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Posted By: DBT Lug lapping. - 03/25/06
Just found out last week that a slight jamming of the bolt on my ruger 77 .308 was due to uneven engagement of the lugs.( I thought I'd been having pressure spikes)

It's now at the gunsmiths getting the lugs lapped, and I'm wondering if as a bonus of this treatment I might also see some noticable improvement in accuracy?
Posted By: GunGeek Re: Lug lapping. - 03/25/06
Maybe, maybe not. Common logic has it that when the lugs are in equal contact, then accuracy should be better. However; I had a Howa Lightning in .243 that only had one lug in full contact and it shot groups in the .30"

If your lug job is done right, I wouldn't expect accuracy to be any worse, and it could improve.
Posted By: Jim in Idaho Re: Lug lapping. - 03/25/06
Not much more to add except if your lug engagement was so uneven to cause torsion to the action upon firing, then evening out the engagement should see an increase in accuracy. Whether it is significant enough to really notice, only trying it will tell.

But it surely doesn't hurt as long as it's not so overdone to increase headspace, but you'd have to really lap those lugs to get that headspace to a hazardous condition.
Posted By: Royce Re: Lug lapping. - 03/26/06
DBT
I have had the lugs lapped on two Model 700 Remingtons and lapped the lugs on a third myself. In all three cases, I noticed a marked improvement in accuracy. Mediocre accuracy was what prompted the lapping to begin with. I believe that there are a lot of rifles that have poor contact on the lugs that shoot very well. However, if I have a rifle that doesn't shoot well, and the lugs show poor and/or uneven contact, I'll have the lugs lapped.
By the way, the first one I had lapped was a 7 Magnum, and the groups went from 1 1/2 inch to well under an inch. The second was a 35 Whelen with very much the same results.
The third rifle was a 223 and the groups went from over an inch & a half to under an inch and a half. Examination of the bore on that rifle with a magnifying borescope revealed that one land and grove had been spalled badly during the rifling process. Nothing save a new barrel would have ever made that rifle a shooter.

Royce
Posted By: DBT Re: Lug lapping. - 03/26/06
Quote
DBT
I believe that there are a lot of rifles that have poor contact on the lugs that shoot very well. However, if I have a rifle that doesn't shoot well, and the lugs show poor and/or uneven contact, I'll have the lugs lapped.

Royce


Mine could shoot some excellent groups, but there was a tendancy to throw fliers, even though everything else has been done. (glass bedding, trigger job, etc)

BTW, thanks for the replies, much appreciated.
Regards,
DBT
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