really worn microgroove rifling

[castalott]

Has anyone ever seen REALLY worn micro groove rifling? How did it shoot? Please tell all as I am curious.
Thanks in advance, Dale

[pietro]

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I've never run across any really worn MG rifling, since it was introduced, except for a few MG bbls worn near the muzzle, from improper cleaning rod wear / cleaning from the muzzle ILO removing the lever/bolt & cleaning from the rear.



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[missionary5155]

Good morning
I await with interest on this one. Most Marlins are shot so little they could never wear out. At a box a year of "j" thangs it would take 100 years for the avarage rifle to digest 2000 rounds and make it "worn out".
But As soon as one did I would send it to JES and get it fixed to the next step up in rifling and never have to wonder again.
Mike in peru

[ReloaderFred]

My wife and I put a couple thousand rounds of .38 caliber bullets through our Micro-Groove Marlins each year in SASS shooting, and have been for about 7 years now. Our rifles are shot more in one year than most of them are in a lifetime, and the rifling is just as strong as it ever was in both rifles.

Of course, most of our shooting is cast bullets, but the point is, they get lots of cast bullets fired through them.

I also size all our bullets at .358" for both rifles.

Hope this helps.

Fred

[Lonegun1894]

My only microgrooved gun is a Marlin 336 in .30-30 that gets at least 200rds fired through it each month, and it is a 1971 model, but I just bought it a few years ago so can't speak for how many rounds it had fired before I got it. Its ugly as sin due to having been mistreated before I got it, but the rifling and action are good, so my shooting hasn't hurt it any. As far as wearing out rifling, my most shot non-.22 is a Springfield 1911A1 Loaded that I have had since it was new, and according to my notes, it is well past the 85K rd mark and approaching 90K quickly, and the rifling in it is still fine. Now the vast majority of that has been with cast, but you get the idea. I would just shoot your gun and see what kind of accuracy you're getting. If it's accurate, I wouldn't worry. If it isn't after actually trying different things to make it shoot, then I would start thinking that maybe it is time to rebore or rebarrel it and get it back into shooting shape, but I would be surprized if yours is truly shot out.

[6pt-sika]

I've shot a bunch of Micro Groove barrels over the last 13 years and some of them quite alot .

Now bear in mind I don't shoot jacketed in most of them just cast .

Anyway I had a couple 30-30's I shoot a good many Ranch Dog 311-165GC bullets in that never showed signs of wear and they were used when i got them .

Of my herd of Micro Groove 444's they all get cast only and 3 or 4 of them get shot 500-1000 each most years and they show no signs of wear . I think the one I chopped the barrel and I call my "Retro 444P" has been fired about 2500 times since I got it and all with cast . And it certainly shot well when it was 24" and as well if not better since it was cut to 19" .

I have another 444 that was made in 1968 that gets fired quite a bit as I am trying to get it doing well enough to shoot in the Cast bullet Association Matches in the Hunter Rifle Class . I would say I've put well over a thousand thru this one in less then a year with no adverse effects . First with stout loads of H322 and IMR8208 but more lately with what I would call moderate loads of XMP5744 .

Bottom line is I have some Micro Groove barrels that have had a rather large amount of bullets thru their barrels by lever action standards and NONE of them showed any great amount of wear !

[runfiverun]

how would you know?

[6pt-sika]

how would you know?

To me signs of wear would mean diminished accuracy with proven loads in a barrel I know to be clean .

Once I have a load worked up I've not seen anything to make me think this . And by dimished I mean going from say a 1-2" group at 100 yards to about a 5-6" group .

[MtGun44]

Never happen with cast in one lifetime.

Bill

[castalott]

I have one 30-30 Marlin with 5000 rounds thru it. Maybe 10,000. It was our go-to rifle on our 'poor boy silhouette range'. Now these loads were very soft 130 cast plain base with 4 to 4.5 grains of whatever fast powder was available. This load is as close to a 22 lr as I have found.
I can't tell it has any wear on it at all BUT I know it does...it HAS to with that many rounds thru it.... 'Uncle Larry' says we will wear the trigger off before we wear the barrel out. And to think I bought 2 spares in case this one would wear out...