40MM CANNON PI
By GROG Copyright 2016 3LC Productions
Scot Pace at Reloadableshells.com has improved on the design of the 40MM CANNON base by adding a stainless steel high pressure chamber. This, the latest and most likely the last version of this reloadable round has a powder chamber capable of holding 20-23 grains of Bullseye Pistol Powder. This power, added to the reliability of the system makes the 40mm CANNON the best reloadable 40mm casing on the market, hands down. The design is lightweight, strong, and capable of being reloaded a multitude of times. Scot uses the best materials and has spent much of his time and effort in bringing this reloadable munition to the 40mm community. Since this munition came out, I only use these in my own weapons systems, and have loaded up several for my own use in personal protection. I would never bet my life on crap, nor would I recommend something if I myself did not personally believe in the product. Since I had a hand in the design, and improvements, I know of what I speak.
The recoil of the new CANNON round is substantial when loaded to full capacity. One thing that makes this reloadable munition stand out from all others is the capability of changing bases, thereby changing power if the need arises. For a LE or Corrections department, you could have several barrel portions loaded with different payloads, ready for use at one time. You could use basically three loadings in bases, low, medium, and high, and decide at the time of need, which to use. Say you had the ability to choose from rubber baton, rubber stingball, OC powder muzzle blast dispersion, CS, door breaching, wooden baton, frangible buckshot, lead buckshot, steel flechette… then you had the ability to tailor the loadings to achieve the desired effect right there, at the incident. Grab a pre-loaded barrel, screw on the power you desire, and let loose. This as opposed to staring at a bag full of costly, one shot and done, different rounds, loaded with what the factory thinks fits all situations… Personally, I’d choose the round that gives you “on the fly” options. I’d also choose the munition that allows you to train as you fight. With the exact payloads, loaded to the exact specifications YOU need for the situations that YOU are going to deal with. Responding to a prison riot in a large open area with multiple bad guys? Rubber buck, medium power base, and you are ready to go. Responding to a single cell with one or two bad guys in an enclosed space? Rubber baton with low power base. Being attacked by North Koreans or zombies? Steel flechettes with a high power base. With these rounds, you have OPTIONS that YOU control.
Are these rounds more expensive than other 40mm ammo? Up front, yes, they are. BUT… factor in the number of times you will reload them, for the cost of the payload (which YOU choose and can buy cheaply), the cost of a primer, and 5-23 grains of Bullseye per round… and things turn around pretty quickly. Imagine having to buy a brand new $35-50+ round for every possible occasion or use. Now add to that the cost of buying “training” ammunition that is loaded the same as your duty ammo. For the minor costs outlined above, and a little time in cleaning and reloading, you can have so much more. Once you fire one, these munitions sell themselves.
Case in point. My local Sheriff qualifies retired LEOs in our area for the 50 state LE concealed carry. During one of these qualifications, I brought my LMT 40mm and a few CANNON rounds loaded with high power bases and flechettes. I let him fire a few, and after looking at the range targets, decided not only to invest in the munitions, but buy his department 40mm launchers to fire them. This from one range session with a couple rounds fired.
Anyone with experience in the 40mm field will appreciate and fall in love with this round. It makes your launcher not only a signal device, or a thing for launching explosive grenades, but a truly versatile weapons system.
Reloading the CANNON bases is a very simple thing. You will need a few tools, a reloading powder scale, and burst discs, and some sealant if you wish to store your rounds long term or in wet conditions. Reloading the base consists of the following steps:
1. Remove the base from the barrel section by unscrewing.
2. Remove the vent plug from the top of the base.
3. Remove the expended copper burst disc and discard.
4. Knock out the expended primer.
5. If desired, you can use Hoppes #9 and a q-tip to remove any fouling from the stainless high pressure chamber, the vent plug, and the primer pocket. I usually do this after every 5 or so firings, but I fire mine a lot and do not store them.
6. Replace the primer with a Remington #2 small pistol primer or similar soft primer. Do not use magnum primers.
7. Measure out your powder charge. 3-7 grains is a low power loading used for baton, rubber buck, or similar less lethal munitions. Experiment to get the results YOU want. 7-15 grains, medium power, 15-23 grains high power.
8. Replace the copper burst disc.
9. Screw on the vent plug. I usually use a wrench or socket and only tighten it until it stops. No need to torque it like a car lug nut… The harder you tighten it, the harder it will be to remove…
10. Reload and replace your barrel, done.
Loading the CANNON with flechette darts:
First, choose your carrier (wad). Make sure the wad extends to the top of the darts. I recommend covering the side slits with tape, to keep darts from popping out and scratching your barrel. These are string wrapped so no worries. I wrap the darts around a small wooden dowel, centered as in the photo below.
Ready to load 4 barrel sections:
In the below photo, you can see the PI bases, flechette roll, and black foam top wads. I cut them using a gasket cutter set to tightly hold the darts in place. Seat the carrier to the base of the barrel, then insert a foam wad, to the top of the carrier.
In the photo below, you can see the interior of the 40MM CANNON PI base. The stainless steel high pressure chamber holds the primer, and a slightly smaller vent plug than the original design. This is to restrict the amount of powder one can place in the base. The interior of the high pressure chamber has a rounded base, to direct the power toward the ventholes. The burst plate that goes between the powder and ventholes can be either purchased from Scot, or made using a punch and either copper or brass sheet metal, .015” thick. Variations in pressure can result from changing metals, so start testing low (3 grains) and work your loads up from there.
I can do all the above steps in a few minutes a round. There is no resizing like in brass reloading. The components do not expand when fired, so there is no stress on the barrel of your launcher. There is recoil, so be careful if using high power loads in rail mounted M203 style launcher systems.
Maintaining the CANNON rounds is also simple. Cleaning the barrel portion can be accomplished with a 10ga or similar shotgun brush, mop, and patches. Don’t use steel brushes as they will scratch the surface treatment on the interior of the barrel portion.
If you decide to store your loaded CANNON munition, I recommend you seal them as in the diagram below:
I was provided with several of the new CANNON rounds for testing, and loaded them with various loadings of buckshot, flechette, and shot. Using 20-23 grain Bullseye loads, I was able to fire the casings provided more than 5 times each with the 20+ grain loadings. No adverse pressure problems were viewed with the casings. They were measured after each firing, to check for pressure problems, and the primers were checked, and no adverse observations were made. The CANNON PI will serve the reloader very well. It is stronger, safer, and performs better than the first version. If you liked the first version, or were waiting for improvements to be finished, now is the time. These work fantastic!