16ga.com ~ View topic - 16gaugeguy

Joined: 03 Jul 2005 Posts: 370 Location: Amarillo, Texas

You told about polishing forcing cones in a post a few months ago and i can't find it. The forcing cones on my favorite shooter are always crapped over after a hunt. I had them lengthened by a "name" gunsmith but geez they get plastic fouled and leaded up easy so I am thinking maybe the polishing will help.

Would you mind repeating the process you used please? Or do you know where the post is?

Thanks!

Mike

Its easy Mike. If they are fairly rough, first take a foot long 1/2 inch hard wood dowel and cut a 1/8 inch slot across the top to about a depth of 1-1/2 inch. Take a thin piece of rubber like from an old inner tube 1-1/4 square and a piece of #400, #500, or #600 crocus cloth as needed, the same size and insert both into the slot so the cloth will bear on the metal when rotating in an electric hand drill. Insert the dowel into a hand drill with a 1/2 inch chuck or trim the dowel to fit a 3/8 inch chuck. Insert the end with the cloth and rubber and give the cones a good polishing by slowly moving the cloth up and down the lenght of the cones and into the bore just ahead of them. You might have to add another piece of crocus cloth to get it snug enough but don't overdo it. The centrifugal force will work for you if all is right. you should feel just a little resistance but not a lot when the drill is on. Just add or subtract whatever you need to to get the right feel. You will know it when everything is working smoothly. The abrasive cloth will ride in and out with a smooth feel like you were applying a heavy grease to the bore. you will feel just a bit of resistance. Do not force anything into the bore. Go easy and don't let the steel get hot, just mildly warm. you will feel it with your palm. a little motor oil on the cloth will help if the cloth is a wet or dry type. The oil and grit will form a slurry which will help the polishing along.

Next, clean thebore with mineral spirits to remove the oil and old grit. Then take the brush end section of an old three piece shotgun cleaning rod with an old 16 or 20 ga bronze brush in it and wrap the brush with a layer of OO steel wool peeled from a pad of it. Put enough steel wool on and spun in the right direction so it stays on the brush and its a little bit of a snug fit in the cones, but not too tight. Insert the rod end into the drill and polish away. Do this dry with no oil. Add steel wool as needed. follow up with OOOO steel wool and Flitz, Semichrome, or Puma knife polish. follow up with a clean cotton patch or two to remove the flitz and spin them until the cones are dazzling shiny. That should do it.

I polish out my bores all the way to the muzzle with OOOO steel wool and a brush on a long enough rod in a drill a couple times a year in my trap guns. Keeps them shooting well and the fouling just zips away. However, easy does it. Just a few passes is all it takes if the bores are smooth to begin with.

You can also remove mild pits, rough spots and staining in an old gun or a neglected one this way too. Use the grade abrasive cloth that suits the job, but avoid anything coarser than 220 grit. Also, go very easy in the choke areas on older guns with softer steel barrels than today's 4140 moly steel grade barrels. However, OOOO steel woll won't hurt these modern steels at all so have at it.

Joined: 03 Jul 2005 Posts: 370 Location: Amarillo, Texas

Wow! Those are very good, thorough, and clear directions. Thanks for taking the time to post them for me. I may try the finer grit crocus cloth tonight and see how the gun cleans up after this next hunt.

Thanks again!

Mike

Joined: 23 Nov 2006 Posts: 58 Location: Northeast

With all due respect to 16gaugeguy, I wouldn't try to do my own work on the forcing cones or especially the bores. If the cones were already done by X gunsmith, I would send the barrels back to X and ask the gent to do a better job of polishing them. Keep in mind though that the longer the forcing cone, the worse they tend to look from the breech end. Short, sharp cones tend to look dark and even, but you can see the reamer marks more easliy on longer ones. They would have to be very rough to get any significant buildup of plastic from the wads. Regarding the bores, it is not commonly known but the surface finish (rms) of the bore has a great effect on the performance of the choke. The more highly polished the bore, the less tight the patterning for a given choke configuration and constriction. Polished bores look nice and spiffy but they may not achieve the patterning you want. This was brought home to me when I spent a few days pattern testing in a master barrelsmith's shop, and I personally saw the effect that different polishing grits had on the patterning efficiency we were trying to achieve. Incidentally this noted barrelsmith avoided polished bores like the plague. Silvers

