Casing Review

Aluminum 2 piece 26.5mm Black powder casing with screw off bases

and cardboard tubes, made to fit.

Manufactured by MLR distributing LLC



This review will be on 26.5mm black powder aluminum casings manufactured by Mark Rogers from MLR Distributing LLC. Mark sent me four casings to review, two shorter 4.100” long, and two longer 5.600”. The casings have removable bases that are machined to accept a #209 primer, and approx 40 grains of FFFG black powder or BP Substitute. The bases are milled from solid bar stock, and are 1.100” tall. The top .500” is threaded. The powder chamber is .800” deep, and goes to the top of a seated primer. The bottom is concave to the primer top. The sidewalls are .185” thick to the outside of the threads. The casing sidewalls are .120” thick, which is pretty thick when compared to any other 26.5mm casing I’ve ever seen. The sidewalls are made from extruded aluminum tubing, and the interior of one end is threaded to accept the base.


The fit and finish of the base and tube wall is normal where MLR is concerned. The base is highly polished and machined for years of use. The tube walls are thick, and also made to last years. When the base and sidewalls are screwed together, there is no play or gap in the threads. They screw together tightly.


Mark also provided 6 cardboard tubes with fuses plastic molded in place. There was ¼” of fuse protruding from the base of the tube, secured in place with resin plastic, poured around the fuse, to seal the base of the projectile. There appeared to be at least ¼” of exposed fuse inside the tube, on top of the resin plug.



I prepared 4 of these projectiles by adding two stars to each, two red, and two green, two pairs. One for use in the short two casings, one for use in the tall. I loaded a bit of burst with the stars, and filled the remainder of the tubing with dry paper towel folded and compressed with a punch. I then capped the tube with provided cardboard discs, wood glued into place. These were allowed to set for a day before loading in casings for testing. I used my M203 for this test, with a 40mm to 26.5mm adapter.


I loaded one short casing and one long casing with 40 grains of FFFG BP, and one short and one long casing with 20 grains of FFFG BP. I thought about using the smaller cardboard discs supplied to seal the chamber where the BP sits, then thought it would be better to use no wads or discs between the powder and the fuse. The top of the projectile is flat, and this will seal the BP in position good enough, and the projectile tubes fit tightly into the casing.


I loaded all 4 projectiles into the casings, then went to the range. All 4 fired, all 4 lit, all 4 functioned. The wind was horrible, and blew most far from where they were fired at. The projectiles with the 40 grain lift charge obviously went quite a bit higher. How much higher, I can’t say, because with a projectile moving that fast, and that small… well… you don’t see it until it bursts. What I can tell is, they burst fairly low to the ground, due to the length and type of the fuse used. Time fuse can burn at different rates, some burns 21 sec/ft, some burns 28 sec/ft and there is quick fuse that would have to be coated before pouring resin around it. I’m not sure which was used in this application, but the length used set off the payloads of the 40 grain lift charges at around 50’ altitude, and they were returning to earth when they went off. In order to get a quicker payload detonation, I recommend shortening the fuse a bit before loading your projectile, or MLR could load them with a quicker burning time fuse. When fired, the projectile is moving so fast that you want about ¾ sec before the fire reaches the payload chamber and ignites your main burst charge. This will allow plenty of time for the payload to reach a good altitude before igniting.


The 40 grain lift charge appears to be adequate for the intended signaling use.

Here’s a short video of this test: 26.5mm MLR test video


When I receive casings for review and testing, I mark them as in the above photo, to keep track of loads fired from this particular casing, and performance notes.

Mark Rogers from MLR, the same manufacturer of the “Slam Fire” launcher,  provided me with 4 casings to test and evaluate. Two of them were 5” and two were 3.720” tall. He also provided 4 cardboard tubes, OD 1.230”, ID 1”, and 3” in length, with 8 fused cardboard end plugs, and smaller plugs for the casing bases.


The interior of this casing is ready to be loaded with a powder charge, and projectile.


Using the supplied tubes, I prepared 2 green smoke markers. A diagram of the smoke marker projectile used in this test:


Here is a photograph of the actual smoke markers used, pre hole drilling:


Here is a photo of a fired smoke marker. You can see the holes the smoke escaped from:




Here is a link to the video of the test:  MLR Casing test launch smokes


I loaded one of the short casings with  20 grains of American Pioneer fffg black powder substitute. The other was loaded with 30 grains. Both smoke marker projectiles were then loaded into the casings. The cardboard top cap does not fit into the casing, so it rests on the top of the casing. I used four small dabs of RTV to hold the smoke marker in place in the casing. The rounds were allowed to dry and set for a day before the test. The tubes fit tight enough in the casings that you do not need an interior wad over the black powder. Make sure the fuse is in direct contact with the powder.


