COTEP.org  

Go Back   COTEP.org > Main Category > The Dremel Room

Reply
 
Thread Tools Display Modes
  #1  
Old 12-27-2016, 09:28 AM
AFJuvat's Avatar
AFJuvat AFJuvat is offline
COTEP Member
 
Join Date: May 2016
Location: Jacksonville, FL
Posts: 1,278
Thanks: 120
Thanked 283 Times in 63 Posts
Default Magazine springs too strong.

I picked up a few USGI spec 3 Round M1 Carbine magazines.

They are marked 'UU', which means they came from Korea, The body and dimensions are exactly to the original USGI spec.

That said, the magazine spring is too strong - Pop a round out of the magazine and 2 - 4 rounds pop out. Last time I took it out, the bottom of the bolt was gold colored from rubbing on the brass.

Anyone know a reliable way to make a magazine spring weaker?

Thanks
__________________
There are no dangerous weapons; there are only dangerous men.

To speak without thinking is to shoot without aiming.
Reply With Quote
The Following User Says Thank You to AFJuvat For This Useful Post:
FfNJGTFO (12-27-2016)
  #2  
Old 12-27-2016, 11:01 AM
sdmc530's Avatar
sdmc530 sdmc530 is offline
Founding Member
COTEP Member
 
Join Date: Nov 2011
Location: South Dakota
Posts: 14,962
Blog Entries: 3
Thanks: 4,497
Thanked 2,787 Times in 730 Posts
Default

if the spring is too hot you could just cut off one coil at a time, then try it. this should alleviate the issue if the spring is the issue.
__________________
Reply With Quote
  #3  
Old 12-27-2016, 08:42 PM
Riverpigusmc's Avatar
Riverpigusmc Riverpigusmc is offline
Founding Member
Super Moderator
 
Join Date: Aug 2011
Location: Archer, Florida CSA
Posts: 12,957
Blog Entries: 5
Thanks: 1,961
Thanked 3,477 Times in 714 Posts
Default

cutting a spring can make it stiffer sometimes...have you tried stretching it? And are you sure the feed lips aren't stretched open?
__________________
NRA Life Member
Wilson Combat CQB
Kimber Tactical Pro II
S&W J-Frame .38
ect
" I don't own the clothes I'm wearin', and the road goes on forever "

There's a gator in the bushes, and it's calling my name...
COTEP #523
Reply With Quote
  #4  
Old 12-28-2016, 09:21 AM
wxl wxl is offline
Founding Member
COTEP Member
 
Join Date: Apr 2011
Location: South Texas
Posts: 393
Thanks: 4
Thanked 87 Times in 13 Posts
Default

Quote:
Originally Posted by AFJuvat View Post
I picked up a few USGI spec 3 Round M1 Carbine magazines.

They are marked 'UU', which means they came from Korea, The body and dimensions are exactly to the original USGI spec.


Thanks
Could be Korean but original USGI mags from Underwood can also be marked with "UU".
__________________
COTEP CBOB0297
Reply With Quote
  #5  
Old 12-28-2016, 09:43 AM
AFJuvat's Avatar
AFJuvat AFJuvat is offline
COTEP Member
 
Join Date: May 2016
Location: Jacksonville, FL
Posts: 1,278
Thanks: 120
Thanked 283 Times in 63 Posts
Default

Quote:
Originally Posted by wxl View Post
Could be Korean but original USGI mags from Underwood can also be marked with "UU".

Too new to be original Underwoods.

I ordered 2 original surplus SEY hardbacks. Will give them a try.
__________________
There are no dangerous weapons; there are only dangerous men.

To speak without thinking is to shoot without aiming.
Reply With Quote
  #6  
Old 12-28-2016, 01:02 PM
Caleb's Avatar
Caleb Caleb is offline
COTEP Member
 
Join Date: Sep 2013
Location: Earth
Posts: 11,451
Thanks: 4,189
Thanked 1,137 Times in 254 Posts
Default

I'd try stretching them before snipping.
__________________
**I have been Enlightened**
Reply With Quote
  #7  
Old 01-05-2017, 12:23 PM
AFJuvat's Avatar
AFJuvat AFJuvat is offline
COTEP Member
 
Join Date: May 2016
Location: Jacksonville, FL
Posts: 1,278
Thanks: 120
Thanked 283 Times in 63 Posts
Default

Update.

Received the 2 SEY magazines and compared them to the 'UU' marked Korean magazines.

The SEY magazines are 'hardbacks', which were the first 30 round magazines produced, whereas the Korean magazines are the later 'splitback' type.

Body thickness and weight are actually pretty close to each other - within 5 grams. USGIO magazines are blued, whereas the Korean magazines appear to be painted.

The SEY spring is actually thicker and longer than the UU springs, which since I was operating on the presumption that the Korean springs were too strong.

Breaking out the calipers, I found the issue - it was the feed lips.

Though they are profiled exactly the same as the USGI feed lips, the lips on the Korean magazines were 0.002" higher on each side, thus making the opening on the magazine 0.004" wider than the USGI magazines.

Loaded the magazines and with a small brass hammer, tapped the lips profile to match the USGI magazine. No double or triple feeds after.

What is interesting is comparing my USGI 15 round magazines to the Korean ones, the Korean magazine feed lips are also about 0.002" higher, but don't double or triple feed rounds. I suspect that is due to the 30 round spring having to be significantly stronger.
__________________
There are no dangerous weapons; there are only dangerous men.

To speak without thinking is to shoot without aiming.
Reply With Quote
Reply

Thread Tools
Display Modes



All times are GMT -4. The time now is 10:26 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.