How Common are Barrel Constrictions?

[ejcrist]

I've read a lot about barrel constrictions in revolvers on this forum and I'm wondering how common the condition is, and is it more or less common now than in the past. Per Jeff Quinn it sounds like it can be encountered regardless of revolver quality, and I trust his opinion as I've been reading Gunblast for many years and find the reviews and information very accurate. I've never measured for constrictions but I have a set of pin gauges for every caliber I own (which is all of them I believe) and I believe I'm going to start checking. I only have one SBH that leads somewhat but I haven't gotten around to developing a good load for it yet so I can't say for sure if it's caused by a constriction. I'm going to start checking all of my wheel guns though to see if anything indicates a constriction, and if any do I'll certainly give fire lapping a try. But in the meantime I'm just wondering how common the condition is. If anyone has any idea or opinions I'd love to hear.

[rintinglen]

Not as common as some folks would have us believe. There was an issue with Ruger 45 Colt revolvers that was widely bandied about on the internet, but it is my opinion that the severity and frequency were both over reported.

[ejcrist]

Not as common as some folks would have us believe. There was an issue with Ruger 45 Colt revolvers that was widely bandied about on the internet, but it is my opinion that the severity and frequency were both over reported.

Do you know if it was any particular vintage or has it been an on-going issue? I remember reading something about that awhile back but then I also read it can occur in just about any manufacturer. I know there's a couple of references to it (LASC http://www.lasc.us/Fryxell_Book_Chapter_7_Leading.htm) and also Jeff's article (http://www.gunblast.com/FerminGarza-Firelapping.htm).

[Catshooter]

Well, I never counted, but at a guess I'd have to say half.

This was only Smiths and Rugers. Never checked the few Colts I've owned and never owned anything of lessor quality.


Cat

[DougGuy]

Big bore Ruger SA revolvers made before they started making the medium framed guns are pretty much hit and miss maybe 50/50 chance you would get one with a little choke in it, some were severe. No rhyme or reason to the timetable, the front sights are soldered to the barrels before they are threaded into the frames so if they had to torque on a barrel pretty good to get it to "clock" the front sight to 12:00 straight up, it got choked. The most common choked barrels being in .44 and .45 caliber since all the barrels were the same size on the OD, but the .44 and .45 caliber barrels had the thinnest walls and had less resistance to thread choke than the smaller calibers which of course had thicker barrels because the bore was smaller.

The medium frame guns, those of recent production that have 3 digit prefixes in the serial numbers have been the least choked of all the Rugers that I have ran across. Not saying that these are free of choke, but the handful I have had in my shop have been 100% choke free.

[dubber123]

Well, I never counted, but at a guess I'd have to say half.

This was only Smiths and Rugers. Never checked the few Colts I've owned and never owned anything of lessor quality.


Cat

At least half here. All but the very last Ruger I got, a medium frame Vaquero has had thread choke, and a good bit of my S&W revolvers have shown some. All of the S&W's thus far have been .38's, and have shown less choke than the Rugers. Firelapping has greatly improved them all.

[44man]

After seeing extreme off center wear to throats, cone and rifling on a very expensive revolver fit too tight and poor alignment with around 300 rounds of jacketed, I would say just shoot more jacketed to start.
Fire lapping is also very good and will not harm a thing.

[ejcrist]

Wow, that's a fair number. Thanks for passing along the info gents. I'm going to check mine and hope I don't find any, but it wouldn't hurt to at least check. I haven't had any accuracy or leading issues with any but the SBH so I think I'll be alright. Even if there are any restrictions I'm guessing they aren't much or I'd have seen the symptoms since I only shoot softer cast and none of the "j" boolits. At least I don't think it'd be enough to do anything about. I think the hardest boolit I shoot is BHN 13 or so in a 357 @ ~ 1,480 fps and I just use Lyman Alox lube - all plain base boolits. That's good info to know and something to look out for if you'd tried everything else and can't get decent accuracy.

[DougGuy]

You get your bore nice and clean, take the cylinder out, hold a piece of white paper against the back of the frame and shine a bright light on the paper. Look down the bore. First off, this has nothing to do with choke but if the rollmarked warning on the barrel is very strongly impressed, you can SEE ridges behind each of the words inside the barrel! Yep, the impressions make humps inside the barrel that you can see, that will serve to swage the boolit down when it passes.

Now look farther down the bore to the area where the barrel meets the front of the frame. If you can SEE a hazy circular ring up about 3/4" from the forcing cone, then you are looking at thread choke. As the torque from tightening the barrel distorts the steel in the threaded area, so will it distort the reflections of light and you can see this bigtime.

