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Merle Bitikofer 22 Thompson Kit Question


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Hi,

 

For several years I've been enjoying Merle's 22 conversions in the Thompson. I've had great success with the M1 and 1928 models. They would run all day long with failures being few and far between. Unfortunately, both of my kits with both of my Thompsons have stopped running. I've cleaned, switched ammo, changed recoil springs, changed lube, changed magazines, and still have the same type of jam.

 

The jam - The round is stripped from the magazine and the nose of the bullet strikes the rear face of the barrel @ 2:00. The nose of the bullet is 1/2 inside the chamber and 1/2 outside the chamber. The jam happens several times/magazine. It has taken much of the fun out of the kits.

 

Temporary relief (a magazine or so) from the problem can be gotten by removing and re-oiling the bolt. After a mag or two the jam is back.

 

If anyone has seen this type of jam or can think of where to look, I would certainly appreciate some help. I'd bother Merle but I think the man deserves some rest at some point in his life.

 

Sincerely,

 

Grasshopper

Edited by Grasshopper
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Ammo is my first thought? What type ammo are you using? Merle recommended to me Federal Bulk Pack.

 

Next thought would be mags and the spring, has the spring gotten tired. I highly doubt this but with must weapons, ammo then mags are the primary cause of FTF.

 

Next, you say it hangs partially inside the barrel. Any burrs or other blemishes? Maybe a nick is causing drag?

 

I feel something is causing drag.

 

Paul

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Hi Folks,

 

Thanks so far for your help. I'm running Federal Bulk Pack.

 

The jam has the tip of the bullet split and stopped on the chamber opening @ 2:00 and the rim of the case in the bolt face. It really bends up the bullet. The cartridge does not even start to enter the chamber. I'm surprised I've had no out of battery explosions. It is very consistent in this jam.

 

I have cleaned and checked everything for burrs (except the extractor). The extractor is not fun to remove and bends rather easily. I'll pull and check it tonight.

 

I'll load it in guns into the car Saturday w/some new magazines, different brands, and different 22 kits as I've got a bunch. I've tried several different recoil springs with no significant change.

 

As mentioned earlier, I've shot these kits quite a bunch w/o a problem. Somewhere in the 20,000 rounds/kit w/o a problem.

 

Just for fun, I'll even drag out a Ceiner conversion. It has worked great in the past but has a much higher cyclic rate.

 

Thanks,

 

Grasshopper

Edited by Grasshopper
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Have you recently changed .45 ejectors?

A slightly longer .45 ejector can push against the .22 bolt and cause exactly the malfunction you are having.

Only takes a few thousandths to mess up the feed. You could check this with some layout fluid on the bolt.

The solution is to remove or clearance the .45 ejector, or clearance the .22 bolt, as I detailed in a post a couple of years ago.

Even with the same .45 ejector, If your .22 ejector got a little bent between installations, it can be pressing against the .45 ejector and push the .22 breech slightly out of alignment, which can cause the same kind of misfeeds.

 

The other major cause of this misfeed is the top of the .22 bolt rubbing on the hole in the receiver as the bolt is entering the magazine well. This is almost guaranteed with Hurleys, but I have had it happen with two out of three original guns. Sometimes the .22 bolt head sits ever so slightly higher than a GI bolt, and depending on the gun, can rub at the top. Layout blue again, or just manually moving the bolt in the receiver and feeling the "bump" as the bolt nose moves into the mag well.

 

A .22 bore snake is a nice thing to have at the range.

Every bulk pack or so, I will pull it through the barrel and get rid of much of the gunk that comes with .22RF.

I shoot mostly Federal bulk pack, per Merle, but have also run a lot of Winchester copper plated bulk pack with similar success.

Edited by mnshooter
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Check to make sure your firing pin is not sticking in the bolt and not fully retracting. I had the very same problem with mine as what you are describing as you can see in the attached photo. My firing pin would not fully retract and was sticking out just enough to cause the cartridge to drag on the face of the bolt and jam. I had to take the bolt apart and with a fine file polish out the area of the firing pin that was sticking. Cleared the problem right up and everyone lived happly ever after.

bullet jam.jpg

bullet jam 1.jpg

Edited by lpedersen
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Ding, ding, ding, ding,ding,

 

The winner is!

