Improving Old Barrels

[Photog]

Both barrels slug at .267”
your minimum size is going to be .268" and the carcano is gain or progressive twist, made specifically for a LONG jacket bullet. Without the long boolit, you jump a huge gap at the throat, and cast boolits strip the rifling due to the gain twist. IMO its a lost cause to try anything other than factory style loads.

[zymguy]

Per the Frank de Haas book "BOLT ACTION RIFLES". the Italian Carcano M91 shank is .805 long including .050 unthreaded dia .968 at the rear, outside diameter of threads 1.065 with "approx 14 V threads per inch".

sounds like the savage would be .010 too small then, bummer

[TheAbe]

My intent is to keep the original chamberings. Approximately how much does a custom-profile new barrel cost these days? The most cost-effective solution would probably be for me to find a barreled receiver with a good bore. I’ve seen those floating around for Carcanos, but not KNIL carbines. In the meantime, I’m going to experiment with the suggestions here and see what impact each process has. I’ll post results here with before/after photos, though it’s going to take me a while to actually test shooting results.

[Scrounge]

There might be other posts on this topic, and surely on the subtopics it will involve, but how does one go about improving the performance of old military rifle barrels?

I have an Dutch M95 KNIL carbine and an M91 Carcano long rifle that both fail to stabilize their respective bullets the majority of the time at 25 and 50 yards. Targets have bullet-shaped holes instead of round holes in them. Both barrels slug at .267” and I’ve tried nominally .263”, .265” and .268” jacketed bullets, with no noted improvement. The KNIL has dark, worn grooves with a fair bit of pitting, while the M91 has stronger rifling, but also a fair bit of pitting.

Between re-crowning, fire-lapping, and other processes, what steps would others suggest I take and in what order, to attempt to get these rifle barrels serviceable again?

See if you can lay hands on a .269" boolit. My Lyman's #3 Says that most casters & shooters think .002" oversize is the largest you should go, so it should be safe if your barrel is reasonably consistent the whole way down. Of course, if it won't chamber properly, DO NOT shoot it. If the barrel has been slugged properly, and it chambers, 5 or 10 rounds downrange should tell it if it's worth the effort. You might also try a paper patched bullet or boolit. I'm told Zigzag cigarette papers are .001" thick. Machinists use it for checking clearances.

I have a 91/30 Mosin, for which the nominal groove diameter is .311, bore is supposedly .314. Factory ammo will not print on a 100 yard target except by accident. It does pretty well with .316 cast boolits.

Bill

[elmacgyver0]

When you finally give up on those barrels, try one more thing.
Wrap some scotch bright around a bore brush, wet it and sprinkle some scouring powder like Comet or Ajax on it and go to work on those bores.
Stainless steel scour pad material used the same way also works well.
You will be surprised on the gunk that will come out of those barrels.
Will they shoot better, maybe, but you will never know until you try.

[ascast]

I have a few old black cartridge guns that are very sewer pipe like, but rifling still shows. With a cast bullit 2 to 3 or even 4 thousands over groove dia they seem to shoot much better. My Stevens 32-40 will print about 1 1 1/2 inch at 90 yds. with black or pistol powder. The crowns can be checked by doing a "chamber cast" of the first few inches. (open breach to drive it out?). I have done this also with a Bannerman Trapdoor that (like new) was a junk shooter to now hitting rams all day. Cleaning rod damage. Bored out about two inches. ave a side hammer Peabody that somehow got a horrendous ding right on the crown. That got a trim and now shoots well. Problem with counter bore is you need a good spot back there to bore to. good luck

[TheAbe]

If nothing else, I’ll end up with a couple of shiny, of ineffective bores.
How does one make a chamber cast? Just push some soft lead into the muzzle, then push out to look at the shape? Sounds like I need to invest in some low-temperature melting slugging material.

[Bent Ramrod]

Bores that are dark and even speckly or have a few pits will still usually deliver at least halfway decent practical accuracy. But what is fatal is a barrel that has been converted into a blunderbuss by cleaning rod wear at the muzzle.

Tap one of your bore measuring slugs about 1/2” into the muzzle, push it out from the breech, and compare the measurement to the one(s) you pushed all the way through. If it’s any larger, the barrel will never shoot. Cutting it off ahead of the damage at the end and repositioning the sight might help, if you have the capability.

[elmacgyver0]

If nothing else, I’ll end up with a couple of shiny, of ineffective bores.
How does one make a chamber cast? Just push some soft lead into the muzzle, then push out to look at the shape? Sounds like I need to invest in some low-temperature melting slugging material.

You may indeed.
What I suggested is a very last-ditch effort, prior to rebarreling and you can still reline if it doesn't work out.
At that point you do not have anything to lose.

[M-Tecs]

My intent is to keep the original chamberings. Approximately how much does a custom-profile new barrel cost these days? The most cost-effective solution would probably be for me to find a barreled receiver with a good bore. I’ve seen those floating around for Carcanos, but not KNIL carbines. In the meantime, I’m going to experiment with the suggestions here and see what impact each process has. I’ll post results here with before/after photos, though it’s going to take me a while to actually test shooting results.

You will be lucky to find a contoured and threaded unchambered or short chambered barrel for under $250. Since these are not commonly rebarreled chances are you will have to go custom all the way. If that is the case $500 is a starting point.

https://www.fieldandstream.com/guns/...barrel-makers/

[john.k]

A takeoff Mauser 98 barrel is easily fitted to a Mannlicher ...........even a beginner can reduce the thread the few thou with a hand chaser .........however ,the 95 is one of those guns with a fully supported cartridge ,so the barrel has to 'clock' with extractor and ejector recesses.........IMHO ,the Mannlicher action is a klunker ,and not worth time or money ..........get a 98 Mauser.

