Shortening smallbore rifle barrels

[James Storm]

I often see reference to shooters shortening the barrels of their smallbore rifles to make them easier to hold in offhand. Nowhere have I seen how they do this. Do they just saw off the muzzle end and then face them with a lathe or with a file and then chamfer the muzzle with a tool from Brownells? Does the shortening affect the accuracy of a fine barrel by removing the subtle choke imparted by careful lapping? Any reports of personal experience with this matter will be appreciated. Thanks, Jim Storm jamesestormmd@yahoo.com

[left360]

No experience with it but have always heard/read that it is best done from the breech end and rechambered.

[Cumbrian]

Others will offer more expert views, I hope, but here is my two penny worth.

On the one hand, shortening a barrel does not necessarily impair accuracy, though it will diminish muzzle velocity. An expensive experiment was carried out on a Sako (or Tikka?) barrel ( I forget what calibre), which was progressively cut in 2 inch instalments from its original 26 inches or so down to 14 inches, re-crowned (I think) and tested at each stage. Its accuracy varied a bit, sometimes better than originally, but it was not fundamentally adversely affected. And hunting rifles are often shortened to accommodate the length of a moderator (as in the case of my own .223, by 2 inches only) or to make them more wieldy.

On the other hand, I shudder at the thought of cutting down a precision German or Swiss or British or American target barrel and would be fearful of the consequences for accuracy. As you say, you risk losing the benefits of any 'choke' that is present, which Anschutz barrels possess, I believe - perhaps others? You would also lose the dovetail for the foresight. I have seen Anschutz rifles for sale with shortened barrels, screw cut for moderators etc., but for me that is butchery.The one exception, I suppose, would be a very limited shortening if the muzzle were damaged and the barrel needed to be re-crowned anyway.

[Tim S]

@ Cumbrian, I think the Original Poster was thinking of shortening target rifles for weight reduction on a budget, probably for junior shooters. British vermin shooters often shorten and screw thread, but there's no decimal scoring on rabbits. Shortening a .22LR is unlike to reduce MV, as most ammunition reaches peak velocity at about 16in; cutting down a 26in target barrel may actually increase MV.

Shortening from the breech end, and re-chambering does preserve the factory muzzle (and removes any wear from past use) but it's definitely a gunsmith job, or one very serious amateur machinist, not the casual DIYer. If you can only find/afford an old 690mm heavy barrel, professional re-chambering may be too expensive.

As for losing the foresight mount, you'd fit an extension tube anyway to restore sight radius.

@ Jamesstorm
There are several threads on this forum about Anschutz muzzle chokes. It's generally held to be a by-product of button rifling, rather than lapping. Some report poor accuracy after removal, other no loss at all. Forum member Bob Smalser described the process a few years back, albeit with a Valmet barrel. I have a memory he slugs the bore with a pulled bullet to find a tight spot at the approximate location for the new muzzle.

I'd consult a reputable gunsmith myself, but I never learnt metalwork. Unless the muzzle was already visibly damaged, and so DIY repair won't make it worse, I'd want a professional to do the work.

[beye]

Jim, the short answer to your question is that it depends on the barrel as to which end you can cut off. I have shortened a large number of .22 target barrels over the years for varying reasons. I generally do not cut off the muzzle end of a factory button rifled barrel, such as an Anschutz. While I find it not injurious to cut a small amount off for recrowning purposes, cutting off the whole "knot" and more has seldom been productive, although a few have and as Tim has mentioned, slugging the bore would tell you where not to cut it off (crown needs to be where the bore is the smallest). I have cut off a number of Win. 52, Rem. 37 & 40X barrels on the muzzle end without ill effects as long as they were not so short as to cause standard velocity target rounds to become supersonic. Many years ago I achieved Master class in conventional prone with an old Win. 52 with a 20" barrel which was cut off mostly from the muzzle and set back slightly on the chamber end.
On the subject of velocity, a .22 target round achieves maximum velocity around 18", give or take a little. Eley uses 26" barrels to determine velocity and a good 8" or so are used to slow up the bullet so that it exits subsonic. If you are shooting past 50 yds. this is important. Cut the barrel too short and it will exit at supersonic speed and will have more wind drift and accuracy will be worse at 100 since it will pass through the transonic range. Benchrest shooters rediscovered this in the early days of national BR rimfire competition as they made barrels shorter and shorter in order to make weight. Most now keep their barrels at 20" or more, generally 22-24" to avoid the problem. Also Eley is offering lower velocities than they did some years back, perhaps for the BR & silhouette shooters and more importantly the shorter barrels with barrel extensions that Anschutz has been selling.
The thing that is hard to quantify is how much cutting the barrel off will affect barrel harmonics. It's a crapshoot on that question. The old 52 barrel I made Master class with would not shoot well after shortening unless I used a tuner. I shoot a variety of rifles in SB prone these days, none shorter than 25 1/2"; some are factory length, some are cut off factory and some are custom barrels and all shoot well without a tuner. So that effect is hard to predict, but none shoot well if the muzzle is cut where the bore is larger instead of smaller.