 

Mr. lpederson. That's my jam! Thank you so very much. Exactly the same "customized" ammo I've been making. I'll give a range report on Sunday as it looks like the "Boss" has got me changing the oil in her Beetle today. (Florida. It is not a bad thing this time of year.)

 

Time to knock out the cross pin for the "hammer" to remove the nose of the bolt. A bit of cleaning and careful hunt for burrs and I bet things will be back to normal. Nothing like a camera when you need it. I think it will go in the range box.

 

Thanks again lpederson.

 

Sincerely,

 

Grasshopper

 

This Board is Great!

Edited by Grasshopper
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Obviously not feeding straight from the magazine into the chamber, but I have not a clue why this is. Is the round under the round that jams pushing up under spring pressure at an odd angle?

 

My own .22 conversion kit is in a Vector Uzi, so any comparison I could make would be apples to oranges. I do notice that the top round in the .22 Uzi magazine is very tightly controlled by the magazine's feed lips. It's straight. When the bolt peels it off of the stack, it can only go into the chamber, not off to the side somewhere. The breech face is immediately in front of the magazine. Basically, it looks like the nose of the bullet is in the breech before the rim ever leaves the magazine. The round is controlled through the whole process, in other words.

 

The Uzi's cyclic rate is very fast; I'm guessing 1,000+ RPM. I wouldn't think this would be possible unless the alignment of everything is just perfect.

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Hi TSMGguy,

 

I've got the Vector's running great at between 670-770 rpm. A little weight, some spring tune, some gun tune and fun at the range. I've even got some 40 round magazines that run nicely for the Vectors.

 

Here's my first day of getting it running right. It was raining but I didn't care.

 

https://dl.dropboxusercontent.com/u/938061/2012_09_30_range_day/IMG_1471.MOV?dl=1

 

I forgot to check the firing pin as the Vector kits have a fixed pin. I'm sure lpdersen has pointed me in the correct direction with the hanging firing pin or possibly a broken or weak rebound spring for the firing pin. I'm in the middle of surgery on the 22 Thompson kit right now. I might have to try it out as I got a supressor adapter from Merle around here someplace.

 

Thanks guys,

 

Grasshopper

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Only part I ever had a problem with in the kit is the extractor. Take it out ,straighten it and make sure it has good spring tension to get a good grip on the shell

Edited by Chopper28
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Hi Folks,

 

Spent the morning at the range today. Still no joy. At least 1 jam/magazine.

 

The firing pin was in bad shape when I checked it last night. The end that strikes the cartridge was mushroomed to the point that the pin didn't slide well in the bolt. I carefully stoned the sides leaving the length alone and took off enough that there was no binding at all. The spring that pushes back the firing pin is in good shape. The rocker or hammer is aok w/o any breakage or egging of the hole.

 

Extraction is now also an issue so I'll pull the extractor and check to see that it is straight and the spring is in good shape. No binding in the slot.

 

The .45 ejector was removed as I've got some early kits that do not have the bolt clearanced for the ejector

 

I'm back to putting everything back to the last known good running configuration. A complete cleaning (with me wearing magnifiers so I can see) is also on the list of things to do this week. The layout die is coming out of the cabinet this week also. Just because I can't feel or see the interference doesn't mean it isn't there. Due to work, my next test will not be 'till 3/15. (Is there something I should remember about the ides of March? )

 

Thanks for all the help so far.

 

Sincerely,

 

Grasshopper

Edited by Grasshopper
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Hi Everyone,

 

I got a chance to get the 22 conversion out to the range today. Before the trip to the range I read all the posts. The extractor had become bent and that leaves the tail a bit high. I bent it back as best I could w/o removing it but it still rubbed a bit.

 

Shooting - Ran pretty good. Only had the 2 o'clock jam about every other magazine. I attribute that to not completely eliminating the rubbing of the tail of the extractor on the receiver. The bad news is that the firing pin must be just a bit to short these days. All primer strikes were extremely light and about 2 rounds/magazine would not fire. I checked and the "nose" of the bolt is just contacting the barrel insert at the same time the bolt strikes the inside of the receiver (hammer is therefor flush with the front of the bolt.)

