Ca m15 possible problem?

[BORDENSNIPER]

ok so i was using my stock CA M15A4 tactical carbine in my basement doing some range tests and at:

at 6 meters, 20feet both .12 and .20 go through thick cardboard (2 layes of normal grocery carboard put together)

but at 10.2 meters, 33.46 feet, the .20g go only partially in the first layer of the cardboard and not through...

to those who own the gun, is this normal? ive read reviews on other stock guns that claim at 50 feet and under 100feet their guns are accurate, but what the effective range to which a person would actually feel the sting at with a stock gun?

(my hop-up is about 25% in)

[thephenom]

The better way to test it is to test it with a chronny to see if you're losing FPS.