Bolt lapping

[45r]

What is the best way to lap the bolt lugs for even wear and help prevent bolt breakage.

I remember it being recommended but can't find the how to stuff.

[burkew23]

There's a good thread covering this on sniper's hide, check it out:

http://forum.snipershide.com/sniper-hide...ck-up.html

[NugginFutz]

Here's the thread on this board I think you meant.

http://www.65grendel.com/forum/showthrea...#post77655

[LRRPF52]

That thread on Sniper's Hide is an excellent one. It covers a lot of detail on bolt work that is common with Hi-power shooters.

[explorecaves]

I noticed it said in order to lap the lug engagement with the barrel extension you put the lapping compound on the rear of the lugs (bolt carrier side)? Can someone verify this is correct?

[LRRPF52]

That is the only place you have lug engagement with the extension, so yes, back of the lugs is where very fine lapping compound is used.

[customcutter]

Any thoughts on lapping a NiB bolt? I have a NiB carrier with a standard bolt, but was thinking of getting a NiB. No sense in getting the NiB if I'm just going to lap off the NiB in order to "square" the bolt, and insure maximum contact on the lugs, IMHO. Was wondering what anyone else thinks about it?

[45r]

Lapping my bolt made the BCG cycle very smooth and looks to have the lugs evenly polished and square.
Seems worth it to me.
I've never got a coated bolt since I clean and oil it every time after shooting.
I like chrome and NIB carriers.
They clean up easier and don't need to be cleaned as often.

[jurassic]

Any thoughts on lapping a NiB bolt? I have a NiB carrier with a standard bolt, but was thinking of getting a NiB. No sense in getting the NiB if I'm just going to lap off the NiB in order to "square" the bolt, and insure maximum contact on the lugs, IMHO. Was wondering what anyone else thinks about it?

I would think it would be counterproductive to spend money on a NiB bolt and lap the finish away. I saw a picture of an HK 416 bolt, it looked to be completely deburred, and polished, much the same way a custom 1911 pistol would be. I have an extra bolt that I plan on trying that with. I bet that kind of detail work helps to eliminate stress risers and makes for a very smooth cycling action.

[customcutter]

I'll see if I can locate an HK416 bolt or picture and take a look at it. I guess the rest of the bolt would clean easier, and hopefully function smoother with a NiB coating. I hadn't thought about that aspect. I do think it will be a good idea to lap the bolt regardless of which one I go with.

[jurassic]

http://www.hkparts.net/shop/pc/HK-416-Bo...s-c135.htm

The image is small, easier to check out the link.

[LRRPF52]

With NiB bolts and non NiB extensions, one is going to wear into the other, in that case, the NiB will win against the steel. It won't matter if you lap the NiB bolt into the extension, and will be better for evenly distributing the lug load across the extension, rather than leaving it up to chance and have only 2-3 lugs with engagement.

[BjornF16]

That thread on Sniper's Hide is an excellent one. It covers a lot of detail on bolt work that is common with Hi-power shooters.

Do you polish the bolt face? If so, what do you use?

[montana]

I took two Dremel tool buffing pads and glued them together, "one on top of the other" and they fit perfectly in the bolt face. I used the red polishing compound that came with my Dremel kit. Make sure the bolts extractor and ejector are dissembled first. My bolt face came out like a mirror.

[cst]

Can someone explain to me the reason for polishing the bolt face..?.. I get all the other bolt lapping, ejector, extractor, lugs etc,,,,

Every bolt face ive seen has been smooth... dont want to remove too much material so basically ur removing the finish on the face?

[LRRPF52]

Squaring the bolt face can only help with accuracy, and is a common precision rifle tweak done by accuracy smiths.

There is also less friction between the case head and the bolt face, and there are some other little tweaks that are mentioned in the Accurate Shooter article.

[BjornF16]

That article didn't really discuss squaring the bolt face...just "polishing" with 320 grit and a hand drill. Did I miss something?

[LRRPF52]

Most smiths I know will turn the bolt on a press or lathe to square the face, using Dykem and a very light kiss, then polish it.

[BjornF16]

Have you seen a need to square AA Grendel bolts?...or PF bolts?

[LRRPF52]

Don't have a Maxim bolt yet, and no on the AA bolt.