This breechplug is tapered and flared with a rounded end. Patterned from a Indian Trade Rifle by H.E. Leman this breech plug is designed to fit a 1" octagon barrel with 3/4-16 threads and is ideal for larger calibers up to .62. The tang is just under 2" in length, and has a through hole located for the tang bolt.
Wax cast of malleable 8620 steel, made in the USA, by Track of the Wolf, this strong plug is made to fit your 1" octagon barrel. It is very slightly oversize at top and bottom flat, to allow draw-file polishing to match your barrel. Sides have tapered "draft" to simplify hand inletting.
Threaded for a 3/4-16 breech, the threads are exactly .550" length, single point CNC cut, to fit Colerain or Rice barrels. Getz barrels are .500" depth. Green Mountain barrels are threaded slightly deeper to allow trimming the barrel's breech only, normal gunsmithing practice.
This .550" thread journal length solves many lock placement problems, clearing the vent. Original plug faces were nearly always grooved to clear the drum, vent, or vent liner.
This plug has no thread relief, front or rear. All 8 threads are good. Thus, it is necessary to chamfer the breech end of the barrel, slightly, to allow the turned tang faces to fit the breech end snugly. Failure to chamfer the breech end may cause thread galling, if the plug is ever removed.
Dope all threads with anti-seize (nickel emulsion in grease, or Birchwood Casey's Choke Tube Lube (our #BC-CTL
)) before first trial fitting, to prevent galling the threads.
Adjust the thread length to seat the plug face snugly against the inside shoulder of the thread cavity. Assemble and tighten with a conventional wrench and one hand. No need to over-torque a breech plug.
Measure the number of flats or the fraction of a turn needed to "index" the plug to align with the top flat. For instance, if the error is one flat (1/8 turn) for this plug with 16 threads per inch, then each full turn is 1/16" or .062" per turn. Each octagon flat is 1/8 of .062" or .007" per flat. Approach a perfect fit slowly, testing as you go.
Trim the thread length, and matching breech depth, until the plug aligns to the top flat. When “indexed” to the top flat, match-mark the bottom flat with a sharp chisel mark across the draw-filed smooth joint.