Altering chokes of a chrome lined 12 ga semi [single barrel]

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Willy Tincup

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Would like to alter the choke on a 12 ga full choked semi chrome lined barrel.
-first choice would be to have it threaded for thin tubes
-2nd choice would be to open it up to Imp Cyl.

The muzzle measures .832 and has a wall thickness of .069"
Can it be done, reasonably?
Who in Ontario can do it? .....probable cost?
Thank you for 'experienced' input.
 
I dont know if it can be done on your gun but carbide tools are needed as thats what ive been told. Alot of gunsmiths dont have them is what ive found. They are expensive to buy from pacific tool
Iirc epps did a baikal for a buddy a few years back. It cost more than a regular barrel to do
 
brybenn said:
I dont know if it can be done on your gun but carbide tools are needed as thats what ive been told. Alot of gunsmiths dont have them is what ive found. They are expensive to buy from pacific tool
Iirc epps did a baikal for a buddy a few years back. It cost more than a regular barrel to do
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You can get basic brazed on carbide boring bars for not much; the cost would be fairly negligible if you factor it over multiple jobs.
 
I think you will find that the cost of having the barrel threaded for choke tubes by a competent barrel smith plus the cost of a set of tubes and wrench may be greater than the cost of another barrel, especially a used one. Another factor here is that your preferred smith probably only is set up to do one brand of chokes, usually not thinwalls, frequently Remington chokes. The different brands are not interchaneable and he will probably only tool up for the one that he prefers.
Opening your existing choke to maybe an all round modified choke (more open if you prefer) is quick, easy for a smith with the proper tools and should cost less than $100, although it's permanent of course, you can't go back. Chrome lined barrels are no problem for gunsmiths who have the proper tools. Those who do lots of shotgun barrel work for trap shooters, especially on Berettas regularly deal with chrome lined barrels. Do your homework, phone around.
 
I used to do it. I had to remove the chrome lining in the choke area with a carbide reamer first. Then did the alteration for Thin Wall tubes. When completed there was a very small area of the bore before the choke tube that had no chrome lining. The bore needs to be measured for concentricity and a decision made by the installer if they can do it or not.

I would opt for the improved cylinder choke alteration... It will also require carbide tooling.
 
The only 2 'smiths that I knew that did that sort of work, do not any more. One just stopped doing it citing a lot of work for little return and the other died.
 
In the past I removed the barrel chrome and choke with a cylinder hone. The guns seemed to work ok after my modification. I also used to get choke tube jobs done by Bob Foreman, (now deceased) who lived in Sooke. He had tooling to deal with chrome bores and he did two different styles of thin wall tubes. I sometimes wonder what happened to his tooling after his death.
 
Be aware that if you attempt to open the chokes up by yourself without doing it concentrically in a lathe it may come out egg shaped, bell shaped, elliptical, off centre, etc and will no longer shoot to point of aim.
 
buckbrush said:
what do you base this statement on?
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I think he said "it may come out egg shaped, bell shaped, elliptical, off centre, etc"... the key word being may.

And it is entirely possible if it is not done correctly... at home or in a shop... but the odds favor experience over do it yourself...
 
I speak from experience, I've been the new owner of a couple of these beauties purchased second hand on CGN. Logic will tell you that the choke area needs to be perfectly round and perfectly concentric with the bore if you want it to shoot to point of aim and throw great patterns. Yes, someone may open up the chokes with basic tools but there is a reason that the true gunsmiths take the time and care to do it properly. You can do it the cheap and easy way or you can take the care to do it the proven best way. Do you feel lucky?
 
I received an email reply from Epps saying that they can't do chrome lined barrels. Kinda surprising to me. I'm good with just getting it reamed out to IC; just need to find someone with a carbide reamer and a willingness to do it.
 
buckbrush said:
if you just want to open up a choke on a chrome lined barrel, a ceramic ball hone works great. KBC tools has them.
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Agreed.
Anybody believing that carbide tool (85 HRC) can cut hard chrome (HRC 80) with ease is going to be disappointed.
That might work if gunsmith is ready to destroy couple of tools worth multiple times as much he earns from job done.
Before my retirement when working in machine shops the one of more difficult jobs was to machine replacements of destroyed hydraulic cylinder shafts.
Those were induction hardened high alloyed steels with hard chrome on top of it. Removing first 1/16" layer was almost impossible even with coated
carbide inserts. The only solution was to use ceramic inserts (HRC 95 or so) with tight and stiff lathe taking no more than .020" cut and very slow feed.
The chips were very bright red and very thin and crumbly after when cold.
Of course diamond (HRC 100) hones would be the best to open chokes in chrome lined barrels.
Believe it or not.
GR8 2c worth.
 
I hear you, ive turned those hydraulic cylinders as well, but that hardened chrome lining isn’t comparable to shotgun barrels, barrels are much softer and Carbide has always worked for me.
My vote would also be open to Improved.
 
cooperod said:
I hear you, ive turned those hydraulic cylinders as well, but that hardened chrome lining isn’t comparable to shotgun barrels, barrels are much softer and Carbide has always worked for me.
My vote would also be open to Improved.
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Are you saying that hard chrome in barrel is not the same hard chrome on hydraulic shaft?
There is no such thing as soft chrome unless something like nickel is used in the shotgun barrels.
 
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Chrome lining in shotgun barrels is very thin and shotgun steel is very soft...

Comparing that to taking cuts on a chromed hydraulic shaft is ridiculous.
 
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