40MM casing and projectiles using 45cal

By GROG   Copyright 2010 3LC Productions


 This review will be for Scot Pace’s latest creation, the 40MM reloadable casing that uses 45cal casings for a high pressure chamber. These casings also use copper discs to close and cover the vent hole. The casings are high quality, made to last for hundreds of reloadings. Scot provided a number of these casings for my torture testing. He also provided a number of payload containers made of bright orange plastic. These can also be reloaded as long as you don’t use any burst cluster mixtures. The casing is nicely anodized black, with engraved company and casing info on the base.


The base of the casing uses threads to attach to the sidewalls. The base is 0.980” tall with 0.400” of threads. The venthole itself is 0.325”. The base is standard 40MM, same as M118 casing OD 1.710” with a rim thickness of 0.075”. The base has three holes drilled into the sides for a pin wrench to tighten it into the sidewall. Here is a top down view of the base:


The sidewall portion of the casing is 4.490” tall. It is 0.110” thick around the payload section and 0.125” thick around the base where the base threads in. It has a flat knurl in two positions on the side so you can grip it while using the pin wrench to tighten the sidewall to the base. Here is a view of the side of the casing:


With the base attached, the casing measures 4.90” tall and there is no problems with inserting the casing into an M203 barrel, or an M79 barrel. Notice, the casing is lathed to fit the rifling of the 40MM weapons systems. The thicker portion of the sidewall with the base attached is 1.80” tall.


Reloading the casing:

   First, knock the 45 casing out of the base using a simple punch. Knock the expended primer out of the 45 casing. Scot makes tools to do this if you don’t have them. Just ask him. Use a primer pocket cleaner to clean out the residue from the primer pocket. This is a very important step, as if you let the residue build, you might suffer from misfires. The primer needs to be seated well and flat. Replace the fired primer with a large pistol primer 2 ½ Remington are the brand I use.

I then load the 45 casing with 10 +/- grains of Bullseye pistol powder. I use a ¼” thick foam wad on top of the powder to hold the powder in place. It is not needed, but I like something on top of the powder when I turn the casings around and such… I place a .010” copper burst disc inside the 40MM base, then place the 45cal loaded blank into the base, seating it flush in the base. You can then load whatever payload you desire into the casing. If you are going to store the loaded round for any length of time, I recommend using nitrocellulose lacquer to seal the primer, and the 45 cal casing into the base. I also recommend using a bit of RTV sealant around the copper burst disc top before you place the base into the sidewall portion of the casing.

Copper burst discs:


It should be noted here that Scot also makes a different 40MM casing that uses 45 cal casings that have small ventholes. These were developed a while ago, and are also a good performing casing.




The first projectile I tested with this casing was a finned one provided by Scot:

Here is a close up of the base that threads into the payload portion of the projectile:

Notice there is a pre-drilled hole in the center for fused payloads. Never use flash type powders as payloads in these projectiles! The life you save might be your own… Here is the body:

The payload interior is 3.5” deep and has an ID of 1.070”. With the tail attached the projectile is 4.750” long. It will hold quite a lot of smoke mix. I recommend drilling at least two ¼” opposing holes in the base, just above where the fins thread into the top, and cover them from the inside with masking tape or similar. This will allow your smoke to escape from the projectile without popping the tail off and ruining your round.


When loaded, the projectiles fit very nicely into the casings:

The projectile will not fall out of the casing when put in with no sealant. I recommend using a small bit of RTV around the portion of the projectile that will sit at the top of the casing. This will help seal the round against moisture and keep the projectile seated in the casing.


I conducted two tests of this particular projectile. The first was an inert projectile test, to check how it flew. I loaded the payload section with chalk, sealed the fuse hole and using 10 grains of Bullseye and a 0.010 copper wad. When fired, the projectile flew relatively straight, with a slight wobble in flight. With the launcher angled approx 30 degrees the projectile flew around 100 yards. The projectile was recovered for re-use. There was no appreciable damage to the projectile from launch or impact, so it can be used again.