Some barrels even have a spot just in front of the frame where it bulges slightly! (This is quite common with older model SBH). You can see this too with nothing more than the naked eye and a clean well lit bore. Now, take a plastic or brass cleaning jag, patch it -very- tight into the bore, and begin to shove it toward the frame. Observe how much effort it takes to keep the jag moving. When you get to the front of the frame, if the jag gets tight and harder to push, THIS is thread choke you are feeling. If it gets only moderately tighter and you can still push it, the choke is less than .0001" overall. If it stops and you have to dang near beat the rod to death to get it the rest of the way through, choke is severe, and well into the .003" or .004" smaller than groove diameter range. This is an easy way to detect choke, and also to detect how bad it is choked without expensive tools. As 44man says, firelapping will help enlarge the choke and it will also normalize the humps behind the rollmarks. By the way, you can feel THESE with the jag as you slide it down the bore too!

IF the gun is carbon steel, and the choke is not too bad, firelapping will totally remove the choke and cut groups in half while you are at it. Stainless, whole 'nother story. Stainless is very difficult to firelap, it takes roughly 6x the amount of lapping to make a noticeable difference. The problem with firelapping the stainless barrel is that by the time you fire enough lapping loads through it to rid the choke, it can deteriorate the remainder of the rifling that didn't need lapped. If the choke is severe, THIS will likely happen before you get the choke lapped out and the gun should go back to Ruger for a barrel replacement or become a candidate for Taylor throating.

[44man]

For sure, Ruger stainless is some super tough stuff. I tend to limit lapping boolits.

[williamwaco]

I must be lucky. I have owned around 200 revolvers over the past 60 years and I have seen only two. Both were Charter Arms Bulldogs.

[Larry Gibson]

I must be lucky. I have owned around 200 revolvers over the past 60 years and I have seen only two. Both were Charter Arms Bulldogs.

I must have been as lucky as you as I've only found one out of many checked with actual constriction of the barrel under the thread part of the frame. That was in a Great Western revolver in 45 Colt. I've had several Rugers and S&Ws brought to me with reported constrictions but after a pass or two with a Lewis lead remover the "constrictions" went away......point is that there can often be leading or other fouling that is very hard to see in that area of the barrel. Of course fire lapping will also remove the fouling so all appears well and "fixed". I've told numerous others to fire some full powered jacketed loads through there "constricted" barrels and guess what.....the constrictions went away.

I think ever since a famous gun writer wrote an article how his super customized Vaquero 45 Colt had a "constriction" and how he fixed it by fire lapping we have seen an epidemic of constricted revolver barrels.....everyone thinks they have one........

Larry Gibson

[Ola]

I just don't understand WHY there is a constriction.. It is just a thread after all.

Firstly: does the frame has the structural strength to constrict the barrel?

Secondly when they (=the factory) turn the barrel in the frame, how much force are they using? Enough to cause constrictions?

[M-Tecs]

It's a function of the 60 degree thread and being over torqued to index the front sight.

[DougGuy]

The '93 stainless Vaquero I have shot horribly left when it was new. Sent it back to Ruger and asked them to rebarrel it, told them how bad it shot to the left, and they supposedly fixed it, sent it back to me. I shot the gun, at a steady rest it was 8" to 10" left and 4" low of point of aim. I was pissed. The gun laid in a box forgotten about for 17yrs and I dug it out one day and sent it back in again. This time they "fixed" it by torquing the barrel so tight, that it squeezed the bore down to .448" in the frame. There was no leading to speak of because the gun had just come back from Ruger, the 2nd time. I nearly destroyed a cleaning rod with a jag on it trying to beat it through the choked part. I *wish* I had taken a photo looking down the bore, because it was super easy to see how distorted the bore was from the choke.

I taylor throated this one. No amount of firelapping would ever have fixed it.

Larry, I had one sent to me to remove the "constriction" so I de-leaded it with chore boy and there was no constriction.

[Markbo]

I must be lucky. I have owned around 200 revolvers over the past 60 years and I have seen only two. Both were Charter Arms Bulldogs.

What did you do to check that many guns?

[CHeatermk3]

200 revolvers in 60 years is about 3 per year.

[LUCKYDAWG13]

not to high jack this but looked like a good place to put this i sent my Ruger back for repair and they but a new barrel on
for me the fact that they had to unscrew and re-screw my barrel on would that help with constrictions i ran a tight patch
down the barrel and felt the same all the way down

[DougGuy]

i ran a tight patch
down the barrel and felt the same all the way down

That's the very best you could hope for. You'd be surprised -just- how much you can feel with a tight jag. You can feel each individual ridge raised by the roll marked warning, you can feel a bulge on a lot of the old models right where the barrel meets the frame, it's very noticeable when the jag suddenly goes loose as a goose then tightens again.

[deepwater]

My first issue .480 Ruger SRH is constricted at the barrel threads.


deepwater

[Markbo]

200 revolvers in 60 years is about 3 per year.

I didnt ask how did he have time...but by what method. But Im sure he appreciates you answering for him. ;)

[Thumbcocker]

http://castboolits.gunloads.com/showthread.php?285578-Slugging-it-out

[williamwaco]

What did you do to check that many guns?

Load and shoot.
As noted - that that is only 3 per year on average.

