Not familiar with those, but sounds fun! 
Not a toy gun, but my Dad used to have sort of a propane gun that in retrospect looked like a mortar. It went off at preset intervals to scare birds and rabbits from eating his crops.
The Tommy Gun, helmet, grenade, etc. we’re among our toys in the60s. We also had double holster cowboy cap pistols complete with the outfit. Those were my favorite.
http://www.jeffs60s.com/armytoys.php
When I finally could afford to buy “ammo” for my cap guns, here’s how I moved up my game.
If you remove the nut that holds the valve seat washer, there’s a hole where you can put as much gunpowder as you can.
All you need is a nail with the pointed tip removed so it serves as a firing pin.
You want double the boom 
, remove the nut that holds the handle and do the same on the other end.
Yes @Robert_M3, this!!!
I recall mine had round discs on either side of the grips.
My current favorite toy gun. Yes, I will turn off all the house lights, and shoot my family with Nerf for fun.
I can’t believe there isn’t one reference to the Wasp Gun.
The caps were like little primers that were near 100% reliable.
We had no rules as they didn’t shoot a projectile.
Back then we didn’t have the stupid red nose cap on the end either.
We used to put on a neighborhood cops and robbers show.
We’d basically chase each other around the houses shooting each other and acting out getting hit/killed.
We’d charge the other neighbor kids 5 cents each to watch us.
Loved the late early 70’s
We forgot Greeni shootin she’ll stik.M.cap guns. Stick a cap on the back of a real looking brass case and push a plastic bullet into the spring loaded case, loaded like a real six gun. The cap would fire and the spring loaded bullet would come flying out of the six gun. 
Hi Tim- good to hear from you.
Roy Rogers would visit little kids in hospitals and give out cap guns to the little
Boys and girls at Christmas time. I saw a black & white video of him doing it. Back in the day he was the bees knees.
We had rocks.
Born in 1966. Rules? None! In the 1970’s one of our favorite TV shows was SWAT. They carried what looked like M16 rifles. We all had the plastic M16 knockoffs, I think they might have been made by Mattel. We sure saved countless hostages and knocked off a bunch of bad guys …
And a cap-gun revolver, with the red paper cap strips. I can still smell the gunpowder.
Same as the “real” ones… 
That feeling when trying to open a fresh red roll of caps with your fingernail and it ignites. That was some of the worst pain I knew.
Looks like the second column, second one down and the bottom one, right column are the same- different caliber and finish, though…
We would very carefully Scrape off the gun powder from the caps to do dangerous things with the gun powder. A lot of the times the gun powder would ignite and goodbye eyebrows. ( Pain without eyebrows ) nothing like the smell of sulfur and burning hair.
Scraped paper match heads, 2 large bolts & large nut to fit surprised no one got hurt back in the day. Oh & a hoop & a stick…