Both rounds were fired using Mark’s Slam Fire 37mm launcher. Both rounds functioned perfectly. The 20 grain projectile achieved a range of 100 yards. The 30 grain projectile traveled 125 yards. The green smoke mix ignited shortly after the munition impacted the ground. The smoke marker projectile functioned flawlessly, and contained an impressive amount of smoke. The munitions burned for over a minute each!



One of Mark’s longer casings was loaded with 30 grains of AP fffg black powder substitute, and a muzzle blast munition made from tubes supplied by Mark. It was made by simply cutting one of the cardboard tubes lengthwise ¾ the way from top to bottom with a band saw. I used a wad for the bottom plate and filled the tube with orange OC powder. I prepared my camera by placing a ¼” thick plexiglass shield in front of the camera, and taking the shot directly at the emplaced camera. The round functioned very well, in actuality, knocking the camera off its stand, and stopping the video recording. I then had to prepare another muzzle blast round, and aim slightly above the camera. Here is that recording:

MLR 37mm Muzzle Blast test fire


Mark’s casings are very dependable, and easy to reload. The removable base is a very handy feature for the reloader. It will allow you to use various length sidewalls with a limited number of bases. You can now purchase the exact tube sizes you will need for the payloads YOU want to launch. No more need to buy and modify! These are made to your specs. If you want muzzle blast, order the long sidewalls. Buckshot? Short sidewalls. You want options? Order a couple bases, and a bunch of different length sidewalls! Also, the removable bases allow you to perfectly seal your projectiles FROM THE INSIDE! No more goopy hot glue, or exposed RTV. Seal them from the inside, then screw them to the base. Got some things loaded and want to try something else? No need to fire them off, just unscrew them, and use a different sidewall.


Keep in mind, these are black powder casings, and require cleaning and lube after every use! After firing, remove the old primer, and use hot soapy water and a scrub brush to clean the casings very thoroughly. Give them a light coat of oil before storing them. Check on them from time to time to make sure no residue remains. Although aluminum casings will not rust, they will corrode when left with black powder residue inside them. Always clean your launcher well right after firing any black powder casing, even when using black powder substitutes.


In order to use these casings in a survival situation, I would recommend sealing the primer area with Nitrocellulose lacquer (fingernail polish works well), and using blue locktite or a small dab of silicone on the threaded base to waterproof that area. The top end of your projectile can be dipped in latex paint to provide a good positive waterproofing so your powder does not get damp should you and your ammunition get wet. The casing tubes can be loaded with any common star clusters or pyrotechnic mixture commonly used in distress signaling. With over a minute of smoke generation, it gives you plenty of time to be seen from aircraft or ground search parties.


When it comes to survival situations, these casings, and the Slam Fire launcher, will never break and/or let you down when loaded and stored properly.



From the manufacturer:

- 5 inch complete (base and tube) $16.00


- 3 3/4 inch complete (base and tube) $15.00


- Base only $11.00


- 5 inch Tube only $ 6.00


- 3 3/4 inch Tube only $ 5.00


Dealer pricing available as well as quantity discount upon request. Forum

members will enjoy discount as well, like I always do. I will post for sale

ad with member discounts once review is done.


Yes, tubes and bases available separately. So one can buy as many bases and

tubes as they want and mix and match as they wish.


At this time I am stocking the two sizes (5 and 3 3/4 inch)but have plans to

make in a 2 1/8 inch size that will accommodate a film container very

nicely. Pricing will be forth coming on them.


Custom lengths will be available depending on quantity size. Need minimums

to keep pricing reasonable but they will be discounted as well. You know how

CNC works, it only makes sense if quantities are there to run. When a new

length is made from a custom order I will most likely add them as a stock



Other parts -


- 3 inch cardboard tubes $1.00 each or 12 for $10.


(4 inch are available in small quantizes)


- Plugs for tubes are 25 for $5 or 100 for $15.00.


Please visit Mark’s site here: for ordering, or contact him through our discussion forum.

By GROG   Copyright 2010 3LC Productions