Bolt Lug Lapping Tool Choice

[J E Custom]

I did have a good smith true the action. I was just undecided as to whether I wanted a ptg bolt or not. I came to the conclusion that with the tolerances involved I am going to use the existing bolt, have it fluted and skeletonized by Kampfield. Now, from what you gentlemen are telling me, I just need to have my smith machine down the lugs on my existing bolt as opposed to lapping them

I hope I can shed some light on this so here is my opinion.

There are multiple reason for lapping the recoil lugs. The first one is to find out how much engagement you have, (Just looking at it doesn't tell you much unless one lug is not even touching)
Using the spring loaded fixture will show how much engagement you really have.

If the engagement is almost 100 % using the tool, Lapping will do what you want to assure 100%
lug contact with proper fitting ammo.

As stated earlier truing the lugs by machining is the best way if you have access to a lathe but if you don't, and the lugs are not bad lapping will help.

After machining I still like to use some 1500 grit garnet on them to polish the surfaces and aid in bolt opening.

The objective of accurizing is to end up with 100% lug contact so the bolt wont shift during firing.
The method varies depending on the condition and fit of the bolt. The final outcome is what you
are looking for.

Some lugs are not smooth because of machine marks and even though they appear to be in full contact, They aren't. so in this case lapping will polish the surface and gain contact area.

Like everything else, lapping must be done right and with proper tools and procedures to benefit
the accuracy.

Just my opinion

J E CUSTOM

 

[TK 1985]

So to sum up, spring loaded tool, check engagement, machine if necessary, check again, lap for polish.

 

[shortgrass]

I did have a good smith true the action. I was just undecided as to whether I wanted a ptg bolt or not. I came to the conclusion that with the tolerances involved I am going to use the existing bolt, have it fluted and skeletonized by Kampfield. Now, from what you gentlemen are telling me, I just need to have my smith machine down the lugs on my existing bolt as opposed to lapping them

There ya' go, TK,,,,, tell your gunsmith what methods he is to use to 'true-up' your bolt lugs. Don't forget to tell him you "learned it on the interdnet".

 

[TK 1985]

Well obviously I wouldn't "tell" him haha, I would ask and let him run his lathe however he pleases. He doesn't do a lot of milling these days, being semi-retired, which is why I was gonna have Mr. Kampfield do the fluting/skeletonizing. A lot of people here seem to recommend his work.

I have my FFL but I'm doing mainly coatings for now. When it comes to the machining I am most definitely a novice, but slowly learning. One of these days I'll have half the knowledge some of you guys have forgotten and can offer those kind of services. I do appreciate every piece of information you more experienced men put out.

 

[shortgrass]

You will NOT learn machining on an internet forum or by watching U-Tube videos. You won't really learn much about 'gunsmithing', either. You'll learn a lot ways how NOT to do it with a bunch of voodoo thrown in for good measure. If you want to learn something about machining, enroll in a night class (continuing eduction) for "basic machining" at your local vo-tech/community college. From there, go on to the more advanced classes. I've spent a life time learning about machining by doing it. First full time job out of high school, running a W&S #3 turret lathe in a machine shop. That was in 1974. For the finer points of gunsmithing, consider enrolling in one of the two yr. gunsmithing programs,,,,,, after you've progressed a little past that "basic" machining class. I had 16yrs experience in a 'job shop', setting-up, tooling, and operating many different types of manual and automatic machines, before gunsmithing school caught my eye. That experience was a huge plus! I still am active in the trade, today. Keeps me seeing new ideas and methods, besides, that means I don't have to take-on every gunsmithing job that comes along. I can be a lot more 'selective' of the work I take in. Either get serious about it, or become an "interdnet gunsmith"who can 'chamber' a barrel, buy all the tools of the trade instead of making them, basically,,,, become a "one trick pony".......

 

[TK 1985]

I think you misunderstood. I agree with you completely, I'm not even touching machining yet and when I do, well when I get some time, I have a machine shop who will basically apprentice me part time, work on the basics, small stuff. But I do like the advice I get here to get a general idea of how things work, I'm not taking anything you guys tell me and running off to try and do it myself or tell someone I know how to do it. Hell I just recently started offering Cerakoting, Moly Resin, etc... to the general public after almost two years of working on friends, and my own stuff. Color case hardening is the next thing I'm working on.

I like being able to pose a question on here and get either constructive criticism, or just find out that I wasn't too bright for thinking it in the first place.

 

[shortgrass]

Color case hardening........ gather up on that liability insurance! You are "heat treating" a 'part' that needs to be a certain hardness. Color case 'hardening is a heat treating process,,, the 'colors' are just a byproduct of that heat treating process. People may look at the colors, but surface hardness is the goal. Before WW2, lots of things that were hardened, were hardened by the case hardening process as low carbon steel was the most common steel available. High carbon steels and alloy steels weren't made in the quantities we know today. The War was a major influence on materials and manufacturing.

 

[TK 1985]

Ha you pretty much need liability insurance to walk down the street nowadays. But yes it is a whole process, annealing then rehardening, different carbon content in steels. Not to mention what I am 96% sure is real voodoo when it comes to your mixture for colors. Again something I am gonna mess around with and practice, practice, practice, before I ever do it for someone else.

 

[Hired Gun]

On the SPS action. If you are looking at truing the action and a PTG bolt or having the bolt modified by fluting, M-16 extractor, oversize knob, etc, you are at the same price as a nice custom action.

 

[shortgrass]

Ha you pretty much need liability insurance to walk down the street nowadays. But yes it is a whole process, annealing then rehardening, different carbon content in steels. Not to mention what I am 96% sure is real voodoo when it comes to your mixture for colors. Again something I am gonna mess around with and practice, practice, practice, before I ever do it for someone else.

Have ya' got a heat treating oven? I might be interested in parting with mine. Been better than 2yrs since I case colored a set of lock plates that went to a double rifle. It's a nice digital model, single phase 230V, I've got several crucibles of various sizes I built for case hardening. Still have the instruction manual that came with it. Got a nice, heavy duty, stand w/heavy casters that I built for it, too. Chamber size is 13"W x 13"H x 18" deep. I've got a quench tank and aerator, too,,, but they'd be hard to ship. You could "mess around" to harts content with these tools. I could probably throw in some wood and some bone charcoal.

 

[TK 1985]

Short grass I sent you a pm, and hired gun, the oversize knobs don't really do it for me. I know the Sako and M16 style extractors are the cool thing to do, and it's fine on my Sako, but I don't see any need to mess with what is working on the 700 platform. Maybe it's needed in some of the more "wild" wildcats, but for a .308 based case, meh.

 

[tbrice23]

I am in the process of building a custom rifle with Big Horn Arms SR2 LA, just waiting for my Lilja barrel; have another month of wait time.

What Cartridge are you going to build on FEENIX ?

 

[FEENIX]

What Cartridge are you going to build on FEENIX ?

Parent cartridge is 8mm Rem Mag necked down to .308 except with a sharper shoulder angle, I promise I'll write a short blurb about in due time.

Cheers!

 

[tbrice23]

Parent cartridge is 8mm Rem Mag necked down to .308 except with a sharper shoulder angle, I promise I'll write a short blurb about in due time.

Cheers!

30 STW improved?