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View Full Version : To lap or not, if so how much?



mattri
06-21-2012, 09:29 PM
Have an new, unbarreled 200 action. Am looking at ways to smooth up the action, increase contact area and hopefully aid accuracy down the road. Obviously the action will smooth out some with use but would like to the fit and finish from the start.

There seems to be a lot of debate as to whether Savages, with their floating bolt heads, need to have their lugs lapped or not. Some say it helps, some say it could help, some say it could even be detrimental.

The plan at the moment is to make a lapping jig and use a mild compound to smooth and polish as well as help increase contact.

Thoughts?

nsaqam
06-21-2012, 09:59 PM
It certainly isn't going to hurt it to increase the contact between the lugs and their abutments.

Use the same tool with a different stem to polish and flatten the boltface after you lap the lugs.

Spin it with a drill.

Close to 100% lug contact and a boltface perfectly perpendicular to the bore axis can't be anything but good.

ellobo
06-22-2012, 12:53 AM
nsaqam is right. Any surface that rubs or rotates agains any other surface could be polished. Both surfaces. As my old boss used to say "the best bearing in the world is two pc's of polished steel riding on each other." Of course light lube wont hurt. The inside bore of the reciever body and any other part of the bolt that needs it. By polishing I mean polishing, no metal removal just making the surface clean and smooth. A little txture to hold lubricant is a good thing on most surfaces.

El Lobo

darkker
06-24-2012, 02:51 PM
You ask about "smoothing the action", meaning the sliding of the bolt, cycling the action.
Then jump to locking lug contact area for accuracy ???

Well,
IF the bolt head DID NOT move, it would be possible to have a contact issue. This doesn't mean WILL HAVE, but COULD have. The floating action SHOULD fix any mis-alignment. AGAIN if the manufacturing was botched... But SHOULD fix it.

Have you gotten out your marking fluid and TESTED whether or not you HAVE an issue? Don't look at the "wear", use layout fluid and honestly test.
IF, you think it needs it. Why make a "lapping jig"? It's call "the bolt", you already have it. Lapping compound on the bolt lugs, and on the reciever.

mattri
06-24-2012, 03:40 PM
darkker, you're right, I am working on more than one thing at once. I did use a light lapping compound on the lugs and noticed better engagement, and yes I was using die. In regards to the lapping jig, if you close the bolt on an un-barreled action, there is no pressure on the front of the boltface, there is nothing for the lugs to work "against". By using a jig to mimic that amount of "backpressure" you get a more realistic view of what's going on in my opinion.

Just how it worked best for me, I'm sure others have way better ways of doing things but it has been a really fun project so far.

gotcha
06-24-2012, 04:14 PM
Yep, I did my 200 LA as outlined above. Again, just looking to smooth bolt lift by polishing lugs & shelf. I'm sure a T&T would have done a more exacting job. But, all in all, was happy w/ results. I put a washer on chamber face & adjusted polishing pressure by gently screwing bbl against B/F. Used 600 grit lapping compound. I looked for about 70% contact........ If you're using a short cartridge you have an opportunity to polish the innards to prevent gouges on cartridges too..... After polishing lugs & all bolt components including cocking ramp I saw no improvement from a bolt lift kit. Your rifle may be different. This is my experience w/ a single rifle.

Ring31
06-24-2012, 10:01 PM
what i did with mine...

lapped lugs
polished cocking ramp
38spl bolt lift mod
added PTG fluted bolt

nitrided..
its SMOOTH.....

http://i.minus.com/jbbe5ekbKtTKc.JPG (https://minus.com/lbbe5ekbKtTKc)