Improved Muzzleloader Ignition Module

I have found a need for anew style of screw-in breech plugs on muzzle loading rifles. In this treatise the Knight model KP1 break open muzzleloader was chosen for installation of a totally new design of breech plug. This rifle, as purchased, already has two breech plug styles. One accepts bare 209 shotgun primers placed into the mouth of the breech plug which are quite loose and are held in place magnetically.

The other style incorporates a full plastic jacket which holds and shrouds a 209 shotgun primer at one end and is inserted into a screw-in breech plug at the other end. This full plastic jacket requires preloading of the shotgun primers to be used in the field. Fired primers are easily extracted after firing with either method. While ignition is very adequate with each of these 209 primer systems, blow-by smoke is considerable and really fouls up the action.

This was a leading cause for making an improved module utilizing cut down .222 Remington cases with small rifle magnum primers. As the pictures will illustrate, making the new style breech plug for the Knight KP1 muzzleloader rifle falls right in as precision gunsmithing work. Tolerances are close, fully equal to the fitting, chambering and headspacing of a rifle barrel. To begin, I noticed there was ample room The two breech plugs shown on the right come from the Knight factory.

On far right is Knight’s full plastic jacket breech plug fitted with a 209 shotgun primer and to its left is the factory breech plug that accepts bare 209 primers. Continuing left is the replacement breech plug incorporating a special cut-down .222 Remington rifle case which is a totally smoke-free ignition module. for a full 3/4-inch hexagonal shaft to fit into the rifle receiver opening, including a short, thin wall socket head wrench.

Thus, a length of 3/4inch stainless hexagonal stock was chosen to make the breech plug. The over-length hexagonal stock part was centered in a three-jaw lathe chuck with two inches extending beyond the jaws. A center drill was used to establish live tail-stock center while turning and threading the piece. The exposed hexagon shaft was turned to 11/16 inch (0.6875") major

042 inch hole. thread diameter and threaded for a length of 0.785 inch with 20 threads per inch. A length of 0.125 inch of the module was free of threads at the tip end where the gas seal is formed. The tip end was then recessed with an 82-degree counter sink to a depth of 0.185 inch and the part was removed from the lathe chuck. The newly-threaded breech plug was screwed into the rifle and carefully marked for length for a flush-fit at the receiver/barrel juncture.

Following this, it was cut and faced to exact length and again tested for fit. For easy access and extraction an annular recess was then formed at the base of the breech plug to a depth of 0.050 inch. The recess was cut to within 0.250 inch of the breech plug border. Drilling The Flash Hole Prior to drilling the smaller flash hole, a larger hole was drilled with a number 2 drill bit from the breech end of the module to within 0.150 inch of the beveled hole.

The remainder of the flash hole was drilled with a 0.042 inch number 58 bit. Final Chambering As previously mentioned, a cut down .222 Remington case was used in the ignition module cut to a total length of 0.750 inch. A special square-faced, end-fluted reamer was used to cut and form the chamber. Care was taken to finish the chamber as headspace is established at A sample ignition module is chambered here formed from a .222 Remington case. the juncture where case mouth and chamber shoulder meet.

Cases were cut to exact length and the ignition module formed a perfect gas seal. Conclusions Where major improvements can be made in shooting it is normally worth the gunsmith’s time and effort to make the modification. This ignition module conversion was a total success, completely eliminating blow-by smoke as it performs outstanding ignition. Accuracy is excellent as well. AG