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Ive never liked the idea of grinding past the annodizing on the reciever just to add something thats not really necessary to have a reliable gun.
Thanks for the info. |
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I'll second that motion |
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Sorry, my whole site just went down. Hopefully my ISP will fix it soon.... |
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Me too. I'm adding a barrel off a MT6400c (to a pre-ban) that has the extension for the extended ramps. Does it matter if my upper receiver does not support it? Or, break out the Dremel and take my chances? TIA Danny |
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I've dremel'd an upper. Not big deal really. Not pretty either, mind you, but no big deal.
It does'nt "hurt" the functioning of the rifle, I'm sure of that, and that is all that matters. The removal of the anodizing is'nt a big deal to me. YMMV. |
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While you won't be able to take full advantage of the enhanced reliability the full M4 ramps provide, combining a barrel with the M4 feed ramps with a non-M4 upper won't reduce existing feed reliability or cause any problems that I'm aware of. In fact I have had this exact setup, true Colt M4 barrel in a commercial Colt upper without the extended ramp cuts, for years now without any problems. However, combining an upper that has the M4 extensions with a barrel that has the standard feed ramps can cause feed problems as it would create an obstruction that bullet tips could get hung up on. |
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Agree that if you dont have a barrel with the M4 extention, getting an upper with them isnt a great idea. But getting the barrel and receiver with the extended ramps I think isnt a bad option. Surely not necessary, but if building something from the ground up I thik its good to have the option and I would rather have them then not in that case.
Some Dept down here, I dont recall which, uses some type of soft point ammo that did not feed well in their non-M4 feed ramped guns. I swear it was the Dept. of Env. Protection or something. One of their guys shoots wth us and he was having problems. Shooting the same ammo in a Colt with the feed ramps was 100%. |
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yea but there soooo cool! |
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Neil, same happened down here with local LEO's and Bushy carbines w/ no ramps. Only difference was the use of 75 grain Hornady ammo. During fullauto fire feeding was nowhere near 100%. Maybe more like 95%. These uppers have since been replaced by LMT CQBR uppers, and they feed/fire/eject all ammo 100%.
It might not matter to most, but if MY *ss is on the line I'd rather have take what works all the time under all conditions. -Cap'n |
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A local had that same problem with Bushmasters and TAP ammo. It turned out the new magazines were causing the followers to drag, and slow down the full auto feeding. Never had a issue semi auto. They ran the mags until they were "broken in" and after that all was fine. Finding what works all the time, is unfortunately a trial and error type of thing... |
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actually, no, it does not. dremel makes chainsaw sharpening bits that have the exact conture of the M4 ramp. Sure, it will not be a "Colt M4" feed ramp but it will be identicle in every form other than the small amount of anodizing that will be removed. they are sold in a series so a person can grind out the material and then polish it. it's pretty easy. i'm not saying it's right or wrong, just that cutting the ramps is a simple task. installing a new barrel extension on the other hand, that's a major pain in the ass! |
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OK, so you remove the material, that goes no where; you still dont have any feed ramps. Im order to have "feed ramps" they need to ramp up to something. If you dont have an M4 barrel extension, you have nothing to "ramp" to. The ramps cut into the barrel extension, are a completely different angle on the M4. |
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i think you missed my whole point. when you cut the barrel extension with the correct bits it will cut the reciever at the same time. it's pretty simple. ...But anyway, and M4 barrel extension and reciever are unique to themselves but are easy to duplicate yourself. |
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I posted this question a while ago and got no response, I have a Bushmaster barrel installed in a reciever with M4 cuts, it works fine so far, about 200 rounds, but could I or should I dremmel the cuts into the barrel extension to match the reciever?
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If its not broke, dont fix it |
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I'm with the "you don't really need them" crowd, Mine works peachy with out them, but The advice Bigbore gave I think is pretty darrn good for it's cost (free). I like that, buy what ya want, but know what your getting. Plus I was always under the premise that those cuts that extend into the Upper reciever were a proprietery exclusive for Colt and under a Patent. and if that's true, how can anyone else make that claim.
