Collecting velocity data during barrel break-in?

[dougduey]

What do ya'll think about using the tubs final finish to during break.-in. Do you think it will speed things up, help with accuracy, anyone ever used it or used it on an old barrel?
I think I might try this on an old barrel and see what it does.

It works well. You're fire lapping instead of hand lapping. It definitely makes the barrel clean up quicker. I use the TMS system by Tubbs in intervals of after 100 rounds down the tube.

 

[Greyfox]

It's a lapped barrel from Criterion. They don't specify a specific break in procedure but do state it shouldn't take much. I plan to use procedure Nosler has on their website with some slight modification.

• 7 to 10 single shot groups, cleaning in between each.
• 3 to 5 three shot groups cleaning in between each group.
• 1 five shot group and clean
• 1 fowling shot
• 1 three-shot group for accuracy

Should be a 25 to 34 round break-in depending on how much fowling is present towards the tail end of steps 1 and 2.

I have broken in 3 Criterion barrels over the past year or so, all in 6.5 cal. My break-in routine is quite similar to the one you describe. I did monitor the velocity using my Lab Radar until velocities stabilized. While accuracy(measured at 100-200 yards stabilized quite early in the process, ES of < 12FPS with all three barrels required 100-200 rounds. This is pretty consistent with Kreiger, Hart, Bartlien barrels I have broken in as well. Velocities of two 6.5x47 Criterion barrels started at 2700FPS and stabilized at 2760FPS. A 6.5x284 using a Criterion barrel started at 2975FPS and stabilized at 3025FPS. These type of increases appear to be pretty consistent with those seen with a variety of different barrels I have broken in(cut and button rifled) as well as those broken in by my buddies that shoot PRS competition.....doing this quite often.

 

[J E Custom]

Going out to break-in the barrel on my freshly built 280A.I. this weekend and I was wondering if I can collect good velocity data while I am breaking-in the barrel? Especially since I'm using a MagnetoSpeed V3 it would be nice to gather the data before I sight it in and zero it.

I have done this twice now and it provided me with some valuable information.

I had never seen/heard of it being done and am a big advocate of barrel Break in and just wanted to see if it would be an indication of how well the process improved the barrel bore and any other benefits.

This is where I did the test and the results. you should read all the way through the procedure or you can just skip to the test where I posted the results post #54.

https://www.longrangehunting.com/threads/new-barrel-break-in-and-cleaning-methods.160450/

I believe that velocity increases will vary depending on the cartridge and the barrel quality, Also the number of shots before it levels out.

Once it reaches the point that velocity levels out. I start load development. If I see a trend I then began tweaking the load to find it's potential. I also clean between every load tested be it 3 or 5 shots to start each load at the same place and barrel condition. I can find out later if the barrel likes a fouling shot, or will group with the first clean shot. I have several barrels that accuracy degrades between 5 and 7 shots
and some that will make it to 9 or 10. Beyond that, at some point accuracy will stabilize when the barrel becomes completely fouled and be very consistent.

These groups are not as good as the first, shot in a clean barrel but are very dependable if shooting matches that may require more than 50 shots without time to clean. Chronographing a new barrel give you a good start on many things in my opinion.

J E CUSTOM

 

[FEENIX]

I generally don't consider it a solid velocity until I have 150-200 rounds down the barrel.

Ditto!

 

[Chase723]

Like others have alluded to, don't get your heart set on anything until you put ~150 rounds down the tube. Do you reload? Shoot a quick velocity ladder (Satterlee load development) over your Magnetospeed. Find a good node. Can easily be done in less than 20 rounds...sometimes less than 10. Load 140 rounds or so of those bad boys and head to range for some trigger time, have some fun, and get to know that hammer. Won't be the end all be all but will be dang good until it's really ready to shoot. It'll also help you avoid unwarranted frustration. After that, redo your load/velocity ladder and you should end up pretty pleased.

 

[338 dude]

What do ya'll think about using the tubs final finish to during break.-in. Do you think it will speed things up, help with accuracy, anyone ever used it or used it on an old barrel?
I think I might try this on an old barrel and see what it does.

I've been thinking about it on a 20+ year old 3006 that accuracy is gone see if it will help at all but I don't know about using it on a new barrel I think slower is better as far as a break in process on a new barrel

 

[milo-2]

I probably average re-barreling or building new rifles 4 times a yr. There is no set rd count for breakin, I have had a couple Brux barrels broke in in 15 rds, Bartlien's 200 rds. I've have had them setup in 1-3 shots, and others hover between up to a 60fps difference for 50 shots before settling down. Have noticed too, what was normal with say a Krieger 5 yrs ago, may be out the door today, hand lapping is getting better.

