Setting Back A Barrel

In a post to sell a rifle the seller said something to the effect that the barrel has been set back X mm, so I asked Google what this means and it said:

"Set-Back Barrel – This involves a gunsmith cutting off around 1” of the barrel (on the chamber side), then re-reaming the chamber. This essentially removes the part of the throat just forward of the chamber, which is where primary throat erosion occurs. You may lose an inch or more of length in the set-back process, but can dramatically extend barrel life"

Has anyone here set back a barrel and can advise costs/benefits, perhaps indicate which gunsmiths provide this as part of their service?

Cheers

AMac

A good mate had his 6.5-284 set back last year by Alan Carr (Kapiti based) when accuracy drifted from 3 shots 1 hole, to about 1/2 inch, it's back to 3 shots 1 hole. It was under $200. I believe he had 1200 rounds down the barrel when accuracy dropped away.

Doesnt always involve cutting a lot of the front of the barrel.
There may not be enough metal in the knox form to handle that.
It may only be a thread or two

Thanks guys - sounds like a chat with a gunsmith up this way could be worth while

Setting back a barrel does not always do wonders. It depends at what stage of erosion you do it and how fare it is toasted down the bore.

If you take a 6mmbr or 223 barrel you could set back a couple of times and still have a lot of fun with that barrel and not loose to much accuracy.

But in the exemple above about the 6.5-284, you might get an extra 400 to 600 rounds before the accuracy drops agains. There is a point where you are best to invest in a new barrel and not look back.

Hmm - based on my first response from an enquiry gunsmith that getting this done for a T3 might prove to be a challenge.

Its usually used as a cost effective way of trying to get more life out of a worn barrel.

Cost - at a wild guess - maybe a couple hundred $? Its cheaper than a new barrel, which is usually why its done.
Benefits - it prolongs the life of what might otherwise be a worn out barrel. Its not a pro or a selling point like a trigger job, bedding job, or other gunsmith work might be. Its certainly not an upgrade.
Cons - barring some other kind of problem, it means the rifle has been shot a lot, and the barrel is probably well worn.

if its a factory tikka barrel and its starting to go to shit a factory tikka take off may be a better option from where someone has gone custom
similar money and less mileage in my opinion

Whilst setting a barrel back can improve the chamber and throat, it seldom does anything of consequence for an inaccurate barrel. Accuracy is far more dependent upon the condition of the muzzle end. Subject to inspection for wear or damage, removing and inch or two and re-crowning the muzzle will produce better results. Either of these jobs are only a cheap and temporary solution to any barrel problem, as opposed to a complete re-barrel. The usual reason for setting a barrel back is to correct a damaged chamber.

Thanks for your comments all.

My reasons for asking about setting back a barrel is not due to the loss of accuracy or wearing it out - the loads my T3 shoots best do not fit into the magazine as I have seated the Amax's out, this is a bit of a pain in my view.

So I was wondering if setting back the barrel could result in a loads that fit in the mag? As a result of Covid my employers bless them have instituted a 20% salary reduction out to the end of October (I hope), hence the discretionary $ are not there for a new barrel this year, so I was looking for a "Scotsman's" fix...

Cheers

AMac

Quote:

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Originally Posted by AMac

Thanks for your comments all.

My reasons for asking about setting back a barrel is not due to the loss of accuracy or wearing it out - the loads my T3 shoots best do not fit into the magazine as I have seated the Amax's out, this is a bit of a pain in my view.

So I was wondering if setting back the barrel could result in a loads that fit in the mag? As a result of Covid my employers bless them have instituted a 20% salary reduction out to the end of October (I hope), hence the discretionary $ are not there for a new barrel this year, so I was looking for a "Scotsman's" fix...

Cheers

AMac

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As the previous responses have outlined, setting the barrel back is entirely about correcting a poor chamber or getting rid of an eroded throat to redeem a barrel that 'may' have some life left in it.

The issue you are outlining is a totally different thing. To offer up any useful advice we'll need to know some more information:
What calibre do you have?
What is the exact projectile you are using?
What length are you loading to?
How are you measuring that load's length (overall length or base-to-ogive)?

If you are shooting a factory T3 it should have a SAAMI spec chamber and throat (or something very similar). Seating very pointy projectiles out so they get closer to the rifling is a very common situation - luckily with a T3 if it is a short action cartridge you have the option of fitting a new bolt stop to convert your action to a longer bolt throw.
Then you get a long action magazine as well and your problem is sorted!

If it's a long action calibre already then I believe your options are very limited.

It is a very common thing for target barrels. Most of the Palma type profile barrels have relatively long knox form (the thicker part on the chamber end). Lilja is a barrel manufacturer well known for very long knox forms, you can easily set back their barrels 2 or 3 times.

To get real benefit you need to put a borescope down the barrel and see how far throat erosion and fire cracking extends. For barrel burner cartridges like 6.5-284 etc it might not be worth setting back.

Setting the barrel back will have no effect on rounds fitting in the magazine, that is a separate issue.

Greetings All,
Talk of setting back and re chambering barrels reminded me of some other options for recycling rifle barrels that might be of interest.
Years back, when the full bore shooters had to use the crappy 144 grain NATO projectile, their accurate barrel life was very short. The barrels would still shoot other projectiles well but they got screwed out and replaced after about 1100 rounds or so. As a result there were a lot of these barrels about. I was given 2. One was a Sportco with a 12 inch twist which a friend cut the end of and threaded it for my Martini Enfield and chambered in .30-30. The second was a Schultz and Larsen with a tight bore and a 14 inch twist. I gave this to my friend. The Martini wound up re chambered for .30-40 Krag by Dinny Collings. I believe Dinny was fitting some of these barrels to no 4 actions and chambering them in .30-40 Krag. He also offered hand loaded .30-40 ammo for them. I bought some when I was in his shop. The S & L barrels have tight bore and groove dimensions which will run pressure up and the 14 inch twist limits the projectile weights but they work well with selected cartridges.
My Martini Krag or Martini Sportco take your pick shoots really well with light loads. I don't see any point in loading up a 140 year old action. And yes it hasAttachment 146205
visited the Kaweka's.

Thanks Guys

Its a 7mm mag and I load 162 A Max so that the end of that trip down a rabbit hole for me.

cheers AMac