I am curious about how much velocity is lost in one of the little DPMS Kitty Kat uppers, as compared to a standard 16 inch upper.

Kitty Kat 7.5 inch:



A4 16 inch:

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Is that classified as a pistol? A rifle with that short a barrel would be illegal.

Years ago, I chronographed 4 different uppers ( sorry I work in metric)

24" 975 m/s
20" 950 m/s
16" 840 m/s
10" 760 m/s

quote:

Originally posted by onefunzr2:
Is that classified as a pistol? A rifle with that short a barrel would be illegal.

Not illegal, just needs to be registered under the NFA as a short barreled rifle. Takes about 6 weeks to get done and costs $200. Police can use short barreled rifles without registration.

quote:

Originally posted by Edmond:
Years ago, I chronographed 4 different uppers ( sorry I work in metric)

24" 975 m/s
20" 950 m/s
16" 840 m/s
10" 760 m/s

Thank you Edmond! I wonder if the velocity drop from 10 inches to 7.5 will be more severe. ??

I cut a barrel inch by inch and found out that 10 to 11" is the minimum length for the powder to burn correctly. with this length, there is a huge ball of fire that can be tamed by a Vortex flash suppressor, my second choice being a flash supressor used in VN around 67 with ANPVS sight and the third a Fabian Bros DTA Mil Brake.

I tested one DPMS Kitty Kat, it is much too short and in order to cycle correctly with such a short barrel the gas port hole is quite big.

There is a huge stress on the gun and it's fouled quite quickly. it is awfully noisy.

I did not chrono it.

Even an 11.5" M16 is loud! You can feel the blast on your face as well. The only shoulder fired weapon I've shot that's a load louder is a short M60.

I can't even imagine the noise a 7.5" gun makes.

quote:

Originally posted by mstarling:

I can't even imagine the noise a 7.5" gun makes.

So it would not be fun to shoot one inside of a car without hearing protection?