I was just reading a story In SOFiction by None other than Gary Paul Johnson about the Armalite SOF Mid-lengths He mentioned in the artical that the New Flat Tops from Armalite Have the M4 design cut feed ramps. I just received a 20" Barreled Upper from them Last week and decided to check it out, Guess what? It has them too!!!
I know he is not always correct on his facts but I decided to call Armalite today and talk to my sales rep. Guess what this is a standard update on all their M15 rifles, Isnt it Nice to see a company put T&E findings into production Rifles to make them better Instead of only doing it On High Dollar "special order guns", Gotta love that!!!! Go Armalite!!!!!!!!!
cp

With thier continual enhacements, if Armalite starts using 4150 steel in their barrels, they would be extremely, extremely hard to beat.  I want a midlength so bad, but I don't think their is anyone who makes one in 4150.  

It seems a lot of people are pleasantly surprised.

I called Armalite and asked them and I could not even get them to understand what feed ramps were.  They eventually told me they didn't have them and I hung up.

I think Armalites are still cut ramps and not forged/hardcoat anodized in.

I e-mailed Armalite, and they're response was:

The M-4 feed ramps are not cut in the uppers due to the fact they would
not line up correctly all the time. The part # for the complete upper is
EK0130 with a price of $172.

Thanks for your interest in ArmaLite.
ArmaLite Sales
[email protected]

I have experience w/ the Armalite middie.  It wears an ARMS # 59.  On the barrel steel issue, since there were none available in 4150, I useda 4140, my preference is always, stronger etc., but w/o the option, I wouldn't let the slight difference in barrel steel quality deter me from setting up a middie upper, on a 4140 barrel.  Beautiful barre BTW, I wouldn't lose any sleep over it.

My .02c

S2

I dont know if they are cut in or not, and the lady I talked to wasnt sure, I just know mine has them in it and I am estatic. I have never had a Malfuntion in my other ARmalite from them (nose divers) from a lack of the cuts, but its nice to know that they are actually implementing "lesson learned" T&E research, I was also told there are some other changes coming, but The gentelmen I talked to wouldnt be real specific just yet. I dont know for sure But Id guess some extractor / Bolt/ Carrier improvments. Just a guess though.
Barrel steel? I didnt think there was much a difference between 4140 and 4150, Im no metalurgist though so I cant comment on them. All I know Is I own an M15a2 and Now an M15A4 both with 20" barrels From Armalite and Both have RAS's on them and they both shoot Better than I can. I was getting 3/4" groups out of the A4 with 62 Grain IMI Match with a 4X Acog, from a Bench with NO Free float tube and NO break in Time first with Barrel. At 200 Yards it hovered around the 1.5" range with an Occasional group opening up to about 2 1/4". This was a perfect day over the weekend with virtually no wind and bright sunlight in about 80% humidity. Ive put less than 200 rounds though this upper.
cp

I thought Colt patented the M4 feedramp cuts.  Perhaps Armalite has paid for use rights???

IIRC, the feed cuts are part of the M4 Technical Data Package (which is stricty an issue for military procurement), but they (unlike the handguards) are not patented.

The patent on the handguards runs out IIRC in 2004.

Impostor,  if that's the case, why doesn't Bushmaster use them, as well as everyone?  Or are they and I just haven't caught up yet?

Other companies are using them...

My CMMG/DPMS M4A3 upper.
[img]http://a3.cpimg.com/image/BF/06/19895743-00e6-02000180-.jpg[/img]

Most auto-loaders benefit from tuned feed ramps.

A pic of my Armalite Target upper from back in May IIRC. I was shocked to say the least. Made my day.

[img]http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=10884[/img]

MM419

My armalite has the same cuts in the feed ramp !!!
mine is a2 got it oct. 2002 .

I have a bushmaster M4-gery and I'm just wonrdering what kinda benifit on semi auto I'd get out of feed ramp cuts? My rifle already feeds right now and I don't seem to have any issue with that, I'm just wondering why the feed ramp cuts came into spec for m4's I guess..

Think 1911, throating and polishing the feed ramps increases the feeding reliability of the firearm.  

The same is true for the AR, having the extended feedramps will make it less likely to expreince bullet nose dive type malfunctions.  

The extended feedramps along with the green mag followers and extra power extractor spings or even better the LMT SOPMOD II bolt and carrier will help make any AR less prone to malfunctions.

I just checked my RRA midlength A3 upper and it has them too! Pretty minute cuts though, I'm surprised people make such a big deal about them.

Well to some it is a big deal, it can make the difference between a rifle that functions and one that doesn't (in specific situations). It used to be only Colt had them, making some people shell out a lot of extra $$$ to get the factory ramping.

P.S. My newly acquired RRA Match A3 upper doesn't have them.  [:(]

When do they cut the feed ramps?  From the picture above, it looks like the cuts also cut into the barrel extension.  Now, I have never had an AR that far apart, so I am just talking from some limited experience with parts diagrams.  So do they assemble the upper and cut it all as an assembly later?

The reason I ask is because I wish I had the cuts in my carbine.  I have had some jams that may have not happened with those feed ramps cut in--like the first round off a mag, it just jams the tip against a flat spot.  Is there a AR smith who is can do this?

Any info is greatly appreciated. Thanks,
--Dan

Check Kurts over at the Industry section.

My 24" M15A4T upper also has the M4 ramp cuts.

Good Shooting
Red