New Pistol Break In Period Before Load Development?

serf 'rett · January 11, 2013, 02:55 AM

When I started reloading, my pistols were well broken in so I worked up testing ladders (series) to check for function and grouping. What shot well then, still works now in those pistols.

Now a new pistol is on order and I started wondering if it needs to be broken in before I start developing loads.

When a new pistol joins the harem, do you start load testing or do you run 100, 200, 300, 1000 or ?? rounds through the pistol before testing strings for accuracy?

Bart B. · January 11, 2013, 07:43 AM

I don't think any barrel needs to be broken in for accuracy.

I asked Sierra Bullets' ballistics manager decades ago about that for their match-grade rifle and pistol barrels used to test their bullets for accuracy. He said there was no significant difference in accuracy across the first few dozen, few hundred or few thousand of rounds fired. They all did loose a tiny bit of accuracy after about 2/3rds of the expected barrel life in rounds fired was met, but it was only about 10% to 15%; barely enough to be noticable.

A friend was a NRA National Pistol Champion holding several records and his comments were the same on breaking in barrels. He said to just shoot the darned things. Nobody's gonna be able to tell when a pistol barrel has an accuracy change of a dozen percentage points either way; better or worse. Nobody holds and shoots pistols good enough to tell.

One needs to shoot test groups having at least 50 shots for them to be statistically significant anyway. If one does do that, twice, and both groups are not the same size, then they've not shot enough shots per group to get valid data.

kraigwy · January 11, 2013, 10:02 AM

Quote:

I don't think any barrel needs to be broken in for accuracy.

I agree with Bart.

My break in process on a new gun/barrel consist of cleaning the oil out the barrel and sighting it in.

That's for my target rifles, I can't see why pistols are any different.

Brian Pfleuger · January 11, 2013, 04:10 PM

Even if rifle barrel break-in were necessary, handguns are a whole 'nother beast. The inherent accuracy, more correctly the inherent lack of accuracy, far over-shadows any benefit that might theoretically be available from a break-in. Imagine if you gained 1/2MOA at 100 yards (just for arguments sake), you'd be getting 1/8 MOA at 25 yards, which would be 1/32".

Besides which, a few (careful) minutes with a bore mop and some polishing compound would clean up any pistol barrel to a mirror finish. Much easier than with a rifle.

Ozzieman · January 11, 2013, 06:41 PM

I’m one of those nut cases that break in rifles with heavy barrels that are going to be used for target.
It’s a long process and probably does little to help. It’s not going to make a bad barrel good and can (if done wrong) destroy a good barrel.
The best way to test new loads with a new hand gun is to shoot it. That’s one of the great things about reloading, just one more reason to put more down range.

Sport45 · January 12, 2013, 08:57 AM

I don't think anything is gained by breaking in the barrel. Not the inside of it anyway.

There may be something to be said for putting a couple hundred rounds through an autolader to burnish everything in and get consistent lockup though.

serf 'rett · January 13, 2013, 12:26 AM

Thanks for the responses. I was more wondering if mechanical parts; ie, moving/mating/locking parts would have an significant effect. I didn't think the barrel would need anything other than cleaning.

FrankenMauser · January 13, 2013, 03:02 AM

Some polymer-framed semi-autos that use the frame for guide/slide rails (like the Ruger P95) may need some time to wear-in, before they'll reliably cycle light loads.

Other than that... there isn't really anything to worry about.

And barrel break in? No. I don't bother.
I might clean the barrel after 20 to 50 rounds for a centerfire (rifle or handgun).
But, after that... it doesn't get any special treatment.

SL1 · January 13, 2013, 10:54 PM

I recently purchased a Ruger Flattop revolver in .45 Colt with an extra .45 ACP cylinder. When I received it, the cylinder throats would not accept anything larger than a 0.450" (-) plug gauge. After shooting about 100 rounds of cheap Federal .45 ACP loads with thick-plated "TMJ" bullets, the cylinder throats will all accept a 0.451' (-) plug gauge. I did not (yet)measure the constriction of the barrel at the section threaded into the frame, which is notorious for being somewhat constricted by compression during assembly, but I would expect that to have widened somewhat, too.

Before I start working-up loads for accuraccy, I intend to have the constriction removed and the cylinder throats enlarged to 0.001" more than whatever the groove diameter is without the constriction.

Granted, that is a revolver, rather than an auto-loader. But, I would expect that there is some related wear on auto-loaders that could affect accuracy. There certainly is with respect to function with light loads, so for light target loads, you would probably want to make sure that the gun is smoothed-out before deciding how low you want to go before reliability becomes an issue. Also, some auto-loadeers will throw the first round outside the group because it is fed by hand-racking the slide, rather than by auto-feeding, and the lock-up is different between those two operations. That can also smooth-out with use.

SL1

January 11, 2013, 02:55 AM	#1
serf 'rett Senior Member Join Date: June 25, 2009 Location: Stuttgart, AR Posts: 1,569	New Pistol Break In Period Before Load Development? When I started reloading, my pistols were well broken in so I worked up testing ladders (series) to check for function and grouping. What shot well then, still works now in those pistols. Now a new pistol is on order and I started wondering if it needs to be broken in before I start developing loads. When a new pistol joins the harem, do you start load testing or do you run 100, 200, 300, 1000 or ?? rounds through the pistol before testing strings for accuracy? __________________ A lack of planning on your part does not necessarily constitute an emergency on my part.

