bradhe Posted January 17, 2023 Report Share Posted January 17, 2023 I just took possession of a BD/Merle 22 conversion kit. Having read (I think) all the relevant posts on the forum from the last 10 years I am pretty sure I have one of the original BD kits (black delrin case, no slot in the barrel) which is in new condition. I understand that Merle made some useful modifications to the ones he sold directly later and to many of the BD kits. I would like to do the same but need some direction/dimensions (I have a machine shop so doing the work is not an issue). The mods I have seen mentioned include: 1. The slot in the barrel to avoid having to remove the ejector. I would really like to do this since I don't want to keep taking the ejector our of my Colt. Does anyone have or could someone measure the machining dimensions and location of the double slot? 2. Merle apparently made a different 28 actuator. Anyone have a picture of the before / after. Worth looking at? 3. "A few thousands off the bottom of the bolt" Could someone measure a known Merle bolt for me. 4. "recut one of the sear slots on the bolt" What was needed here? 5. Heavy duty extractor. Can anyone tell me what was different? Worth worrying about? I can make more extractors if needed. There were also several good posts on clearance cuts on the bolt which I will deal with if needed. Thanks very much to anyone who might be able to help me. Brad Link to comment Share on other sites More sharing options...
Grasshopper Posted January 19, 2023 Report Share Posted January 19, 2023 Hi bradhe, I can help on some of these right now. It's late for me to add photos tonight. I'll get the '28 actuator photo tomorrow unless someone beats me to it. 1.) Tomorrow 2.) Yes. I'd use the later design specially in a Colt. The initial design Merle used is a copy of the Project-X part from JAC. If the JAC cocking piece doesn't fit tightly in the top of the bolt carrier, it can wobble front-to back causing a scrape in the top of the receiver (who wants to scratch the top of their Colt). The later cocking piece has an elongated base that sits in a recess in the top of the bolt carrier. This later design does not allow the cocking piece to wobble front-to-back and prevents damage to the receiver. It is a welded together assembly of machined parts. (Due to this issue, I shoot my early Merle kits in the M1 rather than a 21 or 28.) 3.) What? I fit the bolt carrier to the gun. I can hear the groans already. Depending on the alignment of the bolt to the barrel, I either add shims between the 4140 HT plate (with the sear surfaces) and the aluminum bolt carrier or add buttons on the top of the bolt carrier. I leave just enough room so the bolt carrier doesn't drag and there is no vertical play. This is somewhat of a challenge on WWII GI guns as the fit-up between the upper and lower can be generous. 4.) Not familiar with this. It may be to put on the safety with the bolt closed. I'd not bother. I flag the guns to be safe as I consider the gun to be safe with something blocking the chamber (the flag). 5.) If you find a better extractor, please let me know. I'm not aware of a heavy duty version. Maybe a bit more spring (I've nested springs with good results). I could use 6 new extractors. I've run out of extractors. My favorite extractors are not a simple hook. They have a curvature to the edge of the hook that matches the cartridge. The bolt (steel part with the extractor) is about worn out in the c'bore where the rim is supported opposite of the extractor. The C'bore that supports the rim is egging out.) The clearance cuts necessary on the bolt for 45 ejector clearance will become evident. I got some of Merle's later kits with the clearanced liner and bolt but the kits still required me to remove the 45 ejector. I also was not fond of the sharp edges on the liner and chamber adapter. If you go that route I'd spend some quality time breaking the edges of the slots. Enjoy, Grasshopper Some old videos, An M1: https://www.dropbox.com/s/f6m9e1kehee0jir/2.wmv?dl=0 A 28: https://www.dropbox.com/s/chvikse9e639m7v/28.wmv?dl=0 Link to comment Share on other sites More sharing options...
Rabbit57 Posted January 19, 2023 Report Share Posted January 19, 2023 Good morning grasshopper, Excellent post, but I do have a question. Do you use the springs that came with your kit to run your guns, do you modify them in any way? thanks, Mark Link to comment Share on other sites More sharing options...
Chopper28 Posted January 19, 2023 Report Share Posted January 19, 2023 I had one of the kit bought directly from Merle. I ran great right out of the box. Only issue I ever had with it was the extractor. It bent outward after much shooting. Called Merle and he said to just bend it back to the original shape. I did so and it worked fine. He did not want to sell spare parts for some reason. That said, if you could make one a little more substantial or hardened it would be a good thing to have and I am sure they would sell if not to pricey. Link to comment Share on other sites More sharing options...
