A little different break-in than I have seen before...

[Jeff A]

I have recently finished a re-barreling project on my Ruger Precision Rifle. I installed a Criterion barrel chambered in 6.5x47 Lapua. I also own a Savage Target Action rifle with a Shilen 6.5x47L barrel on it. It shoots very well.

My original plan was to break in the barrel by shooting one or two rounds, then clean it. Repeat as necessary. That didn't work out because of a cleaning rod problem. The first firing was six shots without cleaning just to get it printing on the target in the center. The rifle was taken home and cleaned and inspected with a borescope.

On the next range day, here is what transpired:

All shots fired from the Ruger and the Savage were the same load. The load was as follows:

· Lapua cases full length resized with .002 neck tension

· CCI 450 primers

· 36.5 gr VihtaVuori N140 powder

· 123 gr Lapua Scenar

All groups were 5 shots at 100 yards and shot off of a Dog-Gone-Good bag. The rifle had been fired previously a total of 6 rounds. The rifle had been cleaned after those 6 rounds and before today’s shooting began.

Two shots were fired from a cold, clean bore to condition the barrel. The shots landed nearly horizontal and 2.3” apart. This was not a good sign at all to me. Two shots out of the Savage barrel wound up touching each other. Next, four consecutive groups from the RPR were fired:

1st five shot group measured 2.146”, 2760 fps, ES 17.75, SD 7.5

2nd five shot group measured 1.198”, 2759 fps, no other data.

3rd five shot group measured 0.791”, 2762 fps, ES 14.87, SD 10.52

4th five shot group measured 0.618”, 2758 fps, ES 14.5, SD 5.8

A group out of the Savage today measured .762”, 2805 fps. About 45 fps faster that the new RPR barrel.

My opinion is that the barrel was “Breaking in” as I was firing the groups. My first impression was anything but good, but by the end of the session I felt that load development on this rifle should proceed normally. Has anyone experienced anything like this? My previous experience with custom barrels has been with Shilen, Krieger and White Oak/Wilson. None acted this way.

 

[Jeff A]

Nobody?

 

[waybones]

Nobody?

I had a 6.5 creedmoor Criterion barrel that did the same and it never got any better with a Savage target action. I ended up taking it off and buying another barrel.

 

[Jeff A]

Waybones, I'm not sure we had the same thing. At the end it was shooting good. Did your Criterion barrel ever shoot well? I have not heard any bad news on Criterion barrels. Have I missed something?

 

[criterionbarrels]

If anyone runs across a Criterion barrel that doesn't group well, please let us know. We're always happy to repair or replace barrels that don't meet a shooter's performance criteria. If you could shoot us an email at contact@criterionbarrels.com we'd be more than happy to help troubleshoot.

Were all of the groups shooting consistently with a horizontal spread, or was there any vertical movement as well? Horizontal stringing is normally an issue with stock fitment (shouldn't be relevant with an RPR unless your handguard is touching the barrel), trigger finger and hand placement (the eventual decrease in group size may have been attributed to a greater level of comfort with the trigger and grip), or a canted/wobbly bipod or rest (a bubble level may help eliminate that variable).

If you continue to experience problems getting the rifle to group (load development with a selection of different bullets, powders, primers, and brass may help in tightening up those groups as well), please shoot me an email and we'll explore the issue further.

 

[Jeff A]

If anyone runs across a Criterion barrel that doesn't group well, please let us know. We're always happy to repair or replace barrels that don't meet a shooter's performance criteria. If you could shoot us an email at contact@criterionbarrels.com we'd be more than happy to help troubleshoot.

Were all of the groups shooting consistently with a horizontal spread, or was there any vertical movement as well? Horizontal stringing is normally an issue with stock fitment (shouldn't be relevant with an RPR unless your handguard is touching the barrel), trigger finger and hand placement (the eventual decrease in group size may have been attributed to a greater level of comfort with the trigger and grip), or a canted/wobbly bipod or rest (a bubble level may help eliminate that variable).

If you continue to experience problems getting the rifle to group (load development with a selection of different bullets, powders, primers, and brass may help in tightening up those groups as well), please shoot me an email and we'll explore the issue further.

Thanks for posting. I don't think I have a problem, I just thought that the initial results were not what I would have expected. I'm anxious to begin load development on this rifle but, unfortunately, it is going to be about 3 weeks before I can get back to testing, Here are the groups. Read left to right across, then down to the second row:

Thanks for looking.

 

[jlow]

I understand that it shot well in the end but even if it didn’t there is a chance that it could be a difference between the two rifles especially if they are of a different barrel length. A barrel that does not shoot well could be the barrel or the load or both for that matter. You need both a good barrel and a good load to shoot well and we have not even talked about the shooter.

 

[Jeff A]

I would not expect both rifles to shoot this load the same, even though the barrel length and contour is the same. They were even chambered with the same reamer. What I am surprised about is the group size changing significantly over a span of 20 shots.

