Are these M4 feed ramps?

Yes.

You mean the standards of actual Colt M4s which do not have feed ramps extending into the receiver or that it meets the marketing "M4 feed ramp" specs?

If for the first, no but no receiver extended feed ramps will. Since M4s do not have them.

If for the second, it depends on which company's standards you're referring to.

To me they look good.

Yes, they are.

Look like M4 feed ramps to me.

If the question is basically "do these look right?"

I would have to say, yes, I think they look about as right as you will find!

Perhaps someone else knows more than me about this.

I certainly do not know everything and I am always willing to learn new things every day!

I found myself trying to stick my pinky in that chamber.......Just messn' with ya

What make of upper is that. The ramps look good. Very clean and the cuts on the receiver match the cuts on the extension really well too. It also looks like the upper was anodized after the cuts were made.

Yup! Sure are!

revolving cylinder, not sure what you're talking about. the colt upper receivers I own (all 4 of them) that are stamped "M4" all have cuts in the receiver.

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The genuine M4s(which is a military designation, not a corporate one) do not have the "M4" feed ramps that are in vogue on civilian rifles. They aren't part of the actual M4 specs.

The newest actual M4s I've encountered were brand new in 2008 and none of them had them. I don't think it's changed since then but I could be wrong.

He asked about specs and "M4 feed ramps" are not in-spec with true M4s nor are any extended feed ramps as far as I know.

I have a picture of a 100% USGI issue M4A1 chamber that I just tried to post, but I'm having a little trouble, will post here in a minute

Ok this is it, as stated 100%USGI M4 chamber/feedramps

The genuine M4s(which is a military designation, not a corporate one) do not have the "M4" feed ramps that are in vogue on civilian rifles. They aren't part of the actual M4 specs.

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Both the M4 and M4A1 upper receiver call for M4 feed ramps since 2001. I don't know where you are getting your information from but it is wrong. The NSN is 1005-01-382-6795 for the upper receiver with M4 ramps.

M16A4's have M4 feed ramps as well.

BR said:

Both the M4 and M4A1 upper receiver call for M4 feed ramps since 2001. I don't know where you are getting your information from but it is wrong. The NSN is 1005-01-382-6795 for the upper receiver with M4 ramps.

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Well, I'll be dipped in apple butter! I wrenched on many an M4A1 in the service and never saw this mythical "M4 Feed Ramp" some folks went on about. Of course, my last day in service was in 1999...

So, what ailment are these feed ramps to fix? Never had a problem with ours' feeding that wasn't fixed by anew magazine. Our saw a LOT of rounds down the bbl.

I have heard that these M4 feedramps were adopted because an awful lot of magazines used in the military are old and in less than perfect condition; LaRue in fact claims that 1.) they put unusual stress on 5.56mm. ammo that may cause inaccuracy and 2.) if you use good magazines --or new ones -- they're totally unnecessary.

Does anyone know if this is true, or not?

ThePunisher'sArmory said:

I found myself trying to stick my pinky in that chamber.......Just messn' with ya

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Me too..