Grasshopper Posted January 19, 2023 Report Share Posted January 19, 2023 (edited) Hi All, The recoil spring question: I used the ones that came with Merle's kit. He often supplied two shortened springs IIRC. They are shortened 45 caliber springs. I'd just get a bunch of 45 caliber springs and start cutting a few coils off at a time until the gun runs well. It is easy to cut them too short. Harder to cut them longer :). Merle indicated Federal Bulk Pack ammo and my kits really like them. As usual, try a bunch of ammo to see what your gun/kit likes best. Some of my kits like the BDM magazines and others like the JAC magazines. The JAC last much longer being aluminum or steel w/aluminum inserts vs the plastic BDM. IMHO the JAC were a steal at $100/each. BDM magazines are more forgiving when a new shooter rakes your prized Tommy with the magazine. Enjoy, Grasshopper Edited January 19, 2023 by Grasshopper Link to comment Share on other sites More sharing options...
First Sergeant Posted January 21, 2023 Report Share Posted January 21, 2023 (edited) I T&E'd one of Merle's early kits and discovered the wobble mentioned above. My WH ended up with finish removed from the actuator slots on top of the receiver. I called Merle from the range and during our conversation he redesigned the actuator. I recall him saying "If a guy would......" Not being an engineer I was lost after "If a guy would." I even posted a warning on here about the potential damage. Within a few days Merle sent me a new actuator and the issue was solved. Not sure what I ever did with the original actuator. My plastic case for the kit has the cut out for the old actuator and the new one just doesn't quite fit. One mod that I wish I would have gotten was the cut out for the ejector. Kind of a pain to take the ejector out to switch over to .22 but I've gotten pretty good at it over the years. A business card under the ejector prevents scratching the finish. I have several spring lengths that work great. My shorter spring will slow down the cyclic rate to 600 or so with Federal bulk and is my favorite. Most .22 conversions in various FA guns shoot around 1000 rpm or higher so 600 rpm is ideal. Edited January 21, 2023 by First Sergeant Link to comment Share on other sites More sharing options...
Rabbit57 Posted January 21, 2023 Report Share Posted January 21, 2023 Good morning First Sergeant, You mentioned a shorter spring that slowed your cyclic rate down to 600 or so, was this spring one of the two springs that came with your kit, or did you make this spring yourself? I read an article by a Capt. Monty Mendenhall, he talked about how he and Merle, and Dr. Ed Shaughnessy, developed a spring that would slow the cyclic rate of the .22 conversion down to 600 rpm. I reached out to him, he gave the specs on the spring. The outfit that made the springs for him was no longer in business, but he had some left and he sent me a sample. He told me that for him, about 12" was the sweet spot, but he sent me a spring that was a bit longer, and suggested that I try it, and cut 1/2 a coil off at a time, until I got the spring to work in my gun. I intend to do this, and when I am done, I will share my results with the forum. First Sergeant, if you already have such a spring, I would be interested in where you got it. Thanks, Mark Link to comment Share on other sites More sharing options...
bradhe Posted January 22, 2023 Author Report Share Posted January 22, 2023 Boy, this turned into a project. I think I got one of the early BD kits. Didn't look like it had been fired, and now I know why. Bolt was unmarked except someone (factory?) had roughly machined off about 0.030 on the lower half of the front of the bolt, clearly to allow the firing pin lever to hit the front of the receiver and actuate the firing pin. In my colt, wasn't nearly enough, lever never touched the front of the frame and therefore no bang. I did find a brief reference to this in a post from PK early in the life of these, that I didn't know how to interpret until I had the thing in hand. Had to face 0.039 off the front of the bolt, leaving a boss for the front part of the bolt (otherwise the firing pin lever and linkage wouldn't line up. Then had to recontour the corners. Now, of course the barrel liner sticks back too far so had to move back the shoulder and "case rim" points the same amount. It worked through a couple of magazines and then it was time for dinner. Given everyones comments about drop in the later ones must have worked this out. The heavier (thought shorter) of the two springs in my kit worked the best. Could someone post pictures of the newer actuator and slot? I can guess given the comments but no reason to reinvent the wheel Link to comment Share on other sites More sharing options...