 

[JarheadAZ]

None of this surprises me.

There are a couple of other factors that influence barrel transit time, which is essentially the criterion that determines the efficacy of any given load.

For instance, bore friction as influenced by internal bore diameters as well as bore friction, which is a moving target as the throat machining become dulled by subsequent shots. Simply shooting a good load from one barrel in another may not be the ideal marriage of load and barrel. Do the homework and develop the new barrel's load in a manner similar to that used in developing the one for the older barrel.

There are no shortcuts. No two barrels are absolutely identical.

I once ordered a pair of identical .260 barrels from another maker in the same run, and they ended up having ideal loads that were .1 to .2gr apart. Each load was developed on the same rifle, with just the barrels being the difference. Each shot differently with the other's load. The second barrel was intended for use by my shooting partner. We were unable to achieve our original goal of being able to shoot the same load interchangeably in both rifles. Even matters like slight variances in headspace can affect a load's performance in two 'identical' guns.

Greg

 

[Jeff A]

None of this surprises me.

There are a couple of other factors that influence barrel transit time, which is essentially the criterion that determines the efficacy of any given load.

For instance, bore friction as influenced by internal bore diameters as well as bore friction, which is a moving target as the throat machining become dulled by subsequent shots. Simply shooting a good load from one barrel in another may not be the ideal marriage of load and barrel. Do the homework and develop the new barrel's load in a manner similar to that used in developing the one for the older barrel.

There are no shortcuts. No two barrels are absolutely identical.

I once ordered a pair of identical .260 barrels from another maker in the same run, and they ended up having ideal loads that were .1 to .2gr apart. Each load was developed on the same rifle, with just the barrels being the difference. Each shot differently with the other's load. The second barrel was intended for use by my shooting partner. We were unable to achieve our original goal of being able to shoot the same load interchangeably in both rifles. Even matters like slight variances in headspace can affect a load's performance in two 'identical' guns.

Greg

I think that you may not understand the nature of my question. I do know that barrels differ, I get that. I've known it for years. The reason I was shooting that load was it was what I had loaded the day I did barrel break in. What I was surprised at was the difference between group one and group four, that's all.

 

[JarheadAZ]

OK, got it now.

Greg

 

[MislMan]

When I started shooting my RPR (factory barrel) my groups improved noticeably during the first box of Hornady match ammo (140 gr.). Measured as 1.57" first group of 5 to .064" 4th group of 5 at 100 yards. My groups now stay in the .043" average over the last 23 groups of 5. Groups 9 and subsequent have been my handloads using H4350 and Hornady 140 gr. BTHP. I have not measured velocity yet and I am just about to startload development after 32 groups of 5 down the tube.
Something to consider may be the barrel settling in with the receiver. Sort of like heat cycling things to get them working together.

... Larry S.

 

[kevinbritvec]

Newly barreled rifle in a new stock is going to settle some before shooting IMO. The bedding may be more of an issue then the barrel itself.

 

[rudy16]

My barrel broke in after about 60 rounds. I have been shooting a 6.5 Creed and it slowly speed up and once it hit about 60 rounds it has stayed put. I never paid attention to groups during this the 1st 60 bc I was shooting at steel during a match. Its normal I wouldn't worry it will settle down.

 

[cmillard]

criterion makes an excellent barrel!! have one on my 1903-a4 that I am very pleased with.

 

[Phil3]

Would like to see how it does after 50 more rounds, with no changes. - Phil

 

[J P Brown]

Good to see the comment by criterion barrels, I just ordered one. ( not fitted yet)
On another note my old tikka 223 used to love 50gr zmax. One holes were the normal.
I get a new tikka and start load development with 50gr and the best I get is some horizontal stringing. I'm thinking this can't be right exact same make and twist of rifle.
So I move on to a 80gr bullet. First test group is probably the best iv ever shot. Definitely nothing wrong with the barrel, just didn't like the 50gr like the other rifle did.

 

[Jeff A]

An update.....
A few weeks ago I was working with some 130 gr Berger Hybrids ahead of H4350. I was doing load development for both of my 6.5x47's. I tested 39.2 grains of H4350 and my Shilen barreled Savage shot a .285" 5 shot group and the Criterion barreled RPR with the same load managed .294". On Friday I retested and the RPR shot a .275" group. There is now 73 rounds down the pipe on the Criterion barrel. I really have no reason to believe it will always shoot this good but whatever was causing it to shoot abnormally poor in the beginning seems to have cured itself. I'll look foreword to putting more rounds downrange with this rifle/barrel combination.

 

[cmillard]

glad to hear it improved, I didn't doubt that criterion barrel one bit. I think it just needed a little coaxing.

 

[rifleman700]

What am I missing here?? How can you judge the accuracy of a barrel without having done a complete load work up? What makes you think this load should shoot better??