M1 Garand enbloc clip feeding problem .308 or 30/06

[timshufflin]

I saw this thread on the CMP and felt that I had to link it here or at least share it. I see this issue all the time and particularly with .308.

http://forums.thecmp.org/showthread.php?t=40862

03-26-2011, 02:42 PM
Patjmc
CMP Customer

Join Date: May 2010
Location: Lancaster,OH
Posts: 92
Reloading JMO enbloc ?
Anyone reload any JMO enblocs? I was trying to load up some of my boxed HXP this morning and just couldn't get the rounds to snap in correctly. I've reloaded a lot of clips in the past. I tried my SA and BW clips and everything worked normally. I finally got one of the JMO's loaded but I had to pull the bullets forward in the clip so that I had a gap between the base of the bullets and the clip. Mine are marked JMO 71. I hope they aren't weird, I've got 32 of 'em.

#2
03-26-2011, 02:48 PM
FiftyCalAl
CMP Customer

Join Date: May 2010
Location: NE TN
Posts: 764

no i have tons of them as well. must be a deformity in the individual clip. Did yo try the other 31 of them before you posted? It is not clear to me whether this was 1 clip or all the JMOs
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#3
03-26-2011, 02:52 PM
Patjmc
CMP Customer

Join Date: May 2010
Location: Lancaster,OH
Posts: 92

I tried about 6 of them.

#4
03-26-2011, 05:22 PM
mattp
CMP Customer

Join Date: Oct 2009
Location: Fair Lawn, NJ
Posts: 1,027

the JMO clips are not able to be used with all 30 06 ammo and that includes certain years of HXP (earlier years). I have a pile mounting of JMO clips. A lot of my loose and boxed ammo is 60s HXP which just doesn't fit the clips. Something with the extractor groove being changed.

#5
03-26-2011, 09:00 PM
ceresco
Participant

Join Date: Oct 2009
Posts: 2,023

The extractor goove on later HXP cases is significantly different from early HXP and most 30-06 in general. It resembles the 7.62 NATO cases. It has been suggested that JMO made enblocs that fit the later groove and will not accept the cases with the more common smaller groove. Having lots of enblocs, I avoid potential problems by not using any JMOs. I suggest placing a spot of white nail polish on enblocs that have been tested a number of times and destroying any that malfunction--at least with regard to those you use in match shooting. You only need 3 or 4 proven "good" ones--unless you are still using your M1 to battle America's enemies.. Good Shooting.....

[timshufflin]

Oryguner
Participant

Join Date: Oct 2009
Location: Oregon's Willamette Valley
Posts: 70

Here's a pic that shows off the rim differences.

http://i110.photobucket.com/albums/n107/Timmypoo52/Garand/RimComparison.jpg


ramit
Participant

Join Date: Oct 2009
Posts: 1,866

M2 ball..

danish dummy round left / hxp center / LC right


http://i110.photobucket.com/albums/n107/Timmypoo52/Garand/m2b.jpg


03-27-2011, 03:29 AM
FiftyCalAl
CMP Customer

Join Date: May 2010
Location: NE TN
Posts: 764

I made a mistake and was in error when I said my experience with "JMO" were trouble free. It was another manufacturer that I was thinking of and when I checked my cache tonight, I realized my mistake - my apoligies.
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#9
03-27-2011, 06:00 AM
Patjmc
CMP Customer

Join Date: May 2010
Location: Lancaster,OH
Posts: 92

Of course these clips came with hxp in them to start with, but my hxp69 definitely doesn't just snap in like a U.S. clip. Trying to leave them forward and keep them lined up takes time. I'll retire these JMO's and use my Borg Warner's and IS's until we have a civil war or something. Thanks for all the info and pics guys.

#10
03-27-2011, 09:27 AM
Fl-Lum
Participant

Join Date: Dec 2009
Location: Florida
Posts: 139

Yep,

Use HXP 72 and up in the JMO's.

[timshufflin]

03-27-2011, 09:08 PM
Soljerblue
CMP Customer

Join Date: Oct 2009
Location: Alabama
Posts: 199

I had all kinds of hassle with JMOs a couple years ago, and there was some discussion on the Forum about it. Others had the same problem. My match-conditioned M1 didn't accept the clips well either. We figured out it was a problem with the extractor groove being wrong for the clip, but this is the first actual photos I've seen showing the problem so clearly. Thanks for posting, Guys!

Got rid of my JMOs a couple of years ago.
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#12
11-07-2011, 04:02 PM
Sea3006

Join Date: Oct 2011
Posts: 28

Question on the JMO Enblocs.

I have JMO en blocs dated from 76 to 70. They all look dimensionally the same to me, and look the same as my SA clips. What is the "extractor groove" dimension of the enbloc that supposedly changes around 72/73 to deal with the larger groove on the later HXM case?

Now to clarify, what kind of problems may one have if using the later enbloc with earlier HXP or any case with "standard" 30-06 extractor grooves?

Pic on this thread I think is supposed to illustrate the groove but does not seem clear to me http://forums.thecmp.org/showthread.php?t=10662&page=20
Last edited by Sea3006; 11-07-2011 at 04:05 PM.

#13
11-07-2011, 04:15 PM
hammonje
CMP Customer

Join Date: Feb 2010
Location: Lilburn, GA
Posts: 2,154

Never had an issue with JMO clips. Never had any issues with any clips for that matter. Never had any SF clips though.