TD. Posted January 22, 2023 Report Share Posted January 22, 2023 bradhe, I purchased my kit in a wooden box directly from Merle years ago. It runs like a top with Federal Bulk Pack 36 grain hollow point ammunition. That said, it did take some tweaking to get it to run right. I have never tried the two springs Merle sent with the kit. I cut down a NOS 1928 recoil spring to just a touch under 9 inches on the advice of another owner. It works perfectly. if this is an option, I suggest starting at 9 inches. I have heard the slot on the chamber and barrel that allows for installation without removing the ejector was perfected by PK. You may want to reach out to him. I tried to buy a spare ejector from Merle when mine broke early on. Merle had me send the barrel back to him and made the repair quickly without charge but would not sell me a spare ejector. Merle was stubborn like that. There are probably a bunch of spare parts and unfinished kits gathering dust in his basement. I hope these pictures help. Link to comment Share on other sites More sharing options...
bradhe Posted January 22, 2023 Author Report Share Posted January 22, 2023 Thanks, very helpful. Any chance of a picture of the actuator out of the slot, and the slot? Best regards, Brad Link to comment Share on other sites More sharing options...
Bridgeport28A1 Posted January 22, 2023 Report Share Posted January 22, 2023 As TD. said Merle was stubborn about letting any spare parts out but was always interesting to talk to. I asked Merle about selling me a couple of his nice machined .22 drum adapters He would not sell his machined part separately. I ended up sending him a couple of Deerslayer modified .22 BlackDog drum assemblies in a trade. I did end up having Merle perform all his modifications on my black Delrin cased BlackDog Machine .22 kit including his modification to the BlackDog Machine magazine followers. I was able to buy a Thompson .22 bolt assembly with ejector and a couple of small parts directly from the owner of BlackDog Machine after they decided not to build additional .22 conversion kits. I did have the pleasure of meeting Merle in person when he attended the TATA Show and Shoot with Glen W. Link to comment Share on other sites More sharing options...
Uncle Dudley Posted January 23, 2023 Report Share Posted January 23, 2023 (edited) I had Merle make the modifications for the barrel groove, actuator/knob and magazine followers on my kit. Originally it scraped the finish on top of the reciever and that was repaired and refinished when I sent the gun to PK. When I ordered the kit, I did order an extra ejector and I have had to "straighten" the original slightly a couple times. Edited January 23, 2023 by Uncle Dudley Add pictures Link to comment Share on other sites More sharing options...
mbc230 Posted January 23, 2023 Report Share Posted January 23, 2023 5 minutes ago, Uncle Dudley said: I had Merle make the modifications for the barrel groove, actuator/knob and magazine followers on my kit. Originally it scraped the finish on top of the reciever and that was repaired and refinished when I sent the gun to PK. When I ordered the kit, I did order an extra ejector and I have had to "straighten" the original slightly a couple times. Great Video and wonderful example of how to assemble the TSMG with the Merle 22 Kit as I have never done one before, but now I have instruction on how too. I have the kit that has the plastic container and not the wood container. Is that the kit that will have problems with the ejector from what I read? Thank you. Link to comment Share on other sites More sharing options...
Uncle Dudley Posted January 23, 2023 Report Share Posted January 23, 2023 (edited) 51 minutes ago, mbc230 said: Great Video and wonderful example of how to assemble the TSMG with the Merle 22 Kit as I have never done one before, but now I have instruction on how too. I have the kit that has the plastic container and not the wood container. Is that the kit that will have problems with the ejector from what I read? Thank you. If the barrel is modified, it will have a shallow groove milled into it so there is clearance to slide it by the 45 ejector in the reciever. Originally, without the groove, you would have to remove the 45 ejector. Also check the clearance of the 22 actuator knob between the knob and reciever top. If the actuator/bolt has not been modified it will rub on the top of the reciever. TD's pictures show the modified bolt/actuator and the barrel groove very clearly. Edited January 23, 2023 by Uncle Dudley Link to comment Share on other sites More sharing options...
PK. Posted January 23, 2023 Report Share Posted January 23, 2023 bradhe Please email me, i can help with the barrel groove. p dash k at q dot com Link to comment Share on other sites More sharing options...
First Sergeant Posted January 24, 2023 Report Share Posted January 24, 2023 (edited) Rabbit57, Honestly I can't remember (CRS) where the shorter spring came from. It may have evolved from a conversation with Merle and I modified an original spring. I am away from the location of the kit but will try to get a measurement on it for you. If I recall Merle thought a 10 1/2" spring worked best, which I believe is the shorter one supplied with the kit. Edited January 24, 2023 by First Sergeant Link to comment Share on other sites More sharing options...