The second projectile I tested with this casing was a pill bottle payload type projectile. This projectile would serve very well in testing your casings and loads for range with different weights. It would also make a very nice less-lethal baton impact munition. You can set and test your own weight and power, not to mention training with the actual round you will use in real life. Here are a few photos of this projectile:


The projectile has three gas checks lathed into the base to help sealing the projectile into the casing and to help with range. The top of the projectile screws off to allow you to load items of various weights into the projectile to test range/weight ratios. As the projectile does not engage the rifling of the barrel, it does not fly straight. It tumbles in flight, which can negatively affect range. During testing, the projectile flew end over end, but still had pretty good range.


The payload area of the projectile is 2.110” deep and 1.180” ID. The sidewall of the projectile is .090 thick. It is 2.245” tall (without the nose attached) and the base is 0.100 thick with a interior rim that adds stability to the area where the gas checks are lathed.

Looking down the inside of the projectile:


The top of the projectile is rounded, with a knurled portion for helping screwing/un-screwing it into the projectile body. It is 0.860” tall and 1.360” OD.


I loaded two of these weighted with steel washers to a weight of 95g. Using 10 grains of Bullseye, both thumped out to 150 yards. Not bad for 10 grains… The projectiles sealed well in the casings and flew as expected. (end over end) Both were recovered for later re-use. Neither were damaged on launch or impact, so they can be used again. There was a bit of copper embedded in the bases, but this was easily removed with a pair of pliers.




The third projectile is actually a very large shotgun wad type projectile. You can load a number of projectiles in the wads. Rubber balls, wooden balls, rubber and wooden batons, for less lethal, and flechettes and shot for lethal loadings. I do not recommend using them loaded with lead shot, as this would over weigh the projectile, which may result in pressure issues.


The wads are 2.35” tall, and have an OD of 1.360” and an ID of 1.300” and payload area 1.565” deep. The base of the wad is 0.335” thick so you can really ramp up the power with these wads! These can be used in many applications. Also, muzzle blast rounds may be loaded using these wads by covering the side vents with masking tape, filling the interior with your choice of CS or OC powder and capping with either a paper or foam wad. When loading, I recommend cutting the wad just above each side vent. This will allow the side vents to open and the payload to be released. If they are not cut, the payload will tend to remain in the wad.


Once fired, the wads tend to deform and open so re-use is improbable but possible. If loaded with a higher grain load, the base of the wad will deform, compressing to transfer the force to your payload. Once compressed, the base will not return to its original condition making reloading impossible.




This casing would work very well for law enforcement/corrections and the basic reloader. The projectiles above can be loaded with a number of less lethal items, and the casings themselves can be loaded with rubber batons wooden batons and such. The best part about these casings is that YOU the owner can determine the loading you use. YOU can practice with the exact same projectile you will use on duty. YOU can set the weight of the projectile and the amount of power it is loaded with. Another good thing about these casings is that they are built to last. You don’t have to worry about buying more and more, and practicing less and less due to low budgets. You buy one set of casings, and projectiles, and the only thing you replace is the powder, copper burst discs, primers, and payloads. These casings use smokeless powder so there is no need to constantly clean launchers and casings after each and every practice session. Run a brush through the barrel, a primer pocket cleaner through the casing, and you are ready to go.


With the large 45 cal high pressure chamber, these are nice powerful casings that can be used in a number of LE/Corrections applications. They are super easy to reload with a minimum of materials. With the wads, the types of payloads are limitless. From flechettes with OC powder, to rubber buckshot… Only your imagination limits you. After only a few practice and sighting in sessions, these casings will pay for themselves. They are good for hundreds of reloadings. If the 45 casing starts to go bad, it can simply be replaced. The sidewalls are thick enough to handle some heavy projectiles, and more powerful lift charges without deforming like thinner sidewalls can.






Copyright 2012

 3LC Productions