What to do with a pair of CMP "Expert" Grades?

[ssgross]

It's should be old news to most here, but the days of unlimited CMP Garands is coming to an end...or should I say going through it's death throws. The service grade's are long gone. The field grades are now gone too. So, they have a new "Expert" grade in 30-06 or 308, pieced together from parts, everything refinished, new criterion barrels and new wood, selling for $1000 and with very short turn around time. My pair was 2 weeks from dropping off paperwork at the post office till rifles at my doorstep.

So what to do, other than shoot of course! Well, I've really wanted an M1C - not happening anytime soon. The new OEM Griffin and Howe mounts are pricey, not the same, and aluminum. Are they even legal for vintage matches? So how about lets make up an M1D.

I have a new mount and barrel with scope block already installed from Sarco, and I have an old, beautiful, field grade that has a sewer pipe that can use the extra new barrel taken from the expert grade.

DISCLAIMER: I have read all the posts and complaints about the repro mounts being crappy. Indeed, Sarco has sold me crap in the past...but is probably the easiest parts dealer to work with on returns, and the fastest too. They stand by their crap. I ordered well prepared for what another thread said 10:1 odds for sending it back.

So here we go. Of course the mount doesn't fit. Being the first one I've ever handled, I studied carefully.

Here is mine...second pick is an "original" right now on eBay with 25 bidders at > $300.

Looks like 3 "pads" of contact...purposefully raised so there is some room to fit. Of all the complaints I've read, I haven't read one where the complainer attempted fitting except to crank down on the screw with a wrench to tighten, or added some shims.

Here it is, with the screw hand tight like it's supposed to be (I think. The soldier is supposed to be able to remove it with his hands right? There was a tech manual with torque specs in a post I read that supports this.)

The problem is clearly seen, and felt. The mount teeter-totters on the bottom pad...doesn't even engage the pad.

Here is my novice opinion on what should happen to properly fit one of these.
The wedge part at the bottom is too thick preventing the mount from settling on all 3 pads. Of course the purpose of the wedge part is to prevent vertical play. We can either stone the beveled edge of the barrel block (easier to do), or work the mount. The barrel block is more expensive should we screw it up. I'll study some more, and plan my course of action while I hear back from some of you. I've fit an OEM mosin scope base. They can be sloppy too until you correctly file down the tabs. There is plenty of documentation out there to correctly fit a mosin scope. Can't find much for the M1D.

EDIT: Here is a better pic of our initial fit.


And equally exciting, this came in the mail today too Happy Birthday George Washington! what to work on first?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[ssgross]

Well, it's not as hard as everyone has made it out to be. I think the main challenge is getting past all the internet "experts" that shout "repro crap, pony up for an original" without actually trying to answer the question. Mechanism is pretty simple - but I'll admit I had to stop and think about how it "tightens" up. Not hard once you draw it out.


So you see, the pads have nothing to do with how tight it gets! - the top two are coarse windage adjustment, and the wedge at the bottom pulls it tight vertically.

So, why isn't it getting tight? The pin is too long, or equivalently the washer is too thin. To be tight, the wheel must press evenly on the whole surface of the washer. It doesn't.
I played with some cut-up pieces of notecard until the whole thing tightened up. This tells me how much of the pin to file off for a permanent fix, or how much shimming to do in the end.

I assume that pin is just a taper pin? or was the whole tapped, screw put in, and head ground off? Does anyone know? I'm worried if I file the pin down in place, I won't be able to keep the point sharp enough to bite firmly in the notches like it's supposed to.

For now, I cut a small piece of 0.03 sheet metal, ground it round to make a disk, and cut a notch in it. It's thick enough so the pin doesn't touch the knob at all. I tested with the knob hand tight and there is no play in any direction. So the pads all make full contact. Next, I need to put a scope in the mount, and laser on the bore to see how "off" the windage with the pads is...If it's way off, I'll start adjusting the pads. If close enough, I'll just build out, shoot it to fine tune the pads, then adjust the pin to make all perfect. (other's may have had other problems...like the wedge not being tight enough in which case there is slop on the upper surface. I seem to have gotten luck and mine is certainly fitable)

[eb in oregon]

Last year I helped a friend and club member to sell a CMP acquired M1D, it was a "nice" rifle. He sold it and I didn't buy it because we are both left handed. And from the day it was bought from the CMP it had fired a total of two clips, 16 rounds. Of course the price of a rifle such as that has escalated exponentially in the last year. Mike should have waited another year.