Varminter Posted January 24, 2023 Report Share Posted January 24, 2023 Are any of these kits available or has anyone tried the Ceiner kit? http://www.22lrconversions.com/tsmgk-pg.htm Am I hopelessly out of date? And this may be a silly question, if I have an NFA M1, are there legal repercussions with adding/or making this mod? Link to comment Share on other sites More sharing options...
Grasshopper Posted January 25, 2023 Report Share Posted January 25, 2023 (edited) Hi Varminter, Kits of both flavors are to my knowledge available only on the used market. JAC has retired and is no long making kits. The kits that Merle made were essentially copies of JAC's kit with a 4140 plate on the bottom of the bolt carrier and a solid aluminum body above the plate (JAC had lightened his carrier to utilize an unmodified recoil spring). The biggest difference was the cyclic rate. JAC's kit was likely North of 900 RPM while Merle's was, if tuned well, down around 675. You can use the kits in the M1. I use mine most of the time in an M1. I did find it necessary to change the M1 cocking piece design as (like the early Merle kits) would allow the cocking piece to tilt in the bolt carrier causing the bolt to bind-up (and stopping) the gun. I made a cocking piece that goes completely through the bolt and the recoil spring locks the part into the bolt carrier. The bolt was also modified with a through hole. I did send some of these to Merle but was not sure if he ever did much with them. Some odd things with the kits: The recoil spring hole location in the M1 bolt is not the same as the hole location on the 1928 bolt. JAC's kits were designed to fit the M1 bolt IIRC. I'm not sure if Merle did for the hole location. Kinda worked in both guns. I made a custom offset guide rod to use the kits in the 28. That took care of the alignment. Might not have been necessary but I love to tinker. To the OP. There were some fitting issues on Merle's kits. This seems to be more true with the earlier kits. Merle faced off many bolt carriers to get the bolt to move to battery and to get the hammer timing correct. The kits appear to be hand fit from the parts Merle had to make it work. I checked a NIB Merle kit and it did come with 2 different spring lengths. Enjoy, Grasshopper Edited January 25, 2023 by Grasshopper Link to comment Share on other sites More sharing options...
Varminter Posted January 25, 2023 Report Share Posted January 25, 2023 Thank you Grasshopper. I'll keep my eyes open for one. Like you, if I need to tinker with it, that's fine. Niche market for sure. Link to comment Share on other sites More sharing options...
mbc230 Posted January 26, 2023 Report Share Posted January 26, 2023 On 1/23/2023 at 9:35 AM, Uncle Dudley said: If the barrel is modified, it will have a shallow groove milled into it so there is clearance to slide it by the 45 ejector in the reciever. Originally, without the groove, you would have to remove the 45 ejector. Also check the clearance of the 22 actuator knob between the knob and reciever top. If the actuator/bolt has not been modified it will rub on the top of the reciever. TD's pictures show the modified bolt/actuator and the barrel groove very clearly. Thank you, Uncle Dudley. I now know my kit is not modified based on the pictures TD posted. Do you or anyone else know who can modify my kit to work as expected. I do not want to remove the ejector to use. Thank you all. Link to comment Share on other sites More sharing options...
pstidan Posted January 26, 2023 Report Share Posted January 26, 2023 Can anyone post a picture of the bolt with what machining is needed to permanently attack the charging handle. This is for a 1928/1928A1. Link to comment Share on other sites More sharing options...
Grasshopper Posted February 8, 2023 Report Share Posted February 8, 2023 Hi pstidan, The bolt with the cocking knob shown above is the later design with the improved charging handle. In the photo from T.D. it looks like it is attached to the bolt but it is sitting in a recess machined about 1/8" deep by 1.5" long into the top of the bolt. If you look at Uncle Dudly's kit in the black delrin box you can see the cocking piece is a slightly different color from the anodized aluminum bolt. It is the extended length of the charging handle weldment (it is a part welded together and machined) that makes it stable in the bolt. I'd not like to try to make that part as it looks difficult. Enjoy, Grasshopper ps. Wish someone would make some quality extractors so I don't have to make them I've worn all my extractors out. Link to comment Share on other sites More sharing options...
Roland the Thompsongunner Posted February 9, 2023 Report Share Posted February 9, 2023 I stopped using my kit for that exact reason my extractor is beat up and Merle would it make or sell a spare back when I bought it Link to comment Share on other sites More sharing options...
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