[nekshot]

Slow down fps and try paper patching. At this point any thing is worth trying if safe!

[Good Cheer]

For a Dutch '95 with badly corroded rifling I did extensive work to try to recondition the bore and finally concluded that nope, it was a lost cause with either lubed lead or paper patched. I really like the piece otherwise so my plan was to have it rebored to .338" and the chamber neck diameter and length enlarged to suit. Brass of course would be formed and fire formed to suit, eventually having a full length sizing die. I discussed the job with a person who had done reboring for me previously and we were good to go, him suggesting that .358" would work as well though I was hesitant due to the lesser wall thickness. I got everything together, got my molds, got the dies worked out. Then again tried to contact the person before sending him the '95. No response. Tried leaving phone messages and received no responses. Not knowing what to think at that point and becoming concerned, I sent a letter with a self addressed stamped envelope. In return the person scribbled a terse don't want your project. Well, that killed my project and I was out the monies involved. I'm stuck with it so perhaps the '95 will make a nice floor lamp.

[Dusty Bannister]

Not the expert here, but the use of various mild acids to remove jacketed fouling in old military rifles might not be the best idea. It will only deepen the pits and may not solve the build up of copper fouling. One might consider the use of Hoppe's bore solvent and repeated brush and soak cycles over a period of time. Swab to wet the bore, scrub with a good Bronze brush to loosen fouling, wipe with dry patch, swab with wet patch and let sit several hours. The SS brushes are so hard that you will just etch the barrel surface where the bronze brush will just scrub and loosen the rust and copper fouling. It might take wearing out two brushes to get the job done and down to bare metal. It has taken years of incomplete cleaning and building up in layers to allow the bore condition to get to this point so expect to take some time to get it cleaned up again. There have been a lot of suggestions as how to clean the bore, pick one and see if you can get a clean bore and improve the way it shoots.

[schutzen-jager]

a few years back i purchased Remington 510 barreled receiver that was damaged by sea water from hurricane Sandy - i purchased it for the receiver, which cleaned up with some filing + polishing - the bore was dark + no rifling visible let it set in scrap pile for months - one boring day i plugged it for the white vinegar treatment - after 3 days now can see rifling + it looks like it might be very shootable -

[ascast]

If nothing else, I’ll end up with a couple of shiny, of ineffective bores.
How does one make a chamber cast? Just push some soft lead into the muzzle, then push out to look at the shape? Sounds like I need to invest in some low-temperature melting slugging material.

yes. but I use a hunk of aluminum foil, just a wadded up ball, snug is good. Get an inch or two into barrel so whole throat, lead, area is captured. Same can be done on the front end ( muzzle) Cerosafe can be reused and it melts around 150.

[Harter66]

I have a pair of Arisakas a 99 at .3165 and a 38 at .270 for those not aware they have Metford type rifling, just humps and valleys . The 6.5 didn't care much for anything I tried until I tried a 266469 as cast and paper patched .272 . 1.5" at 50 doesn't seem like much but compared to jacketed that was jumping the lands and other softer cast it was a huge improvement. The first load key holed at just 5.5 feet at 25 yd jackets were better at 3.5' at 50 yd. The verdict is still out on the 7.7 but the 8×57 neck die is perfect, just lacking in 8mm bullets and really fat 30/31s .

The Carcano shank is actually larger than the LR Mauser . A 1.128 dia blank doesn't leave much room for a shoulder .

The current bid I have for a Savage prefit from a raw blank I own is $200 to turn , thread , and crown to a #2 contour at 24" from a 25" blank and double action thread length with 6" of .750 at the muzzle end .

Past experiences with Malcolm Ballistic Tool makes it worth every penny to me .

[TheAbe]

More interesting comments and suggestions. Keep them coming!
I’m thinking at this point the Carcano barrel is likely salvageable, because though dark, the rifling is fairly strong. I’ll give it a good cleaning, polishing, crown check, and then try cast boolits.
The Dutch M95 I have less confidence in. Apparently a number of these KNIL carbines were rechambered to .303 British by the Indonesian military in the 50’s, and while I’d be hesitant to go that extreme a change, I had the idea that I could have the barrel re-bored to .270 (.277). If I could find a button combo cutter to 6.8 Western specs (.270 land, .277 grove, 1:8 twist rate), that would likely leave a fresh rifled surface (assuming none of the pits are that deep) and give a twist rate close to the 7.7” twist of the original. I have to form 6.5x53R brass anyway, why not make it a 6.8x53R? I would think I could use the same loading data and get very similar performance to the 6.5x53R cartridge, and being a carbine, the greater surface area of the back of the bullet might yield slightly higher velocities at the end of 18”.
Thoughts? I’ll still try to get this one the best I can with 6.5 first, but it’ll make an additional interesting project...

[725]

+1 for an ammonia treatment to attack copper fouling. Followed by some hand lapping with an abrasive and if you can, shoot some paper patched bullets. I've had success with fire lapping, too. Just go slow. Once the metal is gone, it's gone. My final suggestion is to have Bobby Hoyt do a reline. Not that expensive and it retains the exterior condition & markings. Hoyt relined a 43 Egyptian sewer pipe for me and now it's perfect! Even very close exams can't tell it's a reline.

[TheAbe]

I’ve disassembled the KNIL in preparation for transmission fluid...should get that started tonight...