Fifteen hundred rounds using only moly coated bullets and this
guy's T/C Encore .22-250 is now smooth bored for 3" ahead of
the chamber?? How can this be? He's a pretty level-headed guy
and I'm sure he never fired any strings which would over-heat
the barrel. He calls me last night to tell me he had re-scoped
the rifle and sighted it in at 50yds, successfully. Then he
decided to clean it....he had never shined a light down the
barrel until last night, and he could see no distinquishable
lands or grooves for a full three inches ahead of the chamber!
Yes, how can this be??

He is wondering if it is the moly-coated bullets he has been
using. I've never heard of that....but then I've never heard
of smooth-bore for 3" ahead of the chamber, either.

Any ideas?

I use rock creek bbls and he will void the warrenty if you use moly bullets in the bbl. Now he lapps the bbl with moly to burnish the bbl, so moly on moly might be a problem i dont know iam not a metalurgist, but they dont like moly bullets. i dont think its just the moly bullets but it could be. 1500 rounds is a fair amount if your shooting 3800fps or above. a lot of bench rest shooters set there bbls backe at 800-1200rnds to hope to extend the life out to 2000 or more. I have seen barrels with 3-4" burned out in 5-600rnds they werent 22-250 but still it can happen. It also depends on how the bbl was made and what kind of steel was used by t/c. Just ideas i dont think anybody can be certain unless the bbl was tested in a controled lab, so just ideas

quote:

I think what happened in my case is that the bullets were going so fast down the bore, and the moly gave so much lubrication, that the bullets rode over the rifling.

If this was the case then one should have seen a lot of keyholes on the target.

I seriously doubt this actually happened.

When I shoot jacketed bullets I mostly use the ones I molied with the NECO kit I bought when it first came out..
No problems so far after quite a few years of shooting.
The main thing I noticed about using moly is that it made the barrel easier to clean.. I don't usually moly up bullets anymore because with WIPE-OUT bore cleaner one shot cleans nicely..
I wouldn't be surprised to hear in the future that WIPE-OUT will melt your barrel after five cleanings..
And so it goes...

.

quote:

Originally posted by DannoBoone:
...how can this be?? ...Any ideas?

I use Moly coated bullets in about everything I shoot. Have done so for many years and have no idea what some of the posters are talking about. Moly is a great coating for both my Bullets and my Bores.

Without seeing your buddies barrel, I'd guess the Lands and Grooves are still right where they are supposed to be. However, my "2nd guess" is the Grooves have filled in with Carbon Residue, making the Lands appear to be invisible. And the Carbon Residue can be difficult to remove.

However, many years ago Bruce Hodgdon made a recommendation to a Gun Rag Hack about removing H870 Carbon Residue that caught my attention. Mr. Hodgdon suggested mixing "Bon Ami"(non-abrasive cleaning powder) with your favorite Bore Cleaner to make a Paste. Wrap a "new" Bore Brush with a cloth Patch and slather the Paste onto the Patch. Then scrub the Bore. You may need more than a couple of new Bore Brushes for that specific barrel.
-----

I'll also offer a "3rd guess" that your buddy does not believe in Cleaning his Bores on a regular basis, (4th guess) he is under the totally mistaken impression that since he is using Moly that he does not need to clean the Bore, or (5th guess) that he really doesn't know how to properly clean a bore. Any or all of that is correctable.

Best of luck to your buddy.

Have him clean the 22/250 with J&B, then report back...

Thanks for the input and suggestions, guys! I'll
tell Bill there MAY be some hope yet for his
barrel, although he is in Tool&Die, perhaps he
just thinks the barrel is totally clean. I've
had barrels that LOOKED clean, but still got
carbon on patches. I'll offer to check out the
lands with a L-N-L OAL gauge. That should tell
us sumthin'.

Grenadier, could you have had an over-sized bore?

If I remember correctly tests done by Norma with the 6.5x55, moly coated bullets greatly extended barrel life with that cartridge.

I have shot moly bullets a fair amount in my Palma, Any/Any Rifle, Service Rifle and my 223 prairie dog gun with no problems.

quote:

Originally posted by N E 450 No2:
If I remember correctly tests done by Norma with the 6.5x55, moly coated bullets greatly extended barrel life with that cartridge.

I have shot moly bullets a fair amount in my Palma, Any/Any Rifle, Service Rifle and my 223 prairie dog gun with no problems.

Yes you remember right regarding the Norma 6.5X55 test.. It was in a "Precision Shooting" article.. Your memory is better than mine as I had forgotten about that article..