Bolt lug lapping

[JR]

Pete,

What I did was used an old remmy barrel, cut the stub short like, then made a brass plunger stuck in old chamber, with extractor slot, so I could lap the face and lugs at same time...jes screw the thing on til it's tight like, and you have spring pressure against the face of the bolt as you arelapping the lugs with pressure...Can make you one up with the next shipment of nubbins if you want...


JR

[Pete Lincoln]

Ive already got same set up mate, the alternative with the case was for someone without the tools to remove the barrel.
but cheers anyway..
Pete

[Daddy Justin]

I was searching for something on bolt lapping and I found it. My question is will this make a big improvement in accuracy? I have a Mark V in 30-06. There are only 6 locking lugs and as best I can tell, only 5 are making any contact.

[jmden]

Sakofan,

My take on it would be to get 'Accurizing the Factory Rifle' by McPherson and follow his advice and directions. You should use a bolt lapping tool (keeps bolt square to action--Brownells will have this and the lapping compound) and remove the barrel to do the job right or you may be wasting your time. Since the barrel is removed to lap the bolt lugs properly, when you reinstall the barrel you can now lap the barrel to receiver joint making that joint more stable and also decreasing the headspace that was increased by lapping the bolt lugs. Don't go cheap on this. Do it right the first time. Get the book and the proper tools. I do think it made a difference in my 300RUM 700. Along with proper bedding, good light trigger, right load, it'll likely drive tacks more consistently.

Just remember to be more careful than ever after bolt lapping to lube the lugs properly and often. Apparently, I've read, bolt lugs are more prone to galling once they've been lapped--go figure.

Daddy Justin,

Getting that many bolt lugs properly lapped would be very difficult and I think it's one of the reasons some folks shy away from that action. Many of them shoot very well, however--no ultimate truth here... I'd question a reputable gunsmith about it. Might put a post up asking FiftyDriver or Chris Matthews with your quesiton in Bullets, Barrels and Ballistics. Just my take...

Good luck.

[boomer]

I take a empty case and knock out the primer and replace it with a piece of pencil eraser, then put rubbing compound on the back of the locking lugs work the bolt up and down and check it for fit. the eraser just adds back pressure to the bolt without damaging the bolt face.

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Can I use Rem. bore cleaner instead of lapping compound?? It's all I have handy right now...sakofan..

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Use JB Compound! Works better than valve grinder material! Not nearly as course! Might take just a bit longer....but not much!! [img]/ubbthreads/images/graemlins/grin.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]