Patching for a real stuffed out bore!

[303Guy]

rayg got me to thinking (he has a medford rifled barrel) that I might just be able to get my seriously rust damaged Lee Enfield to shoot straight with patched boolits. This was supposed to be my project 303-375 wildcat rebore but that's not going to happen anytime soon now. But, the rifling toward the breach resembles Medford rifling. The rifling sharpens up toward the muzzle, creating a tapered bore. Well, I tried it in my 'test tube' and the patch makes it all the way through with no sign of stripping or shearing or whatever. So, I plan on building this rifle with its stuffed bore to see just what patching can do! (There has already been a bit of firelapping).

[docone31]

I would think, that would make a great paper patched bore!
If it were me, I would patch some .3135, and smear some Valve Lapping compound on them.
Touch them off with full tilt loads, and the paper will remove the rust, and sharpen the rifleing.
I did that with mine, and it is my best performer!
I figuired, I had nothing to lose. The barrel was toast anyway.
Suprise! Suprise!

[303Guy]

There is no material to be sharpened. All the rust is out. It noe down to polishing whats left. What surprized me was that a patched boolit did not slip on the really shallow and rounded portion of the rifling. I tried a note pad patch and a tracing paper patch. Both patches held and came off at the muzzle. The tracing paper one shows very faint rifling impressions. This gun is still just a barreled action so it will be a while until I can fire some full tilt loads in it.

This is my fire-lapping bullet.



Valve paste gets packed into the grooves which are then covered by the neck. Only the middle three would get paste. The piece up front is the bore guide which I make as close to bore size as I can without pushing the bullet into the case. The bands are dimensioned to fit the throat and the last bit is over-groove size to get into the grooves. Just one of those removes all the rust.

A fired one

[mdi]

Is your decription right to left? Is the "front" of the bullet on the right side?

[303Guy]

Is your decription right to left? Is the "front" of the bullet on the right side?

Yes it is. I didn't make that very clear.



This one was fired through the 'stuffed' bore. I've shown the position in the neck. Only the grooves within the neck get filled with lapping compound. The idea of the nose piece is to ensure the rest of it enters the bore straight. After all, it's going to remove material from the bore.

[303Guy]

Right, well.... I played around a bit and found an existing boolit that fits the throat and leade of this rifle pretty well. (Thats what made the marks on the patch).




This is a 245gr boolit. Not the most streamlined but I'm sure piggy won't notice! It won't be the fastest either - 2000fps maybe.

[303Guy]

And here is the fired boolit and recovered patch which came off at the muzzle.



The bits on the right are from the outer wrap. The outer wrap wore away to expose the inner wrap which did its job. Notice how the rifling matches the patch angle. That was no accident. It does mean that the edge was glued. I got to thinking that the patch might just come off easier if the edge did not span across several lands. It seems to work.

[ozzie29]

crono tested???

[303Guy]

crono tested???

No. These were fired into my 'test tube' and with very low powder charges. The 'test tube' requires poking the muzzle into an opening. With the boolit weight I want to use, I hope to get 18000 to 19000 fps.

[6.5 mike]

303 Guy, I want to see the powder charge for 18k to 19k. I think you would really blow the rpm theory with that. hahaha

[303Guy]

Mmmm... thinking about it, I may be a bit optimistic about that, not from an RPM point but from the condition of the rifling! But all it has to do is kill pig size critters with a 245gr boolit. A hundred meters is actually a long way but even with 16000fps, that is well within the point blank range trajectory. But I did shoot off some hot loads with quite soft alloy. My camera lense wasn't big ebough to get the group in! But at close range, I hit point of aim. So is the boolit deforming slowly during flight due to high RPM? Pure lead does 'flow' under stress, so.....? Anyway, for now this project will have to wait a while until I have made a stock for it.

Here's a pic of a very slow hollow point fired into wet pack.

[6.5 mike]

Are you really trying to push these at 16,000 fps ? That's want I meant.

[303Guy]

The boolit in the pic is a 245 grainer. A good fit in this particular rifle's throat. 1600fps is what I expect the limit will be in this particular bore but from my good bore, I expect the paper patched 220 grainers to do 2200fps and I have driven them unpatched 220 grainers to about 1900fps with no leading and nice accuracy. I was shooting 183 grainers into the 2400fps region (hard to say, but going by felt recoil that would seem reasonable). I am getting a lathe soon (today) so I will be able to make up more suitable boolits soon. But as I said earlier, I suspect the soft boolits deform during flight. I shall have to repeat the same tests with harder alloy to be able to say one way or the other.

[wonderwolf]

I like the looks of that project, Would be curious how well that shoots at 100 yards.