Why M1 Bolt
Posted 31 May 2004 - 02:00 PM
Posted 31 May 2004 - 03:09 PM
Posted 31 May 2004 - 04:02 PM
I have never seen one "fire out of battry," but I am sure it can happen (especially on an out of spec gun or if there is a lot of crud in the chamber.)
I have seen several closed bolt guns "cook off" rounds. This, of course, is where heat detonates the round before the trigger is pulled (or at least before the firing pin hits.) This is easy to do with a Ruger Mini 14 and/or a Ruger AC556.
Just my $.02 worth!
Posted 31 May 2004 - 04:49 PM
Seriously, for $100 why risk blasting the person in the lane to the right of you? If you have an M1A1, put in the M1 bolt to be more safe and keep the M1A1 bolt for completeness. A M1A1 bolt is about $60 v. the $100 for the M1 bolt.
Posted 31 May 2004 - 08:09 PM
Posted 31 May 2004 - 10:08 PM
The M1 bolt is inherently safer than the M1A1 bolt. I have a piece of brass embedded in my cheek just below my right eye. This was the result of a "slam fire" in the ejection port that occurred when an extractor broke leaving a spent case in the chamber. It was not a fun experience. It has happened to others as well. If you can find a good M1 bolt it's well worth the money.
Keep in mind the moveable firing pin in the M1 bolt can do the same thing if it freezes in the exposed position. I saw this happen when a small piece of brass and a lot of gunk caused a stuck firing pin. Also, make sure the extractor is clean and functioning properly. Lack of proper "set" or a build of gunk under the extractor can cause it to fail setting up the conditions for "slam fire." Proper maintenance should minimize that possibility.
Surplus steel cased ammunition has also been linked to extractor failure in the Thompson that can lead to a "slam fire" condition.
Just my experience - hope the information is useful.
Posted 01 June 2004 - 05:24 AM
|QUOTE (1921A @ May 31 2004, 10:08 PM)|
|Keep in mind the moveable firing pin in the M1 bolt can do the same thing if it freezes in the exposed position. I saw this happen when a small piece of brass and a lot of gunk caused a stuck firing pin.|
Excellent point, Greg. I always clean and check the firing pin and spring by disassebling the bolt.
Posted 01 June 2004 - 08:56 AM
I would not feel uncomfortable shooting good quality factory ammo in a “right” M1A1, but I would never shoot handloads in one. There are circumstances other than failed cases that can cause problems. The truth is that the M1 bolt is safer in any circumstance, and the separate firing pin is a revered deign of the Thompson.
In my lexicon, the problem described is more accurately called “discharge out of battery”. Any gun that fires from an open bolt is a “slam fire” gun.
Posted 01 June 2004 - 01:27 PM
Posted 02 June 2004 - 04:10 AM
If you don't, you might look like this guy after a misfire ----->
Posted 02 June 2004 - 10:48 AM
Posted 05 September 2004 - 11:05 AM
After reading this posting, think will stayk with the M1 bolt in the M1.
Edited by JTinIN, 05 September 2004 - 11:05 AM.
Posted 05 September 2004 - 12:49 PM
Thanks for going into depth with this. That sort of thing is easy to miss, especially to the novice collector. I've always heard people changing out their M1a1 bolts, but never took this as seriously until I read this thread. Sounds like some nasty thing can happen and it is certainly worth the extra $100 to make it a safer gun.
Posted 05 September 2004 - 01:31 PM
Judging by your artistic expertise at rendering, I would
plead with you to switch out to the safer M1 bolt.
Talent would be a terrible thing to lose for lack of a couple of tools (lookers
Posted 05 September 2004 - 02:09 PM
Posted 14 September 2004 - 06:38 PM
Posted 14 September 2004 - 07:45 PM
Before blowing $100 on an M1 bolt, I would check to be sure you actually need one. I could be wrong, but it's my understanding that the Kahr '27A1s, like their NAC predecessors, already use an M1 style bolt - that is, a sear-release firing pin rather than a fixed one. The Kahr guns may have other issues that require attention for reliability, but I don't think this is one of them. BTW, a fixed firing pin (i.e. an M1A1-style bolt) on a semi auto Thompson is strictly VERBOTEN, since that makes it a full auto weapon!
Since you're new to this game, welcome to the wonderful world of Thompson addic... uh ... enthusiasts!
Edited by Bob B, 14 September 2004 - 08:29 PM.
Posted 14 September 2004 - 07:53 PM