Merles New Cocking Knob

[just4grins]

I finished modifying my BDM .22 lr conversion kit to fit Merle's new cocking knob. Smoother action, eliminates wearing of bluing. I installed my own - he will do it for you if desired. Runs really well, and the knob looks more like the original than the one in the kit. Worthwhile mod to make if you plan to use the kit a lot, especially if you are fond of the finish on your Thompson.

 

 

http://i580.photobucket.com/albums/ss248/just4grins1/Cockingknobmods1A.jpg http://i580.photobucket.com/albums/ss248/just4grins1/Cockingknobmods5A.jpg

http://i580.photobucket.com/albums/ss248/just4grins1/Cockingknobmods8A.jpg http://i580.photobucket.com/albums/ss248/just4grins1/Cockingknobmods11.jpghttp://i580.photobucket.com/albums/ss248/just4grins1/Cockingknobmods14A.jpg

http://i580.photobucket.com/albums/ss248/just4grins1/Cockingknobmods16A.jpg

Edited August 28, 2010 by just4grins

[darrylta]

Very nice work!!!!

-Darryl

[just4grins]

Very nice work!!!!

-Darryl

Thanks! It was fun to do, and I really like the result.

[First Sergeant]

just4grins,

 

That is some fine machining work there ! I don't have the tools or the skill for that.

 

Glad to see people jumping on his newer bolt design. He had several at TATA. It is a major improvement that will, as mentioned, prevent the wearing of the bluing on top of the reciever's cocking slot and looks so much better. Mine is actually knurled.

 

Merle "designed" that over the phone in about 20 seconds while I was explaining the bluing wear I was experiancing on a WH and a 1928A1. Within in 2 hours Merle called me back advising he had made one up and it worked prefect in his gun. He sent me the prototype to try. Worked perfectly. It was very tough keeping that secret but I had to pass on the potential damage. Not sure all the kits do it, but it's something to be aware of.

 

Mine runs perfect with all lengths of springs and in particular the light spring. It gives that slow methodical cyclic rate. That spring lives in the gun now. Enjoy it, they are a blast!! Chuck

 

 

 

 

[OldFalGuy]

The kit knob definitely rubbed mine real bad-

 

I do not have the tools either- Does the bolt itself have to be modded or just the knob?

 

It looked like the base just needed to be thinned a tiny bit.

 

Mark

[just4grins]

The kit knob definitely rubbed mine real bad-

 

I do not have the tools either- Does the bolt itself have to be modded or just the knob?

 

It looked like the base just needed to be thinned a tiny bit.

 

Mark

The knob is actually a new piece that replaces the one in the kit. A 5/8 wide slot has to be milled in the bolt, approx. 1/8" deep, sized for a close fit to the new knob, and a small flat has to be milled on the cylindrical part of the bolt (the part that gets pinned in place). A mill is required. Merle charges $50.00 for the part alone if you wish to install it yourself, or $75.00 for the part plus installation ($25.00 for the machining). Having done the machining myself, Merle's price for the machining is, in my opinion, very reasonable.

Edited August 31, 2010 by just4grins

[OldFalGuy]

Just sent my knob and bolt to Merle this morning and I intend to find a couple of stock 28 recoil springs somewhere

to cut down for the kit- like to slow it down a bit.

[First Sergeant]

Definitely dexperiment withthe spring length. Merle told me the best seems to be right at 9 1/4". I'd adjust yours until it feels right for you or sacrafice a sping until it won't run then cut another and then stop at the last lenth it ran good on. I have a 9" inch spring that runs and another longer one that runs too fast for me. If you can get the light spring to run (no cutting) the rate of fire is in my opinion just perfect. Good luck. Chuck

[just4grins]

I used the stock spring cut down to 9 1/4" per Merle's recommendation. Runs great, and likes the Walmart Federal Bulk pack the best. Pretty cool that it runs the best on the cheapest ammunition. One caution: Stay away from the Remington Golden Bullets (also sold at Walmart). It will jam the gun, and I know of 2 people (including myself) who have had it go off out of battery. In my case it damaged the extractor, which I replaced (BDM sent me a free replacement part). If you stay with the right ammunition (which seems to be almost anything except the Remington ammo) the kit is a gem. I shouldn't have tried the Remington anyway - doesn't run well in any of my semi-autos either.

[Bob]

That new cocking knob is made the way it should have been from the start.

I gave up on my BDM kit because of several problems, one being the cocking knob poping off when cocked and always having to dick around with it to get it to run.

 

Went back to .45 for reliable shooting in the Thompsons and stick with the m16 in .22 when I want to shoot on the cheap.

[OldFalGuy]

Thanks for the heads up on the Remington-

 

I bought a bunch of CCI MM, Federal bulk and a Remington-

 

CCI ran pretty well but I did have an out of battery with...something- man, that was load

 

I will obtain and cut a spring to 9 1/2 or so to start then fall back to the 9 1/4 as ya'll suggest.

 

Bob, I agree with you about that knob being easy to pop out and lose in the grass.

Hopefully this modification will be more like the 45 Thompsons cocking setup.

I like all sorts of 22 conversions HK, FN FAL, AR etc, but the Ar is one of my favorites for over 30 years-

With Black Dogs new drums its a joy loading and shooting them.

Really look forward to getting my Puma drums running right in the Thompson- They look at home with it.