setting back a barrel
setting back a barrel
by brickmanDan on Sat 21 Nov - 17:45
Guys, bear with me, I'm not a smith and would have asked this question on another forum, but since we have a "smith's special" forum these days... Perhaps someone could try to help me in layman's terms...
Imagine you had a "old and dear" factory rifle, shooting well, no real visible wear of the throat. Still, the darned factory chamber has so much freebore, you can hardly reach the lands with any bullets suitable to your barrel twist rate. Possible remedies: new barrel or set back old barrel.
Let's explore the option of setting back the old barrel for a while.
1) since (part of) the chamber has to be recut after the barrel has been set back X threads, how does one insure that the reamer to be used for recutting the chamber "matches" the dimensions of the old chamber?? Or does one simply grab the first and best factory chamber reamer handy??
2) is it normal for the throat of a chamber to be cut separately, or is it better to have the freebore determined by however the available reamer is set up?? If the latter, does that mean a custom reamer is necessary if you want to get close to zero freebore??
3) is it reasonable to expect to be able to set back the barrel exactly right to have the markings on the barrel be useable after the modification?? I.e. can the barrel be set back exactly right to have the barrel indexed as it was before the mod, markings in their old position??
4) if this is a blued action/barrel, can one expect to have this mod done without having to reblue??
And finally, since the price of setting back a barrel is probably about the same as it is to chamber a new barrel, is it worth saving the cost of the new barrel (i.e. 2-300$) by not buying and installing a new barrel in the first place?? I.e. is the whole idea of setting back the barrel a waste of $$$? I'm aware that setting back the existing barrel will cause the barrel channel inletting to become somewhat "loose", but maybe I could live with this, if the results were otherwise good.
Imagine you had a "old and dear" factory rifle, shooting well, no real visible wear of the throat. Still, the darned factory chamber has so much freebore, you can hardly reach the lands with any bullets suitable to your barrel twist rate. Possible remedies: new barrel or set back old barrel.
Let's explore the option of setting back the old barrel for a while.
1) since (part of) the chamber has to be recut after the barrel has been set back X threads, how does one insure that the reamer to be used for recutting the chamber "matches" the dimensions of the old chamber?? Or does one simply grab the first and best factory chamber reamer handy??
2) is it normal for the throat of a chamber to be cut separately, or is it better to have the freebore determined by however the available reamer is set up?? If the latter, does that mean a custom reamer is necessary if you want to get close to zero freebore??
3) is it reasonable to expect to be able to set back the barrel exactly right to have the markings on the barrel be useable after the modification?? I.e. can the barrel be set back exactly right to have the barrel indexed as it was before the mod, markings in their old position??
4) if this is a blued action/barrel, can one expect to have this mod done without having to reblue??
And finally, since the price of setting back a barrel is probably about the same as it is to chamber a new barrel, is it worth saving the cost of the new barrel (i.e. 2-300$) by not buying and installing a new barrel in the first place?? I.e. is the whole idea of setting back the barrel a waste of $$$? I'm aware that setting back the existing barrel will cause the barrel channel inletting to become somewhat "loose", but maybe I could live with this, if the results were otherwise good.
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Re: setting back a barrel
by ronryder on Mon 23 Nov - 16:05
Question what rifle are you talking about with such a long freebore? A weatherby?
You need to set the barrel back one turn at least, in most cases,enough taper is in the case that new metal will be cut with most any SAAMMI spec reamer. There would be rare exceptions of course, the chambers in sporting rifles are rarely cut so tight as too see any difference in a set back, again, exceptions may appear.
I have chambered dozens of rifles with seperate neck/body setups.
Only the most well supplied gunsmith has separate throat/ neck reamers. Most cut with one reamer, and perhaps have a throating separate for the extreme reloader wanting VLD bullets, or trying to imitate a weatherby long throat.
Certainly the gunsmith can put the sights back on top, or markings where they were, if he cant, he shouldnt be standing in front of a lathe.
Three, it depends some guys can pull the barrel, and take enough care that it wont need reblued. But any body that promises that for certain, will sooner or later get caught with his face red.
its better to presume a re blue will be needed, and then if not, its a gift. It can be done, but by the time you get the tube out, and in the lathe, etc, etc, and back in the vise to re install, generally some scratch of owie will appear.
Last reamer I bought was over 100 bucks, and it wasnt even a custom reamer. Several guys offer reamer rentals now, and is the way to go for most jobs, unless of course you can find one of the old guys with hundreds of reamers on hand.
but anytime you start talking custom reamers, you are talking a couple hundred bucks to start, and down time waiting for the maker to supply the dern thing.
You need to set the barrel back one turn at least, in most cases,enough taper is in the case that new metal will be cut with most any SAAMMI spec reamer. There would be rare exceptions of course, the chambers in sporting rifles are rarely cut so tight as too see any difference in a set back, again, exceptions may appear.
I have chambered dozens of rifles with seperate neck/body setups.
Only the most well supplied gunsmith has separate throat/ neck reamers. Most cut with one reamer, and perhaps have a throating separate for the extreme reloader wanting VLD bullets, or trying to imitate a weatherby long throat.
Certainly the gunsmith can put the sights back on top, or markings where they were, if he cant, he shouldnt be standing in front of a lathe.
Three, it depends some guys can pull the barrel, and take enough care that it wont need reblued. But any body that promises that for certain, will sooner or later get caught with his face red.
its better to presume a re blue will be needed, and then if not, its a gift. It can be done, but by the time you get the tube out, and in the lathe, etc, etc, and back in the vise to re install, generally some scratch of owie will appear.
Last reamer I bought was over 100 bucks, and it wasnt even a custom reamer. Several guys offer reamer rentals now, and is the way to go for most jobs, unless of course you can find one of the old guys with hundreds of reamers on hand.
but anytime you start talking custom reamers, you are talking a couple hundred bucks to start, and down time waiting for the maker to supply the dern thing.
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