PRODUCT NEWS

AUTO-DEPTH BREECH ENTRY CHAMFERING CUTTER $185

This device is a must for those making a quantity of Thompson receivers. The depth of cut is automatically limited by presetting the built-in stop so that chamfer after chamfer is duplicated precisely. The cutter is driven by the hex shaft through the receiver pilot hole by a milling machine, drill press or even a hand drill motor. This is a limited production item for the serious manufacturer.

I realize that some of the cutters used to make Thompson receivers are not readily available. Therefore, if need be, I can supply the cutters listed below. I don't want to get into the cutter business, but I want to help where I can. Cutters 1) through 4) are T-Slot cutters which are similar to keyway cutters but these have the extra long shanks that are hard to find. Finding staggered teeth and being made of M42 and at a reasonable price is another problem.

I will make no attempt to provide cutters that are commonly available from most any machine tool distributor.
Cutters may require special modification to be suitable for the Thompson manufacturing application as described such as reducing the neck diameter or radiusing the corners.

It is not my intention to specially stock these cutters for sale but I generally have them as backups to cutters I have in use.

I also do not have the time to teach basic machine shop practices. I’m trying to help people who know what they are doing and what they need. There are many ways of machining the same part. The choice of cutters is based on the machine available and the machining procedure selected.

All of these cutters can be used in the finishing of the bolt cavity in order to make a working gun from a semi-finished receiver. A person can make a semi-auto gun by himself and for himself without any license but one can not make a machine gun without a license.

1) 1/8"W x 1"D x 5/8"D Shank x 4-15/16"L x 8 Staggered Teeth, M42 Cobalt, T-Slot Cutter. $97 This cutter is used to cut the lock ramps on 1921/8 receivers.

2) 1/4"W x 1"D x 5/8"D Shank x 4-15/16"L x 8 Staggered Teeth, M42 Cobalt, T-Slot Cutter. $89 This cutter is used to cut the lock slots on 1921/8 receivers and the 1921/8 bolt cavity roof when used on machines with computer controlled interpolation.

3) 1/2"W x 1"D x 5/8"D Shank x 4-15/16"L x 8 Staggered Teeth, M42 Cobalt, T-Slot Cutter. $89 This cutter is used for relieving the bolt cavity sides of 192M and 192S receivers.

4) 1/4"W x 1-1/2"D x 1"D Shank x 4-15/16"L x 8 Staggered Teeth, M43 Cobalt, T-Slot Cutter. $107 This cutter is used to form the roof of 1921/8 receiver bolt cavities on machines without computer controlled interpolation. I usually do not have this cutter in stock as I seldom use manual machines for this operation but I can get them along with my special cutter orders.

5) 5/16"D x 4 Flute x 1-3/8" Flute Length x 40 Degree, Carbide, TIN Coated, Single End Mill. $65 This cutter is used to finish profile the bolt cavity walls on all receivers

192M(21/8) Receiver

My original 192M receiver was designed to satisfy the needs of the movie industry, shooting galleries and Class II manufacturers. They wanted a gun that looked like a 1921/8 TSMG but used an M1 or M1A1 bolt (with top mounted bolt handle) to provide simple slam fire operation especially with blanks and be easy to make operational because it did not require the lock ramps to be cut. I will continue to offer that receiver but I now call it the model 192M(M1).

Now that I offer the option of cutting the lock ramps on my 1921/8 receivers, those with Class II licenses can easily finish a standard 1921/8 receiver and so their interest in the 192M(M1) has diminished. However, it has been suggested that since the oiler has questionable value with many shooters not having one in their gun, I combine the front end of a 1921/8 receiver with the back end of a 192M receiver. The advantage is that the 192M is a stronger receiver and the large pocket in the back end of a 1921/8 receiver, which is only necessary to enable the fitting of the oiler, would not have to be cut.