January 11, 2013, 07:43 AM	#2
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I don't think any barrel needs to be broken in for accuracy. I asked Sierra Bullets' ballistics manager decades ago about that for their match-grade rifle and pistol barrels used to test their bullets for accuracy. He said there was no significant difference in accuracy across the first few dozen, few hundred or few thousand of rounds fired. They all did loose a tiny bit of accuracy after about 2/3rds of the expected barrel life in rounds fired was met, but it was only about 10% to 15%; barely enough to be noticable. A friend was a NRA National Pistol Champion holding several records and his comments were the same on breaking in barrels. He said to just shoot the darned things. Nobody's gonna be able to tell when a pistol barrel has an accuracy change of a dozen percentage points either way; better or worse. Nobody holds and shoots pistols good enough to tell. One needs to shoot test groups having at least 50 shots for them to be statistically significant anyway. If one does do that, twice, and both groups are not the same size, then they've not shot enough shots per group to get valid data. Last edited by Bart B.; January 11, 2013 at 07:50 AM.

January 11, 2013, 04:10 PM	#4
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	Even if rifle barrel break-in were necessary, handguns are a whole 'nother beast. The inherent accuracy, more correctly the inherent lack of accuracy, far over-shadows any benefit that might theoretically be available from a break-in. Imagine if you gained 1/2MOA at 100 yards (just for arguments sake), you'd be getting 1/8 MOA at 25 yards, which would be 1/32". Besides which, a few (careful) minutes with a bore mop and some polishing compound would clean up any pistol barrel to a mirror finish. Much easier than with a rifle. __________________ Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley

January 11, 2013, 06:41 PM	#5
Ozzieman Senior Member Join Date: December 14, 2004 Location: Northern Indiana Posts: 6,117	I’m one of those nut cases that break in rifles with heavy barrels that are going to be used for target. It’s a long process and probably does little to help. It’s not going to make a bad barrel good and can (if done wrong) destroy a good barrel. The best way to test new loads with a new hand gun is to shoot it. That’s one of the great things about reloading, just one more reason to put more down range. __________________ It was a sad day when I discovered my universal remote control did not in fact control the universe. Did you hear about the latest study.....5 out of 6 liberals say that Russian Roulette is safe.

January 12, 2013, 08:57 AM	#6
Sport45 Senior Member Join Date: May 25, 1999 Location: Too close to Houston Posts: 4,196	I don't think anything is gained by breaking in the barrel. Not the inside of it anyway. There may be something to be said for putting a couple hundred rounds through an autolader to burnish everything in and get consistent lockup though. __________________ Proud member of the NRA and Texas State Rifle Association. Registered and active voter. Last edited by Sport45; January 14, 2013 at 10:50 PM.

January 13, 2013, 12:26 AM	#7
serf 'rett Senior Member Join Date: June 25, 2009 Location: Stuttgart, AR Posts: 1,569	Thanks for the responses. I was more wondering if mechanical parts; ie, moving/mating/locking parts would have an significant effect. I didn't think the barrel would need anything other than cleaning. __________________ A lack of planning on your part does not necessarily constitute an emergency on my part.

January 13, 2013, 03:02 AM	#8
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	Some polymer-framed semi-autos that use the frame for guide/slide rails (like the Ruger P95) may need some time to wear-in, before they'll reliably cycle light loads. Other than that... there isn't really anything to worry about. And barrel break in? No. I don't bother. I might clean the barrel after 20 to 50 rounds for a centerfire (rifle or handgun). But, after that... it doesn't get any special treatment. __________________ Don't even try it. It's even worse than the internet would lead you to believe.

January 13, 2013, 10:54 PM	#9
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	A different view: I recently purchased a Ruger Flattop revolver in .45 Colt with an extra .45 ACP cylinder. When I received it, the cylinder throats would not accept anything larger than a 0.450" (-) plug gauge. After shooting about 100 rounds of cheap Federal .45 ACP loads with thick-plated "TMJ" bullets, the cylinder throats will all accept a 0.451' (-) plug gauge. I did not (yet)measure the constriction of the barrel at the section threaded into the frame, which is notorious for being somewhat constricted by compression during assembly, but I would expect that to have widened somewhat, too. Before I start working-up loads for accuraccy, I intend to have the constriction removed and the cylinder throats enlarged to 0.001" more than whatever the groove diameter is without the constriction. Granted, that is a revolver, rather than an auto-loader. But, I would expect that there is some related wear on auto-loaders that could affect accuracy. There certainly is with respect to function with light loads, so for light target loads, you would probably want to make sure that the gun is smoothed-out before deciding how low you want to go before reliability becomes an issue. Also, some auto-loadeers will throw the first round outside the group because it is fed by hand-racking the slide, rather than by auto-feeding, and the lock-up is different between those two operations. That can also smooth-out with use. SL1