AR Barrel feed ramps & M4 feed ramps

[man151]

I want to upgrade my AR15 with A1 sights to an A3 receiver. I would like to us my 20" H barrel with rifle feed ramps. But all the A3 receivers I see online seem to have M4 feed ramps. Is there any way to make my barrel ramps and M4 feed ramps work together? Online research seems to be negative. Does anybody know how to do that? I wound like to find a receivers with no feed ramps. Does any one know what brand sells A3 receivers with no feed ramps and where to purchase one. Thanks for your opinions & suggestions.

 

[rbernie]

Why not just work the barrel extension to add the feed ramps? It's not hard, and it can't hurt.

 

[mtrmn]

In the past I've matched up feed ramps with a broke-off chain saw file, but this is not for the faint-of-heart or the impatient.

 

[BBBBill]

Why not just work the barrel extension to add the feed ramps? It's not hard, and it can't hurt.

Exactly.

 

[man151]

Thanks for the info. I will match the feed ramps.

 

[burrhead]

I'm in the process of building a coyote gun around an HBAR barrel. M3 uppers without M4 ramps are out there but you have to look. I don't want to spend $200 on an upper receiver so this is what I've found;

http://www.brownells.com/rifle-part...eivers/flat-top-upper-receiver-prod26989.aspx

This one is available in standard height;
http://www.brownells.com/rifle-part...receivers/lo-pro-sku231015111-5604-13031.aspx

Not sure about these two;
http://centerfiresystems.com/arup-a3stripped.aspx

http://www.stagarms.com/a3-flattop-upper-assembly/
I'm going with the lower profile DPMS.