[williamwaco]

I must have been as lucky as you as I've only found one out of many checked with actual constriction of the barrel under the thread part of the frame. That was in a Great Western revolver in 45 Colt. I've had several Rugers and S&Ws brought to me with reported constrictions but after a pass or two with a Lewis lead remover the "constrictions" went away......point is that there can often be leading or other fouling that is very hard to see in that area of the barrel. Of course fire lapping will also remove the fouling so all appears well and "fixed". I've told numerous others to fire some full powered jacketed loads through there "constricted" barrels and guess what.....the constrictions went away.

I think ever since a famous gun writer wrote an article how his super customized Vaquero 45 Colt had a "constriction" and how he fixed it by fire lapping we have seen an epidemic of constricted revolver barrels.....everyone thinks they have one........

Larry Gibson

I do that before cleaning any badly leaded barrel. Best method I know of to get rid of the really bad part.

[Markbo]

Load and shoot.
As noted - that that is only 3 per year on average.

Then you didnt really check or measure for any restriction

[DougGuy]

I've told numerous others to fire some full powered jacketed loads through there "constricted" barrels and guess what.....the constrictions went away.

Larry Gibson


I do that before cleaning any badly leaded barrel. Best method I know of to get rid of the really bad part.


Shooting FULL POWER JACKETED LOADS into a known LEADED barrel is firing a full house load into an OBSTRUCTED BARREL. Best way in the whole world to BULGE a barrel. This is NOT GOOD ADVICE and I don't care HOW MANY years you have been doing this or advising others to do it.

[ejcrist]

For what it's worth, I use the Lewis Lead Remover most every time I shoot and very rarely get just a few specks of lead here and there, and none of my revolvers have ever been fire lapped. I get more than a few specks out of the SBH though but that's the only one I've noticed it in. That's why I was thinking to check for a constriction using pin gauges just to rule out a constriction. On a side note, I've read shooting jacketed boolits will clean out the lead pretty well but like DougGuy said, I'd be very nervous doing that in a heavily leaded barrel unless I cleaned most of it out with the LLR first.

What happens to the cylinder throats when you firelapp? I'd think they'd open up too.

[DougGuy]

You should do any correcting the cylinder throats need before firelapping, as they will swage lapping boolits down to their diameter if they are tight. Once they are sized properly there will be very little resistance to the lapping boolits so they probably won't change at all.

[44man]

You should do any correcting the cylinder throats need before firelapping, as they will swage lapping boolits down to their diameter if they are tight. Once they are sized properly there will be very little resistance to the lapping boolits so they probably won't change at all.
This is why lapping boolits are a certain hardness and very light loads are used so they don't expand in the throats.
They would still do the job if they fell on the ground 10' in front of you.
Boolis should only need to be groove size measured at the end of the barrel and not fit to the throats.
Doug knows so trust what he says.

[44man]

Shooting FULL POWER JACKETED LOADS into a known LEADED barrel is firing a full house load into an OBSTRUCTED BARREL. Best way in the whole world to BULGE a barrel. This is NOT GOOD ADVICE and I don't care HOW MANY years you have been doing this or advising others to do it.
Well said, a bullet will just run over bad leading and iron it in. It CAN bulge a barrel.
I never get leading at all but for those that suffer, I have wondered about something and maybe Dough will think it over.
Load a light load of powder, put some cream of wheat or corn meal on it and seat a GC ONLY on it. Pop a few but make sure ALL exit. Don't crimp, shoot single shots.
Hey, just maybe!

[DougGuy]

Hmm.. At the risk of brain engaging before fully depleting coffee, I thought first of this.. Why not devise a load using a magnum primer and something wrapped in chore boy? A piece of corn cob or a section of plastic rod of a certain diameter or something along those lines that can be fired by just the primer OR we come up with a jig that fits in the frame and uses the cylinder pin to mount and index it, and hook it to an air compressor, open it and insert a plug with chore boy into the thing, close it and press a button, voila! Leadaway!

But once the initial rush of ideas passes and said coffee is sufficiently inducted from mug, the truth comes down to the fact that when you are doing it right, there is NO leading that would require more than a pass or two of a brush with a couple strands of chore boy wrapped on the outside.

Come to think of the heavily leaded barrel, once it is leaded, pressure wise it would be just as dangerous if not worse to continue firing hard cast lead boolits as it would to fire jacketed. Several of the firearms manufacturers have specific warnings about NOT firing jacketed boolits into a leaded barrel, but do any of them say to stop firing the gun until the barrel is lead free? I don't think so.

Beretta, in their pistol manuals, recommends against the practice. The exact quote is: "DO NOT ever shoot cartridges with jacketed bullets through a barrel previously fired with lead bullets before the bore is thoroughly deleaded."

