'Search' doesn't reveal anything. Does anyone have any experience using, for example back boring reamers to open fixed chokes. I have a few guns that have been redone or refurbished so to speak that are begging to be opened. These are pretty much run of the mill guns (94 Rem, Flues). I'd like to shoot them occasionally but extra full and fuller than that are tough to take. And $45 per barrel is a little tough to swallow at the smith's.
Any alternative suggestions? I'm very open to and in need of advice.

well if you screw up one barrel the 45.00 will look real cheep.just wait a little longer to shoot.the shotgun class is coming up in trinidad co,take the class you will have a good time. mc

We all look at things differently, I know, but IMO $45 per barrel for choke reaming is by an expert is well worth it. mc hit the nail on the head about the "cost" of a botched reaming job. If you plan to do a considerable amount of it in the future, by all means invest in some training and equip yourself with the right reamers to do the job. If you just need a couple or three guns done, I'd farm the work out. I've had a few barrels' chokes opened, and have always been pleased with the results.

Guys, I appreciate your advice and admonitions and perhaps I should have been somewhat clearer. The advice I'm persuing is how to do the job, as oppossed to whether I should do it myself or not. I get a great deal of enjoyment out of fooling around with my aquisitions as well as using them. I am going to do it myself. The last time I did this I used an aluminum rod slotted to hold emery cloth and a drill. It took forever.What else you got for me? All appreciated.

Here in Mexico we do not have expert gunsmiths to open a choke, so I do all my work in this arena.

You need: 1)A good quality variable reamer (actually you need 2 to open a 12 ga from full to skeet because diameters) and a handle, 2)a digital caliper, 3)a telescopic gauge (last 2 items to take mesures from the choke you are working), 4) some pork lard (I think other lubricants also work, but I use that because an advise from an old machinist) and 5) some fine sandpaper (600 girt).

Procedure:
1) Adjust the reamer to cut 0.001-0.002" (never more than 0.002")
2) Apply a little pork lard in the blades of the reamer
3) slowly cut the choke by hand motion (the reamer autocenter so you do not cut uneven as many people say)
4) Clean steel particles cutted from the reamer.
5) Repeat until the desired choke is obtained.
6) With the sandpaper polish a little (or as much as you desire) to abtain a nice finish (normally the cut from the reamer is nice, so you do not need to sand a lot.

I opened some chokes, both single barrel and doubles, by this procedure with always very good results.

Best,

I was employed as a machinist for 35 years & in the course of those years reamed a lot of holes. I can assure you that an adjustable reamer will not center automatically in a hole "Unless" there is already a parallel section for it to follow.
Try the above advise on a taper choke & be prepared for it to hit anywhere but where you look. You can expect good results on a conical parallel choke, just be certain & discern which type you have prior to taking out any metal.

Miller hits the nail on the head exactly. I reamed a lot of holes myself so I can recognize an expert.
Nial

I go a lot lighter on the cut, .0005 feels good, I use lard oil for cutting fluid and a parallel section is a must. I use a micrometer,telescope gauge and and an internal dial indicator and lots of pattern paper. Patterns give you the best answer.
bill

I have done quite a few, for an amateur, with good results. I now use a long, centering handle from Brownell's that uses two pilots, in the bore. It works from the breech end and I added a chamber pilot, made from a plastic snap cap. I use an adjustable reamer and a half-turn on the adjusting nut gives me about .002-.003". When I'm about .001-.002" from what I want, I finish it with a brake hone type tool, also from Brownell's. Like Ctroy, I do it because I want to. It's not brain surgery. In the earlier years, I did several from the muzzle, using a guide I made from a 3/8" rod with a plastic jag on the breech end, also with acceptable results. I like to put the barrels in a vise vertically, so there is less likelihood of leaning toward one side or the other. Some had a parallel section originally and some did not. The Lefevers have a continuous taper with no parallel section. This, I think, is where the bogus claim of a continuous taper from the chamber story came from.
If you want a pro, I'd certainly recommend Mike Orlen.