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I have owned and shot dozens of Colt M16's over many, many years. 95% of them, of all barrel lengths did not have M4 feed ramps and all worked 100% provided they were feed good ammo out of good mags.
I currently have 2 Colt M4's, real ones, and they work fine too. Is the M4 cut really necessary? My experience says that they are not. Good mags, in good repair, with lips that feed the rounds at the proper angle are. The M16 system was never ever intended to shoot other than FMJ ammo. That said if you shoot match type ammo with its small hollow point you will experience zero malfuntions due to lack of M4 cuts. Lead exposed tip ammo is not a good idea in any military type weapon, M16s, FALs, G3s etc. If I feel the need to use hunting/anti-personell ammo I use ballistic tips. They feed 100% due to the plastic tip that does not deform under beating around in the mag or during feeding. Removing the anodizing on the receiver is not a good idea. The upper is aluminum and soft, once you go thru the hard anodizing you expose the aluminum and suject the feed ramp to excessive wear by the ponts of the full metal jacket projos we use most of the time. Denny |
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I would suggest the "naysayers", (if I can use that term) go out and buy some soft point ammo and shoot it, see what happens.
I did, and it made the advantage of the M4 cuts obvious. Again, it does'nt really "hurt" anything, unless it's a complete moron doing the work. Don't cut too deep into the barrel extension, and don't butcher the aluminum. You can see in the pics, a very slight shoulder to the standard rifle extension that "could" cause a hangup. |
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Tell me...
Is there anything wrong with using a standard barrel extension along-side a receiver with M4 feed ramps? |
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Yes, the ramps in the upper would lead up to a flat wall before the ramps in the extension began. Not usually a good thing. |
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That's what I was afraid of. Any chance you can post a pic of this? |
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All my LMT uppers are assembled, or I would have posted a pic. I'll do so as soon as I get more in.
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M-4 ramping serves a purpose, and that is to allow non-standard Ball type rounds from being feed into receiver lower flat just before the standard ramps.
Note: Fact is that a lot of sellers really don't want to "lead on “ is the fact that only Colt offers the M-4 ramps from the factory. If you want the M-4 ramps, then you will need to buy a Colt M-4 upper and barrel. If you want the ramps added to a Non-Colt upper/barrel, then you would need to either add them yourself, or send the upper/barrel off to have them milled. To worry about something so mundane as a little aluminum expose at the front of the receiver, when the carrier is exposing other parts of the upper receivers aluminum by scrapping the anodizing off, is just a little deep to try to wade threw. Trust me, I have a tendency to load some pretty weird loads, and the M-4 ramps are the difference between them feeding or not. To dismiss them as just a fancy is just way over the top. |
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Isn't that a bit of a contradiction, though? Isn't the uselessness of the "dremmel ramps" predicated on the assertion that the bullet tips don't contact them but rather only contact the normal rifle ramps in the barrel extension? If there is no contact, then there is no wear. On the other hand, if the bullet tips are contacting the "dremmel ramps" so that they can wear the bare aluminum, then doesn't that mean that the "dremmel ramps" are being utilized and presumably might improve feeding? I realize this is probably picking at academic nits, but it would seem to me that even if the "dremmel ramps" don't improve anything, unless you butcher the job they won't make things any worse either.
I fully understand and agree with both Boomer and bigbore, but don't these statements also tend to contradict the assertion that extended ramps (dremmel or original) provide no value in typical use? If a properly set-up and maintained rifle with quality magazines in good repair with in-spec lips will never FTF due to the bullet tip missing the standard barrel ramp and impacting the standard receiver, then there is no worry that a bullet tip will ever pick up the "M4" receiver ramps and get caught on the ledge formed by the standard rifle barrel ramps. On the other hand, if a bullet does contact the receiver ramp first and get hung up on the ledge, then it would have missed the barrel ramp on a standard receiver as well and likely (?) misfed - a misfeed that presumably would have been prevented by the extended ramps. Bigbore, when you state that RRA uppers don't have M4 feed ramps, do you also mean they don't have the "dremmel ramps"? I recently purchased an RRA Entry Tactical that came with "dremmel ramps" as you helpfully explained in an earlier thread I started: I didn't cut these "dremmel ramps". They came from the factory that way. |
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Well Dang . Looks like I don't have them after all. Oh Well it hasn't jammed yet so no worries .