I agree with 16Gaugeguy. If you're worried about taking off to much metal, try it first with the steel wool. If you're still worried, use oil on the steel wool. Dry you'll take off more metal then wet. Start out with 0000 steel wool. Polish them . Take a look at the barrels. Clean them good, go out in the backyard(if you can) pattern the gun. Check for fouling. If that didn't help, work your way backwords. Use the steel wool dry as that will effect the metal more then if wet. Then do it wet again, Clean it out and pattern again. Check for fouling. I'm lucky, I can just go out my back door and shoot up a storm, the only one that ever comes around is the DNR looking for that deer hanging in my shop. Woke me up one morning at 3:00 looking.

Member Joined: 28 Oct 2005 Posts: 665 Location: Louisiana

If removing metal is really your worry, use bronze wool---it's less aggressive and will surely cut the fouling that concerns you.

With all due respect to Silvers, the methods of regulating patterns and the ammo that produced them are both passe and have been for decades. This practice of leaving the bores unpolished used to be a common method when custom gun makers built guns. Once the desired result was obtained with a specific brand and type of load, the work was done. Changing anything including the bore surface would most likely change the results. However, that particular gun was recommended for use only with that specific load and no other. Also, cardboard and felt wads do not foul up an unpolished bore like a plastic wad will. This approach is not possible today for obvious reasons.

Times, ammo, the barrels to shoot it with, and even the chokes have changed because of mass production and materials. Unpolished bores are now a liability. Since the advent of the plastic, one piece wad and the explosion of relatively inexpensive mass produced ammo in almost any configuration, buying or obtaining a consistantly and uniformly made type of ammo is about impossible unless you happen to handload your own. Manufacturers change componants as needed to get the results they want at a price they can afford. If you handload, you will most likely need to use plastic wads for convenience and cost savings.

Unpolished barrels crud up with plastic residue quickly both at the cones and in the choke tubes or in the fixed chokes. This build up of plastic residue will play hell with consistant patterns and effective shooting regardless of the type and brand of ammo used. count on it. That is why most shotgun barrel bores and choke tubes are now highly polished on new guns.

A well polished bore is a consistant, predictable surface. An unpolished one is not. If you doubt this, just glance down any clean, well made new shotgun bore from a manufacturer with a good track record. The barrel is smooth and shiny from a good polishing or should be. If the barrels have been roto forged, the surfaces come off the forging machine with coined, very smooth surfaces. Polishing is not ususally needed except to clean up any verey minor flaws. Some manufacturers apply chromed surfaces to both smooth the bore and keep it from corrosion. Others lap the bores to a high sheen after they are reamed. none are left rough on purpose today. Unpolished bores are the sign of slipshod work in this modern world. Somebody has been cutting corners.

The effect of plastic wad residue build up might not be so bad for an upland gun fired a few times a week. However, it is poison for a gun used to shoot long strings at targets. Since more folks now also shoot their hunting guns for recreation targets and practice, better to go with polished bores and adjust the chokes and/or the loads to pattern well out of them. This solves all the problems and results in consistent effective shooting anytime for any reason.

I also agree that the shop doing the work should have followed up better on the polishing job. However, polishing a bore is now part of routine maintainance, so learning how is now manditory unless you can afford to hire it done all the time.

I also pointed out the difference between older barrels and newer ones made of the very tough modern steeel alloys employed today. OOOO steel wool will not begin to touch 4140 moly steel. Steel wool is made of very mild steel. It will cut through plastic build up like a hot knife through butter. It will also remove any corrosion or rust which is far softer than the steel under it. It will not polish the steel to any great degree nor wear it out of spec. More aggressive abrasives are required to do this. That is where crucus cloth and wet or dry oxide paper comes in.