Also, Allen Jones, formerly of Speer reloading and also a former forensic firearms examiner, recommends against the practice. In the February 2010 issue of Shooting Times, he writes that shooting jacketed bullets down a leaded bore is "A Big 'No-No'". The article is in the "Going Ballistic" Column and is entitled: "The Lowdown on Lead Fouling". His quote was: "How many times have you thought it easier to shoot the lead out with a jacketed bullet? Well, don't even think about it. In extreme cases, this can cause irreparable damage. I've seen revolver barrel throats deformed and thin-walled barrels bulged. Either means a new barrel."

Any plumber knows that lead will solder to copper with enough heat. This I think is more responsible for de-leading a barrel with a copper jacket or a gas check than any scraping effect you may get from the jacket. If you fire a j-word into a leaded bore, the first few shots won't remove all the lead, it takes a few. Some of the lead gets removed, some of it gets pushed around and ironed in.

Consider this.. When you size a cast boolit, if you have to go more than about a thousandth in a sizing die, it gets tough the more you have to reduce the size of the boolit. It will dang near BREAK THE ARM OFF THE PRESS at the effort required to accomplish sizing down .005" so let's suppose you have a thin coating of lead all the way around the bore, let's say it's even with the tops of the lands which is not at all out of the ordinary, and if the lands are .0025" in height, then the bore diameter is reduced by .005" if I did the math correctly, you know how much effort it takes at a sizing die to reduce a cast boolit by .005" right? How high of a pressure spike do you think it generates by applying 30,000psi OR MORE to the boolit and firing it through this "lead sizing die" that is in the bore?

And then there is the age hardening effect of antimony in the mix, if you think sizing a water dropped boolit is hard to do immediately after quenching, give it a few months and try sizing it then. So the loads that are getting fired into the leaded bore have been sitting how long? :shock:

Scary huh?

[44man]

More good stuff from my friend Doug. If that doesn't convince anyone, read it again and again.
There is no reason to lead a barrel--PERIOD.
You will read a billion things, make the boolits softer, use a GC, it will scrape out lead, not true, if the boolit fails to take rifling, the check can fail. Then hard boolits will lead the bore.
The only thing that will not be shot out is the carbon from the last shot if done right. The right lube and boolit will self clean.

[tazman]

More good stuff from my friend Doug. If that doesn't convince anyone, read it again and again.
There is no reason to lead a barrel--PERIOD.
You will read a billion things, make the boolits softer, use a GC, it will scrape out lead, not true, if the boolit fails to take rifling, the check can fail. Then hard boolits will lead the bore.
The only thing that will not be shot out is the carbon from the last shot if done right. The right lube and boolit will self clean.

True that. I have several handguns that have hundreds of cast boolits fired through them without cleaning the barrel. They have no visible leading in them at all. You could run a patch through them and only come up with a little carbon.

[williamwaco]

Then you didnt really check or measure for any restriction

Check yes. Measure no.

[Larry Gibson]

If you have a severely leaded barrel I would not suggest shooting jacketed through them either. However, if you all bother to read the discussion my statement applied to the "restrictions" were not visible, barely detectible and not what anyone here would call "leaded". It is/was no more hazardous than firing the same ammunition into any fouled bore.

Also all the old famous hand gunners never had any problems shooting jacketed bullets after cast bullets. It was often a recommended way to "get the lead out". Now, to be sure I do measure pressures and have several times fired jacketed loads (rifle and handgun) after cast loads. I have not been able to detect any dangerous increase in pressure. I fully understand the reason for such statements to not shoot any jacketed after cast from manufacturers who also warn against the use of hand loaded ammunition in todays litigation crazy environment. When someone here actually can demonstrate there is a potential hazard I will change my way of thinking. I don't think the sky is not falling but thanks anyway for the advice, I will take it under advisement.

Larry Gibson

[44man]

Larry, that depends on IF you have a large lead buildup. If none, then you can shoot bullets.
The question is, can you shoot bullets out of a badly leaded bore or just after a few boolits that don't lead.
With some of the guns brought here I would not shoot toilet paper. Ever see a .38 that looked like a .25? Need a .22 jag for the first patches with a mallet.

[Ola]

I have once "shot the lead out" of the bore. It was not my intention.

I have this mild, trusted load that never leads. Once I tried something else and got mediocre leading in the barrel. I was supposed to clean it out but FORGOT. On the next trip to the range I shot maybe 50 rounds of that mild load before I remembered. I snapped the barrel open and took a look. I was pretty worried but there was only little traces of the original leading left. So I decided to shoot some more and after other 50 rounds the barrel was totally lead-free..

I wouldn't do that on purpose and I certainly do not recommend it. But it seems to be possible to use lead bullets to clean the barrel.

[Markbo]

Check yes. Measure no.

How did you check?

[44man]

A good boolit and lube can clean the bore fine if shot with lighter loads. I would worry about top stuff though. Even a softer boolit then I use will not lead and the only reason I stay harder is fliers. I think some of them get deformed with my hunting loads.

[Tackleberry41]

So is there a reason Ruger cant put the sight on AFTER they put the barrel in? Or simply use another method to hold them down? Be really nice to be able to drop a different front sight in a blackhawk fairly simply.

