 MM Berger, 80 Grain, Flat Base,. Varmint / Target, Bullets.
IF it doesn't shoot, THESE,.. you've got, other,.. Problem's.
Also, you might Try, some JB's, in the Barrel, a FEW strokes, to "Smooth" it, out ! Good Luck !

Have some of those scheduled for delivery today.

 

[STOMP442]

Would be interesting to know how far you are bumping the shoulders back when re-sizing as tight-chambering will cause vertical in your groups? Also, have you tried a neck tension test with different sized bushings? Alex Wheeler will attest to neck tension issues.

I am bumping .002" according to my measurements. I don't have a bushing die just Redding full length sizer and seater. I load for three other BRs that I own and they have no problems shooting very well consistently. They are all 8 twist shooting 105s or 107s though.

 

[STOMP442]

If it were mine I'd cut the barrel off to remove those pitted areas

Thats where I am at. Definitely cheaper than a new barrel.

 

[STOMP442]

Two questions:
-What are you using for flags?
-Have you tried another scope? -Al

Not using flags. I shoot at a busy public range and now everyone is ramping up for deer season and it's busier than normal. I don't spend a second longer down range than I have to. Yes, I have tried two different scopes now with the same results.

 

[Bill Norris]

I am bumping .002" according to my measurements. I don't have a bushing die just Redding full length sizer and seater. I load for three other BRs that I own and they have no problems shooting very well consistently. They are all 8 twist shooting 105s or 107s though.

Understand completely but some rifles are just different and require more attention to the small things than others.

 

[6BRA]

what distance? L to R wind? Is that 100 or 200?
I would not worry about the bbl imperfections. I have seen these several times...

 

[STOMP442]

Groups were shot at 100 yards. I have always shot this in good weather, winds were probably never more than 5mph any time I have ever shot it. Conditions of the target I posted was 85ish degrees, winds 3-5mph from right to left, clear skies around 9am.

 

[Idaho-Lefty]

Personally, I'd do some, JB "Work", on the last 4-6 inches of, the Barrel with, a FEW Stokes of a tight fitting, Wool, Fiber Pellet and some JB's BEFORE,.. cutting it, off.
THEN, Copper it,.. UP ! ( Clean at about, 100 - 120 shots ). Copper will Fill, any imperfections,. Nicely !

 

[AlNyhus]

There's always a lot of assumtions made when try to work through this stuff long distance. But assuming nothing obvious, if it was sitting on my work bench, I'd double check two things.
-First would be the seating depths for the different bullets you've tried. With a standard seating die, it's real easy to get seating depth off.
-Second, I'd take a hard look at the bedding and check it with a dial indicator.

Once all that was verified, it would be off to the range with flags, loading gear, primed cases, N135, the Berger 64's and the seating die set to seat the bullet .010 past the 'T.P.' Three shot groups starting at 30.0 and going up .5 gr. at a time should find some goodness quickly. I'd toss in a known good scope too. Two flags at 100 will do it.

For what it's worth. -Al

 

[ballisticdaddy]

If you are getting single digit SD'd then your charge weight is likely not the issue, have you tested seating depths? Also most my barrels don't shoot their best with a clean bore, have you tried tested without cleaning them?

 

[STOMP442]

There's always a lot of assumtions made when try to work through this stuff lo g distance. But assuming nothing obvious, if it was sitting on my work bench, I'd double check two things.
-First would be the seating depths for the different bullets you've tried. With a standard seating die, it's real easy to get seating depth off.
-Second, I'd take a hard look at the bedding and check it with a dial indicator.

Once all that was verified, it would be off to the range with flags, loading gear, primed cases, N135, the Berger 64's and the seating die set to seat the bullet .010 past the 'T.P.' Three shot groups starting at 30.0 and going up .5 gr. at a time should find some goodness quickly. I'd toss in a known good scope too. Two flags at 100 will do it.

For what it's worth. -Al

I have tested seating depth from touch all the way to .060" off. I can find a spot where it will shoot very good just about anywhere in that range. It just wont do it a second time when I go verify. 30gr of N135 and the 64s is exactly where I started with this rifle based on what I was reading on the cartridge guide on this site. 30gr will give me flattend primers and hard bolt lift. 29ish grains is where this barrel seems to like it. As far as cleaning goes I will give it more time between cleanings to see if that offers any positive influence. I don't believe in 3 shot groups.

 

[STOMP442]

If you are getting single digit SD'd then your charge weight is likely not the issue, have you tested seating depths? Also most my barrels don't shoot their best with a clean bore, have you tried tested without cleaning them?

I generally load a few foulers to shoot before shooting for group. Maybe this barrel is like a Savage and likes it dirty. I will give it a try.

 

[Murray Brook]

-Second, I'd take a hard look at the bedding and check it with a dial indicator.

What amount of barrel movement would you consider too much. TKS

 

[swd]

Go back to the basics . While your checking the bedding check that the trigger isn’t touching the stock or trigger guard, the bolt handle isn’t bottoming on or touching the stock anywhere, magazine if applicable isn’t binding and the action bolts aren’t binding in the stock holes or too long.

And what happened to the barrel?

 

[jimmymac]

I would do as Al said and work into the lands, not away all the way up to and including leaving big square land marks imprinted on the bullet. If you polled successful short range BR shooters I would suspect you'll find most are seating their lightweight bullets into the lands to one extent or another.