Of course, this advise about abrasives does not apply to some of the softer steels used in older, pre WWI guns and some of the cheaply made pre-WWII guns. However, nearly any modern, post WWII gun barrel is made of very tough steel. Product liabilitry alone calls for this. So don't sweat the use of OOOO steel wool on your modern barrels. It will help keep them clean, polished, and shooting consistantly if done correctly.

There is one more point I should have already made. This polishing does not apply to the chamber surfaces--only the bore. A highly polished chamber will cause the shell case walls to slip upon firing the shell. this is not a good thing. It causes excessive thrust against the bolt or breech face. Both recoil and stress will increase. Chamber walls are left with a machined surface. This does not translate to a rough surface, just an unpolished one. Leave the chamber alone and avoid polishing it. Just clean it out with a brush and a patch. thats all.

Member Joined: 01 Dec 2006 Posts: 524

I respect 16Ga Guys preference to do his own cone polishing, and I'm sure his method works. I would agree with slivers though and never attempt to do that on any of my guns. I'd have to be shown hands on first, then attempt with an old gun I don't care about, show it to a pro to get his okay. Until then, especially with an old collectable double gun, I 'll farm it out to a pro.

Joined: 23 Nov 2006 Posts: 58 Location: Northeast

I'll paraphrase Jack O'Connor and ask those of you following this thread to "pick your expert" when it comes to polishing the bore(s). The master barrelsmith I referred to in my earlier post is Kenny Eyster of Centerburg, OH. Ken does competition barrel work for noted shooters like Jon Kruger, Tom Mack, Andy Duffy, and a host of others who are into serious trap, skeet, sporting and long range pass shooting at game birds. His shop walls are literally covered with photos of his clients with personal endorsements to Ken. He does not believe in forcing cone or bore polishing. In fact he told me it's counterproductive to efficiency. While in his shop I've watched Ken and his sons cut cones using reamers only (no polishing), and hone the bores with various emery cloth grit sizes until they get the pattern efficiency desired by the owner/shooter. They do not use very fine grits nor steel wool, etc. Looking down the finished bores you will not see a shiny reflection like cheap dime store jewelry that would appeal to a starry eyed gal. Even so, the cones and bores DO NOT build up with plastic from the wads if you are doing your job keeping the barrels from being grossly overheated from shooting, and brushing them out with a stiff bronze brush and solvent once in a while.

You can compare the foregoing description of the Master's work against the theory espoused by others who think that polished bores have just got to be better, same as a shiny polish job on a car body.

Like I said earlier, you'll have to chose your expert.... Silvers

Member Joined: 25 Jul 2006 Posts: 781

Since the invention of the plastic cup wad how can the level of polish of a bore have any impact at all on the pattern a gun throws?

Based on no facts, just intuition alone this is a placebo effect.

Jeff

its simple Jeff. Plastic wad build up adds both roughness and constriction to the bore and the choke, especially the choke. It changes the harmonics of the barrel during firing and changes the results. As I posted, this build up may of may not be a factor if just a few shots per day are being fired. However, for a competition gun like a trap or skeet gun where several hundred can by fired in a few hours, it can be the kiss of death to good consistant patterns and the resulting scores.

I've seen the results of wad build up right in my own patterns out of my Perazzi trap guns. After a couple of boxes, my lengthened cones and the choke tubes were picking up a coating of plastic and looked like they were corroded. My handicap patterns showed degradation and even my scores dropped a bit at the last two houses of a 100 bird event. The effects were worse if I was shooting a 200 bird event.