[dubber123]

Veral Smith of LBT recommends shooting the lead out of a barrel with cast boolits lubed with good lube, and shot at a slower velocity. Lead sticks to lead, and with a good lube will clean a pretty nasty revolver barrel out in about a cylinder full. Way more fun than a cleaning rod :) If I get leading, I find out why and fix it. Unless you are shooting over about 1,600 fps with a plain base, or 2,600 fps with a gas check, (my personal tested limits at this time) you probably have a "fixable" problem. I don't remember the last time I had to brush out a bore. I have had to firelap quite a few to make a problem go away.

[williamwaco]

How did you check?


Accuracy and leading.

If you have a constriction, leading will be severe and accuracy non existent.

Accuracy in my experience ( Exactly two ) will be on the order of 10" patterns at 15 yards.

[Larry Gibson]

Larry, that depends on IF you have a large lead buildup. If none, then you can shoot bullets.
The question is, can you shoot bullets out of a badly leaded bore or just after a few boolits that don't lead.
With some of the guns brought here I would not shoot toilet paper. Ever see a .38 that looked like a .25? Need a .22 jag for the first patches with a mallet.

I understood the question; my advice isn't given with regard to "badly leaded bores". As I stated clearly the "constriction" (the leading or fouling) was so minimal as to barely be seen if at all and was minimally felt when the barrel was slugged.

Larry Gibson

[dubber123]

Accuracy and leading.

If you have a constriction, leading will be severe and accuracy non existent.

Accuracy in my experience ( Exactly two ) will be on the order of 10" patterns at 15 yards.

Those were obviously severely choked examples. I however have had quite a few that leaded only minimally just after the forcing cone, that after cleaning showed a constriction when slugging. All of these revolvers shot into 2" or less at 25 yards which many handgunners would be happy with. Every single one fired smaller, sometimes significantly smaller groups after firelapping.

The constriction wasn't enough to cause undue leading, or leading that increased with use. It in my experience in the dozen or so I have done, was obviously enough to affect accuracy negatively. I have also never seen one made worse by firelapping, so I am not afraid to try it if I feel a gun can be improved.

[williamwaco]

Those were obviously severely choked examples. I however have had quite a few that leaded only minimally just after the forcing cone, that after cleaning showed a constriction when slugging. All of these revolvers shot into 2" or less at 25 yards which many handgunners would be happy with. Every single one fired smaller, sometimes significantly smaller groups after firelapping.

The constriction wasn't enough to cause undue leading, or leading that increased with use. It in my experience in the dozen or so I have done, was obviously enough to affect accuracy negatively. I have also never seen one made worse by firelapping, so I am not afraid to try it if I feel a gun can be improved.


Dubber:

2" at 25 yards with minimal leading.
I need to get some more constricted barrels.

I would never suspect a problem with a revolver like that.

[tazman]

Accuracy and leading.

If you have a constriction, leading will be severe and accuracy non existent.

Accuracy in my experience ( Exactly two ) will be on the order of 10" patterns at 15 yards.

That sounds remarkably like the RBH in 45 LC my neighbor had. The only way we could get it to shoot anything like a group was to powder coat and thereby soften the boolits. It stopped the really severe leading he was getting but was still inaccurate to an unacceptable degree. I tried to check for a constriction but was unable to tell for certain.
That revolver has now left the area.

[dubber123]

Dubber:

2" at 25 yards with minimal leading.
I need to get some more constricted barrels.

I would never suspect a problem with a revolver like that.

That is my entire point William, many people don't realize the problem exists because for 99% of what most of us expect from a revolver, a minimally choked example will meet it. I include myself in that 99%. I was perfectly content for years with my guns. The last one I firelapped was a 1917 vintage 6" S&W .38 Spl. It shot well, in the 2" range, with not much leading. It did get a little in front of the forcing cone, but it never really seemed to get any worse. After firelapping, my best group with the same load was .8", and the average was in the 1.25" range, with some a little better. It also does not lead at all in front of the forcing cone any more.

I have done one rifle that did not improve much, except a dramatic reduction in fouling. It could shoot a full 2 grain higher charge before leading appeared, but groups were not measureably improved. This particular gun has been a real pain to work with. Still it was worth doing just for the cleaner bore it has after shooting.

[williamwaco]

Dubber:

My point is that a barrel with a constriction that shoots that well with minimal leading is not a "Problem" but a blessing.

I would not think of changing it.

In my experience consistent 2" groups from a revolver is pretty rare.

Perhaps I have been settling too easy. I should check some of the revolvers I consider very good and maybe, I can make them better.

[DougGuy]

Perhaps I have been settling too easy. I should check some of the revolvers I consider very good and maybe, I can make them better.

Use the tight patched jag method. I often patch them with paper towels or whatever is laying close by on the bench. Doesn't have to be cloth, just as long as it doesn't tear. You may be surprised at how much differences there are in them. For instance I can feel the ridges behind the roll marked warning on a Ruger barrel *IF* the warning is pressed in very deep like a lot were, I can feel a bulge where the barrel meets the frame on a lot of the old model SBHs, and you can sure feel it if it gets tight where the barrel threads in.

