Latteral movement at the lug hinge (?)

[necchi]

 Been haveing a dickens of a time with this 308 barrel I got. Head space lock-up is good, just right. But trying yet another round Sunday afternoon I found some movement I didn't like.
 Closer inspection at home and I found the barrel has .002-.003 back and forth at the lug hinge.(tough spot to measure) It's gotta get the fix, it's a barrel from a member so the factory fix is out. This frame is used for 2 barrels, the factory 223 fit's and shoots great so I don't wanna/can't do a full bedding.
 Some of Fredsters accurizing pages are gone, I found one short paragraph where he mentions soldering shims to the sides of the lug where the contacts are. (solder on stainless?) Question is, Can I just use Devcon/JB/Goop with some feeler stock like on a hinge fix? Or will the stainless be too soft. I have access to shim stock at work and could beg some, or get it from Brownells. Lord knows it's gonna take just a tiny piece on each side, those contacts on the front of the frame are kinda small.
 I know if I try solder the blueings gotta come off. Dare I attempt Acraglass or simular?
 Any experiance with a fix for this one? Or Point me in the right direction at least?
 
 

[quickdtoo]

Here's Fred's accurizing link including bedding the underlug.

Tim

http://www.angelfire.com/ma/ZERMEL/hrultrawp.html

[bikerbeans]

Necchi,

I had this problem with a 30-06 barrel as someone got the pivot out of square (me of course).  I had to double over a piece of feeler stock until I had one side was 2 thickness of shim and the other side with only 1 thickness of shim. Bonded it to the barrel with JB Weld because nobody had the Goop Super weld.  Working okay after 50+ rounds of hand loads.

There is a post, but I don't remember from who, where they put lithium grease on the inside of receiver and hinge pin.  They then made up the Goop Super and let it ALMOST completely cure so it was a really thick.  They then put it on barrel pivot and shut the gun.  This was done without a shim and was done to remove a small amout of barrel slop.  Tim might remember who posted this as I think he commented on it.

BB

[quickdtoo]

Sounds familiar, but I don't remember who did it. 

Tim

[bikerbeans]

Tried searching for it without luck.  Whats the strength on Super Weld, upper 30,000 pound range?  Better get the grease on the right spots.

BB

[quickdtoo]

There's a link to the specs in the FAQs in the barrel fitting info, 36kpsi IIRC, JB Weld is 10-14kpsi depending on which type.

Tim

[necchi]

Better get the grease on the right spots.

That's the part I'm worried about  There's enough play in there so the barrel is not going to be in the same place each time, and/or move when fired with the barrel whip. I am getting the outside edge of the 2" at 100 H&R guarentees but it's by far the poorest shooter I have and I'm sure it's because of this play.
 The previous owner had trouble with pop-open, a non issue here with a little shelf work.
 I need to do something here to tighten the movement, but I still wanna be able to OPEN it   

[gcrank1]

Do some careful eyeball and/or measurement, you may only have to shim one side (which would simplify things. no?)

[MSP Ret]

I also recommend trying shimming only one side, easier to get a good fit and it should be just as accurate with less to move as you shoot it....<><....

[bikerbeans]

I used aluminum foil and keep increasing the number of thickness to determine what shim i need to get rid of the play.  I measured the thickness of foil strips with a micrometer after getting a good lockup.  Ended up with a shim that is 0.0025 on one side and 0.005 on the other.  I only put the JB weld on the back side of the permanent shim and then I sprayed everything in the front of the receiver with Dillon case lube.  Then I worried about not being able to open it for the next 24  hours.  Came right open, this time.   

BB

[gcrank1]

What was the accuracy before and after?

[bikerbeans]

Gcrank1,

I bought the 30-06 barel used out of the classifieds and never shot it.  I screwed it up relieving the hinge pivot and then had to shim/JB weld.  I have shot it with the following optics, 4X Horton Crossbow scope and 3x9x32 Bushnell Sportview that has the eye piece epoxied in place because of stripped threads.  I was getting 3 to 4  inch groups @ 100 yards, but I don't think this is a fair test considering the optics I used.  There is a brand new Redfield 4 12 40 headed my way as we speak so I should have a real answer regarding accuracy in a week or two.

BB

[Mac11700]

I believe Quick told me a new style Pepsi can was .020" thick..you might try cutting a long enough one and double it on the one side and see if it works..

Mac

[quickdtoo]

That would have been ~.002" Mac, I just measured a diet Dr Pepper, that's what the wife drinks, I don't drink pop, it measured .0025"-.003" thick.

And this will be added to the FAQs under accurizing and barrel fitting, good stuff, thanks! 

Tim

[gcrank1]

Hey Necchi, did you get the lateral play with the forestock/spacer mounted or just without?

[briannmilewis]

I just measured a diet Dr Pepper, that's what the wife drinks, I don't drink pop...

Tim

Ah, but the most important question is does she drink soda, pop, or soda pop? You Americans have funny names for soft drinks!

[quickdtoo]

She drinks carbonated soft drinks for clarification, I only drink water most of the time, even when we dine out, the only other drinks I partake of are Tazo Zen green tea, OJ, Grape or pomegranate juice, and occasionally an irish cream decaf coffee.....so the only drink cans here are diet pop cans. 

