[YoSam22]

Actually I'm asking about a 70, but they appear to all be the same.

I've got a barrel with a ring or bulge in it. Bought it that way, but did not know it. This gun has been a real education for me, and that's not all bad. Numrich has barrels at reasonable prices so I'm going to continue my education on these Marlins. Also an RFC member thinks he has a friend with a barrel for me. So that's not a problem.

Anyone have instructions, advice, etc.? I found some on another forum, but I'm going to have to register to see the photos. At this point I know it's pinned, and the pin is directional.

Also, I have a regular vise. I can see this receiver getting deformed pretty easily. How should this be handled? What should I use in the vise to protect the receiver, in addition to common sense? I'm not worried about the paint on the receiver, because the previous hack already spray painted it. In fact, I now believe he had the barrel off the gun to punch out the stuck bullets. Anyway, since I am going to refinish the receiver, would it make sense to heat up the aluminum receiver with a heat gun before driving the barrel out?

 

[YoSam22]

That's extremely helpful. I love that jig. Thanks a bunch!!!

 

[YoSam22]

Bwahahahaha!!!!

Thanks TMG!

I wasn't getting it to budge so rather than whack it harder I decided to try some heat. I used my propane torch and heated the front end of the receiver to probably 250-300º F. Then the barrel moved fairly easily.

Now to refinish the receiver while I wait for a barrel.

 

[YoSam22]

TMG I notice the barrel in your photo has splines. Mine is smooth. Can anyone comment on what my choices are far as replacements? Do I have to use a smooth one? Just guessing but I'm thinking the receivers all start out smooth, and the splines cut into the receiver as the barrel is driven in. Then again, that might take a specially designed press to make that happen. I'm sure not going to be able to push it in by hand.

If I can use a splined one, it opens up my field of choices, I would think. Anyone have the scoop?

 

[YoSam22]

I bought a barrel from Numrich, it came in today. One hurdle I did not expect is that it comes with no groove for the pin. It seems they must push the barrel into place, then place the receiver into a jig and drill right through the receiver and barrel.

So I have to decide how to proceed. I have access to a drill press but I fear I'm out of my league for a task requiring this kind of precision. I'd have to set up the drill to be in line with the two existing holes in the receiver. Then remove the receiver from the setup and install the barrel. Then back into the drill press setup and make the hole. All the while hoping nothing wanders.

Or I could simply use epoxy or Loctite. I build golf clubs with epoxy. They used to be held with pins a long time ago but now they are all done with epoxy. It can be broken down with 250+ºF heat, which will never be seen in normal usage here, yet is easy to apply if need be. My concern with epoxy is that the fit is so tight that there isn't really a gap for the epoxy; it will all be driven out and will only be there along the margins.

I could figure out the appropriate flavor of green Loctite. Never used it but it sounds like it could work.

Anyone been through this? Thanks.

 

[YoSam22]

If you have access to a drill press AND a drill press vise, I recommend that you go ahead with the barrel installation and redrill for the pin. Use a drill bit that is no longer than what you need, even if you have to shorten one and resharpen it.

You're probably right about most of the epoxy being driven out. On the other hand, loctite is much thinner.

I'm probably missing something obvious, but why is it a problem is the bit is long? It has to go through both sides, right?

I do have a drill press vice. It's probably considered a crude one, but it works. My thinking is, if I get the vice set up so the bit is exactly perpendicular to the work, I might be able to remove the receiver from the vice and then put it in again with the barrel in place, while not losing the perpendicularity. If so, when I start it in the top side hole, it should come out the other side hole. You can see why I'm nervous.

 

[YoSam22]

Yeah if worse comes to worse, that's when the epoxy or Loctite can come into play. It's an old beater so I don't have to worry about anyone re-barrelling it again.

I am concerned about the bit because it will be starting out by the edge of the barrel, on a very angled surface. I really don't know how it will do.

I made up a good holding jig for drilling. It uses your barrel-installation jig, shimmed and then screwed down to clamp the receiver. And another stop screwed tight against the receiver from above. It's just shown in mock up form here:

 

[YoSam22]

I expect to have something to report in a few days. Too much going on right now to get to the project.

 

[YoSam22]

Bad news

The drill press hole drilling failed. It's only a 1/8th inch bit. First I tried it with enough length to go all the way through. But the bit wanted to walk south, and started enlarging the hole in the receiver. I seated the bit deeper into the chuck until there was just enough sticking out to get started in the barrel. So when it couldn't really walk, instead it broke the tip off inside the receiver, as soon as it got the first bite. I did not think I was pushing too hard but maybe I was. I'm not experienced with a drill press.

I had to leave it at that for now. I'm not sure I can get the bit out of there. Or maybe I can just drive the barrel out anyway, and regroup. But I think there is a limit to how many times you'd want to push a barrel out and into one of these receivers.

Probably the best remaining options are to leave it assembled, and:
A) try to drill a completely new hole, or
B) apply the green loctite that wicks into place.

Someone mentioned cutting the groove rather than drilling it. Maybe that would have been better, but it would sure require fine precision in both measuring and cutting.

Follow up posted below...

 

[YoSam22]

Good News

I decided to regrind my broken bit. Something I have no skill at. But I did it and it looked good.

So, maybe not too smart, but I decided to drill, by hand!, from the opposite side, just to get a feel for what the bit was doing. Well, it went okay, so I kept going. I could tell it had walked a hair towards the bottom of the barrel, but I figured at the minimum I'd be able to get a pin installed and functional. And I did.

I had to drive the pin in from the opposite side of original, but who cares. Here is the side I drove it from:

Here is the other side, where the hole was enlarged by the new path:

Yes, it's a farmer-amateur hack job. But it will work. The pin is good and tight. I'm going to fill in the big hole with thick-ish black epoxy I have for another hobby.

In doing some searching, I now wonder if I should have used an "end mill" bit the first time. Sure seems like it.

EDIT MUCH LATER TO ADD:

I think you would want to buy a 1/8" end mill bit such as this:
http://www.amazon.com/4Fl-SE-Carbide-End-Mill/dp/B000I6I5NK/ref=wl_it_dp_o_pC_nS_nC?ie=UTF8&colid=6DLPSP8PJG1R&coliid=I254EBGLXWGYX8

The end mill bit will make it much easier to get the hole started on line. After you get the hole started in the barrel, you can switch to a regular 1/8" bit to finish the hole. If you don't have an end mill, the way you have to drill across the edge of the barrel will cause the bit to try to wander off.

This is assuming you are starting with a new barrel which comes without the groove for the pin, as I was. If you buy a used barrel, you'll have to hope the holes and groove line up. They probably will, but I just don't know. Marlin obviously drills the hole/groove into the barrel after it is installed into the receiver, so it's custom fit in each gun.

 

[YoSam22]

Thanks for the advice TMG (and others). This gun has been one learning experience after another. Very valuable. I've got the epoxy setting up in the bad hole now. It will also add some strength and security.

I'll post another photo of the completed gun. It definitely will look better than before. Hope it shoots better too!

 

[YoSam22]

Here is the old girl

Here she is with the new barrel. Also, I refinished the receiver with Birchwood Casey Aluminum Black. I had some on hand so I figured why not see how it comes out. It's better than before. Not perfect, sort of blotchy on top but it's acceptable for this gun. It's not a paint or coating, it's a mild acid that blackens the aluminum.