Barrels that start out even and have a very even resistance against the jag are perfect. It would be hard to accurately predict which models would have the highest percentage of this amount of smoothness and consistency.

I will say it again, I have been REALLY favorably impressed by the medium framed Ruger 45s that have come through my shop in the last year or so, the best bores I have seen on any Ruger production runs.

[dubber123]

Dubber:

My point is that a barrel with a constriction that shoots that well with minimal leading is not a "Problem" but a blessing.

I would not think of changing it.

In my experience consistent 2" groups from a revolver is pretty rare.

Perhaps I have been settling too easy. I should check some of the revolvers I consider very good and maybe, I can make them better.

I know the trepidation many must feel when messing with a "good" gun, It has kept me from fiddling with a lot of mine. I have had such great results from firelapping, I am getting less and less hesitant to use it. I have a F/A .475 Linebaugh that has been an excellent shooter since day 1. It does however not have the smoothest bore I have encountered, and it always has a gray "wash" to the bore. Accuracy doesn't change, but I suspect it can be better. I intend on firelapping it soon. You can always just shoot a few and re-test if you are worried about it. That is what I will do with that one.

[44man]

I know the trepidation many must feel when messing with a "good" gun, It has kept me from fiddling with a lot of mine. I have had such great results from firelapping, I am getting less and less hesitant to use it. I have a F/A .475 Linebaugh that has been an excellent shooter since day 1. It does however not have the smoothest bore I have encountered, and it always has a gray "wash" to the bore. Accuracy doesn't change, but I suspect it can be better. I intend on firelapping it soon. You can always just shoot a few and re-test if you are worried about it. That is what I will do with that one.
The WASH is nothing. Leave it alone. Lead buildup is different.

[Char-Gar]

I've read a lot about barrel constrictions in revolvers on this forum and I'm wondering how common the condition is, and is it more or less common now than in the past. Per Jeff Quinn it sounds like it can be encountered regardless of revolver quality, and I trust his opinion as I've been reading Gunblast for many years and find the reviews and information very accurate. I've never measured for constrictions but I have a set of pin gauges for every caliber I own (which is all of them I believe) and I believe I'm going to start checking. I only have one SBH that leads somewhat but I haven't gotten around to developing a good load for it yet so I can't say for sure if it's caused by a constriction. I'm going to start checking all of my wheel guns though to see if anything indicates a constriction, and if any do I'll certainly give fire lapping a try. But in the meantime I'm just wondering how common the condition is. If anyone has any idea or opinions I'd love to hear.

Let me offer you my experience and probably and opinion or two.

I started shooting handguns about 60 years ago and handloading cast bullets for them in 1961 or thereabouts. This was long before Veral Smith discovered these constrictions and labeled them as evil entities that have to go.

In my learning curve against handgun barrel leading, I found that 99% of the time that leading could be eliminated with the proper size bullets, of the proper temper, and the proper lube. "Proper" is a moving target depending on the pressure/velocity of the load.

However in a few handguns, all the "proper" in the world did not yield a clean barrel. The cause was the barrel was not smooth but had little unseen micro-machine hickies in them. These few barrel could be tamed by firing 200 full snort jacketed rounds as fast as possible, followed by a through cleaning and a multi-hour polish with a fine polishing compound like Flitz, Semi-Chrome or Mothers Mag Polish. After this was done, the micro-hickies were gone, and the barrel was smooth and mirror bright. Gone was the leading with the added benefit the barrel was a snap to clean.

This high polish revealed an interesting fact. With a strong light shining down the muzzle, these constriction were easy to see in the breech end of the barrel. They varied, but every barrel so treated revealed them. I am talking Smith and Wesson revolvers here.

So, did I panic and see the need to take them out? Nope, I did not. They are still there, and the handguns are still producing first rate accuracy and no leading at all. I am left with the conclusion that they really don't matter all that much in an otherwise good barrel.

I really don't know what causes these circular constrictions. Some folks say it is from torquing the barrel into the frame. I am just as apt to believe they were produced when the barrel was threaded before installation.

Now with rifles where the rear sight dovetail is cut with a broach on the barrel producing a non-concentric lump inside the barrel, these things can raise hob with accuracy. But we were talking about sixguns right?

So there you have it, my experience, opinions and notions on the subject at hand.

[Char-Gar]

I know the trepidation many must feel when messing with a "good" gun, It has kept me from fiddling with a lot of mine. I have had such great results from firelapping, I am getting less and less hesitant to use it. I have a F/A .475 Linebaugh that has been an excellent shooter since day 1. It does however not have the smoothest bore I have encountered, and it always has a gray "wash" to the bore. Accuracy doesn't change, but I suspect it can be better. I intend on firelapping it soon. You can always just shoot a few and re-test if you are worried about it. That is what I will do with that one.

