First time Garand build and problems –M1 smiths, please help! (very long)

[Brett]

Kurt, good inputs, thanks. I will buy a reamer.

Mark,

I used a bubble level and the Badger Ord gauges. I don’t have a $200 machinist’s level, but a metal 3” level that is quality enough for the job. I remeasured the alignment this morning. The bubbles were not “dead nuts” to each other. Using the rear gauge as a baseline, I had to raise an edge of the level with a .007 feeler gauge on the front gauge. The gauge is 3” long. I did the trig and .007” over 3” is 8.02 minutes (the barrel is under indexed). So I should be well within index tolerances. Also, I have at least .008” clearance between the inside rear of the hump and rear sight base (from Dan’s post above). I know Kuhnhausen says do not exceed 15 degrees hand tight, but the McKee book (pg 63) looks for 7 to 8 o’clock (30-60 degrees) calling 7:30 (45 degrees) ideal. A significant departure from Kuhnhausen! A discussion on this topic a few months ago had the consensus that 60 degrees was too much but I think under 45 was workable.

I feel I can confidently rule these things out: Barrel indexing, gas cylinder, op-rod, lower band, front hand guard.

My problem is this barreled receiver combination and any op-rod placed in it (4 so far now). I gauged the track channel and it specs out fine. Friction occurs during the last half inch of travel when opening the op-rod. I cycled it out in bright sun today and found what I think may be the biggest point of friction: the forward most part of the receiver. It looks like the bottom of the op-rod handle (the thin side) is bearing down on the flat surface beneath it just above the receiver pin/receiver drawing number area. I am now thinking perhaps the barrel is indexed correctly but perhaps TILTED down, causing the op rod to bind at the saddle/barrel area and op rod handle as it gets fully retracted.

And now the rest of the story—the shop press I used had the center of the press about 5” away from the edge of the bench. This did not allow me to center the press on the middle of the barrel vise and still have clearance off the bench to spin the receiver wrench. This caused me to pull the barrel vice out (towards me) until I had enough clearance to spin the wrench. When the press clamped down on the vice there were more pressure on the rear (far side) of the barrel vice, causing the vice & barrel to tilt about 5 degrees muzzle low. I knew this was not ideal but had no other option at the shop. I was careful when applying force to the receiver knowing I couldn’t pull the wrench perpendicular to the floor but had to be perpendicular to the barrel. I was careful and deliberate. The two other receivers I barreled that day in the same manner both pass the tilt test fine (they did not require as much torque, however).

Has anyone heard of the barrel being tilted down (muzzle low) during assembly and then this type of op-rod problem occurring? It's what is making the most sense to me right now, but I’m just amazed that the barrel would have gotten bent that much.

Thanks to all who have help so far. Gus, Roland, Dean, Ted or any other full-time smiths care to opine?

Thanks, Brett

[Brett]

All right guys, I’ve put by “bad” barreled receiver and a good one on a true surface (scrap piece of polished granite) and measured just abut every way I could to determine any barrel “down tilt.” To me it seems the best way is have a barreled receiver sitting on the granite with the points of contact the bottom of the front receiver legs and the outside diameter of the muzzle. This gives three stable points of contact. I then measured the height of the receiver heel off the granite, both were 2.5 inches. If my bad combination had a down tilted barrel, I would expect the receiver heel to be lower to the surface than a good barreled receiver would. I also had the receiver sit on all four legs and measured the height of the muzzle off the granite, both were 3 5/16.” So over a distance between 25-28 inches, both were well within a 1/16” of each other (0.14 degree). Does anyone know a better way to measure? I’m hoping now that I didn’t tilt the barrel, but I’m still at a loss for where my problem is.

Thanks,

Brett

[Devil Dog]

Hhttp://img.photobucket.com/albums/v321/Parker1144/dcp_1990.jpg?t=1236898793
Here's a pic of the machinists level I use

[Brett]

I’ve spent so much time on this barreled receiver measuring and comparing with others and I still see nothing wrong. I’m pretty sure the barrel is not bent as I was guessing previously; it parallels all my other barreled receivers. I guess I’m just going to have to send it off to a professional smith to work on. I imagine they are hesitant to speculate on what could be wrong on a forum.

Thanks to the guys who provided ideas.

Brett

[trfindley]

Trigger housing fitting:
http://www.trfindley.com/pgtgfix.html

[Gus Fisher]

Brett,

From what point on the receiver did you use to align the barrel? If it wasn't the flat milled out section under the rear sight, that could well be a problem. The top of the front ring of the receiver is NOT the place to put a level or parallel bars.

I've found the very best way to align the receiver is to use a piece of 1/2' or better still 3/4" square stock about two inches long, that has been precision ground on two opposing sides. You lay that block where the rear sight base sits with a ground side down, use a angle finder that is graduated in every degree of 360 degrees and get a reading off that. Then put the angle finder on the gas cylinder with the front sight taken off. (If there's ding on the top of the cylinder there, you have to clear it with a fine file so you don't get a false reading.) There should be no more than one degree difference between the front and rear for a standard barrel. For a NM barrel, there should be 1/2 degree or less.

If after ensuring the barrel alignment is right and the op rod still doesn't slide freely, that isn't all that uncommon with M1 op rods. Many, MANY of them had to be hand bent to work correctly. If you don't know how to do that, then I suggest you send the op rod to Jim Schwarts and have him bend it to the gage.

[Brett]

Gus,

I used the Badger Ordnance gauges from Brownells. I aligned the barreled receiver with a very tight NIW gas cylinder (no burrs) and using the rear sight flat. I measured the barrel alignment multiple times and am confident it is under 8 minutes from vertical. The NIW op rod passes the tilt test fine in other barreled receivers, but other op-rods (4 so far) fail the tilt test in this particular barreled receiver. So I can rule the op rod out and I'm confident I can rule out barrel rotational alignment, although there may be some less common barrel alignment problem?

Thanks for chiming in,

Brett

[Gus Fisher]

Brett did you use a different gas cylinder to align the barrel rather than the one you wound up using?

[Devil Dog]

If you are sure your barrel is indexed properly and you have tried muliple rods....I would try a different (perhaps used) gas cylinder.

[Brett]

Gus,

I used the same gas cylinder to align the barrel. No parts swapping.

DD,

The binding happens when a gas cylinder is not even installed.

With just an op-rod (all rods I've tried), receiver and barrel I have the op-rod friction the last half inch of travel when opening. It binds on the barrel bottom/op rod saddle, the op rod handle/forward edge of receiver guide rail and I think in the rear near the tab/receiver guide rail.

Besides barrel rotational indexing is there another type of barrel misalignment I can check for?

Thanks,

Brett