M1 rifle reciever question

[jimorat]

Does anyone know what the width of the op rod groove is to be? Not incluing the v cut in the groove. Just the dimension from the top lip to the bottom lip with calipers in thousands of inches. Mine is measuring .290" wide. And also what was the tolerance on this held to?

 

[krs]

Do you mean the Garand or the carbine?

If Garand, mine are measuring at .270" but I'm not sure where you're finding a "V" cut in the oprod channel.

 

[jimorat]

A garand. The "v" cut should be in the bottom rail where the lug goes in to help guide the rod. The Op-rod on the bottom under the handle has a v-shaped lug. I think. Thanks for the info.

 

[krs]

Hmm, that should be a square cut lug and channel. Maybe you're not looking closely enough?

It's hard to imagine where a "V" cut channel with corresponding oprod lug could have come from.

 

[jimorat]

Yes you are right. I took another look at it last night and the channel is sqaure. I was looking at my op rod lug. I am not sure if it is suppose to be square or not. Currently it looks like it has a 45deg. angle on the lug facing away from the center of the rifle. But it has a lot of slop up and down and side to side. I am NOT a Garand expert by any means. But I do know alittle about machining.

It seem like it would be better if it were square off with about .010" clearance for movment and grease. I have read that these lugs can be repaired. If it is to be a square lug I can get the welder at work (Gov. Cert.) to touch it up and then I can machine it to size. Mine op rod lug looks like about .080" wide. Distance from the top contact surface to the tip of the lug
is mearsuring .300". Looking closely at the maching marks on the rod looks like it was made originally to .315".

Does anyone know what size the original design was?

 

[krs]

Measuring a used one I get it .0880" wide and .2775" long.
It is rectangular and if you were to grind off the original and make a new tab you'd want it .3080" on it's third dimension with the new piece attached with it's top edge .0750" above the adjoining surface.

I'm not recommending removal and replacement as the best fix - only trying to give an idea of the overall picture. It'd be better to tig up your existing edge at a pretty high temp so it'd be hard. That's a wearing location as you already can see from the sound of it.

I've got the engineering drawings but for some reason I'm having a heck of a time seeing them today. Damned reduced image copies!

Anyway, what you have should fit the rectangular groove. If it's badly worn - enough to appear 'V' shaped, it'd probably pop the oprod fairly often during firing. Could that be why you've raised the question?

 

[jimorat]

YA it comes lose during firing alright. Its dwg# is d35382 -3 SA so its seen some use. I got it welded up over the tabs that were already there and I'll be working it in to spec tonight. Thanks for all of your help!

This is why I use "The High Road" because of the excellent people that make up it.

THANKS AGAIN

 

[krs]

It's my pleasure....anything that helps keep the old girl happy!

 

[rondog]

I have an M1 receiver question too -

The "US Rifle, cal .30 etc" rollmark on my Springfield receiver is very faint, like someone sanded or blasted off some rust a little too aggressively. The serial number is quite readable, but it's been eroded too.

Does anybody know of anyone that can re-stamp all this? It's just a cosmetic thing, but it irritates me.

 

[jimorat]

Maybe laser etching maybe better to retrace the original numbers and letters. We have a laser etching machine at work that can adjust the letters for the contoured surface so that it is even. Stamping is a little tough to match up what has already been stamped. From what I have stamped before (nothing like a reciever surface), you aline the die and strike it once, HARD. And then go to the next letter.

 

[krs]

Ron,

Repeated reparkerizing will sometimes leave that sort of appearance but I think I'm getting an overflashed look at it because the overall color is too light and the markings washed by the light.

At least that's what I hope I'm seeing.

I agree with jimorat about stamping it but for another reason in addition to his. The receivers were very hard, hard even to the point of such brittleness that the bolt could break out the back of the receiver. So brittle that another step in their manufacture was added to anneal the rear of receivers after they'd been forged and heat treated. The use of a grenade launcher was causing receivers to break because of the higher pressure blank and grenade system that was devised. (one reason not to use heavy loads in Garands, BTW)

So besides missing individual markings or marking off register there's be a chance of breaking the receiver.

If you can find someone (he's right here above... ) who can follow the original marks with a lazer etching machine it'd be the way to go.

 

[rondog]

That's why I was asking if anyone knows of a restoration specialist that does this all the time, and knows what he's doing. I'm certainly not going to try. I'm thinking of the Bill Adair of M1 restorations, if there is such a man.

But, it's not that big of a deal, and it shoots just fine. And yes, krs, the lettering really IS that far gone. It's quite hard to read.

Laser etching would be OK with me, if I can find someone who knows how to do it, not just someone who has access to a machine and is willing to try.

 

[krs]

Maybe you just need to look at it in a different way, Ron....your rifle's markings were eroded by..... The Sands of Iwo Jima.

 

[jimorat]

I have another question. What is the width of the follower assy grooves in a M1 Garand receiver? And what are the tab widths of the follower assy?

The reason I ask is that my M1 sometimes as a problem feeding the frist round. The angled neck part of the case on the bullet is hanging against the receiver. It could be my en bloc clips. They are made by "Leapers" a China product I think. Or I need some new parts.

I am determined to get this rifle running as smooth as glass. Thanks for your time and help.

 

[krs]

You're trying to force me to dig out the drawings and a magnifier, aren't you?

I make the receiver groove cuts to be nominally .1500. Truth is that on a loose receiver I have here the left groove came up .1530" and the right one .1485", hence my use of "nominally".

I don't think it's a critical dimension - as long as the follower doesn't bind or doesn't fall out of it's runs you're probably good.

Loosened clip upper lips could cause your problem. Maybe a worn bullet guide could.

 

[jimorat]

Thanks again. I guess I am going to have to break down and pay for some drawings if I am going to start collecting M1s

 

[krs]

Don't get the idea that it bothers me to try to help you in any way that I can.......I just kid around some while doing it, OK?

But if you do want to get some reliable information about that rifle or any more that you may want to gather up there's a book, Jerry Kuhnhuasen's "The U.S. .30 Caliber Gas Operated Service Rifles Vol I &II" that details both the M1 and the M14 rifles as well as any other or better, and a Volume III that covers the M1 Carbines.

Volumes I &II are both in one cover, one book, that's available for less than $30. in a bunch of places.

There's also a guy who's put together collections of technical drawings, the blueprint drawings for a whole bunch of interesting things that can be bought here: http://www.nicolausassociates.com/

 

[jimorat]

Thanks for the links. I appreciate all of your help. And ya I knew that you were joking around. Sometimes its hard to understand the toneset of emails and messages.

Thanks again.

 

[krs]

jimorat,

I posted one of my photos in another thread and noticed that the gun pictured is siting on the exact page in Kuhnhuasen that describes why your oprod could be "V" shaped on the holding tang.........look at the page under this pistol and let me know if you can read the text that's associated with the picture/drawing:

He's saying that if the rod handle runs at a downward bend it'll cause the tang to wear against the receiver and eventually take a "V" shape. The drawing is showing the rod with the handle lifted to move the tang away from the channel. Get it?

 

[jimorat]

Thanks. Is that the book you where talking about? That has excellent ref. info.

 

[krs]

Hi,

Yes. I have a small flourescent undershelf light at one of my workbenches that I found makes for good lighting in quickie photos of guns. Jerry's book happened to be open to the section when I needed to photograph the pistol.

It's this one, although you should be able to find it in Midway or Brownells (or most anywhere) for less than the price shown: http://www.gunshowbooks.com/cgi-bin/webc.exe/st_prod.html?p_prodid=GS153719&sid=9a1Ux7zh