A couple of years back I ran a long thread on this board asking folks to define what they consider leading in handgun barrels. After it was all over with many pages, the conclusion was that this "grey wash" was not leading and was common in almost all cast bullet handgun loads. It is mostly powder trash, bullet lube and perhaps a smidge of lead added to the mix. It is not a problem that merits concern or needs to be fixed.

I have never "firelapped" a barrel. I have an aversion of pushing abrasive grit down a fine barrel under pressure to fix a theoretical problem that is probably non-existent in the first place.

[Larry Gibson]

"I have never "firelapped" a barrel. I have an aversion of pushing abrasive grit down a fine barrel under pressure to fix a theoretical problem that is probably non-existent in the first place."

+1 in so far as handguns/revolvers are concerned. I have occasionally firelapped a very rough rifle barrel. I have never found any need with any handgun. Much ado about nothing in my opinion.

Larry Gibson

[Char-Gar]

"I have never "firelapped" a barrel. I have an aversion of pushing abrasive grit down a fine barrel under pressure to fix a theoretical problem that is probably non-existent in the first place."

+1 in so far as handguns/revolvers are concerned. I have occasionally firelapped a very rough rifle barrel. I have never found any need with any handgun. Much ado about nothing in my opinion.

Larry Gibson

I have hand lapped some rifle barrels as well. I prefer to apply the grit to the trouble spots.

[DougGuy]

I have never found any need with any handgun. Much ado about nothing in my opinion.

Larry Gibson

A fella can take a perfectly good Ruger, complete with it's factory tool marks, however minimal or noticeable they may be, one that doesn't have a visible or measurable problem, shoot it for group, then go firelap it and watch the groups shrink by half. I personally cannot explain WHY this happens, but I can tell you by personal experience that it DOES happen. I think if you shoot one enough you arrive at nearly the same as firelapping. It would not surprise me to discover that the same improvement could be had by using a cast lap instead of firelapping.

One of the BH I firelapped had ridges behind the roll mark and after firelapping the ridges were gone only shiny spots remained. Groups cut in half. This a perfectly good Ruger BH that didn't need nothing. Could have been shot another 75 years without issue and the owner would have NEVER known that an improvement could have been made and would have been none the wiser 75 years later. If you have never tried this, you will never learn anything from it.

[M-Tecs]

I really don't know what causes these circular constrictions. Some folks say it is from torquing the barrel into the frame. I am just as apt to believe they were produced when the barrel was threaded before installation.


That is an easy one. Remove the barrel and if the constriction goes away it is the torque. The 60 degree thread form vectors some of the pressure inwards causing the constriction.

The machining for the threading can release stress, however, this stress relief will make the bore larger not smaller. This may not be correct for roll formed threads but I am not aware of any barrels that have roll formed threads.

[44man]

"I have never "firelapped" a barrel. I have an aversion of pushing abrasive grit down a fine barrel under pressure to fix a theoretical problem that is probably non-existent in the first place."

+1 in so far as handguns/revolvers are concerned. I have occasionally firelapped a very rough rifle barrel. I have never found any need with any handgun. Much ado about nothing in my opinion.

Larry Gibson
I agree, Most is a cover for the inadequacies of loading and shooting proper. The number of out of box revolvers I have shot into 1/2" at 50 yards is staggering.
Roll marks on a barrel distorts the bore must mean you can detect it and must be the best shooter ever on earth. Dove tails are cut, not broached and do not show inside.
I will tell you one thing, remove your thread choke and marks, then come shoot against me with out of box Rugers or BFR's and I will own several cases of single malt.

[Markbo]

A fella can take a perfectly good Ruger, complete with it's factory tool marks, however minimal or noticeable they may be, one that doesn't have a visible or measurable problem, shoot it for group, then go firelap it and watch the groups shrink by half. I personally cannot explain WHY this happens, but I can tell you by personal experience that it DOES happen. I think if you shoot one enough you arrive at nearly the same as firelapping. It would not surprise me to discover that the same improvement could be had by using a cast lap instead of firelapping......

Doug do you make your own or do you use the 'kits'? I have only ever used the latter, fearing I could not get a smooth, even coating on my own slugs.

[DougGuy]

When I did mine they didn't have Beartooth Bullets or LBT or any "kits" and there weren't really any directions that I found anywhere. I got a bottle of JB bore cleaner that was broken open, sat on a shelf for x number of years (lots) so I poured the oil off the top of it and used the paste. I cooked lube off some 255gr LSWC boolits, flared the cases extra wide, seated the boolits partially in the case over 8.0gr Unique, then I proceeded to cram the dried up bore paste into the lube groove and the flared case mouth and finally seated and crimped the boolits in the normal way. I shot full power loads to firelap with because I didn't know there was any other way to do it. I think I fired all 50. The gun was a total mess, had to very carefully wrap it up in cloth and carry it so it didn't lay against anything on the way home from the range, as it would have worn the bluing off from the ride home.

