No. You are probably looking at the bearing and locking surfaces. The one close to the muzzle is for the "cage" that holds the 6 muzzles together.

This video is from over 8 years ago.

The firing problem is solved already. It was specific to using 50 BMG primers and 20 mm pockets. They require a spacer. The mechanism works just fine.

@@jestertoo ALRIGHT... ALRIGHT... ALRIGHT... =) WELL DONE

These were the very first firing attempts. The 50bmg primers were being pushed too deep into the 20mm primer pockets. With spacers it works great.

Dog leash is a great idea.

@@jestertoo its a a method of priming a howitzer. A priming lever rotates a firing mechanism in places and then disconnects to lock it in place. The disconnect lanyard is then pulled to disengage a lever held away from the primer under spring tension, allowing that lever to forcefully punch the firing pin into the primer, igniting the charge and firing the round out of the tube

@@ButtcheekOnaStick oh, I understand what you mean now. This is a cam-over hammer design. I do intend to build a squeeze linear disconnector to prevent the lanyard from affecting the aim, but the hammer firing mechanism is working well now.

@@jestertoo it is still a well built design, but I would make a few changes. If you can, make a self ejecting falling block. Use the US WW2 57MM AT as an example. Just makes ya coom when it fires lol. Next I would add a trigger instead of a lanyard, my example earlier was just that, a slightly better example than your mech. Its 20mm so a trigger, even a button like a pak36 or pak40 would do and accuracy would be fine, and finally I would allow recoil compensation. Hydropneumatic would be most efficient, but simple pneumatic or buffer spring would work just fine with a 20mm. Keep up the good work friend!

@@ButtcheekOnaStick There is already a Fox Offroad nitrogen charged shock inside the mechanism. It has been tweaked a lot since this video. You can see more of the changes in later videos. A self ejecting action on the falling block would be nice for sure, but outside of my abilities at this time. It might happen. A squeeze trigger instead of the lanyard I am working on.

Was not intentional and fixed later.

Imagine remote control tank combat

You can call pioneer weapon systems in Arizona and see if they still have any of the breeches. They come to you like that with no barrels so they are just a firearm at that point.

@@jestertoo Thanks!

Yes, it was an old PICA 1/5 kit.

@@jessjohnson8576 Cool! I just scratch build a p40 from flite test plans :D Any tips for the maiden?

@@Sawer have someone double check every connection, weights and balance and thrust line. Practice flying planes with trims all the way off. This one was not straight at all and rolled/yawed very hard to the left. Wasn't straight.

@@jessjohnson8576 thanks for the tip! Will look into it:)

Call Thunderbird cartridge company out of laveen AZ. Ask for the guy who makes 20mm cannons.

Will do thank you very much

The breech is commercial. The rest I drew up in a free CAD software and machined/welded.

Jess Johnson where did you get the beech from? This would make an awesome winter shop project.

Pioneer Weapon Systems, out of Laveen AZ.

Thank you. This is definitely going to be fun. Is yours fairly accurate at longer ranges?

It's been a fun project. I haven't shot it farther than 100yds and only recently with a scope with enough eye relief. I need to shim the base about 30moa just to get it on target.

+Sha Sta Yes 20x102 is the US standard 20mm round and is very common. There are several other 20mm rounds used by NATO.

PS I can't seem to get in touch with Pioneer: nobody answers the phone and there's no email address!

Mike Riker died.

WHAT?

Jess Johnson Yes, that is my understanding. Some time last year from what i heard. Ive yet to call Thunderbird Cartridge Co. and confirm. Always a weird call to make.

Dang. Did the design die with him?

I think it's the swaging of the 20mm to 50cal primer pocket allows the primer to shift forward slightly. I'll figure it out. Yup, when I get back to it, I have a section of rail to mount a sight on top of it. Eventually it will have an offset scope like the ww2 M3 antitank cannon.

Do they still sell that breach system? Also how did you mount the barrel to said breach?

drew abegglen Yup, you can buy the breeches from Pioneer Weapons out of AZ. Let me know if you can't find Mike's # on the web. You simply have the barrel threaded for the breech. It takes a big lathe, but any good shop with the right size lathe can do it.

Yup, regular 50cal tripod with a re-valved offroad nitrogen charged truck shock buffer. When I get time to get back around to it I'll make it more eloquent.

Yup, the 20mm target practice rounds are unregulated. You treat them just like your 30-06 hunting rounds.

+jestertoo I found a couple of new (old stock) 20mm vulcan barrels for sale for about $800. First thought was to make one of these. Do they need a DD stamp? Would i be able to build it on a form 1 or do i have to find a SOT to build it for me or is a stamp not required because it is a breech loading cannon?

Mine is a DD. You can make bag guns that use separate propellant and projectile without NFA registration. Mine is a form 1 build.

The barrel is a regular M61 vulcan barrel. I'm not sure what steel PWS used to make the breech. Yes I load my own rounds, 500+grns of WC867/872 under the TP or TPT projectiles. Cases are swaged to use 50bmg primers.

@@jestertoo you should use Anzio primer bushings for 50cal bmg primers or you can take a 32 acp pistol case cut to .240'' with a pipe cutter loaded with small rifle primer w/ 5/16 rod stuck into the case to hold while cutting it to length and then spun to turn down the case rim, then loaded with black powder and a gluded on overshot card made from a 5/16 hole punch then the loaded cut turned case is swaged into the Vulcan primer pocket =home made priming system!

@@bretnmannn That is definitely a solution for when I run out of the cases I have. Very much like the 25mm+ priming systems.