[bartmasterson]

Has anyone else tried firelapping one of the Subject rifles?  If so what was your level of success?

I'm in the middle of the barrel breakin period (ran out of patches) and so far am severely disappointed.  I've run 28 lappers through this barrel per instructions in the Beartooth Technical Guide, and I can tell little, if any, difference in barrel leading.  It's possible that it cleans a little easier now but I don't know because I never cleaned it this much previously.  As for accuracy, I have nothing to report yet but hope to get some range time in this weekend.  Maybe this part will put a smile on my face but I'm not expecting it.

What I see in this barrel is a relative corn cob.  The tool marks just inside the muzzle, as far down as I can see them, are absolutely terrible.  These are lateral, not longitudinal, so I don't think they could be from rusting or scratching.  They look just like, well, tool chatter marks.  For years the scribes have been telling us that the microgroove barrels aren't suitable for cast lead bullets.  This must be the reason.  Maybe the manufacturing process is such that cutting this type of rifling is difficult, leaving tool marks, with the undesirable side effect of making them almost useless with cast.  Or maybe the manufacturing quality was just so poor that this is the end result.  Whatever, the barrel on mine is a POS.  At this point I'm about ready to relegate this rifle back to jacketed bullet use only and go buy that unfired Win 94 in 38-55 I've been eyeballing, for use with cast bullets.  It also makes me want to avoid Marlins like the plague in the future, even though I know there are better ones around.

Sorry for ranting but I've got many hours into this project and don't see how I can achieve the desired end result without putting in at least that many more hours, probably twice as many.  Maybe the solution is just pay the bucks and have it handlapped by a smith.  Before I invest more time in this project I'd also like to get an idea of why I'm not seeing any results.  The barrel constriction at the rear sight dovetail isn't completely gone, although much reduced, and I suspect that's why I haven't been able to detect improvements further out.  Maybe a little 220 grit would speed that up.  Since you can't put it back after it's gone I've elected to be conservative and stop before I risk ending up with a lever action smoothbore.

What I'd really like to know though, is whether any one else has had the same experience or do I just have an unusually rough barrel?

 

[pourboy]

Bart- I haven't (yet) started lapping my 1894 44 mag, but may be able to help you get on track. Have you read Marshalls Tech notes on the .444 yet? It seems to me that he was working with a Microgroove barrel. I believe parts one and two of the 444 series could help you out. By the way, without seeing the barrel, the marks you see running across the bore are likely reamer marks. While not desireable, they may be (sadly enough), what passes for "normal" these days. also, when you lap a bore, the area at the muzzle laps last, so you might want to slug your bore again, especially in the throat area, to compare the measurements with your original dimensions.

 

[MikeG]

It sounds to me like you're just not "done" yet.  I wouldn't give up till after the 50 round mark.

By the way... tell us more about your lapping process.  What is the bullet size, hardness, who's lapping compound, etc.  It is not hard but it is definitely not foolproof.  Probably the main thing that people don't do correctly is imbed enough lapping compound in the bullets, or use bullets that are undersized or too soft.

If you go 220.... don't use very many.  It cuts real fast.  You are right to take it slow, hard to grow rifling back!

Don't give up yet.  When that dovetail constriction is gone bet it'll show marked improvement.

Oh and be sure to scrub it within an inch of it's life before starting lapping.

Just my take on it, sounds like you got an exceptionally rough one and it needs more than the normal amount of lapping.

By the way I have a micro-groove .22 that will outshoot many fancy .22 target rifles.  So there are some good ones floating around for sure.

(Edited by MikeG at 10:10 pm on Dec. 29, 2001)

 

[bartmasterson]

I think I agree with you...I'm not done yet.  Really the rear sight dovetail constriction needs to be lapped out at a minimum.  That's just got to play havoc with accuracy and leading.  I think this barrel MUST be one of the really bad ones.  I've cleaned more lead out of it since Thanksgiving than I know what to do with.  Even the Chore Boy technique wouldn't get it all.  Here's a hot tip...buy stock in KleanBore.  I've got the market cornered in Southern Colorado on patches.  My local store had to reorder because I cleaned them out.

I got the bullets and lapping compound from Beartooth.  As for embedding, the first few might have been a little light, and I caught that problem early.  After that I probably averaged 5 minutes per slug.  I've been almost anal about cleaning the bore.  That's been the real time consumer.  I was thinking of repeating the entire 28 rounds again and then make a judgement on whether to punt or not.

And regardless of how this turns out I think I'll buy that 38-55 anyway.  Can never have enough 3/8 bores.

 

[IDShooter]

Bart,
      I have a Marlin 336A 30-30 from the late 70's that i have firelapped, and I got great results. First off, I didn't slug the barrel, I just wanted to smooth things up to reduce fouling. I used .310 cast bullets and Midway lapping compound (the middle grit, 320). By the 30th round I could detect noticable polishing at the muzzle, so I quit. Jacket fouling was considerably reduced, and lead bullets leave no detectable residue at all, just powder fouling. Plus the rifle is wonderfully accurate, having fired 3/4 minute groups, and always staying under two minutes with the open sights.
      I suggest you stick with it. Once you see polishing at the muzzle you should be in business. By the way, where is the leading occuring? Throat, dovetail or muzzle?   Good luck,    IDShooter

 

[bartmasterson]

It's hard to tell where all the leading spots are.  I'm sure that from the chamber to the rear sight dovetail is bad.  I also expect that the area from the magazine dovetail to the muzzle are bad as well.  Based on how rough the latter area is it just HAS to be holding lead.  In fact I can see it with a flashlight.

I plan to continue the firelapping experiment at some future date, perhaps when the weather gets a little warmer.  In the meantime, I went ahead and bought the model '94 in 38-55 that I mentioned in my first post.  This will become my .37x toy until I can get back to firelapping the 375.  Maybe I've gotten myself into another firelapping project, don't know.  Does anyone have experience with Winchester barrels in this chamber, or in general?  Assuming I get a good bullet fit I wonder if I can expect a leading problem?

I saw some loads mentioned way back in the early pages of this forum that make me think this rifle could possibly rock.  With a 24" barrel it could approach my 375.  Who knows, maybe the 375 will end up gathering dust.  But I know which one will accompany me to the woods.


(Edited by bartmasterson at 6:54 pm on Dec. 31, 2001)

 

[IDShooter]

Bart,
      I also have a '94 in 30-30 that was made about 1980. (Angle eject, but no crossbolt safety). It was harder to learn to shoot this rifle accurately than my Marlin, but now that I have learned it's quirks it shoots cast very well and has not required firelapping.
     I'd bet that 38-55 WILL rock!     Good Luck,   ID