New Barrel Break-in (with Tuner) -- 6mm Dasher

[Mikemontminy]

Picked up my barreled action from my gunsmith about a month ago. It’s a 28” Kreiger 8 twist. Same varmint contour as the last and chambered with my dasher reamer. This one seems to shoot about 80 f.p.s. Slower than my last Kreiger. This was confirmed by looking at my notes from the last barrel at about the same round count and shooting at the same temperature. Started with three shots and cleaning between each shot. Then sighted in and shot my old load of 34.0 grains of RE16. The velocity of the load in the previous barrel was 2940 f.p.s. Shot three 5 shot groups with all bullet holes touching. Made sight adjustments between each of these groups. That’s why they appear in different areas around the bull. The velocity was only 2860 f.p.s. in the new barrel. Did another barrel clean and no copper was removed just carbon.

I then loaded another 21 rounds increasing the powder charge one tenth of a grain for each three shot group. I was able to get just over 2900 f.p.s with 34.6 grains of powder but had to use a drop funnel and tapping the cases to settle the powder down so that I could seat the bullets without crunching the powder. Next I loaded 50 rounds of 34.6 grains of Reloader 16. I figured this would get me above 100 rounds thru the new barrel and hopefully the velocity will climb to where the previous barrel was. I shot all these as three shot groups and adjusting the tuner I click between each group. I forgot to advance the tuner at setting 12 so had to relabel my target showing tuner setting 12 being shot twice.

Cooled the barrel down three times during this tuner test to be sure the velocity wasn’t climbing because of barrel heat. The conditions were good for testing. Ran 5 flags out to 100 yards for the tuner test. Probably will have to repeat this test as velocity seemed to climb a bit during the test. Not sure if I’m reading the test correctly but I’m leaning towards tuner setting 18 with the shot that I fell I pulled to the right. The group before and the two groups after are at the same area on the target. I would like to see a little more velocity from this barrel so that I can back the powder charge back down. It should definitely go up some when the outdoor temps climb into the 80’s. None of the cases show signs of pressure. Running about 8 thousands jammed into the rifling. I have a couple f-class matches coming up in two weeks. Not sure if I’ll get to put more rounds thru the barrel before then.

 

[swd]

What’s the cartridge? Looks like a Dasher or BRX by the charge weight. Bullet?? I’d reshoot with 5 shot groups 17, 18, and 20

 

[Mikemontminy]

What’s the cartridge? Looks like a Dasher or BRX by the charge weight. Bullet?? I reshoot with 5 shot groups 17, 18, and 20

It’s a 6mm Dasher shooting 105 gr. Berger hybrids.

 

[Tesoro]

The bore must be different from previous. No two barrels will ever shoot identical velocities. This is why serious competitive shooters will get a barrel that shoots well and has excellent velocity and then screw off after break in and rack it for matches only!

 

[FeMan]

I agree that you should shoot 17-20 again. If you can shoot it at longer distances that would be helpful in really sorting through the nuances. Since your round count is low on the barrel, watch for potential speed-up. With RL16 in a Dasher I wouldn't expect you to run into pressure but its also possible that after 200 rounds or so you are back down around the powder charge in the last barrel.

 

[gunsandgunsmithing]

I like 17 also. One of the things I look for is poi and then predictable group shapes as it progresses away from what appears to be a sweet spot. I'd test there and see how it holds up, keeping in mind that tune may change a mark or so with varying conditions. So, say roughly 16-18 is probably where you'll be.

 

[swd]

It’s a 6mm Dasher shooting 105 gr. Berger hybrids.

With 105’s and RL16 your no where near max. Like I mentioned earlier reshoot 17-18 as 5 shot groups. Then I’d push load up to see if you can find a higher node. With RL16 you’ll need a drop tube but will probably find something nice in the 3020-3060 range. I’ve shot as much as 35.7 with 107’s and 35.0 with 109’s in my BRX. Hard to get it in. But be careful you can and will hit pressure with RL16 even though it’s bulky. And don’t be afraid of a little crunch when you seat. RL16 doesn’t care it just flat out shoots! It took me to HM in midrange.

 

[Pete Wass]

I thought it was interesting, One of the barrel makers said in an interview aired on Youtube he felt breaking in barrels was unnecessary. I agree with him and quit doing it years ago. Barrels are too preciously to waste shooting shots needlessly through, IMHO.

Pete

 

[Mikemontminy]

Thanks for all the helpful tip guys. My normal shooting season will start in a week. Shooting through the summer the temperatures could get up into the 90’s during our matches. The velocity will climb a bit with the rise in temperature. Looks like the velocity climbed a bit during this test. I will have to repeat the tuner test again when it gets a bit warmer out . At some point I will have to settle on a velocity and adjust the load to maintain it.

