Barrel wear vs lapping

[the blur]

I was talking to a knowledgeable guy. They lap barrels with an abrasive compound. Like a toothpaste with grit. Then I ask if that opens my .308 to a .3081
His answer was no, it doesn't affect the bore diameter. I can't see how it doesn't open the bore a thousandth, but ok, i'm not the gun smith.

Then I'm thinking, isn't lapping the same thing as wearing out your barrel ??

Just curious... not a gun smith..

 

[bozoben]

Lapping does open up barrels ever so slightly but it is a time consuming and meticulous process so it is not over done. I worked as a barrel lapper for a reputable barrel maker for a bit.

As far as I understand it, "burning out a barrel" means essentially rounding out the riflings, not exactly opening up the diameter of the bore. So as I understand it, they are two completely different things.

Lapping keeps riflings sharp while simultaneously "sanding/grinding" the reamer marks out of the bore.

 

[WildRose]

I was talking to a knowledgeable guy. They lap barrels with an abrasive compound. Like a toothpaste with grit. Then I ask if that opens my .308 to a .3081
His answer was no, it doesn't affect the bore diameter. I can't see how it doesn't open the bore a thousandth, but ok, i'm not the gun smith.

Then I'm thinking, isn't lapping the same thing as wearing out your barrel ??

Just curious... not a gun smith..

It would take a very, very long time using standard lapping techniques to increase your bore diameter measurably.

Lapping basically knocks off the high points and dulls sharp edges, that's about it.

 

[WildRose]

Lapping does open up barrels ever so slightly but it is a time consuming and meticulous process so it is not over done. I worked as a barrel lapper for a reputable barrel maker for a bit.

As far as I understand it, "burning out a barrel" means essentially rounding out the riflings, not exactly opening up the diameter of the bore. So as I understand it, they are two completely different things.

Lapping keeps riflings sharp while simultaneously "sanding/grinding" the reamer marks out of the bore.

"Burning out a barrel" is throat erosion.

People used to look at old barrels that had indistinct rifling thinking they were "shot out" when in reality, in almost every case they were just never really cleaned properly an there was a heavy buildup then of lead, copper, and carbon in the grooves.

 

[26Reload]

I got a new bolt for one of my rifles..took it to gunsmith..cranking on it really hard he could close the bolt on a resized piece of brass that had been shot in that chamber...he just smiled and said "do ya wanna save yourself some money".....well duhh.....
He set me up with a little lapping compound..more like a heavy grease containing different grit sizes...
I got back to residence and stripped the bolt...plugged the chamber....and lapped the lugs in....took about 20 minutes...
Bolt works great..brass looks good after firing......little secrets make jobs easier...& cheaper......
Just bought a rem 222 mag from a guy..took it to the smith.. he neutered it to a 223..that nite....he didn't want me to pay in advance...but that's the way I roll....sometimes....

 

[WildRose]

I got a new bolt for one of my rifles..took it to gunsmith..cranking on it really hard he could close the bolt on a resized piece of brass that had been shot in that chamber...he just smiled and said "do ya wanna save yourself some money".....well duhh.....
He set me up with a little lapping compound..more like a heavy grease containing different grit sizes...
I got back to residence and stripped the bolt...plugged the chamber....and lapped the lugs in....took about 20 minutes...
Bolt works great..brass looks good after firing......little secrets make jobs easier...& cheaper......
Just bought a rem 222 mag from a guy..took it to the smith.. he neutered it to a 223..that nite....he didn't want me to pay in advance...but that's the way I roll....sometimes....

I've been writing about doing just this for many years. Usually people seem to be looking at me like I have snakes coming out of my head.

It's time consuming but it definitely works to smooth out an action and bolt closing.