[Kael]

Apologies if this in the wrong place...

I took my enfield scout out to the range today, and found the targets completely keyholed at 50 yards. evey shot appeared to be completely sideways.

I had cut the barrel down to 20", and I know the muzzle crown I put on wasn't great. could a bad crown be causing this, or is indicative of something else?

Thanks in advance!

[SDC]

It's possible a burr COULD cause this, but what ammunition are you using? Does it change if you use a lighter bullet? How is the rifling? There are a bunch of factors that could come into play with this.

[Kael]

I'm using factory UMC 303. I haven't tried with any other ammunition yet.

I thought the rifling looked to be in pretty good shape.

[Sunray]

The bullets are too small for the bore. Slug the bore to find out what diameter it is. Hammer a cast .30 calibre bullet through the barrel and measure it with a micrometer. Enfield barrels can measure from .311" to .315" and still be considered ok. Larger than .315" and it's shot out. Then use bullets that are as close to the barrel diameter as possible.
Fix the crown too. It has to be correct. Brownells sells a crowning tool.
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=1032&title=MUZZLE+FACING%2fCROWNING+CUTTER+DRILL

[Kael]

Thanks for the advice, I do have the crowning tool on order.

when I find the diameter, how do I tell what commercial ammo has that diameter? or is that only an option for reloading?

[nicholst55]

It's more likely that the throat of your bore is eroded from firing Mk VII service ammo loaded with cordite. Try ammunition loaded with a flat base (as opposed to boattail) bullet, but only after you have the crown cleaned up.

[Kael]

I actually had it out this morning, and the throat erosion would make the most sense. UMC still tumbles, but the wolf gold did fine. I wonder if the UMC is boat-tail and the wolf is not.

Thanks,

[Jim K]

How did it shoot before you cut and crowned the barrel? The wrong bullet size may be the problem, but in a case where a barrel has been crowned without proper equipment and bullets keyhole, I tend to associate the two conditions.

Jim

[Sunray]

"...how do I tell..." It should say on the box. Most commercial factory uses .311" or .312" bullets. If you are reloading, and need larger diameter bullets, you can get 200 grain .313" and .314" bullets from www.303british.com.

[Kael]

Jim,
to be honest, I hadn't fired it prior to cutting the barrel. I should have, I know. ;)

I redid the crown with the brownells 11 degree cutter, and still have the same problem with the UMC. I shot a 2" group with the wolf, however.

both bullets are the same size (.310 and 174 grain) so the throat being eroded seems to make the most sense if one is boat tail and the other isn't.

[Sunray]

You really should slug the bore. .310" is nominally under size.

[Jim K]

If throat erosion is bad enough to cause bullet tumbling, you should be able to see it from the breech with the naked eye as the absence of lands ahead of the chamber.

I find it hard to believe that TE could cause that much of a problem. What happens with TE is that the bullet comes out of the case and if the TE is bad enough it actually can turn and skid at an angle into the barrel, deforming itself. That ruins accuracy, of course, but it takes a lot of erosion to make it as bad as you say.

How is the rifling in general? The Wolf ammo is likely steel jacketed and if the rifling is well worn it might grip better than the gilding metal jacket of the Remington bullets.

It is easy enough to see if the bullets are boat tail, just pull one.

Jim

[Kael]

The rifling seems ok, it looks sharp without any pitting that I can see.

I couldn't take a photo of the rifling in the barrel, but it's definitely sharp at the muzzle. perhaps you could also say if the crowning job is good enough or not.

http://img115.imageshack.us/img115/7831/muzzleav4.jpg

[Jim K]

The crowning job looks OK, but I can't really tell from a picture.

I suggest trying some other kinds of ammo and if you don't reload see if you can find someone you can trust who does and see how reloads will work.

There are a lot of factors in play and at this point, I am pretty puzzled.

Jim

[DeltaGunner]

[/B]By picture the crowning looks good. I would not call it complete with the sharp edges present.
Brownells also sells a crown laping tool, which basically is a tool with a half round end. It can be bought with or with out handle. Basically it's use is with lapping compound applied to it and with a lathe spinning barrel you place it against the bore and lap a slight inner chamfer to the muzzel. With out the handle you can spin the tool in a hand drill and accomplish the same thing.
Back some 30 years back, when I went to smith school, we were instructed to go to the local hardware store and by an assortment of round head brass screws, varying in size for different caliber sizes. and we used those afte being screwed into wooden dowel pieces. We also used "clover" brand valve lapping compound from the local auto suppy.
As to the keyholing bullets I doubt it to be a cown issue, although I have seen it with severely damaged crowns.
I would lean more towards a throat errosion problem, and would probably look at making a casting of the chamber, throat and a small portion of the entry riflings and go from there.[/B]

[Kael]

Delta,
I do have the muzzle lapping tool + compound, though all it achieved for me was a groove cut into the tool, with no change to the barrel. ;) I'll give it another go.


I spoke with a gunsmith yesterday, and he told me that wolf ammo is generally a little hotter than US made stuff. Perhaps with the shorter barrel UMC doesn't quite have the velocity to stabilize the bullet, but the wolf does.

Either way, with wolf I shot a 3 moa group yesterday. That I can live with...I'll just keep buying the wolf. :)

Many thanks for the suggestions.