Multi Projectile

18/22 and 12/22 T&E and Review


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       This review is going to be a two part review, first of Scot Pace’s 18/22 multi projectile munitions, then of his rifled barrel 12/22 munition.

Scot provided me with a sample of his new 18/22 multi projectile round. It is a three component round, with a screw off base with a replaceable press fit 45 auto brass base, a barrel section that is smooth bore and holds 18 .22 cal short or long rifle rounds, and a striker plate section that is spring loaded steel.


The base is threaded to accept the barrel section, and gold anodized 6061 T6 Aluminum. It contains a press fit 45 cal brass that will accept a large pistol primer. OAL of the complete round is 3.920” Weight of the round unloaded is 9.8oz. Weight of the loaded round with .22 LR- 12oz. Weight loaded with .22 short- 11.4oz.

The striker plate section is a 17PH stainless steel unit that contains 6 triangle (with one tip cut slightly off) shaped strikers that will engage three of the .22 cal bases at once. They are stainless steel spring loaded. The outer top plate has six holes those strikers ride in. The outside of that plate has groves that engage with the inside of the barrel section, keeping the strikers in the proper position and the insert from spinning. The bottom plate that the strikers are milled into has a small “tail” section that goes into the 45 casing in the base. When fired, the primer pressure alone forces this base plate with strikers up, firing the .22 rounds. No smokeless or black powder is used in this adapter.

The barrel section is not rifled on this round, and is made of 7075 T6 aluminum. It has 18 holes that the .22 rounds travel through. It is threaded to accept the base. There is a central hole inside, that a pin from the striker plate section rides in, to keep that section traveling straight when it moves. Once put together, it makes quite an impressive round of ammunition.




Since this round uses non-rifled barrels, it is expected that the .22 projectiles will not travel in straight lines, as rifling is needed to stabilize rounds in flight. Expect to have .22 rounds “key holing” and tumbling in flight. The purpose of this round is a close in, multi projectile munition that can be reloaded in the field with minimal tools. OAL of this round is 3.890”. Weight unloaded is 14oz. Loaded with 12 .22 LR- 15.4oz. Weight loaded with 12 .22 short- 15oz. Also, since this is smooth bore, and space is needed around the ball, it is expected the velocity will be lower as some of the propellant gasses will escape around the ball after firing.


This round is loaded by removing the base, and the steel insert, placing 18 .22 cal short or long rifle rounds in the base, replacing the steel insert, placing a large pistol magnum primer in the 45 base, and screwing the base into the upper portion of the munition.


I have found that aiming this round can be done using the AR sights when the launcher is attached to an AR rifle, or the 50 meter sights when attached to a stand-alone launcher with ladder sights. When aiming at targets 10-20 meters away, aim bottom of the orange circle portion of the target.


.22 rounds used: CCI Long Rifle

Distance: See below photos

Spread measurement- Measured from point to point of furthest rounds striking the target

Point of aim: Bottom of orange circle unless otherwise stated or POI on blue tape in photos

.22 LR: AVG-

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18/22 fired from 10’, POI base of orange circle, 5.5” spread.

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18/22 fired from 15’, POI same as above, 10” spread

Data from next shots:


18/22 fired from 35’, 8” group


Fired from 45’, 13” group


Fired from 55’, 21” group


Fired from 65’, 36” group

CHRONO results:

Lowest result= 263.9 FPS measured 5’ from launcher.

Highest result= 396.1 FPS measured 5’ from launcher.


12/22 adapter with rifled steel inserts

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The 12/22 adapter uses an aluminum 7075 T6 anodized upper section with steel Redmans 22 LR rifled barrel inserts with the intent to provide more stability and accuracy to the .22 projectiles while in flight. The base contains a press fit 45cal brass base to hold the large pistol magnum primer, which, when fired, slams the triangles in the steel insert into the bottoms of the .22 shells, firing them all at the same time. The rifled inserts are in a grid pattern in the upper portion of the munition. The 17PH stainless steel firing pin assembly is stainless steel spring loaded and there are four holes in the top of the insert that the four triangle shaped firing pins ride in. There are four grooves in the side of the plate that keep the insert from rotating in the base and keep the firing pins aligned. It is also expected that velocities, using .22 rifled barrels will be higher as the tolerance of space between the ball and rifling is much tighter. With this, pressures will also be increased in the round itself.


Is the same as in the 18/22 above. Load 12 short or long rifle .22 rounds into the base of the upper portion. Place the steel plate into the upper portion and after placing a magnum large pistol primer in the base, screw the base onto the upper portion. The round is now loaded and ready to fire.



All rounds marked for testing

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Rifled adapter 12/22—Fired from 35’, 17” spread, key hole observed in some impacts

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12/22 rifled adapter, fired from 35’, 16.5” spread, key hole observed in some rounds. 1 22 round failed to fire.

Additional test:

12/22 rifled adapter, fired from 45’, 18” spread (not photographed)


Low result = 496.5 FPS measured 5’ from launcher.

High result = 653.9 FPS measured 5’ from launcher.

.22 LR: CCI standard long rifle

OBSERVATIONS- It is observed during testing that the rifled steel barrels do not add to the accuracy of the 22 munitions, and do not prevent key hole impacts with the target. This may be due to the spinning of the rounds in close proximity of each other and the exhaust gasses expelled after firing at the end of the adapter. These gasses may be affecting the flight path of nearby projectiles. They will however add substantial life to your adapter and will not wear as much as the aluminum smooth barrels in the 18/22 adapters will. Also, the tight fitting nature of the 22 rifled barrels add substantial velocity to the 22 rounds as they exit the launcher (653.9 FPS compared to 396.1 FPS on the high end). On observation of each round after firing, it would take some heavy use to wear out either the 12/22 rifled or the 18/22 smooth adapter. I fired two bricks of 22 ammunition from these 6 adapters, (4 18/22 and 2 12/22) and noticed no ill effects on any of them. As a round of ammunition to add to your combat capability kit, it would be a good idea to have a few for close combat capability in a 40MM package. The spread of the 22 rounds as observed in testing would be sufficient to engage targets within 25 meter ranges (with the 18/22), especially in ambush conditions. The multi shot adapters would be a good ambush initiator round, followed up by host rifle fire. Also, the multi shot adapters can be loaded with 22 tracer rounds to add in the visual effect. Cleaning of the multi shot adapters does take some time, and I completed cleaning of all 6 only after firing two bricks (1K rounds) out of the adapters, so they were DIRTY. I observed no negative effects on function or firing due to this fouling.

During testing I also used a few rounds with assorted .22 rounds, adding an inner band of shorts, or tracer, or other brands of .22 ammo. These did have some effect on the number of chambers that fired or misfired. Most of the loadings of .22 LR I loaded in the 18/22 adapters fired all 18 rounds. There were a few single round misfires here and there. The 12/22 adapters… One functioned flawlessly on every firing, with no misfires. The second adapter had one barrel that malfunctioned on every firing. One inner barrel. On inspection, it appears this particular barrel was seated a tiny fraction deeper than the others, which did not allow the firing pin the depth of impact needed to fire this round. Scot offers excellent customer service, and if you experience a malfunction such as this, I’m sure he would repair or replace the faulty adapter barrel section. Questions about these adapters can be submitted to Scot Pace at

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Last modified:  8 JULY 21