Troubles with a carbine called Jayne (Puma 92 tube slippage)

[Cosmoline]

I picked up a Puma '92 in .44 mag a few months back, and got it all tricked out with a customized Mojo sight:





It won't cycle max OAL rounds, but while I figured out how to fix this I opted not to as it's an easy matter to simply seat the bullet a little deeper.

Once I got the front sight filed down to a 50 yard zero, the carbine has been shooting very well. Accuracy with 240 grain Keiths and 300 grain XTP handloads has been great. There's no blowback even with stout loads of 2400. The sights aim instantly. The carbine is FAST, really fast. And shooting it is loads of fun.

But then there's the #@$#$@ magazine tube. Rossi made a really nice carbine for a reasonable price, but then just stuck on a tube mag with nothing but friction from some loose clamps and the forestock to hold it in place. It's no surprise that the thing starts heading out every time it's shot. With stout loads about 20 rounds are all that's needed to send the mag tube an inch rangeward. Amazingly it still functions even then, but it's not kosherized to have your mag tube sticking out an inch beyond the end of the barrel!

I keep a hammer with me to smack it back in place, which prompted me to dub the rifle "Jayne" after the lethal but oft-straying character from Firefly. I've tried these fixes:

--Remove the weight of the light mount and tighten down everything (no effect)
--Slice open the bottom of the front clamp and tighten it even more (slowed down but did not stop the drift)
--Epoxy the entire fore-stock to the tube and to the rifle itself (held for 15 rounds, then gave way and started drifting again)

I could of coures simply solder the tube to the receiver or otherwise permanently afix it, but I'd rather not take such a drastic step.

Drilling and tapping the hole under the sight and screwing the tube to the barrel there is one option, but I really do NOT like the idea of putting that kind of stress on the barrel or the tube. Both wiggle like snakes on high speed camera footage, as I'm sure you know. Tie the heads of those snakes together with a screw and who knows what will give. Unlike a clamp, a metal screw doesn't have much flexibility, so my guess is it would put stress on the barrel and tube alike as the shockwaves rolled past. I don't mind messing up the stupid tube, but the barrel is kinda sacrosanct.

My next step is going to be to lock it in place with some industrial strength clamps. Maybe hose clamps, maybe U clamps! Something. And I may drill and tap for a hole locking the clamp to the tube. These should have some degree of flex but keep the tube firmly in place. I'm also debating cutting a notch in the side of the tube--a small one--and puling up the steel to rest against the clamp, so it can't drift forward.

Any suggestions would be greatly appreciated. This is intended to be a working Alaska carbine so how it looks afterwards is of absolutely no concern. If I have to paint it with auto sealant and wrap it with tape to fix it I will, just as long as it works.

 

[Fburgtx]

Suggestion #1- Take the flashlight off the mag tube!!

Suggestion #2- Put a shallow notch in the front mag tube (up by the muzzle crown). Then tap out the hole in the front clamp to use a larger screw (or use another method) to somehow engage that slot in the mag tube so that the tube can no longer move forward. (This would look much like the system Marlin uses)

 

[Cosmoline]

That was the first thing I did, as I noted in the post. It had no effect, unfortunately.

Anyway, I picked up some hose clamps from hell today at the industrial hardware store. If these don't work, I fear it's going to be time for major alteration. It's a shame, since Rossi aparently fixed this problem for their Casull versions.

 

[ffg]

Don't know about the newer puma but the old rossi 92 used the screw that holds the tube end cap to hold the tube in place also. It should have a small extension that fits up into a hole in the barrel. I can kind of see it in the picture. Maybe recoil has sheared of the end and allowed the tube to slip.

Brian

 

[MAX100]

That rifle was not designed to handle the loads you are shooting. Get a Puma 92 454 casull magnum and retire that rifle to standard loads or sale it. You are wasting time and money. It will never be the rifle a Puma 92 454 rifle is.

The hard truth but true.




GC

 

[robert garner]

hey
Slip a small piece of rubber between the front band and around tube, tighten.
This should give it traction while allowing some give,the epoxy had no give so it failed.
robert

 

[Cosmoline]

It should have a small extension that fits up into a hole in the barrel

It does, but the recoil is enough to make the little screw pop out and go along for the ride. The only way to fix it would be to redrill and tap the round hole so it can accept threads from the screw coming up through the mag tube. I'd rather not do that, as I'm not sure what it will do to barrel harmonics. I'm also not sure how long it would last before the little screw just sheared in half. But it is an option.

Slip a small piece of rubber between the front band and around tube, tighten.

Done. We'll see how much it helps, but it should be useful.

It will never be the rifle a Puma 92 454 rifle is.

Of course not, esp. since this is a .44 mag not a casull. The rifle itself has presented no serious problems, and is more than strong enough to cope with high powered magnum rounds. The tube is the problem.

 

[Sistema1927]

Try Steve Young. He is the 92 guru. He did wonders for my .45 Colt Rossi 92, to include fixing a hinky magazine tube.

 

[MCgunner]

That rifle was not designed to handle the loads you are shooting. Get a Puma 92 454 casull magnum and retire that rifle to standard loads or sale it. You are wasting time and money. It will never be the rifle a Puma 92 454 rifle is.

The hard truth but true.

