Muzzle Filing Worked

[410-er]

Tried this on a double where the left barrel was about 8"low.Filed about .003 off bottom and blended sides.You can't see it even if you know it.Pattern it the other nite and it brought it up to 3-4"low.Gonna file a little more and leave it at that.
Worked great.Thanks Britsmoothy! :thumbsup: :hatsoff:

 

[Britsmoothy]

Good for you buddy :hatsoff:

B.

 

[M. De Land]

Did you pattern it before and after? 30 inch circle at 40 yards is the general pattern criteria.
I doubt with a open bore that you will get 50-55 percent but the shot should be well dispersed throughout the circle with no gaping holes in it.
I could be wrong but I can't see how a muzzle filed out of square would be any benefit to pattern uniformity and density.
The other thing I have my doubts about is, does the shot column keep right on rising after it crosses the trajectory path of your other barrel.

 

[Brokennock]

I don't understand why you have such an aversion to this. It has been used successfully by a few forum members, from what I understand, it is how final regulation of factory doubles is/has been done. It can also be undone by filing the muzzle back to square, which I doubt can be done when one bends a barrel or a stock.

 

[Artificer]

Did you pattern it before and after? 30 inch circle at 40 yards is the general pattern criteria.
I doubt with a open bore that you will get 50-55 percent but the shot should be well dispersed throughout the circle with no gaping holes in it.
I could be wrong but I can't see how a muzzle filed out of square would be any benefit to pattern uniformity and density.
The other thing I have my doubts about is, does the shot column keep right on rising after it crosses the trajectory path of your other barrel.

Like you and others, I have been reading this thread with interest and in my case, because I don't do very much fowler/shotgun work.

In theory, I can see how a muzzle where the bottom is filed back at the bottom allows the propellant gas to escape at the bottom earlier than the top of the barrels. That propellant gas would therefore seem to cause the shot column to raise higher as it exits the bore?

Gus

 

[M. De Land]

The aversion is because of two things:
1. gun school training.
2. fairly informed general knowledge of shot column behavior and proffered remedies.
How ever, my desire to learn something new is very strong "if correct" but there are lots of unanswered questions in my mind that have not been answered so I remain skeptical to this point in the never ending learning curve.
If one barrel with a square muzzle centers the pattern generally where it is pointed and the other barrel has the muzzle filed on an angle to redirect the shot column to intersect that trajectory path at a given point than it will not be parallel to it. It will in fact intersect at one point and be below or above as it approaches and then moves past convergence.
The idea is to regulate both barrels to shoot parallel to each other as closely as possible so that they can both use the same sighting plane for windage as well as elevation throughout their respective trajectory paths.

 

[M. De Land]

Now in a double rifle one would regulate to converge at a give point,generally 50-75 yards. This is generally for close in shooting of dangerous game on the ground but with a shot column one needs close coupled parallel trajectory for close in shots as well as 50-60 yards.
Cross trajectory,convergence shot column paths would only work in a very a narrow corridor if I'm thinking this out correctly.

 

[nhmoose]

The aversion is because of two things:
1. gun school training.
2. fairly informed general knowledge of shot column behavior and proffered remedies.

Then you should know .410's are not patterned at 40 yards by shotgun folk.

everyone knows you do not like filing the muzzle.

 

[M. De Land]

Were we talking about .410's exclusively or shot gun columns and patterns in general?
By the way a .410 is a caliber not a gauge and if I were to use one for game shooting on the wing I would subject it to the same criteria.
I don't like the practice for a very good reason: not screwing up a good double gun!

 

[M. De Land]

Test the pattern center and uniformity close in than out at 40 yards after filing the muzzle to an angle to see if it is parallel and tracking to the untouched barrel, regulated to the sights.
My guess is it will cross trajectory and the pattern uniformity may be compromised.

 

[Britsmoothy]

Boy, some folk don't half like hearing themselves hey.

Just let the expert whitter, he'll need a sleep again soon :hatsoff:

B.

 

[M. De Land]

Well, do they file the muzzles on Holland and Hollands, Purdey's,Browns, Rezzini's Burretta's or any other high end double barrel or do they regulate the barrels to shoot straight and fit the stocks to the customer? That alone should be enough evidence!
You can go the Bubba route if you like but don't pretend it's standard practice for quality gun building.
The discussion is about provoking thought,testing ideas, and defending ones position with reasoned explanation. That requires correspondence on the venue were using.
Apparently you wish for all to just except what you say as fact because you say so.
If I thought you knew what your talking about I would!

 

[Zonie]

Several times you have said, "the discussion is about provoking thought, testing ideas and defending ones position with reasoned explanation."

I have yet to see where you have tested anything.

Have you taken one of your smoothbores and actually tried filing the muzzle at an angle to see if the shot pattern actually changes in a predictable way.

I suggest that rather than relying on,

"1. gun school training.
2. fairly informed general knowledge of shot column behavior and proffered remedies.",

you actually test it to see if it works.

While your trying it, you might smooth the filed area and reblue or touch up the exposed metal so it looks like it did before you started your experiment.
Then stand back 3 feet and see if the change is as noticeable as you think it would be.

 

[azmntman]

Holland and Hollands, Purdey's,Browns, Rezzini's Burretta's NO

My cheap arsed spainish 20GA dbl 20GA Oh yea!

