Poor groups with mark II target competition model

[obdocab]

I need some advice. I have a used mark 2 competition target model slab side that is giving horrible groups. I bought this gun used about 2 months ago and have worked with it to no avail. I looked at the crown under magnification and it appears that someone has cleaned this from the muzzle and nicked up the muzzle a little. Anyone offer any suggestions as to what I can do on my own to help or fix an abused muzzle

 

[kacher1]

From what I have read recrowning is not that expensive. If the nicks are causing the bad groupings then recrowning is the answer.

 

[alizard]

I would look around on the net and see what the recommended crown angle is then dig through my Dremel tips and find a nice fine tapered stone and give it a very light touch. Clamp the barrel in a panavise for stability and just do it easy.

Or, send it back to Ruger but the shipping is ridiculously expensive to send a gun anywhere.

Before doing anything I would shoot it from a benchrest to see what the best groups are.

 

[wwb]

Recut the crown yourself..... requires the proper size pilot:

http://www.brownells.com/.aspx/pid=628/Product/79-deg-MUZZLE-CROWNING-CUTTER

 

[obdocab]

I have heard of a technique of using a ball bearing welded on I small rod, then use some very fine lapping compound, anyone have experience with this technique?

 

[obdocab]

I have heard of a technique of using a ball bearing welded on I small rod, then use some very fine lapping compound, anyone have experience with this technique?

 

[Deadeye Tom]

Don't use use a ball bearing. You can get a properly sized brass lap from Brownell's. Clamp the barrel in a vise using proper padding and lap the crown with jewelry rouge and a low speed drill or power screwdriver. Go slow and look frequently. I have done a couple of pistols this way including an old Woodsman. It went from 5" groups to 1.5". If the nicks are too deep a good gunsmith should charge about $40 for a full recrown.

 

[Jayhawkhuntclub]

I don't like the ball bearing idea either (sorry).

The normal recommendation is to get a brass screw with a round head the proper size (obvioiusly a little bigger than the bore). Then get some valve lapping compond and a drill press. Make sense?

 

[Fox Mike]

Recut the crown yourself..... requires the proper size pilot:

http://www.brownells.com/.aspx/pid=628/Product/79-deg-MUZZLE-CROWNING-CUTTER

Which 'brass pilot' does one need for the Ruger? There are three listed: .211", .213", .and 215".

 

[Deadeye Tom]

The best way to figure out the pilot size is to mic the barrel diameter. Slugging the bore is more accurate but you need the diameter across the rifle lands. A so called tight .22 barrel should be in the .215 ballpark. A more standard barrel should be around .217 and makes the .215 pilot a good choice, but you don't want more clearance than required to turn and keep the muzzle crowning tool straight.