Tim

[necchi]

Hey Necchi, did you get the lateral play with the forestock/spacer mounted or just without?

 I could feel it with it on if I twisted hard, I was actually trying to settle into the bags on the bench when I noticed, then it was very prominate with the forearm off. Good point, I know I can gain some stability if/when I bed the forearm and spacer for this barrel, (I use dedicated forearms for each barrel).
 I got some .002 and .003 steel shimstock from work tonight, smallest he had. And it'll be time to get serious about measurment and fit. I think I'll try to use the epoxy bonds from the faq's and fit a shim or 2 on the barrel lug. Fredster advises "honing" to fit and that makes sence, the shim(s) will need to be somewhat tappered on the bottom so they slide into the contact points on the frame as the barrel hinges into lock-up. I'm guessing it'll take some time with a stone for a good fit.
 Thanks for the tip's fellers , I really want this 308 to be the tack driver my 223 an 708 are.
 I'll take photo's of the process and if it works I'll share'm.

[bikerbeans]

I think it's in the FAQs, but if you go to Harbor Freight and buy a cheap feeler gauge you can use it for the shim.  Should be able to find shims as thin as 0.0015 or maybe 0.001 thickness.  Gage still works when you are done, just has a couple of bobbed off feelers.  I cut them off with a Dremel and the mini-buzzsaw blades.

BB

[gcrank1]

FWIW, feeler leaves are often brittle. Grab the amount you need with a flat jaw pliers or in a vice jaw and snap off. Watch out whatever method you use, they are sharp when that thin (thinner than paper, and we all know what a paper cut is like).
Because of the contact area I would think the slower setting 'gooy' 'super-glue' would work pretty well. Anybody tried it?

[necchi]

"Super Glue" aka; Cyanoacrylate,, doesn't work well in an application like this or around gun metal. I'm not sure of it's pressure ratings (there are different strengths), but in laymens terms it won't handle the sudden high pressure.
 The stuff may well lift a volkswagon attached to a crane hook with an easy pull, but if you jerked that hook she'd let go. In my experiance it doesn't handle extreme temp swings either, it might work great all summer, but if it's -10 in December it'll pop right off.
 I wouldn't hessitate to use it for a temp fix if it's all I could find, but slow set two part epoxy types seem to be the most reliable. I have Devcon and J-B at hand, I've used both and have first hand wittnessed those holding together for years. I'd like to try the Goop listed in the faq's if I can find it local, I'm not going to bother ordering it.

[gcrank1]

Good idea to 'dance with who ya brung' since youve got them and used them. Are you going to go with just 'clean and dry' or rough sand off the blue to bare metal for some 'bite'? If so, that would be the point to make a final determination of the thickness required.
Cyano.....wow! I can spell super-glue, but that Id have to look up! You be a scholar!

[necchi]

Cyano.....wow! I can spell suer-glue, but that Id have to look up! You be a scholar!

had'ta look at the back of the jug,,   It's important to know that word in case you need to lift finger prints from sumthin 

I'll cut through the blueing abit, blueing is rust,,

[necchi]

Interesting Discovery; follow-up

 A few gents recomended I shim just one side of the barrel lug at the frame contacts, this made sence to me not only for ease of application but an oppertunity to create a "cast-on" or "cast-off" aspect to the rifle.

 So I sat down too find which side had more play, and was suprised at the measurement's I found. When I checked this barrel for the initial fit, I was happy to see it locked up on a .0015 feeler and could see no light. I was content just to leave it, there was no side to side at the time. But I couldn't get the thing to group, at about 150 rounds of mediocer shooting is when I felt the play.

I discovered an improper fit, the top of the barrel had no gap, BUT,,the lower sides of the barrel face and frame had alot of slop. I don't know how to describe this, but it's that the barrel went PAST latteral with the frame;



photo's might be better,,
That foil ain't movin!




I could push the barrel to the other side and fit .003 in there!



 Now I needed to fix that gap first, addition of a .001 shim with JB at the lug pin did the job, the latteral play has become a minimum at this point, I cannot fit even a .001 in the side of the barrel where before I could fit the .0025/.003 and I think I can bed the forearm to find the solid fit I need.
 There is still a .010 differance between the barrel lug and the frame contacts, but I can't make it move,(much).
 I'll post results after I have a chance for range time.

[bikerbeans]

Necchi,

Your sketch documents what I do to the lug hinge with a couple two many stroke of my rattail file.  If you remove too much metal from the pivot the barrel face touches only at the top of the receiver.  When you haven't removed enough from the pivot the barrel face touches towards the bottom of the receiver.  I think the difference in the gap, side to side, can occur during the fitting process because it is very hard to keep the lug pivot exactly parallel to the receiver pivot pin.

Twice now I have removed too much metal from the pivot (Tim, I know I am supposed to go real slow and check often, but my Adult ADD doesn't allow patience ) and both times I have installed a feeler gage shim with JB Weld and I have perfect lockup.  I just fired some very hot reloads, courtesy of an unnamed GBO member, through a 45 70 and the shim stayed put no problems.  Forehead is bleeding again, but that is my poor shooting technique.  Note, when I installed the latest shim I used spray on white lithium grease to coat the parts of the receiver I didn't want to JB weld and it worked great.

BB