13 March 2008, 00:57
500grainsVelocity of .223 from 7.5 inch AR-15?
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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13 March 2008, 01:56
onefunzr2Is that classified as a pistol? A rifle with that short a barrel would be illegal.
13 March 2008, 02:04
EdmondYears 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
13 March 2008, 03:26
500grainsquote:
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.
13 March 2008, 03:27
500grainsquote:
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. ??
13 March 2008, 14:13
EdmondI 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.
16 March 2008, 06:22
mstarlingEven 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.
17 March 2008, 01:41
500grainsquote:
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?