I have read that reaming chokes can possibly set up a chatter or harmonic vibration that can loosen the ribs on doubles. Is there any truth to this?

Thanks for the thread, it's very informative and sorta makes you want to try it yourself (starting? of course, with a gun you might just as well throw away).

I've got a question concerning chrome-lined barrels - can you open them, too? I've been told that if you damage the lining, the corrosion is going to get under the lining, where you can't possibly clean it out, and is going to ruin the barrel - is there any truth in that?

Jim;
As I understand your post you were providing a positive means of assuring the reamer aligned with the bore. I presume you do understand I was not speaking of this, but my caveat referred to simply reaming with an unguided reamer, depending upon it to "Allign Itself". If only very light cuts are taken it will generally do a pretty good job of this when there is a parallel section to guide. In the case of the taper choke there is of course nothing to serve as a guide.
Statements made in Lefever catalogs actually said their chokes extended from "Breech to Muzzle". I suspect this was simply a poor choice of wording on the part of the writers, but many writers, without "Finding out for Themselves" have repeated over the years they were choked for the full length of their bbls. I have never seen one so made or have any knowledge of anyone else who has.

Alot of good information here. Thanks folks. The wheels are in motion and I've ordered the adj reamer and a D reamer + blades and a long handle. I'm a little vague on 'parallel surface' so if one of you could further explain I'd appreciate it. I like that idea of modifying a snap cap to use as a guide. I have the rest of the tools. I have a small lathe to create bore size guides. I'm going to make kinda like reverse pilots. Here are the first three candidates. 94 Rem, Flues and an AJ Aubrey.

2 Piper. I too was surprised to learn of the Lefevre being a full length choke. I knew that my H grades / 2 1/2"s were indeed tapered full length but I thought it was a flukey thing. My bores above the cones are .747 and taper to the last 2" inches where they dive to IC an XF right and left repectively.

I do not want to argue with the experts; I am just an "amateur" gunsmith basically because I need to be my own gunsmith, but I never have a problem with an off-center cut opening a choke.
Perhaps just plain luck or, as you said, the chokes I opened have some parallel at the end of barrell (Winchester 101, Browning A-5, Ugartechea sxs, Remington 870 and some others I do not remember now).
What I noticed is that my 3 reamers (Expanding reamer made by Taylor and Jonnes, England) H6, H7 and H8 size, have some conical shape in the blades. If you measure them in the tip, you obtain about 0.005" less diameter than in the center or at the end. I think that this conical shape in the reamer helps to "autocenter" the blades and cut straight.
If you do this cutting by hand I can not see how you can cut off-center, because the reamer has the blades opposite to each other, so one blade can not cut if there is some "pressure" from opposite side.
I do not want to be a "hard head", but I still think an adjustable reamer is made to "autocenter" and made parallel cuts.

Anyway good luck with your shotgun´s choke opening proyect, you will enjoy to do it yourself and I am sure you will do in right!

Best,

What kind of comic was that in? If the ribs are loose then any work can loosen them further. I've bored hundreds of chokes and never had it happen.

Jose;
The two major types of choke constriction encountered are the conical/parallel & Taper. On the first type you have a cone section which reduces the dia of the bore which is followed by a short parallel section at the muzzle. On the later the entire choke section is a cone ending at the muzzle.
Imagine two bbls both having .729" (18.5mm) bores & choked to .690" (17.5mm), one having each type of choke. Then imagine inserting a solid rod which will just enter the choke to a depth equal to the length of the choke from the muzzle end. If you then tried to "Rock" that rod the one in the parallel choke would be un-movable, but the one in the taper choke could rock until it hit the angle of the choke wall, as it only has that one point of contact.
I can assure you that an adjustable reamer can do the same & will cut at what ever angle it happens to be started in this case. After the first few cuts create a parallel it will then tend to follow that parallel whether it happens to be in line with the bore or not. Those first few cuts however are totally dependent upon "EyeBall" alignment to the outside of the bbl, one can't see the bore while doing the reaming.
Of the guns you mention I know that some of them had & highly suspect they all had the conical parallel chokes, which would account for your positive results.
I do appreciate your input on this & hope my explanation clears up what I was saying. Successful operation of one of these adjustsble reamers for this task is dependant on taking only very light cuts & being very careful "Not" to apply any sideways pressure. If enough sideways pressure exists to hold the cutting edge into the meatal they can cut on one side only.

