AR rework

logeorge · March 28, 2020, 07:08 PM

I don't know a lot about ARs. I'm working on this Colt Target model with built-in carrying handle with rear sight. I got a new receiver with flat top in order to get the scope down to a reasonable height above the bore. I thought I made it clear that I didn't want M4 feed ramps, as the original doesn't have them. They sent one with M4 ramps anyway. People on forums say you can't use a ramped receiver with a non-M4 barrel assembly and trying to match the old barrel to the receiver ramps is certain doom. Any reason I can't wax coat the barrel extension, de-grease the ramps in the receiver, and fill them in with JB Weld? Is looks to me like if the bullet noses were striking the receiver below the barrel extension, I would be having feed problems already. So far it has fed anything I've tried in it. I worked as a Toolmaker in the auto industry for 29 years and I believe I could grind the feed ramps successfully, but see no reason to, if it's not necessary. What you think? L. O. G.

rickyrick · March 28, 2020, 11:58 PM

Get another receiver.

If the receiver has ramps and the extension doesn’t, it probably won’t feed correctly.

If you have a carry-handle receiver, someone may pay a decent price for it as they aren’t easily found.

Another suggestion, get a barrel with M4 ramps on the extension or have a Smith install an extension with M4 ramps. Most stuff now days has the ramps.

brasscollector · March 29, 2020, 06:31 AM

You can do as you wish, it's your project but I wouldn't fill in with epoxy OR grind them out myself. Personally I would buy a new barrel to go with the new M4 receiver. Everything has the M4 cuts nowadays, hard to find a flat top w/o them.

logeorge · March 29, 2020, 03:00 PM

First, let me make it clear that I'm not knocking anyone's advice. You make good points. The facts are that cost is of primary importance. I'm in my eighties, retired and am about $150K in debt due to some family problems. My chances of getting it paid off in my lifetime are about the same as my becoming the first non-catholic pope. I wouldn't even have an AR to work on except it was a trade. I can't really afford to buy a lot of parts, and besides, with my machinist background I see it as a challenge. I'm determined to make this thing work one way or another. As I said in my original post, it looks to me that if the bullet points were striking the receiver below the barrel extension, I would be having feed problems with the original receiver, which I don't. It even feeds some odd soft point reloads I got in a gun deal about 30 years ago. ( Already shot most of them up getting the scope dialed in.) As far as a new receiver, Aero Precision makes one without the ramps. It's about $90. The one I have is a Stag Arms blem, which was considerably less. This AR is set up as a target rifle, with a 20", 7" twist barrel. I assume it has the rifle length gas tube. I expect I'll need a new gas block to get rid of the original front sight, too. By the way, a hat tip to the folks at Anderson. When I called them about a non-ramped receiver, they told me they didn't make them anymore, but Aero precision does. Pretty good PR in my opinion. Anyway, any more advice, opinions are welcome. L. O. G.

**Aguila Blanca** · March 29, 2020, 06:41 PM

Quote:

Originally Posted by logeorge

I thought I made it clear that I didn't want M4 feed ramps, as the original doesn't have them. They sent one with M4 ramps anyway.

Why don't you return it and ask them to send you what you ordered?

logeorge · March 29, 2020, 07:05 PM

I''ll probably do that Monday morning. It just came in Saturday. I'm just curious if this could be made to work. If they don't have what I need, I'll probably order one from Aero Precision. I know they have it. Maybe I'll just keep this one for future reference. I guess I could always sell something else to pay for it. Guns seem to be in short supply right now, along with toilet paper, eggs and hand sanitizer. I don't have any extra of the last three. L. O. G.

Skans · March 30, 2020, 08:59 AM

I know from experience that if the receiver has ramps and the barrel extension does not have the M4 ramps, cartridges WILL NOT feed. I was trying to mate a Colt A2 government barrel to an M4 receiver. The tip of the bullets will get hung up on a ridge created by the wrong barrel extension.

I even tried to grind the barrel extension to get rid of the ridge - i.e. make it more like an M4 barrel. I did get it to work a little, but never got it even 60% reliable, meanwhile I ended up with a butchered Colt A2 barrel that is pretty much good for nothing.

