M4 feed ramps receiver cutouts

Allstone

Allstone

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Another newb question...so I'm about to complete my very first AR build. I'm a lefty, and decided I wanted to build a lefty AR that I would like to keep. Bought a Stag lefty upper receiver with the Stag lefty BCG, and ordered a 16" Stag barrel assembly from Arms East. I've built a Spike's lower with a Stag lower parts kit for it.

The Stag barrel that I bought has the proper ambidexterous barrel extension with the M4 feed ramps. My Stag lefty upper does not have the M4 feed ramp notches/cutouts in it. When I took a look at my Norc M4 that has functioned flawlessly, I also noticed that while the Norc barrel extension had the M4 feed ramps, the receiver did not.

For those of you who have a lot of experience with AR's, how important would it be to you to have that little bit of metal shaved off to make the feed ramps line up with the receiver? Since my Norc has functioned flawlessly with them, I'm assuming that it's a non-issue. And in all honesty, I don't really want to cut into the finish of my receiver to do it.

Leave it?
 
i would leave it.

i've never had any issues running ar's with our without feed ramps. i think m4 feedramps were developed to address feeding issues under full auto conditions.
 
Leave it, it should run fine without them in the receiver.
If it doesn't, you most likely have issues somewhere else (99.9%).

As a fellow lefty, you are better off in the long run to run a regular right side ejection model and augment it with an ambi safety and mag release. Imho.
 
all my AR's have the M4 feed ramps on the barrle and the upper reciver but i would not worrie.

if stag is makeing barrles with M4 feed ramps and their uppers dont have the ramps i would imagine that you are fine to go other wise they would end up with all kinds of warenty claims for jaming and feeding issues.

and i have not heard any of those issues with Stag rifles Lefty or Righty

hope this helps:cheers:
 
Thanks, folks...I was leaning towards leaving it the way it is...and I think that's what I'll do. :)


Beltfed...I've been shooting a Norc so far. It's righty with ambi controls...and you're right, I haven't had much of an issue, except for the occassional hot brass on my right arm or jacket. :) Still would like at least one lefty AR though.
 
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Hope this helps.
 
I ended up with the "Bad" situation after changing my CQ311 over to an A2 upper. Was kind of disappointed that the Gunsmith didn't point the situation out before doing the swap and charging me for it.

Haven't had any problems running it as is tho.

M
 
Crosshair...that chart is very helpful. Thanks! I guess I'm going to be in the "OK" category. I had no idea the feedramps between the rifle and M4 were different.
 
M4 feed ramps are a solution to a .0001% problem. Unless you are making a living dumping full 30rnd mags on full auto every day you will never see an advantage to having them.
 
Gunnerlove said:
M4 feed ramps are a solution to a .0001% problem. Unless you are making a living dumping full 30rnd mags on full auto every day you will never see an advantage to having them.
Click to expand...

BINGO. M4 feed ramps were introduced to solve full auto problems. Not really an issue with our 5 round semi-auto AR's
 
As noted, introduced by Colt to solve potential problems associated with high cyclic FA rate of fire of the original M4 Carbine, with bad mag springs, a potential problem already solved by the rate slowing H and H2 buffer.

But, one of Colt's 'M4 Patents' certainly at the time of Stag Arms birth. Stag did go out of it's way then to differentiate its STAG-15 AR15 production from Colts patents, particularly the extended feed ramps, AKA the M4 Ramp.

Functionally, if not for FA fire on guns without H or H2 buffers, and with weak mag springs, the 'rifle' or M16 Ramps offer a more gentle feed path, and should be 'technically' superior accuracy wise. (to pick fly s**t from pepper).

After a bit of shooting, have a look at the feed ramps and see where the copper from the bullet does come into contact. I suggest you will see the bullets are coming into contact well up beyond where either M16 or M4 type feed ramps will make any difference.

There is a common theme that says 'M4 ramps do not aid performance on a semi-auto AR carbine'. I am afraid it is true.
 
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