AR15 M4 feed ramp cut

[Outlaw45]

I've been looking at building an AR15 myself. Looking at the upper receivers and some talk about not having a M4 cut. What does that mean? For instance MEGA uppers offer standard cut or M4 cut, what's the difference?

I'm looking at a VLTOR or SUN DEVIL upper on a Seekins lower with a 20 inch stainless barrel.

 

[rijndael]

Re: AR15 M4 feed ramp cut

Here is a picture comparison picture:

 

[427Cobra]

Re: AR15 M4 feed ramp cut

I have never had a AR15 with M4 cuts, and I have never had a feeding problem, so to me there useless, but I don't own any full autos either.

 

[Outlaw45]

Re: AR15 M4 feed ramp cut

Anyone know what a shilen barrel comes with, standard rifle or M4?

 

[9H_Cracka]

Re: AR15 M4 feed ramp cut

Most of the custom makers just ship barrels only with M4 cuts given the number of M4 receivers out there these days. I know Shilen's supplier and can about guarantee you they use M4 extensions.

 

[Outlaw45]

Re: AR15 M4 feed ramp cut

I talked to shilen and they said they don't supply their barrels with M4 cuts. But they could do it if I wanted it.

So, I'm thinking of getting an upper without M4 cuts and a Shilen barrel with stardard rifle cuts. Is that the best way to go? Or should I get a Shilen barrel with M4 cuts and find a upper with M4 cuts as well?