SPECIAL THOMPSON CUTTERS
Most of the cutters used to manufacture a Thompson Receiver are available as standards even though some searching for a source might be necessary. If only one or two Receivers are to be made, there can be a lot of “make do” selecting. But even so, there are a few that are a “must have” and some more that are in the “nice to have” category. Regardless, the Thompson Receiver is difficult to make, especially when the quantity is small. Complicated set-ups and/or expensive fixtures are required along with custom gages. Richardson does offer a selection of custom made and hard to find cutters as shown below. Only cutters 2) and 3) are required to finish Ultimax Receivers. Semi-finished Receivers offered by others may require additional cutters.
1) RAMP SLOT CUTTER $195
Long neck T-Slot Cutter, 1/8" wide x 1" diameter x 5/8" shank, 8 staggered teeth, 8% M42 cobalt steel, ALTiN coated. This custom made cutter is for making the 45 degree lock ramps
2) SIDE SLOT CUTTER $195
Long neck T-Slot Cutter, 1/4" wide x 1" diameter x .031" bottom corner radius x 5/8" shank, 8 staggered teeth, 8% M42 cobalt steel, ALTiN coated. This custom made cutter is for making the horizontal lock tracks amd front undercut on 1921/1928 Receivers & the side slots on 1921/1928/2M2/2MM/2S Receivers.
3) BOLT CHANNEL SIDES END MILL $95
Single end mill, 1/2"D x 4 (1-3/8"Long) flutes, center cutting flutes x 40 degree helix x .031" bottom corner radius x 3-1/2" L, micrograin carbide, ALTiN coated. This custom made cutter is designed for finishing the bolt channel sides of all Receivers. The minimum cutting length design makes this cutter very stiff which is needed for the long length of cut required.
4) BOLT CHANNEL CORNER END MILL $65
Single end mill, 5/16"D x 5 (1-3/8"L) center cutting flutes x 40 degree helix x 3-1/2" Long, micrograin carbide, ALTiN coated. This custom made cutter is designed for forming the rear corners of M1/M1A1 receiver bolt channels and the front corners of all Receivers. The 5-flute design makes this cutter very stiff which is needed for the long length of cut required. A 4-flute or smaller diameter cutter would tend to deflect in the cut resulting in a tapering receiver side wall.
5) RIVET HOLE CUTTER $15
Combined drill & countersink sized to drill the rear sight rivet holes and countersink the holes to fit the Thompson rivet heads. Single end, 5/16" shank diameter x 3" long. HSS. This custom made cutter can be used in drill chucks whereas the more common double ended style does not work well in drill chucks.
6) EJECTOR HOLE TAP (No longer available)
This is a 2-flute machine plug tap custom made to the exact original Thompson “National Thread Form” specifications for the ejector hole threads. It is also suited for all the other Thompson .242" diameter bolt threads.
7) BREECH ENTRY COUNTERSINK $75
This is a custom made, piloted, HSS, 50 degree included angle countersink designed to be driven by an arbor through the receiver pilot hole. This cutter is used to form the cone at the front end of the bolt channel on all Receivers which guides the bolt shank into the breech.
The above UNIVERSAL BARREL WRENCH is no longer available. The REPLACEMENT JAW ASSEMBLY is available.
The STANDARD FRONT SIGHT PULLER shown below is no longer available.
COMPENSATOR TAP & DIE SET
The Thompson uses the old National thread form which is no longer available. I was offering American custom made to the original National specifications taps. I can not do that any longer. Since these taps and dies are vital to refitting used compensators, I have selected the best foreign Unified thread form taps and dies I can find to offer my customers. It is not the perfect solution but it is the most practical. Note that the die is for repairing barrel threads only. It is not suitable for threading and unthreaded barrel. Tap is $52. Die is $39. or $85 for the Set.
FLOATING REAMER HOLDER
This tool is primarily used in the manufacture of barrels. It provides a #2 Morse taper floating chuck for the chambering reamer to eliminate any side forces that would prevent the reamer from centering itself in the bore. The holder is new in fitted wood box with papers. SMP (Rohm) model 122. Cost $2000. Sell for $1400.
There is an article about my barreling tools in this Issue.