 

Now it is time for a new firing pin or build up the face of the hammer by about .003"-.005" unless anyone can think of a better way to make the firing pin just a bit long. (I must not be thinking very well. I've got several other kits. Time to go measuring firing pin length and see if there is a suitable donor.)

 

Bolt coming apart again. Firing pin & extractor work. Just about home.

 

Thanks Everyone,

 

Grasshopper

Edited by Grasshopper
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I would call Merle. He was very helpful to me when I was learning how to get my kit running properly. If your firing pin is worn down, I bet Merle will replace it or sell you a new one at a great price. Give him an approximate round count and he will treat you fairly.

 

I have noticed with rim fire full auto that dumping the drum or magazine works best. Short bursts work most of the time but can cause a few hiccups. I paid two hundred dollars for the privilege of holding the trigger down until the drum is empty. I like to take full advantage of that privilege :D

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Remove the .22 barrel and see if the .22 bolt will travel further forward.

If it does, the .22 conversion barrel is not seated far enough into the .45 chamber. As I mentioned before, you might need to clearance the chamber portion of the .22 barrel to allow it to seat further into the .45 barrel. This will let the bolt travel further forward, giving you proper firing pin hits.

After I did this and clearanced for the .45 ejector, I can fire semi, full auto 2, 3, etc., or empty the mag (that's the only way, really).

Edited by mnshooter
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The bad news is that the firing pin must be just a bit to short these days. All primer strikes were extremely light and about 2 rounds/magazine would not fire.

 

GH,

I had a similar experience with my Ceiner/Thompson. It worked really good for years, then all of a sudden, misfires with light primer hits.

The first thing I discovered was the hammer had a crack at the thin point of the hammer pin. I repaired the hammer, but was still getting misfires/weak primer hits. I made a new firing pin out of drill rod and got her firing. But it still misfired with the original firing pin. I cut .010 " from the firing pin shoulder (where it is stopped from forward movement, by the bolt. Now the original FP is dependable. Don't understand why any of this happened, but at least its working now.

I don't know if the Merle and Ceiner kits are identical, but I thought you might be interested in how I solved the problem.

Jim C

PS there is no way the front of your firing pin should be peened at the tip unless its striking barrel steel, and it shouldn't do that.

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Hi Jim c351,

 

Good thought on the hammer. I should really examine around the pivot hole carefully to see if there is a crack developing. This kit only has about 5000 rounds down range. It was working pretty good when I started shooting it but recently deteriorated. I agree the firing pin should not be mushrooming at the cartridge end. I checked the back of the chamber on the barrel insert and there were no strikes. The firing pin may have missed the heat treat process. I did talk to Merle as my extractor lost its edge early on. I've got a note here someplace with the heat treat Merle suggested for the extractor. That worked out well.

 

I looked at using a JAC extractor in Merle's kit and it appeared that the extractor that JAC used is about .007" shorter from the hook to the pivot hole. While I've got it down I'll compare the firing pins.

 

mnShooter - I'll pull the barrel insert and double check for dirt between the insert and the and of the .45 chamber. As I mentioned, the kit did run pretty well when I got it so that is a good place to look.

 

I've got an earlier kit in an M1 (the kit requires .45 ejector removal) and it runs so well it scares me. The barrel gets hot enough that you don't want to touch it for long. The kit in question right now was out of what I think was the last run by Merle.

 

Merle is great to talk to. I've learned important stuff like how to keep a pony motor on an old CAT diesel alive when the dozer is trying to nose dive into a hole. (Ok. The secret is to overfill the crankcase with oil. You have to keep the main & rod bearings lubed somehow.)

 

I'll give it one more examination and range trip before I bother The Man. He has certainly put in his time to support the Thompson community.

 

Sincerely,

 

Grasshopper

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  • 2 years later...

Hi All,

 

I figured out what was going on with my Thompson 22LR kits. I had upgraded my extractor, fit the kits to the guns (mine needed a .007" shim between the steel bottom of the bolt and the aluminum upper part of the bolt), got everything working slick as can be and it jammed 2x per magazine. Hmmm. 4 guns stopped working at the same time. The only common element was ammo and magazines. I'm not for suspense. The BDM polycarbonate magazines had worn out.