The last thing I am going to do is load 100 rds in anticipation of a breakin, may end up pulling half of them for being over pressure or inaccurate, no reason to waste barrel life here.
I do not believe in breaking in custom handlapped per see, but I will have cleaned the barrel 3 times by the time I have 70 rds down a new barrel. I usually just run a velocity check of what I plan on using, 10-16 shots, I will the borescope the barrel to see if there is a problematic spot or spots I need to concern myself with. Clean, shoot a modified ladder at distance, clean, find a satisfactory breakin load, clean, clean again once breakin is complete. Do final load dev.
Edit: Once I have a breakin load, the magneto hangs off the end till speed up is complete, I can bang steel with it on w/o much accuracy degradation.

 

[Bob Wright]

That's good to know. I finished breaking the barrel in last night and the velocity spread was aweful at 2984fps low to 3092fps high and an average velocity of 3067fps from factory loaded Nosler ammunition. I came home a little disappointed in Nosler's factory ammo but I suppose after I finished breaking it in and after I final clean i shot a fowler shot and then a 5-shot group and all five rounds were touching and dead center on the target so I can't be too disappointed. It's g2g for hunting next month at the very least

I bought the same ammo for the reloading of the once fired brass. Did not have any luck with it as the velocities were all over the place either new or reloaded. Determined that the powder they used had left a residue in the necks that created neck/bullet release issues even after cleaning and tumbling. Hand polishing 100 cases in the necks settled it down enough for a junior deer hunt. The brass was just a disappointment and is different than the new brass in a box. The interior contour at the head around the flash hole is raised and limits powder space and who knows what else.
Starting over again with new unfired Nos brass and I believe it will be better. We'll see.

 

[SavageHunter11]

I have broken in 3 Criterion barrels over the past year or so, all in 6.5 cal. My break-in routine is quite similar to the one you describe. I did monitor the velocity using my Lab Radar until velocities stabilized. While accuracy(measured at 100-200 yards stabilized quite early in the process, ES of < 12FPS with all three barrels required 100-200 rounds. This is pretty consistent with Kreiger, Hart, Bartlien barrels I have broken in as well. Velocities of two 6.5x47 Criterion barrels started at 2700FPS and stabilized at 2760FPS. A 6.5x284 using a Criterion barrel started at 2975FPS and stabilized at 3025FPS. These type of increases appear to be pretty consistent with those seen with a variety of different barrels I have broken in(cut and button rifled) as well as those broken in by my buddies that shoot PRS competition.....doing this quite often.

Question for you since you have done essentially what I did more than a few times. When you clean your barrel between shots what is your process? I fear I went a little wrong in my cleaning. I was using M-Pro 7 Gun Cleaner and Copper Remover. I would run two patches with the gun cleaner to clear out the carbon. Then I would run a patch or two with the copper cleaner followed by a dry patch. Then finally I would run a patch of gun cleaner and finish with a dry patch.

Each cleaning took about 5 minutes from start to finish and after I got home I saw the copper removers suggests 5-10 minutes of soak. Kinda feeling like I wasted my time on Friday because the copper remover was only allowed to soak for about 30 seconds before I sent a dry patch down.

 

[J E Custom]

I've been thinking about it on a 20+ year old 3006 that accuracy is gone see if it will help at all but I don't know about using it on a new barrel I think slower is better as far as a break in process on a new barrel

I always do my break in using mid velocity loads to give the barrel a little time to adjust to the heat. I also consider this a good time to fire form to the chamber without hammering the case.

Even though the initial velocity is down from the desired velocity, with the increase in velocity, it can end up being a good load or at least a good place to start.

I have not seen the same thing that others have about needing 150 rounds to reach maximum accuracy. In fact, all the rifles that have been broken in correctly (At least in my opinion) have shot there best groups during or right after break in while the barrel is at its best condition. To be honest, I don't know if it was because of pristine rifling or the clean (Not worn throat), Or just the reduced loads, but maintaining the starting accuracy requires constant attention.

Each year i test the accuracy and compare it to the starting accuracy and have found that there has been very little degradation of the original group size. I just checked the accuracy less than a week ago for my primary deer hunting rifle. and after 16 years of shooting/hunting it is still just under 1/10th MOA (.097 5 shots at 100 yards, compared to the best when new (.054) and I'm not sure that it may be my getting older and just not seeing as well. Based on my records I have over 1100 rounds down the tube (Not really that many) but enough to see any change and so far It seems to be holding up good.

J E CUSTOM