I thought that was a really good idea but I took the idea one step farther. By making the 1921/8 pilot hole the same size as an M1, an M1 pilot with a shortened spring end could be used with one of my urethane buffers. That would eliminate the 1921 or 1928 pilot and (non-buffering) buffer. By being able to install the pilot and recoil spring through the back end of the receiver as is the case with the M1 gun, the 1928 recoil spring would be better controlled with less likelihood of kinking and the difficulty of installing the 1928 pilot and recoil spring would be eliminated. Of course that was never a problem with the 1921 but even the 1921 recoil spring would be easier to install.

The 1921 setup would be the same as the 1928 but would require an adaptor bushing fitted to the modified M1 pilot. In my opinion, this arrangement would improve the 1921 and 1928 guns. This new configuration receiver will be known as the 192M(21/8). It will be identical to the old 192M except that the pilot hole will be in the 1921/8 position To make sure I have not confused anyone, the 192M(M1) will have still have the pilot hole sized and positioned like an M1 in order to work with M1 and M1A1 bolts; the 192M(21/8) will have the pilot hole sized like an M1 but it will be in the 1921/8 position in order to work with 1921 and 1928 bolt/actuators.

Both receivers will be offered only in the "Shop" configuration. Lock Ramps & Bevels will be offered on the 192M(21/8) as an option. I will also offer the 192M(21/8) Pilot, Urethane Buffer and 1921 Recoil Spring To 1928 Pilot Adaptor Bushing to make finishing the gun as easy as possible.

For those who want to build a semi-auto gun, I offer my newly redesigned 192S and MS (“Shop™”) receivers which rely on the Numrich/Kahr (N/K) gun design approval. (There is no approved design that allows a TSMG receiver to be made into a semi-auto.) These receivers are 1/10” less high than a TSMG receiver and are interchangeable with the corresponding (N/K) 1927 and M1 semi-auto receivers except that the firing pin clearance groove in the top of the N/K trigger housing must be extended rearward. This is because my 192S and MS receivers are meant to have a bolt cavity that extends all the way to the back of the receiver like a TSMG. (This has nothing to do with the gun being semi-auto or full auto.) This is done in order to use the extra bolt travel to absorb the recoil rather than depend on ultra stiff recoil springs to do it. This requires the recoil springs holes in the bolt to be deepened to enable the use of longer pilots which are necessary to retain the recoil springs. To accommodate the extra travel and to eliminate the problem on N/K guns of the bolt handle being able to twist and jam when it reaches the hole at the end of the bolt handle slot, the bolt handle slot is also extended rearward. This does prevent the bullet logo from being engraved on the top of the 192S receiver. These receivers require a modified N/K bolt assembly, special springs (3) and a special Recoil Springs Pilots & Plate. A standard M1 TSMG pilot is used as the firing pin spring pilot. My 2S and MS bolt handles are recommended. The 192S and MS receivers also differ from their N/K counterparts in that they are made from the same steel used in my TSMG receivers, the rear sight is properly positioned and the quality is much better.

These discs are exactly like the originals which sometimes go missing from 1921 buffer housings. The collar on the pilot should be about 1/16" from the back end of the buffer for proper operation. The discs are about 1/8" thick but the originals varied so it becomes almost a custom fit. Theoretically, a 1921 buffer housing is fitted with 9 fiber discs. The hole in the center of the discs is to relieve air pressure but can also be used to remove the discs by screwing a wood screw into the hole and pulling the discs out one at a time. The original discs were made of red fiber rod. I still have a small supply of that material but when that's gone we are in trouble because red fiber is no longer made in the U.S. and I can't find anyone who is bringing it in from China or Japan. If anyone knows a source for red fiber rod, please tell me.

March 10: 2007

I have been re-engineering all my pilots and buffers. The photo below is of the new M1 Quick Detachable Sling Pilot. It replaces the standard M1 pilot. It has a special end on it that accepts a detachable sling swivel. The purpose is to enable an over the top sling to be fitted to the gun or a sling fitted when there is no buttstock being used. The other end of the sling can be attached to the horizontal forearm using a Quick Detachable Sling Swivel Base that replaces the standard sling swivel or a Quick Detachable Sling Barrel Band can be fitted on the barrel. I will be offering sling pilots that replace my Pilots For Urethane Buffers and semi-auto pilots.

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(counter reset December 22, 2006