 

First I switched to JAC 's new billet aluminum Tommy mags. These are the gold standard so far as my testing is concerned. They come apart for cleaning very, very nicely also but I digress. The guns ran 100% on the JAC magazinesTommy%20Mags%20small.JPG. That is nice but with new-be shooters, I like using magazines that will not mar the finish on the guns (plastic mags). It turns out it is easy to detect a worn out magazine.

 

To detect tired mags for my guns isn't that difficult. I load about 4 rounds in the magazine. Next gently pull up on the nose of the top round until the sides of the cartridge contact the feed lips on the front side of the magazine. In the row of magazines above, the left pair are AOK. The ones on the right are worn out. The worn out tend to have 2 o'clock impacts of the cartridge nose on the rear of the chamber causing a jam. When you see how the front of the cartridge can ride up w/o hitting the feed lips (RH mags), it is not a stretch to see why there may be feed issues.

 

As usual,

 

YMMV,

 

Good Luck,

 

Grasshopper

 

ps. I need to post the spring swap in the lower to make the gun have a 4 lb trigger for 22RF. It saves your trigger finger!

Edited by Grasshopper
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This has always been my concern. wish BDM made ones with metal lips like their AR-15 mags. As for JAC, really love his mags, just won't deal with him on principal. wish there was a better option.
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Hi Bridgeport28A1,

 

I didn't keep track of the rounds to "worn" magazine. For the most part I ran 3 magazines for 2 years. My best guess is about 2000 rounds/magazine. The club I belong to in town is having an open house in November. I'll start with a new magazine that day and see how long it lasts. I'll likely get 1000 rounds through that one mag in a day.

 

I don't know if how you shoot has any influence on the wear rate of the magazines. I'd think mag dumps might be most harmful based on friction/temperature of the feed lips.

 

Mr. Paul in PA,

Metal, preferably steel, would be optimal for the feed lips. I'm going to keep my worn mags in a box just in case I get really, really ambitious and make replacement feed lips or adapt another magazines feed lips to the Thompson mags. Fortunately I've always had good experiences dealing with JAC. He has always treated me professionally and fairly in all my transactions. I'll be buying a bunch more of the new billet mags as they look correct in the guns. I'll try to wear one of those out also at the open house at our club in November.

 

I wish I would have figured this out before I sold one of my Merle kits to a board member here awhile back. I'm not sure Merle is making the kits any more. The last Merle kits have a very nice cocking handle for the '28s.

 

Enjoy!,

 

Grasshopper

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Funny, just look a look at Black Dog Machine they have the Thompson 22LR 30 round plastic BDM magazines on sale for $12.99.

 

blackdogmachinellc.net/thompson-22.aspx

 

You get 7 1/2 BDM mags for the price of One JAC Metal one. May just need to break down and buy a fee from JAC, they will last my children's lifetimes if we get "Gun Reform" from our next President.

 

- - - - - UPDATE - - - - - -

Looks like BDM also sells Stainless Steel Feed Lips for their AR-15 22LR magazines. They are $5 each, maybe we can mod the BDM Thompson magazines?

 

blackdogmachinellc.net/stainless-steel-feed-lips.aspx

Edited by Paul in PA
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Hi Paul in Pa,

 

I was thinking the same thing about using the AR feed lips on my worn Thompson mags. In addition, while polycarbonate is not know for good forming properties while hot, I may try to "pull" the front edges of the feed lips inward on a mag to see if that helps. Haven't got anything to loose.

 

I agree. The $12 or so for each BDM mag makes them very attractive. They are also easier to load than the JAC mags. Now I wish I'd have taken better care to get some sort of rounds-to-failure on the BDM mags.

 

At the moment, JAC is out of the billet mags. I had tried to get some about 2 weeks ago and he was out of stock. I'll update this post when they are back in stock. I might even buy 1 20 round mag as they look nice in the gun. The billet mags are offered in a high-gloss anodize and a satin finish anodize from what I've been told. I've only tested the satin finish as it came with one of my kits.

 

Take care,

 

Grasshopper

Edited by Grasshopper
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