M4 feed ramps

[Deckard]

I hear they are popular now.
I hear they are mostly for FA rifles.
I hear you can get uppers cut with M4 feed ramps.

Q: Is the barrel constructed and mated specifically for a feed ramp upper, or can any barrel be placed within an M4 feed ramp upper?
Q: Does a feed ramp upper make in difference in shorter rifles?
Q: Is this then just a trend or something I should look into for my next build?

Any pictures you have would be appreciated.

 

[acrashb]

http://www.m4carbine.net/showthread.php?t=193

 

[koalorka]

There's a wealth of info on this topic at AR15.com, it comes up almost daily.

M4 feed ramps are supposed to enhance feeding with the longer 62 gr. SS109/M855 cartridge.

- Yes, the barrel extension and upper receiver need to be matched up and aligned.
- It does increase feeding reliability.
- If you plan on shooting any heavier, longer bullets, then yes, it's recommended.

Here's a shot of my RRA 20" rifle, the ramps were cut rather crudely with some kind of dremel device after anodizing, leaving raw exposed aluminum. Why Rock River Arms continues to this remains a mystery.



The ramps in my LMT are machined prior to the finish process and properly aligned:

 

[mebiuspower]

Please right click and save...

 

[Hungry]

If I don't have feed ramps on my competition AR's, will my #### fall off ?

 

[acrashb]

Check frequently to see if it's getting loose - you should have a few day's warning.

 

[NaOH]

While it has generally been proven that your #### will fall off without M4 feed ramps you can get around this by shooting with an ACOG. The resulting lengthening of your #### the ACOG accomplishes will more than make up for the loss.

If I don't have feed ramps on my competition AR's, will my #### fall off ?

 

[Deckard]

So then, I have an M4 feed ramp barrel (right?) and therefore need an M4 feed ramp upper?

 

[Scarecrow]

Yes you do. Armseast has some I beleive.

 

[tiriaq]

Interestingly, there was a Colt Canada representative at the CLEFG this past week. Had some interesting guns on display. The M4 feedramp question was raised. He had little good to say about them.

 

[Deckard]

Thanks! I learned something! And I'm a know it all.

 

[acrashb]

So then, I have an M4 feed ramp barrel (right?)
[...]need an M4 feed ramp upper?

Yes on the first one, no on the second one. Per the previously-posted pics and article, you can use an M4 barrel in a non-M4 upper. Having said that, if you don't already have an upper for your barrel, you might as well get one with the cuts to match.