????? M-4 Feed Ramps ????

Can someone enlighten me on the purpose of these,....Good, Bad, or Ugly.............With or without pics......

they are supposed to help make cartridge loading into the chamber more reliable. They are basicly exagerated feed ramps that extend from the bbl receiver into the lower receiver.


there are 'fake' feed ramps out there, so be careful. (basicly a little handywork by someone with a dremel.)

Thanks,.....I had found some pictures too,......

http://img.photobucket.com/albums/v1.../feedramps.jpg

Basically designed to feed full auto with a bit more reliability....Should help in semi-auto mode too you would think.
If you are looking to build on an upper with m4 feedramps, you MUST use a barrel with m-4 feedramps.
If you are building on an upper without m4 feedramps, you can use a barrel with or without the ramps.
Seems to me a barrel with and a receiver without would be less than ideal.
I like to keep them matched up myself.

I read an article once, a very long time ago, by Colt engineers. They said it was designed to address a very, very rare situation involving full auto only, and a specific round, and a specific magazine. Apparently when fired on full auto with that round and that magazine, the "next" round in the magazine tended to bounce or rattle around a little bit and could stub up without a ramp. They said it would never, ever occur on semi, even as fast as you could possibly pull the trigger.

I don't know. Just passing on what I remember reading.

P.S. I think the round had a very high rate of fire that was far beyond what the current recomended rounds were finally toned down to.

Thanks to everyone for the Help.....

One more aid to reliability

7 is correct...a lot of tier 2/3 mfg's use a barrel with feed ramps and then dremel the receiver to match