re-bore barrel break in

[Pioneer2]

Had a Marlin 336 30-30 re-bored to 38-55 by Ron Smith.Haven't picked it up just yet but wondering on how to treat the new bore.Likely cast bullets but also maybe some jacketed.Supposed to be .376 groove and 1-15" regular twist that way I can shoot .375 jacketed and a little larger cast GC.Already factory D+T without the annoying extra safety/not a waffle top.

[Grizzly Adams]

Ron will tell you when you pick it up. Be sure to ask.

Grizz

[Salavee]

FWIW, I've never broke-in one of Ron's barrels yet. Take them out and shoot them .Clean as you normally would and they will shoot as good or better than any.

[260 Rem]

I have come to the conclusion that using the term “break-in” is tantamount to waving a red flag in front of a bull, so I answer with some trepidation and with no intention of engaging in a grueling argument related to the merits of BI. My understanding is that when any chamber is cut (regardless of how talented the “Smith” is), the reamer leaves tiny marks/striations across the bore in the leade (cone shape ramp) which tear off small amounts of copper from the jacket as the bullet passes. This copper, under tremendous heat and pressure ...becomes plasma like and deposits just forward of the leade. Repeated shoot and clean cycles, removes any copper that gets caught in the cross striations which makes it easier for subsequent bullets and heat to “iron out” the stations ....after which subsequent copper fouling should be reduced. And, most of us accept that copper fouling degrades consistency.
So, I BI all fresh cut chambers with the hope that it will reduce fouling which (if I do my part), will result in better consistency when shooting longer strings.
Now, given the consistency I would expect from a Marlin 336 action and the game bullets I would typically shoot ... I doubt there would be any measurable difference noticed between the BI chamber and one that was not. However, it it was my rifle, I would do a BI, just because I think it is the right thing to do

[dogslayer403]

Well said ^^^^
But i will add one thing you will not hurt it by not doing a breakin

[260 Rem]

Originally Posted by dogslayer403

Well said ^^^^
But i will add one thing you will not hurt it by not doing a breakin

Correct.

[sns2]

Voodoo

[sns2]

But listen to 260... he knows that of which he speaks.

[Pioneer2]

Ron didn't like the idea of shooting jacketed in the old timers caliber as it may foul the bore causing cast to shoot poorly.He advised shoot it and clean it.I'll wait on the weather to warm up and need to get some bullets.I have some .381 cast but they may be a little large to size down to .378 The groove is .376

[score]

Originally Posted by 260 Rem

I have come to the conclusion that using the term “break-in” is tantamount to waving a red flag in front of a bull, so I answer with some trepidation and with no intention of engaging in a grueling argument related to the merits of BI. My understanding is that when any chamber is cut (regardless of how talented the “Smith” is), the reamer leaves tiny marks/striations across the bore in the leade (cone shape ramp) which tear off small amounts of copper from the jacket as the bullet passes. This copper, under tremendous heat and pressure ...becomes plasma like and deposits just forward of the leade. Repeated shoot and clean cycles, removes any copper that gets caught in the cross striations which makes it easier for subsequent bullets and heat to “iron out” the stations ....after which subsequent copper fouling should be reduced. And, most of us accept that copper fouling degrades consistency.
So, I BI all fresh cut chambers with the hope that it will reduce fouling which (if I do my part), will result in better consistency when shooting longer strings.
Now, given the consistency I would expect from a Marlin 336 action and the game bullets I would typically shoot ... I doubt there would be any measurable difference noticed between the BI chamber and one that was not. However, it it was my rifle, I would do a BI, just because I think it is the right thing to do

Any time another "breaking in a barrel" thread pops up again, this should be linked. Last sentence is the best.
Asking the Smith is an obvious thing to do.
An expensive aftermarket barrel? Follow instructions.
A run of the mill factory rifle clean, shoot, enjoy. Clean once in a while...