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

Reply
 
Thread Tools Display Modes
  #1  
Old 08-25-2019, 03:18 PM
Bennett8 Bennett8 is offline
 
Join Date: Oct 2009
Location: Virginia
Posts: 452
Default Help: causes of bolt throwing the extractor

I am having issues with my Rack Grade SG shooter. I have tried two different bolts - both of which headspace correctly with a field gauge, and each bolt has thrown the extractor - one after 3 shots and one after a single shot. The first was with factory ammo the second with reloads using 15 gr W296 and a 110 bullet. I had disassembled and cleaned both bolts and reassembled using a GI bolt tool. The only thing I can think of is that the plunger holding the extractor did not seat correctly?? Both plungers were the split type and seemed to be seated. Is there anything else that could be causing this? All thoughts appreciated!
Reply With Quote
  #2  
Old 08-25-2019, 03:45 PM
W5USMC W5USMC is offline
 
Join Date: Sep 2017
Location: Edgar Springs, MO
Posts: 103
Default

Sounds like the flat part of the plunger did not engage the extractor lip as it should. page down on the link below for a good picture of how it should seat.

http://www.uscarbinecal30.com/bolts.html
Reply With Quote
  #3  
Old 08-25-2019, 05:41 PM
6 Ring 6 Ring is offline
 
Join Date: Apr 2010
Location: South of Atlanta, Ga
Posts: 3,039
Default

The first thing I would check is:
A slide stop pin spring is the same diameter but shorter than an extractor spring. If you are using the incorrect spring, not enough pressure on the plunger to the back of the extractor to keep it in.
Reply With Quote
  #4  
Old 08-25-2019, 07:01 PM
HB of CJ HB of CJ is offline
 
Join Date: Nov 2011
Location: 42N -123W OR USA Kinda
Posts: 1,227
Default 6 Ring May Have It ...

Grab the assembled bolt and squeeze the extractor back with your thumb. It should move freely BUT have some real resistance behind it. It should NOT move that easily.

Easy to have had the wrong spring assembled in the bolt. Easy to have a bad extractor spring. Find and use a USGI extractor spring. The felt resistance is a learned thing.

Also eyeball the extractor for chips dings and errors. If your wanna, polish both sides of the extractor face. Also check the ejector while you are doing all of this. All fun to do.
Reply With Quote
  #5  
Old 08-26-2019, 05:28 AM
309Carbine 309Carbine is offline
 
Join Date: Feb 2017
Location: South Mississippi
Posts: 232
Default

Plunger spring free length should be close to .410. If it measures shorter than .400, replace it. Like others mention...extractors, plungers and springs are not that expensive.
Reply With Quote
  #6  
Old 08-26-2019, 06:53 PM
Bennett8 Bennett8 is offline
 
Join Date: Oct 2009
Location: Virginia
Posts: 452
Default Thx!

Very helpful!!
Reply With Quote
  #7  
Old 08-30-2019, 02:08 PM
DaveHH DaveHH is offline
 
Join Date: Nov 2009
Posts: 4,698
Default

It is very important to clean out the hole for the plunger spring. It can be full of crap like unburned powder, carbon chips and lint scraps. You can also take a small jewelers file and dress up the surfaces of the shelf and the plunger. Of all of the carbine parts, to me the extractor is the one that looks crude and odd. I would expect that a lot of marginal parts were out there.
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 03:07 PM.