 

[gunsandgunsmithing]

Thanks for all the helpful tip guys. My normal shooting season will start in a week. Shooting through the summer the temperatures could get up into the 90’s during our matches. The velocity will climb a bit with the rise in temperature. Looks like the velocity climbed a bit during this test. I will have to repeat the tuner test again when it gets a bit warmer out . At some point I will have to settle on a velocity and adjust the load to maintain it.

I no longer adjust my loads. Kinda the whole point of a tuner.

 

[Rset]

With 105’s and RL16 your no where near max. Like I mentioned earlier reshoot 17-18 as 5 shot groups. Then I’d push load up to see if you can find a higher node. With RL16 you’ll need a drop tube but will probably find something nice in the 3020-3060 range. I’ve shot as much as 35.7 with 107’s and 35.0 with 109’s in my BRX. Hard to get it in. But be careful you can and will hit pressure with RL16 even though it’s bulky. And don’t be afraid of a little crunch when you seat. RL16 doesn’t care it just flat out shoots! It took me to HM in midrange.

Completely barrel dependent. I have seen loads from 2880 to 3030 work very well, but it completely depends on the particular barrel. My loads are in the same brass, same chamber, same action, same stock, same powder and lot, same bullet and lot. Only change has been the barrel. Test, retest, and accept the result on target with you barrel, or move on to the nest one.

 

[swd]

Completely barrel dependent. I have seen loads from 2880 to 3030 work very well, but it completely depends on the particular barrel. My loads are in the same brass, same chamber, same action, same stock, same powder and lot, same bullet and lot. Only change has been the barrel. Test, retest, and accept the result on target with you barrel, or move on to the nest one.

Absolutely, that’s why I recommend shooting 5 shot groups at those tuner settings. But he probably has higher node he hasn’t got to yet. And there’s way to know which node is better until he tries it.

 

[Rset]

I no longer adjust my loads. Kinda the whole point of a tuner.

Is the lack of load development the use of a tuner? I thought the idea was to develop a load without the tuner and then use the tuner to keep it in tune. I don't use one currently, but if all I get by using one is the ability to slack off off on load development, I guess I saved myself a few hundred dollars. I will take the extra few shots to develop the load I guess. You should be able to find a charge weight that allows for some temperature change. That being said, I shoot F-Open, not bench rest.

 

[Bill Norris]

Is the lack of load development the use of a tuner? I thought the idea was to develop a load without the tuner and then use the tuner to keep it in tune. I don't use one currently, but if all I get by using one is the ability to slack off off on load development, I guess I saved myself a few hundred dollars. I will take the extra few shots to develop the load I guess.

That thought is absolutely correct. There is no free lunch. The tuner is just that. A device to keep the load in tune.

 

[Mulligan]

My f-class load for a couple of years was 35.0gr of RL16 with a 105gr berger VLD........ 3000-3015fps
Slow pour, 6" funnel easy peasy

CW

 

[gunsandgunsmithing]

Is the lack of load development the use of a tuner? I thought the idea was to develop a load without the tuner and then use the tuner to keep it in tune. I don't use one currently, but if all I get by using one is the ability to slack off off on load development, I guess I saved myself a few hundred dollars. I will take the extra few shots to develop the load I guess. You should be able to find a charge weight that allows for some temperature change. That being said, I shoot F-Open, not bench rest.

Of course I do load development. Ya gotta read my post in the context of the post I was replying to. But I do my load work with the tuner attached. It does work either way...on and off. On, you establish a base setting at the same time vs not, is all.

 

[Rset]

Of course I do load development. Ya gotta read my post in the context of the post I was replying to. But I do my load work with the tuner attached. It does work either way...on and off. On, you establish a base setting at the same time vs not, is all.

My post was being sarcastic. I understand your context. My point being that even with a tuner, you still need to do the work. From what I have seen though, a tuner can certainly make that process easier, and may actually eliminate the need for fine seating depth adjustments. The only reason I am not using one is because I haven't worn my current barrel out yet. The next one will have a tuner installed.

 

[gunsandgunsmithing]

My post was being sarcastic. I understand your context. My point being that even with a tuner, you still need to do the work. From what I have seen though, a tuner can certainly make that process easier, and may actually eliminate the need for fine seating depth adjustments. The only reason I am not using one is because I haven't worn my current barrel out yet. The next one will have a tuner installed.

Agreed. One thing I have stopped doing, is chasing seating depth. Using group shape rather that a pretty nominally number on the tuner, I don't even notice seating depth changes. I just move the tuner based on group shape, regardless of what the tuner is set on.

 

[quest450]

tuners are overrated.

 

[TylerFromMS]

tuners are overrated.

Truly. Do you have a book that I can buy or a podcast I can subscribe to, by chance?