2 Piper:

Thank you for your explanation.

I just had good luck when I cut those chokes! No change for point of impact, but wider patterns that helps a lot to be a better shotgun shooter.

Best,

2 Piper: If I were to insert the adj reamer from the breech and as I insert it I place turned bore size 'pilots' at intervals, do you think that there would be enough support/guidance to keep the reamer centered in the bore/choke?

The PILOT BUSHINGS go on the REAMER not the reamer drive handle. You will need a smaller "pilot bushing" in the forward position on the reamer and a larger "pilot bushing" on the rear position of the reamer. For more details call me at 703-855-1110.

Good Shooting To You, Jent

More meatheads mutilating fine old guns! Enough to make me sicker than the lukemia I've got. Chopper

Thanks for the sarcastic reply, Richard. I don't read comic books anymore, and only wanted to know if reamer chatter could loosen ribs. I imagine that in all cases of rib solder joints coming loose, something causes the joint to fail. I suppose that could be anything from poor soldering, tinning, or fluxing to the stresses from firing. I have bored exactly zero chokes, but I would surmise that if "any work" can further loosen already loose ribs, then "any work" can loosen ribs that are not yet loose.

Keith: I thought it was me that worked his ire. I couldn't imagine what I had written to cause such a response. And Chopper, I do resent the 'meathead' response. Please don't start crying now. May I ask that those that rely on criticism alone refrain from posting in my thread. I'm getting very good advice and help here and someone chiming in with moronic posts just ruins it for me.

CTroy;
A bushing placed on the end of the reamer shank of a size to just be an easy sliding fit in the bore would keep the reamer in line. The lead taper on the flutes would center them as they made contact with the cone. I would not see a lead pilot as necessary for this purpose. If it was you would have to make a new one every cut. A good way to fit the bushing is after determining the needed size fit an oversize one to the reamer shank & then set the reamer between centers in a lathe for turning to the needed size.

I have never done it, and don't plan on doing it myself.

But here is a clip of it being done.

http://www.youtube.com/watch?v=l7YQf6YWLaM

I too, resent your "meathead" remark. I do not consider what I do, to my OWN guns, "mutilating fine, old guns". I am making MY PROPERTY operate the way I want it to. What I do to MY OWN PROPERTY IS none of your damn business. You're welcome to do, or not do whatever you want, to your property. Allow me and others the same courtesy.

I should start off by stating that I strongly agree with Jim in that one can do with one's possessions whatever one wants.

Having clarified that -"butchering" one's Purdey or one's Crescent is only up to oneself- I would like opinions from the experts as to the following method:

Long wooden dowel with a cut at one end where you roll a piece of oiled sand paper (300 grit) and put some paper under it until it fits snugly when you insert it, from the chamber, into the choke area. With the dowel in an electric drill and while wrapping the end of the barrel with a wet cloth to "refrigerate" you go at it with care, adding pieces of paper under the lubricated abrasive.

Comments will be appreciated.

JC

The video by Larry Potterfiedl referenced above, illustrates the method that I use and the straight type of reamers I use(commonly known in the trade as chucking reamers). Whilst good results can be had using the method, I would not attempt to ream 0.015" from a barrel in one reaming as illustrated by Potterfield in reaming the choke of the second barrel. My experience has been that one should ream 2 or 3 thousands of an inch at a time, up to the final 0.015". This, of course calls for a set of reamers numbering 10 or more per bore size of the gun (20 bore, 16 bore, 12 bore and so forth. However, one usually needs to finish the choke reaming with either lapping or honing.