Legal_trouble · March 30, 2020, 01:10 PM

You mention being a tool maker, can you TIG and/or MIG with an Al spool gun? If so fill in the M4 receiver ramps and mill them smooth. Problem solved for no money.

rickyrick · March 30, 2020, 03:58 PM

Yes, if you have the skill and are a machinist, you could probably fix it yourself.

logeorge · March 30, 2020, 05:41 PM

I'm not a welder. I can do a little, but not on aluminum. Being retired, my access to machine tools is limited. I regret not buying a lathe and milling machine before I retired, as I got used to making things I couldn't readily buy. I sent an email to Stag Arms to see if they even make a receiver without ramps,but haven't heard anything yet. I suppose I'll have to get one from Aero Precision. Most manufacturers no longer make them, but AP does. Being perpetually broke as well as a cheapskate, I hate to spend the money, though that may be the only way out. I guess I could always sell something to raise a few bucks. L. O. G.

smee78 · March 31, 2020, 05:57 PM

I would return the receiver and get one from AP, in the end its easier to do it right than to try to get it right. Or you could just build a new upper all together and keep your original as is. I know its tough being a cheapskate but doing it right when it comes to guns is the only way in my book.

logeorge · April 1, 2020, 11:05 AM

Unfortunately, AP shows them to be out of stock.

rickyrick · April 1, 2020, 02:27 PM

I think still, not 100% on it... that you could sell that receiver for a decent amount even used. I had looked into making an “authentic looking” M16 clone... at the time I would have shelled out some cash for a carry handle upper.
I lost interest eventually, but I remember the upper receivers were selling for enough money to solve your problem.

DnPRK · April 2, 2020, 02:53 AM

JSE Surplus has eighteen A3 upper receivers in stock. A3s don't have M4 cuts.

March 28, 2020, 07:08 PM	#1
logeorge Member Join Date: December 24, 2007 Location: Ardmore, AL Posts: 68	AR rework I don't know a lot about ARs. I'm working on this Colt Target model with built-in carrying handle with rear sight. I got a new receiver with flat top in order to get the scope down to a reasonable height above the bore. I thought I made it clear that I didn't want M4 feed ramps, as the original doesn't have them. They sent one with M4 ramps anyway. People on forums say you can't use a ramped receiver with a non-M4 barrel assembly and trying to match the old barrel to the receiver ramps is certain doom. Any reason I can't wax coat the barrel extension, de-grease the ramps in the receiver, and fill them in with JB Weld? Is looks to me like if the bullet noses were striking the receiver below the barrel extension, I would be having feed problems already. So far it has fed anything I've tried in it. I worked as a Toolmaker in the auto industry for 29 years and I believe I could grind the feed ramps successfully, but see no reason to, if it's not necessary. What you think? L. O. G.

March 29, 2020, 06:31 AM	#3
brasscollector Senior Member Join Date: July 26, 2015 Posts: 526	You can do as you wish, it's your project but I wouldn't fill in with epoxy OR grind them out myself. Personally I would buy a new barrel to go with the new M4 receiver. Everything has the M4 cuts nowadays, hard to find a flat top w/o them. __________________ He may look dumb, but that's just a disguise. -Charlie Daniels

March 29, 2020, 03:00 PM	#4
logeorge Member Join Date: December 24, 2007 Location: Ardmore, AL Posts: 68	AR rework First, let me make it clear that I'm not knocking anyone's advice. You make good points. The facts are that cost is of primary importance. I'm in my eighties, retired and am about $150K in debt due to some family problems. My chances of getting it paid off in my lifetime are about the same as my becoming the first non-catholic pope. I wouldn't even have an AR to work on except it was a trade. I can't really afford to buy a lot of parts, and besides, with my machinist background I see it as a challenge. I'm determined to make this thing work one way or another. As I said in my original post, it looks to me that if the bullet points were striking the receiver below the barrel extension, I would be having feed problems with the original receiver, which I don't. It even feeds some odd soft point reloads I got in a gun deal about 30 years ago. ( Already shot most of them up getting the scope dialed in.) As far as a new receiver, Aero Precision makes one without the ramps. It's about $90. The one I have is a Stag Arms blem, which was considerably less. This AR is set up as a target rifle, with a 20", 7" twist barrel. I assume it has the rifle length gas tube. I expect I'll need a new gas block to get rid of the original front sight, too. By the way, a hat tip to the folks at Anderson. When I called them about a non-ramped receiver, they told me they didn't make them anymore, but Aero precision does. Pretty good PR in my opinion. Anyway, any more advice, opinions are welcome. L. O. G.

