breaking in new barrel

[tbrice23]

Im ready to load for new Criteron rem-age 7RM. Im thinking that it might be a good idea to break in virgin barrel with the bullet im planning on hunting with because it might conform the throat to the ogive profile of the 168 vld hunting bullets.
Am I correct or should I use cheaper bullets of same weight for break in?

 

[MontanaRifleman]

Im ready to load for new Criteron rem-age 7RM. Im thinking that it might be a good idea to break in virgin barrel with the bullet im planning on hunting with because it might conform the throat to the ogive profile of the 168 vld hunting bullets.
Am I correct or should I use cheaper bullets of same weight for break in?

Your throat wont "conform" (change shape) to your bullet's ogive. It is made of much harder steel than your copper or lead core bullets. The idea of the break-in is to smooth out any roughness in the throat or bore and reduce resulting copper fouling.

My approach is to use a reduced load of heavy bullets and slow powder to minimize throat damage as I send my custom barrels to be nitrided. I wouldn't bother doing that with a factory barrel. You can possibly do pressure testing with your selected bullet in conjunction with break-in, but make absolute certain that there is no cleaning product residue left in the bore as it will affect pressure. But if you choose to pressure or accuracy test after break-in, there is no reason not to use the cheapest bullets available.

That said, It might be cheaper just to use your selected bullets if you have to buy a box of cheap break-in bullets and end up with half a box left over. I use leftovers from other loads that I don't use anymore when I can.

 

[tbrice23]

Thanks I will go ahead and do pressure test on my choice of bullet. This bore looks like glass with my cheap borescope so maybe fowling will fade quickly. But ill find out tomorrow.
If I ever find a place to nitride ill be there with a quickness , although its still not too late with this barrel.

 

[tbrice23]

Guess it is too late ive already ceramicoated this one

 

[Varangi]

I used to shoot one clean one- put alot of copper downrange in the hope of making my barrel shoot straighter than I could. I now burnish the barrel before I fire the first round.
Sentry Solutions smooth Kote and BP2000. Puts the Moly in the barrel w/out the problems in the forcing cone and laps, smooths out and seals tool marks and allows me to shoot more than I clean- Groups stay tighter longer- my cold bore shot is consistent and absorbed in a 5 round group. Good stuff, cheaper than a box of Match Ammo.

Cheers,
Mike

 

[tbrice23]

Turns out this barrel rendered little or no copper after the first 2 rounds. Kreiger makes good blanks evidently.
Had 3 loads under .7 moa with h1000 but could have been tighter as the new Basix trigger set at 6 oz. I hold the rifle firm the same way on the bench as I do when hunting (on hunting rifles) so it was too easy to set the trigger off before I was absolutly ready.
Im loaded with same bullet with h4831sc for tomorrow ill try to give range report . Velocity was low with h1000 and a 24in. bbl.

 

[clambdin]

Hmmmm looks like criterion makes a good barrel...!

 

[tbrice23]

Could be better I tightened up the Basix trigger to 10oz so ill be better prepared for the sear break tomorrow. Remember these groups were all out of a clean-shoot-clean-shoot barrel.

 

[gilmillan1]

How did you clean the barrel during your clean/shoot session?

 

[tbrice23]

The routine is 10 shots -clean in between each. 5 groups of 3 clean in between each group. 5 groups of 5 clean in between each group. Using copper solvent each cleaning till no copper is seen .
-or-
Until no copper no copper is seen.


My particular barrel stopped after 3 shots but I continued to clean and check for 10 rounds and I cleaned every 5th shot my 1st range trip just because in an *** .
This was my best group on the 2nd range trip with different primer. (There are 2 speeds listed in notes I was comparing chronographs).

 

[tbrice23]

Did that answer your question or was I rambling?

 

[gilmillan1]

Yes, but I still have another question. What did you use to clean your barrel in between shots? did you use patches and the solution or you used a brass brush and solution?

the only reason I ask is because I have a new gun that I have been putting together but I have not fired it. I already got a jewel trigger, bedded the stock, installed a picatinny rail, and I just installed a scope. It is a rem sendero in 7mm. It should be a good gun, but I have never broken in a barrel.

Answer is well appreciated.

thank you

 

[tbrice23]

I only use nylon brushes. Wrap a patch around it soaked in copper solvent of your choice ( I use hoppes benchrest but im sure there are better ones like montana extreme) run 2 or 3 down bore from chamber to muzzle only with a bore guide and use clean patch each pass till powder is gone that way you are sure the solvent is eating copper. Then l let it set for a few minutes and wipe solvent out with kroil soaked patch then dry with 2 passes with dry patches.
I have a sendero sf2 in 7 rem mag and love it so much I rebarreled my xcr 338 win mag in 7 mag.

 

[tbrice23]

This is from Savage