Upon looking down the bore, I was amazed at the difference in the finish, and I never even knew there were ridges behind the roll mark until I saw a series of shiny spots in the bore where they used to be. Groups with this revolver were cut by 60% on average.

[M-Tecs]

Doug do you make your own or do you use the 'kits'? I have only ever used the latter, fearing I could not get a smooth, even coating on my own slugs.

http://www.midwayusa.com/product/646612/wheeler-engineering-bore-lapping-kit this has everything need to charge the bullets.

http://castboolits.gunloads.com/showthread.php?72706-Fire-Lapping read post #2

http://www.btibrands.com/wp-content/uploads/2014/10/Bore-Lapping-Instructions.pdf

[Markbo]

Cool. I will read up on all those resources later tonight, thanks!

[williamwaco]

Veral Smith of LBT recommends shooting the lead out of a barrel with cast boolits lubed with good lube, and shot at a slower velocity. Lead sticks to lead, and with a good lube will clean a pretty nasty revolver barrel out in about a cylinder full. Way more fun than a cleaning rod :) If I get leading, I find out why and fix it. Unless you are shooting over about 1,600 fps with a plain base, or 2,600 fps with a gas check, (my personal tested limits at this time) you probably have a "fixable" problem. I don't remember the last time I had to brush out a bore. I have had to firelap quite a few to make a problem go away.


i have observed this cleaning of a badly leaded bore by shooting a couple of cylinders of known good cast bullet loads. I did it to see how much the leading degraded accuracy. I was shocked at the results. I just considered it a fluke. Never occurred to me to do it on purpose. I will sure try it again.

[dubber123]

A couple of years back I ran a long thread on this board asking folks to define what they consider leading in handgun barrels. After it was all over with many pages, the conclusion was that this "grey wash" was not leading and was common in almost all cast bullet handgun loads. It is mostly powder trash, bullet lube and perhaps a smidge of lead added to the mix. It is not a problem that merits concern or needs to be fixed.



I have never "firelapped" a barrel. I have an aversion of pushing abrasive grit down a fine barrel under pressure to fix a theoretical problem that is probably non-existent in the first place.


The grey wash is in a gun with a not so smooth barrel shooting 50,000+ Psi lead boolit loads, not the run of the mill .38 and .44 Spls. you are talking about, there is a BIG difference, and I know the difference. I know when I see leading, even in mild .38's. As I have previously stated, if you are content with 2" groups at 25 yds. by all means, never attempt to firelap a gun, the effort is wasted on you. If you ever decide to do so, by all means pick a gun where you can TELL the before and after difference. You may become a believer.

I have noticed with almost 100% predictability, the shooters opposed to the process have NEVER tried it. It won't ruin a barrel in 1 shot. It won't ruin a barrel in 6 shots. It is a slow process that so far, in many trials has produced favorable results 100% of the time. I'm not happy with 2" at 25 yds. if a little work makes it a 1" gun. Simple as that. We all have our limits.

[Char-Gar]

The grey wash is in a gun with a not so smooth barrel shooting 50,000+ Psi lead boolit loads, not the run of the mill .38 and .44 Spls. you are talking about, there is a BIG difference, and I know the difference. I know when I see leading, even in mild .38's. As I have previously stated, if you are content with 2" groups at 25 yds. by all means, never attempt to firelap a gun, the effort is wasted on you. If you ever decide to do so, by all means pick a gun where you can TELL the before and after difference. You may become a believer.

I have noticed with almost 100% predictability, the shooters opposed to the process have NEVER tried it. It won't ruin a barrel in 1 shot. It won't ruin a barrel in 6 shots. It is a slow process that so far, in many trials has produced favorable results 100% of the time. I'm not happy with 2" at 25 yds. if a little work makes it a 1" gun. Simple as that. We all have our limits.

Everybody is entitled to their own experience and their own observations and opinions thereof.

[dubber123]

Everybody is entitled to their own experience and their own observations and opinions thereof.


We agree on that point :) As someone who has tried it, I find it a useful, and sometimes amazing tool for the improvement of as delivered firearms.

[1bluehorse]

Not as common as some folks would have us believe. There was an issue with Ruger 45 Colt revolvers that was widely bandied about on the internet, but it is my opinion that the severity and frequency were both over reported.

My experience differs from your opinion. While none were "severe" I have owned 7 different Ruger 45 colts starting from a 1993 Vaquero and up through 2003 or 04 and they all had barrel constrictions. My last two Rugers are a 4in Redhawk and the stainless Bisley Blackhawk 45 colt from just a few years back. Those two also had constrictions PLUS they ALL had small cylinder throats. I reamed all the cylinders to .4525 and fire lapped the barrels. The least offensive one was the Bisley Blackhawk, the throats on that one measured .450 with a "minor" frame constriction. I've checked a few 44mag Rugers but they don't seem to be as consistantly "bad"..a couple of them were right on with .430 throats, .429 bores with no constriction at all.

[Catshooter]

"Micro-hickies"? Micro-hickies? :)



Cat