March 29, 2020, 07:05 PM	#6
logeorge Member Join Date: December 24, 2007 Location: Ardmore, AL Posts: 68	AR rework I''ll probably do that Monday morning. It just came in Saturday. I'm just curious if this could be made to work. If they don't have what I need, I'll probably order one from Aero Precision. I know they have it. Maybe I'll just keep this one for future reference. I guess I could always sell something else to pay for it. Guns seem to be in short supply right now, along with toilet paper, eggs and hand sanitizer. I don't have any extra of the last three. L. O. G.

March 30, 2020, 05:41 PM	#10
logeorge Member Join Date: December 24, 2007 Location: Ardmore, AL Posts: 68	AR rework I'm not a welder. I can do a little, but not on aluminum. Being retired, my access to machine tools is limited. I regret not buying a lathe and milling machine before I retired, as I got used to making things I couldn't readily buy. I sent an email to Stag Arms to see if they even make a receiver without ramps,but haven't heard anything yet. I suppose I'll have to get one from Aero Precision. Most manufacturers no longer make them, but AP does. Being perpetually broke as well as a cheapskate, I hate to spend the money, though that may be the only way out. I guess I could always sell something to raise a few bucks. L. O. G.

March 28, 2020, 11:58 PM	#2
rickyrick Senior Member Join Date: March 15, 2010 Posts: 8,236	Get another receiver. If the receiver has ramps and the extension doesn’t, it probably won’t feed correctly. If you have a carry-handle receiver, someone may pay a decent price for it as they aren’t easily found. Another suggestion, get a barrel with M4 ramps on the extension or have a Smith install an extension with M4 ramps. Most stuff now days has the ramps.

March 30, 2020, 08:59 AM	#7
Skans Senior Member Join Date: November 20, 2008 Posts: 11,132	I know from experience that if the receiver has ramps and the barrel extension does not have the M4 ramps, cartridges WILL NOT feed. I was trying to mate a Colt A2 government barrel to an M4 receiver. The tip of the bullets will get hung up on a ridge created by the wrong barrel extension. I even tried to grind the barrel extension to get rid of the ridge - i.e. make it more like an M4 barrel. I did get it to work a little, but never got it even 60% reliable, meanwhile I ended up with a butchered Colt A2 barrel that is pretty much good for nothing.

March 30, 2020, 01:10 PM	#8
Legal_trouble Junior Member Join Date: December 30, 2019 Location: Central Ohio Posts: 13	You mention being a tool maker, can you TIG and/or MIG with an Al spool gun? If so fill in the M4 receiver ramps and mill them smooth. Problem solved for no money.

March 30, 2020, 03:58 PM	#9
rickyrick Senior Member Join Date: March 15, 2010 Posts: 8,236	Yes, if you have the skill and are a machinist, you could probably fix it yourself.

March 31, 2020, 05:57 PM	#11
smee78 Senior Member Join Date: July 14, 2008 Location: South Carolina Posts: 2,918	I would return the receiver and get one from AP, in the end its easier to do it right than to try to get it right. Or you could just build a new upper all together and keep your original as is. I know its tough being a cheapskate but doing it right when it comes to guns is the only way in my book. __________________ We know exactly where one cow with Mad-cow-disease is located, among the millions and millions of cows in America, but we haven't got a clue where thousands of illegal immigrants and terrorists are

April 1, 2020, 11:05 AM	#12
logeorge Member Join Date: December 24, 2007 Location: Ardmore, AL Posts: 68	AS rework Unfortunately, AP shows them to be out of stock.

April 1, 2020, 02:27 PM	#13
rickyrick Senior Member Join Date: March 15, 2010 Posts: 8,236	I think still, not 100% on it... that you could sell that receiver for a decent amount even used. I had looked into making an “authentic looking” M16 clone... at the time I would have shelled out some cash for a carry handle upper. I lost interest eventually, but I remember the upper receivers were selling for enough money to solve your problem.

April 2, 2020, 02:53 AM	#14
DnPRK Senior Member Join Date: August 24, 2001 Location: LC, Ca Posts: 1,917	JSE Surplus has eighteen A3 upper receivers in stock. A3s don't have M4 cuts.