Totally new here, and I have done a search but couldn't find anything.

Read an article that indicated that the heat from sweating on a rear sight island would cause all kinds of chaos with a button rifled barrel. Theory being that the heat would allow the displaced metal of the rifling to spring back some minute amount, causing a tight spot. In addition the barrel would then wonder when it heated up from firing multiple shots.

Any merit to this? I see many DG Rifles with button rifled barrels and sights. Seems like there is quite a bit of experience with these rifles here.

Thanks in advance.

Hi, welcome! I suspect there isn't a lot of feedback given the (lack of) response you've received.

I will say that it seems big bores are really forgiving when it comes to barrel work, and almost every one I've ever seen would should better than necessary, no matter what was done to them.

I am still digging into the issue, and I appreciate your reply. I see some of the sights are mounted with a screw. I am inquiring with NECG to see if that is the only thing needed or if it is in addition to solder.

If I remember correctly my smith telling me he uses both the screw and soldering to install the island.Special soft heat not to ruin anything but I would rather have an integral barrel.I know from shooting my 308 rapid fire style that high heat can send accuracy and the barrel down the drain fast.That is why I now use large contour Palma barrels.

In my experience, rear sights, bands, islands, sweated, screwed, loctited is a non issue. Another item to add to my book!

Would you care to share the author of that article?

quote:

Originally posted by Johral:


Read an article that indicated that the heat from sweating on a rear sight island would cause all kinds of chaos with a button rifled barrel.

quote:

Originally posted by custombolt:
Would you care to share the author of that article?

quote:

Originally posted by Johral:


Read an article that indicated that the heat from sweating on a rear sight island would cause all kinds of chaos with a button rifled barrel.

I'll see if I can find it.

No worries.

Here's the piece. Article

quote:

Originally posted by Johral:
Here's the piece. Article

Whenever he said cryo stress relieved barrels, I quit reading. If he hasn't studied it more than he has, it makes me wonder what he really knows. Probably learned it on the internet.

butch: I got the same negative feeling just a few sentences into the article.

Johral: I'd take the advice of experienced gunsmiths before a writer like the one you quoted. "All kinds of chaos" seemed to be overstated just for one example. His claim had no support via hands on tests using identical bores conditions, heat, fittings and the like with the only difference being the rifling method.

Welcome to AR.

Personally the only time I have found that banded swivels have caused issues is when they are press fit and cause a constriction. I've soldered barrel bands onto dozens of Lothar Walther barrels and never had any issues.

Thanks for all the replies. Direct experience is what I was hoping for, and I got the answer.

As a metallurgist I can say there is some misinformation in the article.
Crucible steel makes a stainless steel , 416R which is properly made[as opposed to standard 416 ] .Made for rifle barrels !! Good to - 40 * !!
Solders go to about 450 * [silver solder] and the lead tin solders lower temps not much there to cause heat problems.
How heat is applied matters also. Best to heat around the barrel instead of just one point
Cryogenics ? Mostly misunderstood .Even by those on the cryogenics group of the American Society of Metals ! A few of those came onto knife forums and couldn't even explain what it was!!! Shameful, I was embarrassed to be a metallurgist .
Yes Johral get some facts !

quote:

Originally posted by z1r:
Personally the only time I have found that banded swivels have caused issues is when they are press fit and cause a constriction. I've soldered barrel bands onto dozens of Lothar Walther barrels and never had any issues.

Hmmm...just how thin were those barrels...sorry, I'm skeptical! How did you measure the constriction?

quote:

Originally posted by Duane Wiebe (CG&R):

quote:

Originally posted by z1r:
Personally the only time I have found that banded swivels have caused issues is when they are press fit and cause a constriction. I've soldered barrel bands onto dozens of Lothar Walther barrels and never had any issues.

Hmmm...just how thin were those barrels...sorry, I'm skeptical! How did you measure the constriction?

On my Ruger #1 in 45-70 I could detect a constriction when a lead slug was passed through the bore (not sure how they attach the barrel band swivel). I only shoot lead in it, so I fire lapped the bore with a few rounds and it took the constriction out.