[ssgross]

I hear you. I've waited this long to make one up because, although ambidextrous and right handed for many other things, I shoot best left handed. My son is seriously left handed, but my littler brother is a righty so if I don't shoot it well, he will have something to shoot in the games with me. Who am I kidding. I'm doing it just because it's fun, and because its a damn interesting rifle. I've really wanted an M1C, but mounts are unobtainable. The new OEM Griffin & Howe mounts are slightly different and made out of aluminum now, so I've read - and of course priced through the roof.

[ssgross]

I used a shim to take the pin out of play for now (what to call it...locking pin?), and then I leveled the barrel off the front sight milling and leveled the reticle of my hi-lux scope in the mount. With a laser on the bore, the post lands ~1.25 inches right of the bore line, about 20ft across the shop. So, I need to move the reticle roughly 2.25 inches left to make line of scope parallel to the line of the bore.

A bit of geometry with gives a rough estimate that the rear pad needs to be filed down by ~0.01875. There is about 0.026 thickness to the pad, so well within doable. I think if Sarco added the disclaimer of "some fitting required" there would have been a lot less gripes all across the internet. Then again, maybe I just got lucky and mine isn't that bad.

Next steps...file the locking pin down so the wheel pulls everything tight when it is tightened by hand. The rear of the locking pin protrudes about the same thickness as the rear pad. There is a recess where the block's pin is, but I should file the back of the locking pin flush just in case. Then, we remeasure with a bit more precision, shim the front pad to be certain, then go to the range to confirm (after I actually install the barrel, finish ream, etc.), then come back to the shop and file the pad to make all perfect. measure thrice file once?

[ssgross]

Little bit of movement on this project.
I have 2 expert grades to choose from to make my M1D, an Jan. 1943 receiver, and the other with a (likely) early 1952 one. I chose to take the criterion barrel off the 1952 receiver to complete the build.
I plan to put the m1d barrel on, finish ream, and zero with the iron sights try out the scope (just to gauge the potential of the rifle) with the washer/shim keeping it tight. Then I need to make some decisions about which stock to finish the build with, and finally I'll hand fit the scope as well as can be done with a repro. If I have to use a shim forever I think I can live with it, being an entirely reproduction rifle and all.

[ssgross]

Barrel went on, aligned perfectly. Initial fit was a bit tight, maybe just over 1/8 turn short, but after 3 or for times tightening then backing off, it snugged up just perfect.
They (whoever made these barrels for Sarco) did a good job roughing the chamber. My camera doesn't show any chatter, and it's just a bit short. I've been looking for a couple weeks to buy a pull through reamer, but no one has any in stock and the lead times are pretty long. I may just have to go the rental route, but I'll try calling Manson tomorrow directly.

When I was at the Virginia Gun Collector's Association show last weekend, there was an old smith with a table doing jobs for people. When I walked by, he was doing a barrel change on somebody's garand. I did a lap and came back when he was ready to finish ream. He flipped the barreled action upside down in his vise, pulled out his reamer, and a hinged-socket adapter (joint socket) to drive the reamer. I don't see how that setup won't put extra pressure on the upper half of the chamber and make it slightly oblong in the end, no matter how careful he was.

[browningautorifle]

He flipped the barreled action upside down in his vise, pulled out his reamer, and a hinged-socket adapter (joint socket) to drive the reamer.

I did my 7.62 with a standard ream from the back using six factory cartridges for headspace. I'd tighten the receiver and check if one would seat with the stripped bolt, then unscrew and do another turn with ream, same thing...until the bolt just closed on the first one. Assembled and it never missed a beat with any ammo.

[ssgross]

Manson came through...they have pull through reamer kits in stock, and much cheaper than PTG or Clymer. My other reamers are Manson. I know everyone has their own preferences, but I've been very happy with them.

[ssgross]

Barrel reamed to perfection last night - chamber is very tight. Bolt locks all the way on the go gauge, sticks just a bit at the bottom before closing all the way on a round full sized in my press, and locks all the way on that round when the bolt cycles under tension (all fire control removed from the bolt during testing). Hopefully I'll get the rear handgaurd cut back and fit this weekend, and can try it out...then on to finish the next project rifle!