Would have loved to have learned this before I traded off my pedersoli 10GA as the barrels were off abot 8" at 25 yds too!

 

[M. De Land]

File away Zonie, every thing I have ever learned about barrel muzzles insists they should be square to bore.
I haven't the courage to try it on any gun but a complete wreck.
Any body got a cheap double they want to donate so I can try the experiment and post some pictures of the results? Really, I will do it and pay the freight one way to my shop.
I'd like to see if it works as suggested or if it cross tragects and blows patterns as I think it will.

 

[Zonie]

Just a thought here:

I agree. The books and the experienced gunsmiths all would say the muzzle should be square with the bore.

You don't suppose the reason for this is because if the muzzles are not square with the bore, the shot will be deflected a little as it leaves the muzzle do you?

Hmmmmmm. Deflected in a different direction... :hmm:

My logical, engineering mind says, maybe this is something that can be used to correct a barrel with a bore that's pointed slightly off of where it should be pointed?

If it worked that not only could be handy but it could be controllable.
If the point of impact wasn't moved enough, a little more filing could move it closer to where it should be.

If it moved too much, a little more filing to change the barrel to a more square condition would move it back.

Just between you and me, it's stuff like this that a truly experienced gunsmith would know and use without ever bothering to tell new students.

It's sometimes called, knowing the tricks of the trade. :hmm:

 

[Britsmoothy]

Just a thought here:

I agree. The books and the experienced gunsmiths all would say the muzzle should be square with the bore.

You don't suppose the reason for this is because if the muzzles are not square with the bore, the shot will be deflected a little as it leaves the muzzle do you?

Hmmmmmm. Deflected in a different direction... :hmm:

My logical, engineering mind says, maybe this is something that can be used to correct a barrel with a bore that's pointed slightly off of where it should be pointed?

If it worked that not only could be handy but it could be controllable.
If the point of impact wasn't moved enough, a little more filing could move it closer to where it should be.

If it moved too much, a little more filing to change the barrel to a more square condition would move it back.

Just between you and me, it's stuff like this that a truly experienced gunsmith would know and use without ever bothering to tell new students.

It's sometimes called, knowing the tricks of the trade. :hmm:

:thumbsup:

Of course barrels should be squared off to start with, otherwise one has no datum point.
One thing I have noticed in human history, the ones that think outside their box are usually the ones that do interesting stuff, like for instance, sailing for the edge of the world and finding its actually a sphere

Schooling is about giving the mind a datum point, not locking it down with rules!

For the record, I have put squares to expensive English made doubles and found them to of been adjusted via this method.
https://en.oxforddictionaries.com/definition/datum

B.

 

[Artificer]

One of the extremely important things we had to do on unmentionable rifles was ensure the rear face of the rear lug was at a minimum of 2 degrees angle going down and forward. This because those rifles did not go straight down into the stock, but rather were placed in the ferrule in the front of the stock and the barreled action was dropped into the stock at a sort of curved angle.

OK, we had precision compound squares with angle finders on them, but they didn't fit real well into the small area needed to check the angle on the rear of the block. So one day I went back and talked to our Head Machinist about coming up with something like a small square that would fit, but would be at an angle of at least 2 degrees.

Sorry it took a while to set this up, but his advice was though he/we could have made such a device, the human eye could not distinguish an angle of only 2 degrees even up close. He stated an angle that could easily be seen would have to be more on the order of 5 degrees or more. So that saved us from having to make a special gauge, but it also pertains to this thread from what I have read.

If one files he bottom of a barrel only .002" or .003" in from square, I doubt most people could spot it without a square to check it? After all, that measurement is about the same as the thickness of a piece of paper at the bottom of a barrel that would be about .900" from top to bottom for the outer diameter of a 12 gauge barrel.

Sorry, it's late and I don't remember how to find the angle on a .900" outside diameter barrel where the bottom is only .002" to .003" off square at the bottom. But if filing off the bottom of the barrel winds up with an angle of the face of the barrel of 2 degrees or less from perpendicular, people are not going to notice it without a square.

Gus

 

[In Over My Head]

The other thing I have my doubts about is, does the shot column keep right on rising after it crosses the trajectory path of your other barrel.

Huh? The "trajectory path" of the two barrels is starting at exactly the same elevation, and after careful adjustment by filing, they are >still< at the same elevation at a distance. Where do you figure one shot column is rising?

 

[azmntman]

File away Zonie, every thing I have ever learned about barrel muzzles insists they should be square to bore.
I haven't the courage to try it on any gun but a complete wreck.
Any body got a cheap double they want to donate so I can try the experiment and post some pictures of the results? Really, I will do it and pay the freight one way to my shop.
I'd like to see if it works as suggested or if it cross tragects and blows patterns as I think it will.

I am no gunsmith or expert BUT... I came here to learn and benifit from other mistakes and knowledge, it has been great!

That being said from many many welcomed photo's from Brit it appears his patterns are "blown" in the right direction! :grin:

I respect your posts too, you have alot more gun knowledge than me fer sure. Your'e just different, we all have our druthers. I'd file alot before bending. To me a bent barrel is ruined (even if it does hit where its aimed). If it has to be bent it was ruined before it was put in the stock! Same with filing I guess but it just seems "acceptable" to me :idunno: