nfafan Posted July 16, 2007 Report Share Posted July 16, 2007 Hello all, One of these days I'll get more than a few mags thru my A-O 27A1... Today was plinking away, all was well with the world when suddenly the bolt was "welded" halfway into battery. Locked solid, wouldn't budge. http://www.machinegunbooks.com/forums/invboard1_1_2/upload/html/emoticons/banghead.gif Poked and prodded and discovered that the EXTRACTOR had worked itself partway out of its' slot in the bolt and had jammed the bolt. Pushed a bit with a screwdriver and it fell free, dissassembled gun and went to re-install the otherwaise undamaged extractor. During re-install, I noticed the extractor has an "edge" or "flange" or "lip" - whatever you want to call it - that runs the length of the extractor on both sides, which should fit into a corresponding under-cut in the milled extractor channel of the bolt. It appears that the extractor channel is not under-cut enough for the *length* of the extractor - especially the upper-side (top of bolt) of the channel. There is not enough "under-cut" to hold the extractor for it's length. I suceeded in snapping the extractor back into it's bolt channel, but was a little leery of this lack of sufficient undercut on the upper side of the extractor channel... Sure enough, 10 rounds or so later and the bolt is once again jammed tight by the extractor jumping the extractor channel in the bolt. I'm thinking one fix may be to lightly stone the upper surfaces of the extrator "flange", just to make sure it "bites" into what little under-cut there is that was milled into the bolt. Any other ideas out there in 1927A1 de-bug land? Thanks in advance! Steve in PGH... getting real close to Craig's listing this for a Uzi semi, where I'm sure the extractor is PINNED in place like 99.999% of other guns on the planet. http://www.machinegunbooks.com/forums/invboard1_1_2/upload/html/emoticons/soapbox.gif Link to comment Share on other sites More sharing options...
reconbob Posted July 17, 2007 Report Share Posted July 17, 2007 Interesting Phil, but it raises the question of when is a Thompson no longer a Thompson? (yeah, I know, when its made by Kahr) You could go over the whole gun and "better mousetrap" just about everything. The pivot plate, the mag catch, etc. I think that for the most part, Thompson people are purists, and a gun with the general appearance of a Thompson, but completely different mechanically (which could easily be done) would not be embraced by the Thompson fraternity. Picture a semi-Thompson with a receiver, barrel, and trigger frame, but just about every other mechanical part exchanged for a better, easier, or more user friendly part. Pivot plate nightmare - gone, you don't even need a pivot plate - you can use pins held on the inside like a FAL, you can have an easy button type spring loaded mag catch like a BAR, an M16 type coil spring loaded extractor, a Garand type bolt face ejector - you get the idea. Now you have no distinctive mag catch, pivot plate, or ejector - but the gun is "better". However, somewhere along the way, it would no longer be identified as a Thompson. Love 'em or hate 'em, when it comes to the Thompson Kahr is manufacturing and selling an image, an icon, a collectors item. Because if they drift too far from the original design it would become like those old Commando .45 ACP carbines that used the Grease Gun mags and had (I think) machined aluminum castings for the upper and lower receiver. They were fun, as I recall they worked great but they were never thought to be Thompsons. Bob Link to comment Share on other sites More sharing options...
Merry Ploughboy Posted July 17, 2007 Report Share Posted July 17, 2007 Since the thread is drifting off topic, my two least favorites of the TSMG mechanics - the "oil in your eye" hole in the back of the receiver; and the weak and wobbly frame latch. MHO, YMMV, etc. Link to comment Share on other sites More sharing options...
nfafan Posted July 17, 2007 Author Report Share Posted July 17, 2007 To get back on topic.. And this is assuming that the second dislodging had no effect on the extractor itself; I'm thinking one fix may be to lightly stone the upper surfaces of the extrator "flange", just to make sure it "bites" into what little under-cut there is that was milled into the bolt. And given that I don't weld - maybe some JBWeld epoxy when I re-re-install the extractor. although I do know a welder who can probably spot it, then I'm left to stone it down. Any other ideas out there in 1927A1 de-bug land? Thanks in advance! Steve in PGH... Link to comment Share on other sites More sharing options...
TAS1921AC Posted July 17, 2007 Report Share Posted July 17, 2007 nfafan, I would get the problem resolved before firing the gun again. My West Hurley's extractor came out because the thin ridges on the bolt that held it in snapped off and rendered the bolt worthless. So be careful. I'd hate to see that happen to you. http://www.machinegunbooks.com/forums/invboard1_1_2/upload/html/emoticons/sad.gif Link to comment Share on other sites More sharing options...