Chucking reamers do not come from the manufacturer with a treaded hole in the back end of the reamer, but are soft enough on that end to allow drilling and tapping the hole using a lathe. Another point is that I have my pilot bushings placed on the reamer shaft with a collar on the reamer T handle shaft where the pilot bushing will not move up from the reamer shaft onto the T handle shaft during the reaming. Never turn the T handle counter clockwise after starting the reaming of a choke. It is a good idea to make up a set of reaming pilot bushings. I keep a 3/4 inch round bar of copper to make up a bushing quickly when I encounter a need for a size that I do not have.

I do not do a great deal of choke reaming, however if I did I would have a reamer manufacturer to make me a set of reamers with a two inch taper section at the front of the reamer with a two inch straight section following the taper.

One should also consider that reaming a choke from full choke to say 1/4 choke or cylinder bore will leave quite a long straight section of choke at the end of the barrel bore. Sometimes as long as 1 1/2 inches. Whilst this is not always an issue, it may become necessary to use a tapered reamer to shorten the long straight section in order to have the desired spread and pattern of shot.

For those of you interested in the art of patterning guns view the " A Look Inside Holland & Holland" video and watch Holland's master- Steve, work his magic with changing the patters and point of impact using ancient lapping methods and crude machinery. I need to ask Holland and Purdey's how many of their new guns are ordered with choke tubes. I suspect that in my life time that the majority of bespoke guns will be ordered with choke tubes and the art that Steve practices will fade into the past.

Chopper I agree with Jim you shouldn't call him a meAthead....some guys juat like screwing up guns.




Hope you feel better Chopper.

Agreed...it's Jims gun to screw up if he wants to.

How many mil on average are you taking out with your emery whirligig, J.C.?

I think the magic words are "piloted in the bore".

jack

I would like to thank all of you who have offered help and advice. I have ordered the adj reamer, 34" T-handle and 6 different size bore bushings. I will make the other bushings myself. All of your advice and warnings have been documented and I feel confident that the job will come out the way it's intended.
I won't be checking any posts any more as I no sooner get my request for no more sarcasm or criticism posted and some sneaky little ba stard like 'homeless joe' has to stick his unwelcome nose in. I'm actually sorry I started the f'n thread and yes I have a thin skin and that's because I can.
Thanks again C.Troy

Jack that is a trick question. Not a lot. When I saw it done no measuring instrument was used apart from a Galazan choke gauge. Later the gun was patterned to compare to previous choke. It worked out well. Maybe a lucky result like José's.

Granted, it is a rudimentary method and yes completely agree with the magic words.

JC

jOe, no screws involved. We are talking about fixed chokes here. Do pay attention!

JC

Actually I didn't mean to be critical of the centrifugal abrasive method. I think JL mentioned a long time back that he had successfully opened a choke eccentrically (more off one side and moron the other?) with a rattail file to move POI so anything is possible for those who have the skill and judgment to make it work. That "moron" thing came from proprietary bicycle tubing. Forget the feller who had this line of titanium pipes but it had "moron" the ends thus Moron tubing. But that "Walker" method of handling an unpiloted reamer ( Mike Orlen used to promote it with a little sidebar on his business site) seems especially iffy in the on-axis dept.

jack

Thanks I needed that

Yeh joE, Annual Crankypants Day rolls around again and yOu are there. I like that line "I have a thin skin cause I can!" Saw one of the W&S712's you were talking about. Didn't look that bad; weird wood-on-wood buttplate.

jack

Yeh joE, Annual Crankypants Day rolls around again and yOu are there. I like that line "I have a thin skin cause I can!" Saw one of the W&S712's you were talking about. Didn't look that bad; weird wood-on-wood buttplate.

jack

I hate it when you repeat yerself.

joe: it's becoming clear now...were your chokes reamed a long time ago?

It appears yers might be a tad tight