#14
11-07-2011, 05:28 PM
Orlando
CMP Customer

Join Date: Oct 2009
Location: West Liberty Ohio
Posts: 2,107

I use them all, no issues with any enblocs
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#15
11-07-2011, 06:56 PM
Fl-Lum
Participant

Join Date: Dec 2009
Location: Florida
Posts: 139

Quick MSPaint sketch:

http://i110.photobucket.com/albums/n107/Timmypoo52/Garand/JMOclips-1.jpg


11-07-2011, 09:53 PM
Oldloader
Participant

Join Date: Mar 2010
Location: Sacramento, CA
Posts: 362

What is my problem? Anything and everything I stuff into my M1 goes in and comes out.
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#17
11-07-2011, 10:00 PM
Sea3006

Join Date: Oct 2011
Posts: 28

Nice sketch Fi-Lum .. I looked at my pile of enblocs today and noticed the "ridge" or indentation that's supposed to locate the the round by the round's extractor groove is not there on numerous JMO clips (71 thru 73). On these clips, non HXP ammo has trouble staying in position. On other JMO clips (including 73's), and all SA clips, this ridge is very pronounced and seems to hold the rounds more rigidly in the the enbloc. Loading the ones with no ridge is more difficult. I'll try to post pictures later.

#18
11-08-2011, 12:02 AM
Rondog
Participant

Join Date: Oct 2009
Location: Denver, Colorado
Posts: 1,329

Wow, great info here! This is one of those little things that would drive me to chasing cars and howling at the moon, and I'd still never figure it out.

#19
11-20-2011, 03:55 PM
Sea3006

Join Date: Oct 2011
Posts: 28

Here is a photo I put together showing the difference in the ridge that locates the cartridge between USGI and JMO. Seems random what years JMO have the pronounced ridge like USGI and the shelf. I isolated my feeding troubles to the JMO that do not have the ridge.

http://i116.photobucket.com/albums/o...ocsreduced.jpg

#20
11-20-2011, 09:25 PM
BruceR
Participant

Join Date: Oct 2009
Location: Vermont
Posts: 154

Fl-Lum: Your sketch illustrates the problem exactly. I took the troublesome JMO clips and made wind chimes out of them. Now my neighbors get to hear the M1 'ping' when the wind blows.



11-21-2011, 07:32 PM
Fl-Lum
Participant

Join Date: Dec 2009
Location: Florida
Posts: 139

Thanks BruceR-

Sea3006 might have a point. Comparing a few of my JMOs with some USGIs I can see what he is saying.

There just doesn't appear to be enough room in the base of the JMO clip for the USGI rounds to seat uniformly. Trying to squeeze them in usually makes the sides flare out like in the third pic above.

[canes7]

I've just used the clips the CMP gives when you buy a rifle, they are marked AGE or ACE. The are new manufacure (Made in USA), they are not roughly parked, the grooves work... etc. Anything else is just asking for a headache....

[jak]

I had a whole bunch of JMO 72. I never had a problem. I just had to steel wool all of them because of heavy park.

[Punch The Clown]

Try shooting Korean surplus M2. First of all it doesn't fit half of the en-blocs out there. Second of all they smell like cat piss when you fire them. I have no idea how the Koreans used them. I've also heard they're prone to case failures but I can't say.

[canes7]

I just do not understand how things like this become such a big deal. Find what works, run with it. Life is so much easier that way.

[timshufflin]

I just do not understand how things like this become such a big deal. Find what works, run with it. Life is so much easier that way.

I see hundreds of guns, this stuff has been a big deal. Until you've been driven nuts by a gun that should work by all that is right, you will not understand.

[canes7]

So you are saying that people have been using bad clips then sending the rifles to you for diagnosis?

[timshufflin]

So you are saying that people have been using bad clips then sending the rifles to you for diagnosis?

Sometimes and other scenarios as well.

[cuppednlocked]

JMO: good for business!

[timshufflin]

JMO: good for business!

Not really, not much money in saying "use another clip" and wrapping a rifle back up is tedious at times. Hardly worth it.

[timshufflin]

JMO: good for business!

Not really, not much money in saying "use another clip" and wrapping a rifle back up is tedious at times. Hardly worth it.

[Orlando]

I have used JMO, SF all of the supposably "probelm" enblocs and all my Garands chew them up and spit them out with no problems. Never did a thing to them, just stuck them in the rifle, pulled the trigger 8 times then PING
I'm wondering if people that have issues with them have sligthly out of spec parts on theire rifles???
Worn clip latches, spring, bullet guides??

[timshufflin]

Some rifles wont even fit these clips into the follower area.

[canes7]

That is a tough situation. No one wants to hear that hey shipped their rifle off to have it fixed then there being nothing wrong.

[Sea3006]

Hi Tim, I posed in that CMP topic, here is what I came up with below. Basically, some of the JMO enblocks have trouble locating the standard extractor groove brass. I had fits with FTF and difficulty installing the clips. I could not pin down what was going on. Narrowed it down to the JMO clips with a ledge instead of a ridge. The ones with the ledge caused the rounds to move around enough to cause intermittent loading & feeding troubles.

I just tossed the JMO's with a ledge, as I do not have much of the non-standard groove HXP brass, and the non-standard brass works fine in normal clips.

"Here is a photo I put together showing the difference in the ridge that locates the cartridge between USGI and JMO. Seems random what years JMO have the pronounced ridge like USGI and the shelf. I isolated my feeding troubles to the JMO that do not have the ridge. "

http://i116.photobucket.com/albums/o9/Mopar_Tony_SF/Enblocsreduced.jpg