Agree. The actions ain't strong enough for really hot stuff. I have a .357 version that I busted an ejector in shooting hot stuff I shouldn't have been shooting. Never had a problem with the mag, tube, but I keep the loads well into the safe zone. I can shoot warm loads in it, don't misunderstand, but my buffalo bore equivalents were a little tough on it. LOL

 

[Cosmoline]

The tube slips with moderate loads and Specials as well, so it's not related to any alleged weakness in the action. Besides, the action is working better than fine. If the action was a problem I probably would just ditch the thing. It just annoys the heck out of me to have one simple problem like this that doesn't seem to have a simple solution. It's a slapdash design job on their part. IIRC the real '92's have a sort of locking system to keep the tube in place. I know the Brownings do.

I've talked to Kiowa Jones about the issue. He's a backup option if I can't get it fixed myself.

 

[MAX100]

when I say your rifle is not designed for strong loads I mean the barrel to mag tube design. The receiver and bolt on the 44mag will have no problem handling the hot loads. I have seen this problem before on other Puma 44mag carbines when very hot loads were fired in them. As you know the tube is not threaded into the receiver like the 454 rifle. I see now that you like the challenge. There is nothing wrong with that.

The ejector that broke in the 357mag rifle was not from hot loads. The 357mag rifle can handle them. It was most likely the ejector was not fitted properly from the factory. That is why they put heavy springs in these rifles from the factory so they will not have to fit each part by hand. If you have not had an action job on your rifle it will benefit greatly from one and the parts will last longer. Heavy springs and parts that are not fitted properly wear out fast.

This is what can cause an ejector to break.

When a round is chambered and the bolt closes on the case rim the ejector is push in flat with the bolt face from that point on there is very little pressure on the ejector. The bolt and face take all of the pressure from the fired rounds not the ejector. The heavy ejector spring and the ejector rubbing against the inside of the bolt wall and the ejector collar from not being fitted properly causes excess stress on the ejector as it moves in and out as the bolt opens and closes. That can cause it to break. The ejector collar can break also.

Also, if the extractor has not been fitted properly it will chew up case rims and sometimes it will break too.

Have good action job done on your rifle if you have not done so already. It is well worth the money and will make your rifle smooth as butter.


GC

 

[Cosmoline]

when I say your rifle is not designed for strong loads I mean the barrel to mag tube design.

Yeah, I found that out myself ;-) That's why I was fishing around for ideas to fix it in this thread.

As far as the action job, *if* I can get this problem licked to my satisfaction, I'll likely send it to Jones for sprucing up. I was just seeing if someone had any fixes that had worked for them, but apparently they don't.

I'm taking her out for a spin tomorrow. As it stands now I've:

1--inserted some rubber seal material under the front band, and cut a slice out of the bottom of the band so it can really get a bite.

2--Replaced the weak as water round-tipped screw that had done nothing to slow the slippage with a much tighter fitting pin. Indeed the pin's now tight enough I don't know if I'll be able to open up the tube without a pair of pliers.

3--Placed two industrial-strength hose clamps on the rifle, one between the crown and the sights and the other right in front of the fore stock. These are now quite tight, but of course have a certain amount of material flex to them.

In short, there's now enough holding that tube down to keep a grizzly bear from breaking loose. I've done everything short of welding the tube directly to the receiver, though if it comes to that I will probably send it to a machine shop to have them put some extra steel on the end of the tube and actually thread it, then tap threads into the receiver so I will in fact be able to simply thread it in place.

 

[MAX100]

You may have to see if you can have the Tube and receiver threaded or have it welded or soldered to the receiver. Seems like the best way to me.





GC

 

[Acera]

I agree with Max. You mentioned that you are concerned about barrel harmonics, this might concern you. But with a 50 yard zero, and not needing long range performance, you should be ok. Even if it messes up the harmonics the accuracy will probably not be effected enough to matter. JMHO.

 

[Cosmoline]

Well the straps kinda worked, but not well enough. There was some slippage under them, and the tube eventually hopped (that is the word) forward until the extra tough pin I had put in place of the orginal round-headed one dropped down off the edge of the crown. Then the hose clamps got slack and it was all over.

SOOOO, I'm off to the land of shims and silver solder. I'm going to use some shims to fill as much of the gap around the edges of the tube as possible, get it just in the right place, and fill in the little gaps with silver solder. It's held well for me in the past, and I don't think there's enough expansion and contraction at the point of contact with the receiver to be of much concern.

If this doesn't work, I may convert the whole thing into a single shot! Or hire a commercial welder.

 

[artech]

Just a thought, but TIG welding the mag tube to the reciever may be the solidest option, although it would make pulling the barrel tricky if you ever wanted to later on. TIG would be the only type of welding I would use for this kind of delicate work.

If you don't want to go that far, how about welding some small tabs to the barrel and mag tube right where the barrel band goes? Offset the tabs so they will sit side by side when everything is assembled. Drill the tabs so the barrel band screw goes through both tabs and holds the whole thing together while covering up the tabs and weld job. Would that work?

Hey, there's ALWAYS a way!

 

[pete f]

Clean the tube receiver spot as well as you can, use a bit of sand paper to give the tube a bit of tooth, clean again with acetone, then reassemble using locktite. It will hold, and with just a touch of heat on the tube, will come apart if needed.