Go Back   CMP Forums > CMP Sales > M1 Carbine
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 01-26-2013, 11:52 AM
.30 Carbine .30 Carbine is offline
 
Join Date: Oct 2009
Location: Northern Virginia
Posts: 406
Default How to Test 30 Round Magazines?

I have an assortment of 30 rounders from various vendors, non-USGI, that I bought about 4 or 5 years ago. Back then I put on the M2 magazine catch and tested some and deteremined that some had feeding issues. I still have all of these magazines but I am not sure which are unreliable, what is the best way to test for reliability without shooting up about 300 rounds of precious .30 ammo?
Reply With Quote
  #2  
Old 01-26-2013, 12:14 PM
dnikkor dnikkor is offline
 
Join Date: Oct 2009
Location: Kansas
Posts: 1,752
Default

I don't think there is any other way to test feeding reliability other than test firing for reliability.
Reply With Quote
  #3  
Old 01-26-2013, 12:29 PM
Dwagner825 Dwagner825 is offline
 
Join Date: Mar 2012
Posts: 61
Default

How about loading the mags and hand cycling the bolt. Granted you'll put a little wear on the cartidge rims and shed a few pounds from bending over to pick up all the rounds. Just make sure you have the safety on and the rifle pointed in a safe direction.
Reply With Quote
  #4  
Old 01-26-2013, 12:39 PM
tenOC tenOC is offline
Banned
 
Join Date: Jun 2010
Location: East TN
Posts: 3,991
Default

You have to fire the rifle with them loaded to see if they feed and work.
The only safe place to cycle live ammo through a rifle by hand racking is where you'd be shooting. Don't do this in your living room unless it's pointed in a direction where you don't mind a hole being put through something. I've seen dimples in primers from the firing pin striking when people have done this.
Reply With Quote
  #5  
Old 01-26-2013, 12:48 PM
meplat meplat is offline
 
Join Date: Jan 2010
Location: Prescott, AZ
Posts: 3,761
Default

Quote:
Originally Posted by tenOC
I've seen dimples in primers from the firing pin striking when people have done this.
Remove the firing pin. This will certainly reduce the mass of the slide+bolt+cartridge assembly being pushed forward but I don't believe the difference is a significant one for your testing

Or make your own "action testing dummy rounds" sans powder & primer if you reload


Last edited by meplat; 01-26-2013 at 12:52 PM.
Reply With Quote
  #6  
Old 01-26-2013, 05:30 PM
.30 Carbine .30 Carbine is offline
 
Join Date: Oct 2009
Location: Northern Virginia
Posts: 406
Default

Thanks! I will make 30 dummies when I can get some more bullets to reload.
Reply With Quote
  #7  
Old 01-26-2013, 05:54 PM
meplat meplat is offline
 
Join Date: Jan 2010
Location: Prescott, AZ
Posts: 3,761
Default

While testing consistency of feeding throughout the mag spring's travel, one thing the "action-proving" dummy test won't test for is correct placement of the magazine's holding lugs. If the lugs, as manufactured, are too high, the rattle from rocknroll will cause the mag to slip down resulting in possible failure to feed.

Shoot, guess there's really no other way.


Last edited by meplat; 01-26-2013 at 05:55 PM. Reason: afterthought
Reply With Quote
  #8  
Old 01-26-2013, 06:32 PM
tenOC tenOC is offline
Banned
 
Join Date: Jun 2010
Location: East TN
Posts: 3,991
Default

Yeah, unless you're doing it at cycle speed with the pressures exerted, you aren't going to know if they work correctly. You need to shoot them out.
Reply With Quote
  #9  
Old 01-26-2013, 07:19 PM
J.R.2009 J.R.2009 is offline
 
Join Date: Oct 2009
Location: Mt. Pleasant, SC
Posts: 8,162
Default

+1 tenOC. Using dummy rounds will prove nothing except the mags work at "hand speed". The only way to test them is to shoot the cotton pickin' things !!! Besides whey waste 30 or more good cases making dummies, it s a hell of a lot more fun shootin'!!
Once I tried to check to see if one of my carbines would feed SP bullets. Worked with the "hand jive" speed but other than the first round loaded from the mag by hand every one of them jammed at cycle speed.
__________________
J.R.

Home of the FREE Carbine Club Newsletter Index raeed4@comcast.net
I do NOT have newsletters to sell! ONLY our INDEX of what is in each issue. To get the issues see the link for the Carbine collectors Club.
http://www.uscarbinecal30.com/

USAF 379th Bomb Wing (Heavy) SAC
Gun Owners of SC
GCA

Last edited by J.R.2009; 01-26-2013 at 07:22 PM.
Reply With Quote
  #10  
Old 01-27-2013, 11:23 AM
.Steve. .Steve. is offline
 
Join Date: Oct 2009
Posts: 824
Default

By the time I got to the bottom, #10, I found a good answer. My two cents would be:

The next time you wish to go shooting, take the 30's to test. Load 30. Load 1 into the chamber and lock in the magazine. Shoot five off the top of the magazine. This tests the magazines ability to rise the stack when full loaded AND tests the carbines ability to strip rounds from the tightly compressed magazine stack.

Unload the next 20 by hand. Put the magazine back in. Shoot the bottom five. That will tell you if the uncompressed magazine spring still has enough power to lift the last 5 and lock open. The 6th shot locks it open if I can count correctly.

If it does both ends, it will likely work with the ones in the middle. It saves you 2/3 of the ammo and tests both ends.

As a practical matter, even a bad magazine sometimes works. Likewise, even a good magazine can screw up with a carbine.

The best was to get mags that work are to avoid all the Scherer junk.
*Made in the USA
*M2

With USGI mags, if the feed lips are straight, undimpled and bent, AND you replace the magazine springs, they pretty much work as long as the tube bodies aren't damaged.

The recent Korean ones marked U and UU work until the locking nubs grind off the poorly heat treated magazines.

The magazines most likely to work of all ever made that I have seen are the $100 a piece new condition hard back SEY magazines. They are good ones but for old springs.

The equivalent in dependability is the AYP magazines that are (1) real and not the fakes (2) in new condition (3) not rusty inside. They are as good as any carbine mag ever made.

The USGI ones, commercial ones, Asian-Martian-Moonie military magazines (Ha Ha Ha), what have you work or don't work depending on springs and condition inside.

Although never seen any more, the magazines with all the military features made 40 years ago and reimported 10 years ago as South American military were (probably-maybe-likely-not likely) made by Jahn that became OKay. They are very good magazines just like the J marked ones. Recognizing them with all the other more recent junk made is near impossible. The more features of genuine magazines that were identified, the more the fakes adopted the features. The difference is metal quality.

Last edited by .Steve.; 01-27-2013 at 11:26 AM.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



All times are GMT -5. The time now is 05:07 PM.