Grey Crow Posted July 18, 2007 Report Share Posted July 18, 2007 nfafan, A different bolt may just be your only recourse. Other than having a competent smith add metal to the bolt and re-machining it. With all of that it still may be less expensive to replace it. Kahr sells bolts for $123.20, Gun Parts $137.50. For quite a while Gun Parts was less expensive, but they have probably run out of the older WH stuff, and now buy from Kahr. Extractors are known to break so I wouldn't make them to permanent. Link to comment Share on other sites More sharing options...
nfafan Posted July 18, 2007 Author Report Share Posted July 18, 2007 (edited) Can anyone post a closeup pic of the extractor side of an A-O 1927A1 bolt? I will try and take a pic of my bolt. I think TAS1921AC hit the target in the bullseye... When I examined the bolt closely today, it looks like there was a "chip" in the edge of the milled extractor channel - which to me (the untrained eye) makes it look like there was not enough "undercut" milled to hold the extractor "ledge". There isn't enough as there seems to be missing metal! OTOH, the extractor seems fine for all the excitement. It has a barely perciptible number or letter on the back of the extractor - IIRC, a MIL-spec part(?). I also noticed some smallish gouges in the inner face of the upper receiver where the extractor would pass thru. This is a 1927A1C alloy, so I should gently file those tiny gouges in the extractor pathway smooth. And it ran so nice for several mags before it happened... http://www.machinegunbooks.com/forums/invboard1_1_2/upload/html/emoticons/sad.gif Trying to add a pic of my bolt here... http://i7.photobucket.com/albums/y260/nfafan/AO1927A1bolt/bolt2.jpg else... to P'bucket... http://s7.photobucket.com/albums/y260/nfaf...n/AO1927A1bolt/ Edited July 18, 2007 by nfafan Link to comment Share on other sites More sharing options...
Dylan Posted July 18, 2007 Report Share Posted July 18, 2007 Houston, you have a problem.... this is what it's supposed to look like: http://i35.photobucket.com/albums/d178/SMLE1918/Tommy/bolt.jpg Link to comment Share on other sites More sharing options...
nfafan Posted July 18, 2007 Author Report Share Posted July 18, 2007 Thanks Dylan for posting the pic! Now it's time for a new bolt! Link to comment Share on other sites More sharing options...
TAS1921AC Posted July 18, 2007 Report Share Posted July 18, 2007 I can't help thinking that the horrible spring tension slamming the bolt forward could be the cause of the bolt breaking where it retains the extractor. My West Hurley was made in 1975 and the bolt in it looked to be a modified M1A1 bolt not a new manufactured one. Since we don't hear about M1A1s having the same problem I wonder......... Link to comment Share on other sites More sharing options...
nfafan Posted July 19, 2007 Author Report Share Posted July 19, 2007 Just for the record; The gun was cleaned and lubed before I started shooting, and I was shooting - without any probs until the jam - 30 rd mags of PMC FMJ and CCI Blazer aluminum cased FMJ that I had a stash of. I went thru maybe 120-130 rounds before the jam. No steel cased ammo. Link to comment Share on other sites More sharing options...
Deathompson Posted July 19, 2007 Report Share Posted July 19, 2007 (edited) QUOTE (Dylan @ Jul 18 2007, 02:48 AM) Houston, you have a problem.... this is what it's supposed to look like: http://i174.photobucket.com/albums/w98/deathompson/bolt.jpg Even this one looks as if is peened on the back corners of the foward deep cut. Is this common? Edited July 19, 2007 by Deathompson Link to comment Share on other sites More sharing options...
Dylan Posted July 19, 2007 Report Share Posted July 19, 2007 QUOTE (PhilOhio @ Jul 19 2007, 12:57 PM) QUOTE (Deathompson @ Jul 19 2007, 12:36 PM) ...Even this one looks as if is peened on the back corners of the foward deep cut. Is this common?... Definitely should not be that way. I don't know how common it is. I haven't seen it. Looks like the bolt is too soft or the extractor is too stiff. Do any impact points on the bolt show such peening? About how many rounds has this bolt fed? I would be interesting to do a Rockwell test on the area close to that extractor groove. The bolt has been like that since new, looks to be intentionally manufactured that way to me. I have over 5500 rounds through this Thompson. Link to comment Share on other sites More sharing options...
brian Posted July 22, 2007 Report Share Posted July 22, 2007 (edited) QUOTE (PhilOhio @ Jul 19 2007, 12:30 PM) We've seen all sorts of problems with the Kahr semi extractors and related parts. I personally think this was just a poor metallurgy and/or quality control thing...par for the course with Kahr in recent years. do you know that kahr uses(or did use) USGI extractors? http://www.boomspeed.com/kinky/extractor.JPG i had the same issue with my first bolt. it occured shortly after i aquired the gun. so it was still under warrenty, kahr replaced it for free.....well sorta, i still had shipping. http://www.boomspeed.com/kinky/bolt.JPG the second one has been fine. Edited July 22, 2007 by brian Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now