Tippmann SMG 60 trigger group, how does it work?

[Meleager7]

Quick curious question about full auto on old Tippmanns.

First off , if i had myself a 98 Custom, and could mod my trigger group to hold down the Sear with the trigger held, the gun would cycle way too fast, outrun the hopper and it would be chop city.....and probably shake itself to death in the process.

So how does the SMG 60 slow its fire rate to pull off this feat of full auto ? I don't see any sear piston delay system, like the Tippmann FA has ......

Here is a random smg 60 shooting vid I found to show you the cycle rate

Cheers, M7

[Axel]

The inertia from that enormous hammer probably slows down the rate of fire a bit, but the bigger factor is that the SMG-60 magazine is a force feed loading system. If it relied on gravity feed it would probably make paint soup just like your theoretical 98

[RuleOfSines]

There is a good bit of spring pressure advancing the clips through the magazine, and they are indexed by the firing mechanism so they advance one round at a time. Plus, there is no bolt smashing into the paint, the clip system functions as a temporary breech.

[jerryjjackson69]

Having rebuilt and done lots of test firing, I can tell you that the SMG60 is nearly as fast as a "full auto modded/soup machine" modern Tippmann. The bolt/hammer has a longer travel and is much heavier, so it is slightly slower. The magazine feed is very fast and uses high spring tension with the stripper clips protecting the paintballs inside. There is also no front bolt to actually cause a chop, so a firing sequence that occurs before a ball/clip is fully in position may not cause the ball to break. The trigger mechanism itself doesn't have any secret sauce inside it, and you are correct that the bolt has no mechanism to limit the rate of fire. It goes FAST. But I frequently would have a lot more "bangs" than balls actually fire when testing. I don't know if that was typical or just less than optimal function.

[DavidBoren]

Pretty sure it just farts into the wind one or times between each paintball it fires.

[Hp_lovecraft]

Most blowbacks cycle around 40cps. Way, way to fast for hoppers. But those early blowbacks with the heavy hammers and long slides were slower... around 20cps. Still too fast for gravity hoppers, though I've heard of people having success using forcefeed hoppers with the SMG60 and modified 68's.

The SMG-60 simply used a spring fed magazine, with each ball essentially already in its own breech.
The Tippmann F/A used hydraulic dampers to slow it down to 10cps. Hydraulic dampers have been used in firearms since ww1, so its a well known method, but for the F/A, it had a reputation for being inconsistent.

The AT85 used an elegant mechanical system where the hammer trips a valve, that operates a ram, that resets the bolt/hammer, The trigger acts like an autotrigger, so it trips the hammer, repeating process.

Hellbore came up with a bolt-on pneumatic system that would convert any semi to full, no batteries,

[BretG]

The weight of the hammer makes the rate.
I made a SMG version with a Sheridan JTX, which has a very small hammer. It is very fast.
here is a link to a video I made some time ago.

[COMMANDERBOND]

the clip system functions as a temporary breech.

I was working on a 68 SMG and clips were jamming. I sanded the front and rear of the clip and now it functions perfect. QUESTION? Does carefully sanding clips interfere with breech pressure - and velocity?
Did these smg 60 and 68 develop decent (290 fps)

please excuse my typing

[Apocalypse Meow]

I have an issue with getting mine to fire properly. Are these markers only capable of using a siphon tank? I had tried a regular CO2 tank and HPA and the paint just fires about 9 feet and low fps. Also, I'm in the process of redoing the O rings. Other than that the marker cycles fine and is in good shape.

[Cunha]

Why don’t the “mag fed” dudes use an smg style mag but with semi auto. Cheap to make, and seemingly reliable.

[Axel]

I have an issue with getting mine to fire properly. Are these markers only capable of using a siphon tank? I had tried a regular CO2 tank and HPA and the paint just fires about 9 feet and low fps. Also, I'm in the process of redoing the O rings. Other than that the marker cycles fine and is in good shape.

It does need CO2, but unsiphoned is fine for the SMG-60 (the SMG-68 did need a siphon to push the larger paintball). HPA requires a valve mod to reach playable velocities ( BretG ), but even unmodded you should get more than a few feet. Something else is going on.