Once I learned to polish my own bores, and also wipe out the bores after every 50 targets to boot, my patterns and scores definately improved. Nothing succeeds like success. The polished bores stop this rapid build up and also make it far easier to strip the little that does accumulate with one pass of a dry bore snake. I do not have time to screw around between traps usually. so the bore snake is a blessing. It takes all of 5 seconds.

FYI, the fellow who started me down this path was the same fellow who started this business of lengthening cones and overboring barrels-- the late Stan Baker. I doubt there is an individual alive that learned as much about shotgun bores and how they work than Stan. He was the first to recognize the advantages of overbore coupled with plastic wads. However, he also recognized the down side of plastic wads too. He always advocated as clean and shiny a bore in any trap or target gun to keep things as uniform and dependable as possible.

Like you said Silver, you pick your expert and I'll pick mine. Stan's advice has never failed me. Not once. I'll stick with what works for me, thanks.

Joined: 23 Nov 2006 Posts: 58 Location: Northeast

16gg, that's very interesting... your experience with your P trap gun building up plastic after a "couple of boxes" of shells. I have a P gun too and I use it at 200 bird sporting clays tournaments, including warm up shooting at 5-stand layouts, and make-a-break where many shots are fired in a short period of time. Similar to the timing of trap shooting. That's in the summertime when it might be 90+ degrees outside in the shade. My gun does not build up any plastic at all with perhaps 300-350 shots fired over a weekend, no cleaning in between. Of course mine is "Eysterized" with non-polished cones and bores; and as you said you've been polishing cones and bores for years ever since being influenced by Mr. Baker. Maybe the polished surfaces have something to do with plastic buildup? Incidentally, Mr. Baker is a noted barrelsmith, similar to Ken Eyster, so perhaps you can give me a reference (magazine article, statement in a book, etc.) wherein he advocates polishing bores? Thanks. Silvers

Jeff, the surface finish of a bore (rms) most definitely will influence the patterns. With a given choke, let's say .020" modified in a 12 gauge, the polished bore will throw a less tight pattern than one that is not polished. In the example I cited you might get IC patterns from a .020" choke that would otherwise throw modified patterns. Silvers

Most of the information I got from Stan came during our numerous phone conversations. My relationship with the man began in 1995 when I was having an accuracy/regulation problem with a couple of new Browning Citori shotguns. I called him at his shop. Stan was both generous with his time and a great help and source of info and advice. With his help, I was able to convey exactly what was wrong and Browning was able to identify the problem and replace the barrels and in one case, the gun. Stan's iformation and advice was also instrumental in helping Browning USA get Miroku to address and correct the problem at the source. Since that time, Miroku barrels are typically far better regulated and accurate accross the board at least from my experience.

We became friends during this time. I learned much from his opinions and advice. I'm certain you yourself could learn quite a bit from his column in the back issues of Shotgun Sports. I'd advise you to begin there.

As far as my Perazzi trap guns, both the TMX and the MX-8 I regularly shoot for registered targets were bought used. both are older, pre-1980 models. I do not know who did the work on the TMX. The work on the MX-8 was done by the same man who works on Kaye Ohye's guns. His name eludes me. Its not Ken Eyster. I've not needed any services on either of the barrels for it since I've owned it. The bores were well done and well polished. They never crudded up much. Regular cleaning and an occasional pass with mild OOOO steel wool keeps them that way.

The TMX was a real problem. Whoever lengthened the cone left the surface relatively unfinished after reaming it. The choke tubes, a full set of second generation ones that came with it would crud up just ahead of the seats and also at the muzzle end. the first time I cleaned them, I literally had to carefully cut through the build up with the edge of a knife. After several polishing jobs, this tendency has finally stopped. However, I don't let it get started anymore either. As I said, the little that builds up now jips right out with one pass of a snake. Again, both regular cleaning and an occasional pass with the wool keep them in good shape now.

