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Posted By: Mark Larson Choke tubes in cut barrels - 01/07/13 06:16 PM
I've never had tubes installed in a gun, but I'm thinking about having it done. Do choke tubes in barrels that have been cut to cylinder perform ok? I'm thinking of guns with "tapered" chokes, like Lefevers, and wonder if there is a disadvantage with an abrupt choke constriction versus a gradual one, if indeed such a distinction even exists.
Posted By: builder Re: Choke tubes in cut barrels - 01/07/13 06:55 PM
As far as I know choke is removed to install all choke tubes in a gun making it cylinder bore. It is then internally threaded. The typical choke tube installed is often 1 1/2" long. CZ and Krieghoff have 1 1/2" long choke tubes in their 12g. guns and they perform quite well. A lot of makers use 2" long tubes.

I have had it done two pump guns and it worked very well.

Not all guns have the "meat" at the muzzle to install tubes though. Mike Orlen used to have a pricing sheet that spelled out the dimensions needed before he could install them.
Posted By: builder Re: Choke tubes in cut barrels - 01/07/13 06:55 PM
Here it is:

http://users.dls.net/~rdouglas/MikeOrlen.pdf
Posted By: Bilious Bob Re: Choke tubes in cut barrels - 01/07/13 07:12 PM
Unless you are pass shooting ducks, why bother? Cylinder is fine.
Posted By: CBL1 Re: Choke tubes in cut barrels - 01/07/13 07:27 PM
I have just had Teague chokes inserted in an old, treasured, yet v cheap over/under and the work was excellent. The results have been even better, especially on higher driven pheasant which was the primary reason I got it done to make the gun more appropriate for this type of shooting.

I hesitated getting the work done initially as this was a gun I knew and shot with well and which I have been consistent with - the worry being this could mess that all up. However, I went from a (UK) fixed 1/4 and 3/8 choking to a set of 5 tubes covering (UK) Improved cylinder, 1/4, 1/2, 5/8 and 7/8ths and am delighted. I don't anticipate changing round the long flush tubes on a daily/weekly basis, but do now have the capacity to do so given I also use the gun on other types of live quarry shooting.
Posted By: Mark Larson Re: Choke tubes in cut barrels - 01/07/13 07:57 PM
Thank you. My shooting often ranges 30-45 yds, and I've found cyl choke to be lacking sufficient pattern density for clean kills at those ranges, especially on covey birds going straight away.
Posted By: CBL1 Re: Choke tubes in cut barrels - 01/07/13 10:08 PM
There are so many (opposing) views on choking that I won't get into that here, but for me, the driver behind the choking tubes being fitted was, to a degree, confidence. I genuinely felt that original chokings I had on my gun were not adequate to cleanly kill the quarry I was seeking to shoot (high driven pheasant late in the season), and because of this, I did not wish to use it for this purpose. This is not an issue with the tighter chokes fitted in when shooting this type of quarry and accordingly, my confidence in the guns ability to cleanly kill has improved.

That does not in any way mean my skill has improved however!! smile
Posted By: Rocketman Re: Choke tubes in cut barrels - 01/08/13 03:01 AM
Hi, Mark,

Dr. A. J. Jones, in his book on sporting gun choke performance, pretty much came to the conclusion that choke constriction is the only predictable factor in choke effect. I once spent a lot of time on analysis of various choke patterns. A Charles Hellis game gun with 7" taper length full choke had, surprise, surprise, full choke performance; not better, not poorer.

I think the taper choke Lefever is a red herring. I'm yet to see one in the flesh. Actually, I'm yet to see a choke taper longer than my Hellis guns.

All choke taper is reamed out of a barrel before it is threaded for choke tubes. So, pre-tube choke is no issue.

"Abrupt" could have differing interpertations. A square shouldered diameter change (now, that would be ABRUPT!) probably would not work as a choke. However, a 1/2 inch taper probably would. It is not clear how much shot follows gas dynamics laws; it is clear to me that it does to some extent.

I have had good luck with tubed guns. Go for it if it will make a gun fill your needs.

DDA
Posted By: 2-piper Re: Choke tubes in cut barrels - 01/08/13 03:40 AM
Lefever catalogs of the day stated their chokes were a taper from breech to muzzle. So far I have failed to examine a Lefever so bored. Lefevers I have been able to check which were believed to have original chokes were "Taper" choked in that they had no parallel section following the choke so were tapered to the muzzle. However the taper started about 4" back of the muzzle on full choke guns with a lesser length on guns with less than full. It may well be that all bbls were choked with the same reamer, it simply being run farther out the bbl as constriction was reduced.
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