Personally, I don't have any issues with a bit of constriction, but if the POI is going to wander as it heats up, that's an issue.

Fire lapped ??, I guess you shot out the throat.

quote:

Originally posted by butchlambert:
Fire lapped ??, I guess you shot out the throat.

Nope...shoots into 1 hole. Shooting soft lead slugs at just enough velocity to exit the barrel, using very fine grit.

There is a lot of misinformation and misunderstanding about what fire lapping is or should be.

Chuckle chuckle, where are the targets. I guess you mean when "doing my part".
Misinformation, please explain if you know.

quote:

Originally posted by butchlambert:
Chuckle chuckle, where are the targets. I guess you mean when "doing my part".
Misinformation, please explain if you know.

Didn't come here to start an argument, but you sure seam intent on getting one going...

Max charge of H335 and a 434grn Gas Checked WLN, heat treated.

I "seam" to want to disagree with you. Yes, I seem to disagree with you.

You got me...I didn't proof read.

Hey, We are both entitled to our opinion. I have seen many throats shot out by abrasive fireforming or fire lapping. If, and I say "if" you are stuck with a very rough factory barrel, what do you have to lose? I'm with Duane, why would you have a barrel swivel that tight? No reason for it.

To clarify a few things . I use the term solder to mean something less than about 500 * F. Solder and braze get maximum strength and best capillary action with a gap of .003 " .Not very stressful !
Cryo has been tested by the NRA and some of the best known barrel makers who have found no significant improvement .I wonder what the tests were considering no one seemed to really know what it was all about.

Maybe silver solder that takes a a lot of heat would be damaging but don't know..

I have a gun cabinet full or big bores with soldered on front and rear barrel band sights and barrel band swivels, they all shoot an inch or better or I send them to a gun show or gun dealer..
That guys out to lunch and just repeating what he has read and heard..I see lots of false statements in the gun trade like that..One guy makes a claim, others repeat it and before you know it, it must be true and sworn to many...

I see fire lapping as another example for the difference in men and boys is the cost of mens toys..barrel wear is just that..I see the same thing with ruined scope rings and lapping when a bit of .400 grt on the finger was all that was needed..Lots of toys for the American gunner out there..

I bought a used Ruger #1 safe queen in 45-70 about 30 years ago.
The gun looked unfired when I got it and my long time dealer told me it had just sat in a safe for a long time.

With cast bullets it would not keep 5 shots on a 2 foot square sight in target. The bore looked perfect. After a few weeks of thought I took a few cast bullets and drove them through the barrel. I found a .001 inch constriction at the sling band and a .0015 constriction at the front sight band. Apparently Ruger installed those bands with a heavy duty press.

The same ammo that was so terrible in the Ruger shot well with open sights in a Browning 1885 Highwall.

I shipped the Ruger back to the factory with a letter and 3 .457 round lead balls for them to push through the barrel. I also asked them to test it so I did not get another barrel with constrictions.

About a month later I got the same rifle back with a new barrel and a test target shot at 50 yards. There was about 2" inch group on the test target. I have had no problems with the rifle since its return.

Changing the subject to the original question.
I have a low round count Win M70 Super Express made after they switched to the long claw extractor. It has the soldered or brazed on front swivel base. It is easy to see the distortion on the surface of the bore where the base is attached. It looks a bit like mirage. However the rifle shoots really well as is. I expect that it will improve a little with a few hundred rounds fired.

Were I to have a rifle built to order I would prefer an attaching method that does not constrict or distort the bore. I suppose that might be a sling base soldered with low temp solder.
I prefer a receiver sight over a barrel sight so I would just skip that part.
Were I to use a barrel sight I would prefer it to be full banded and low temp soldered.

Curveball,
Are you blaming soldered on sights for someones sloppy work?? it seems so..and to tell truth I cannot imagine crushing a barrel with a banded sight. I simply don't believe that sight had anything to do with what was a bad barrel to start with..the band is too thin and too flexible to do that.