[James Storm]

Gentlemen: I am very grateful for your responses.
Regarding the loss of a choke by shortening, I thought of machining a steel band with an ID a bit smaller than the OD of the barrel, heating the band and then slipping it over the muzzle end of the barrel while hot and letting it cool in place in order to squeeze the barrel and form a choke. I asked Mr Calfee about this and he said it would not work. He should know, but I am not yet convinced. He writes about slugging a barrel to determine where to cut the muzzle.

I obtained an 18" slip in barrel from Lilja for my 2013 Anschutz. They were not enthusiastic about this length but it does make it easier for me to hold in offhand. I could not see any difference in accuracy from the same rifle with a 26" barrel. Most of my shooting takes pace at an indoor 50' gallery. Also, my offhand skills are not great so this test proves very little.

I had heard over the years that a .22lr bullet reaches max velocity at 16-18" so why ever make a longer barrel other than to provide a longer sight radius? Your information about slowing the bullet so as to gain accuracy at longer ranges by preventing bullet exit at supersonic speeds answers this question for the first time for me. I had zero awareness of this factor and its consequences. At 50' indoors, the effects using a short barrel are very small, but outdoors, in the wind, they are significant.
Recently I acquired an old .22 barrel. If I can ever find a source of lead slugs, I will slug it, then hot sleeve it and see if I can detect any changes. If Readers of this thread can beat me to it, I hope they will give us a report.

Thanks again for your help. Jim Storm jamesestormmd@yahoo.com

[Tim S]

Jim,

Re barrel length, yes an adequate sight radius was a consideration in the days before bloop tubes. Weight was another; both muzzle heaviness, and just sufficient mass. More weight up front seems to have been popular. Also your 18in barrel would have made for a pretty light rifle in a 52 Marksman stock.

The idea of shrink-fitting an external choke does seem odd, although I've heard of bloop tube collars having the same effect.

[pdeal]

I agree with what beye said. I have also shortened a number of target rifle barrels. If you slug many of these barrels you will find the slug is very loose in the middle section of the barrel. If you cut it here you probably will not have good accuracy in the end. Slug your barrel first and see what you have then you can cut it off so you wind up with a tight muzzle. Several times I have threaded the muzzle of the shortened barrel and fabricated a tube from DOM steel tubing and blued that so it still looks like a long barrel and used this to get my sight radius back.

[Trooperjake]

Having a shorter barrel is a very good idea,
But;
If you have a very accurate barrel, chances are you will loose accuracy.
I think it has to do with the different lathes the barrel is cut and crowned on.
And the fact 2 different machinists were used. And is the action threaded or not.
This happened to 2 rifles I had cut down.

If you can swing the cost, have a new 20” barrel fitted.

[beye]

Having a shorter barrel is a very good idea,
But;
If you have a very accurate barrel, chances are you will loose accuracy.
I think it has to do with the different lathes the barrel is cut and crowned on.
And the fact 2 different machinists were used. And is the action threaded or not.
This happened to 2 rifles I had cut down.

If you can swing the cost, have a new 20” barrel fitted.

Should not have anything to do with the lathe it is crowned on or the machinist. The crowning job is either done right or it's done wrong. If you just cut off a barrel to predetermined length without verifying the bore diameter at this point, then it's a crapshoot. One of my best SB prone rifles has 2 1/2" cut off the muzzle and shoots considerably better than ever before. One time anecdotal evidence is a good indicator of the variability of results that different people have. Got to know what you are doing on cutting down a rimfire barrel.