Help with bore condition on old guns

[hemiallen]

I am doing the unthinkable, considering buying an old lever gun off the internet based on owners opinions....

The issue I have isn't about the outside of the gun, as pictures can show much of all I need to know, what is an issue is the bore's condition.

One fellow, who has a very nice gun has a bore rating of 6-7 out of 10, and he says his other shooter is a 6 ( 25-20) and it shoots very well, so I should consider it is hard to get a 100 year old gun with a better bore. The gun hasn't been shot by him, and the bore pict looks like it needs a cleaning for me to see rifling. I trust his opinion, but I don't want to buy it until I understand bore condition needs better.

Another is from a reputable store, and says it has good rifling but is dark, and he mentions dark means micro-rusting. I suspect a good lapping with JB may resolve this, but not sure as I have never worked with old guns before.

My goal is a decent shooter using cast bullets, so lapping to me isn't as critical as we usually size them oversized anyway, vs jacketed where you are stuck with what the barrel is.

Thanks for any help deciding what bore condition is needed to get around 1"- 50 yard groups.

Allen

[Harry O]

My experience with rusted bores is that they are pretty much equal to good bores as long as there is rifling full length (usually said in the ads as "dark bore, but strong rifling". The problem with them is with cleaning. Dark bores are much more difficult to clean.

As far as JB, I tried some lapping compound (different manufacturer) on one bad bore. It shot worse afterward. I would give it a good scrub with a brass bore brush and cleaner, then leave it alone.

[dubber123]

Did you mean 1" groups at 50 yds.? 50 shot groups might be a little harder! I got an old S&W recently off an auction site, and was quite disappointed with the bore. Being stuck with it, I decided to see how it would do. Not bad at all!

It took alot of cleaning, and eventually a firelapping, but around 2" at 50 yds. isn't too hard to take for a 90 year old revolver.

[kir_kenix]

A good scrubbing will do wonders, even for a "dark bore." Firing a few hundred rounds down the bore with a good cleaning regiment inbetween has also tightened up groups for me and shined up some bores. I wouldn't worry too much about a dark bore on a 100 year old rifle, as alot of gunk is bound to cleaned out of them. Good luck and happy bidding.

[hemiallen]

Thanks

Yes, 1" 50 yard groups..... sorry...

Interesting, I'm glad to see your feedback. I may have to put a deposit on her.

Allen

[fourarmed]

My 03A1 has a dark bore, and I wasn't getting the kind of CB groups I hoped for, so I bought one of David Tubb's abrasive bullet sets. I loaded them with a starting load of 4895 and they shot eye-popping groups. (I think they were 190gr. Matchkings.) I still didn't get anything approaching that with CB, but that has been a long time ago, and I know a lot more tricks and have a lot more moulds now. I'll get the bug one of these days and get back to it.

[Bent Ramrod]

I had a .25-20 SS barrel that was near pristine except for the first two inches of the bore, which was badly pitted from corrosive priming. Never could get it to shoot and eventually relined it back to .25-20 SS.

I currently have a Marlin pump rifle in .25-20 WCF that has "dark but strong rifling" but shoots about 10" at best with cast boolits, and maybe 6" with jacketed, at 50 yards. It will probably be relined someday; haven't tried fire lapping yet.

These "small bores" were especially prone to being damaged like this in the early days of smokeless powder. There was a relatively larger amount of primer residue for the smaller bore sizes. You might try to get the seller to knock off a hundred or so from the price, to defray some of the reline cost, if worst comes to worst. On the other hand, it might shoot OK as is. No way to tell, really, besides trying it out.

[9.3X62AL]

1" groups at 50 yards can be a challenge in a 25-20 WCF bore in any condition. I can do that (barely, and not very time) with j-word 75 grain Speers and 11.0-12.0 grains of IMR-4198, but the best EVER in the Marlin 94CL in 25-20 (1988-made) is about 1.6" at 50 yards. That's using Lyman #257312 and #257420 from 1100-1800 FPS, and RCBS-85-CB from 1000-1400.

#257420 is best overall, but can go "shotgunning" with the other two if the velocity sweet spot for each isn't adhered to--which varies from powder to powder, I should add. There is a good deal of strong talk coming from my shooting position when I play with the Marlin in 25-20, to which Buckshot can attest.

The next round of testing will involve use of AA-1680 as fuel, to see what sort of deviltry it can produce. I'm not quite ready to throw in the towel on this project and go "jacketed only" with this caliber, but the prospect has its temptations--ESPECIALLY when the 250 Savage (M-99) can place all three of the above boolits in nice, small clusters--just like it does with the NEI 100 grain spire point. Some of the hyphenated WCF rounds can be offramps to madness on the largely stress-free autobahn of cast boolit hobbycrafting. Just warning ya.

[KAF]

A 25-20SS with a decent bore can shoot 1 1/2" groups at 200 yards with cast bullets.
Do not sell short a small caliber, if the nut on the butt does his job.

[pdawg_shooter]

Try 50 to 60 paper patched bullets loaded without lube on the patch. Brightens up a dark barell real nice.