Trap gun barrels often get too hot to touch in the summer from the fairly rapid firing they are subjected to. I've shot enough 5 stand and SC to know this is rarely the case since the pace is considerably slower. I do not know if this is a factor, but I would not discount it out of hand. I've not experienced the same rapid built up of plastic in either of my Browning SC guns. However, both have very smooth surfaced bores as they came from the factory. Maintainance is not a problem. I just do them the same way as the Perazzi guns.

You are fortunate to have a gun that stays relatively free of plastic residue build up. You obviously do not need to polish your bores. I'm a firm advocate of not fixing what ain't broke. I've seen others' guns that are a problem. Polishing out the bore is one solution that has worked for me as well as others. A quick occasional roto-polish with the OOOO steel wool keeps them that way too afterwards.

I think we have presented our findings from our own experiences well enough. We are both entitled to follow our own bent in the matter. Thanks for the opportunity to debate the issue. Good luck with your barrels.

PS: To those of you folks who might be having a problem with plastic wad residue build up, learning the technique I've layed out is not that hard to do. However, practice makes perfect. I'd advice learning on a junked out barrel like from an old autoloader or pump for one of your older guns. Finding a rusty old barrel is anything but difficult or expensive. If you can learn to transform a junked out bore back to usable again, then its a win win situation. You will get a decent usable barrel cheap, and will also learn a useful skill. Give it a try. What do you have to lose but the rust and rough bore in the old barrel. Good luck.

Myself, I don't know about Mr. Baker. I got my information on polishing chokes and bores from "The Gun Digest Book of Shotgun Gunsmithing" written by Ralph T. Walker. I can't remember how long ago I bought this book, but he has a chapter in there about polishing chokes and bores with steel wool to clean out the plastic from plastic wads. I'm not a trap shooter, but I am fairly good at hitting the birds and I do pattern my guns. I have noticed a tighter pattern after polishing. The gun I noticed it the most on was my LC Smith with Damascus barrels. Yes I use the gun. I shoot Federal 5500 psi shells and I can take down a grouse.

Member Joined: 01 Feb 2006 Posts: 450 Location: Indiana

I hope you guys don't mind if I add my 2 cents to this.

I don't intend to uphold anyones opnion but will give you mine from a metal finishing experience for the medical industry.

Most of my 35yrs in the industry has been for hip, shoulder, and knee replacements. With all other implant joints from wrist, knuckles, toes and all the others.

Most of the metal used now days are Colbalt Chrome and Titanium and 316 Inplantable stainless steel.

Very much research has been done with these metals in the past 30yrs for durabality with various different types of other metals and Poly inserts.

For the past 15 or so years my main experience has been with the femoral knee and the polycarbonate bearrings which the femeral knee is made of colbalt or titanium . This poly is almost the same stuff the plastic wad is made of today. The testing I have seen with poly used on the metals has been put through millions and millions of cycles every month and hundreds of manufactures are doing it.

I can honestly say this. In the medical field the finish is the all most important for the wear on the poly. The standards in which the quality is kept is unbelievable. Much of the standards require the finish to be no more than 2 mircon +or- 1 mircon. I have done finger joints that have required less than 1/2 a micron. All of this is due to resist wear and less pain to the patient.

I have seen many poly inserts torn apart or badly distorted for nothing more than a slight scratch that you need a scope to see the flaw with in the metal. Friction and resistance has an effect no matter how good you think the surface is.

However here we are talking about a poly wad going down the barrel where the surface is trying to seal the gases under tremendous pressure and if it has resistance between one firing and another I'm sure their is less consistancy in pressures and will have more of a affect on pattern from shot to shot.

But we must look at the way a bench shooter works. You have to find what works best for that rifle. I have seen many of rifle shooter lap the rifllings to remove the surface scratches from the manufacture just to try for that little bit more prefection. Here maybe we are not looking for that bit of perfection as we are for that little bit of an edge.

With the many years in the metal finishing industry and the billions of dollars spent on testing of surfaces I don't think you can get a surface to good, just not good enough.

As I say this is just the way I believe what I have seen. I just don't have the flare for the right words to explain it better.