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RRA has the (now coined)"dremmel ramps". Without an M4 barrel extension, you cant have M4 feed ramps. The "Dremmel Cuts" did not come from the factory (The factory would be the foundry), the "dremmel cuts" were dont at RRA when the rifle was assembled. I didnt start this thread to argue the points of whats right and wrong. I just want people to know what they have.
You answered your own question. "a properly set-up and maintained rifle with quality magazines in good repair " will be just fine. IF you pick up a bad mag that constantly hits the "dremmeled" area you will eventually have problems. If thats the case buy a new magazine. Watch a round feed from a good magazine, its no where near the "dremmel cuts". The area "dremmeled" is insignificant. Ball ammo hitting the same spot on a non-dremmeled receiver will work fine. Why do places even add the "dremmel cut" - I'll go out on a limb and say marketing. |
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a buddy of mine had a bushmaster that would consistently have FTF no matter what mag, no matter what ammo, no matter what lower. I noticed there were tiny brass marks right at the top of his lower right where the material for an M4 cut is removed, so i dremelled the ramps and it now runs 100%. I have a bushmaster bench rifle that i had that would occasionally have a FTF and quite often you could feel something like a hestitation as the bolt went home. I looked at it and the same marks though not as pronounced, cut the ramps and it never has skipped a beat since.
I'm not sure that my ramps replicate an M4s, they just look that way to me. I would mention that this is more of a clearance cut in that the tip doesn't really seem to ride all the way up the ramp cut into the upper reciever, it just seems that it provides additional clearance to prevent the tip from getting hung up so it should not be a wear problem. |
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Understood, including the distinction between the foundry(ies) where the barrel and upper receiver were made and RRA where the rifle was assembled. As for right and wrong, I really wasn't trying to argue either. I was just trying to get things straight in my head as per your intention to clear up misunderstandings via this thread.
That is a good point: even if a "dremmel ramp" does improve feeding with questionable magazines, we should check to ensure that our magazines and rifles are in good shape and functioning according to specification rather than relying on "dremmel ramps" or other modifications to overcome bad magazines. Thanks for the responses. I think it would be good to add this thread to the "important threads" FAQ at the top of the forum. |
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So do factory LMT uppers (both barrels and receivers) have true M4 feed ramps or just the "Dremel ramps"?
Added: can anyone post pics of a Colt upper's feed ramps alongside of a LMT uppers' feed ramps? |
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Every LMT upper I've seen has the anodized extended feed ramps. They are definitely not Dremel style and look to be more like the true M4 ramps. As far as actual angles and other measurements I can't say for sure... Edited for typos... |
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LMT upper receivers were designed with the ramps to work with a M4 barrel extension. |
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I think a lot of this confusion is also from the different terminology used to describe this modification and also from possible bad hack jobs done by some well meaning WECSOG graduate.
I think what a lot of people a wanting are basically extended feedramps. As someone else mentioned earlier, to properly change the standard feedramps both the barrel extension and receiver need to be modified to match the Colt M4's angle so that the feed ramps are acutally extended instead of just adding scallops to the receiver. Basically it just boils down to personal preference and what you feel is good enough for you! |
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Outstanding post with lots of great information, thanks bigbore.
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Does anybody know if BM M4 Barrels use the M4 extension or the regular one? I'm talking about the 14.5" version.
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Not to say that they are not out there, but I've had two BM 14.5" barrels and both had NON-M4 extensions on them - FWIW. Edited to add: Both functioned perfectly using all types of mags, ammo, etc but no auto fire, as I am a lowly civvy and can't play like that. |
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Bushmaster has stated several times that they have not and will not add M4 feed ramps to their uppers anytime soon.
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Well, I learned something new today. I can see the dremel marks on my upper.
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I look at all of my weapons as long term investments, and I would not be happy to find a pack-o-jackasses at a factory had taken a "dremel" or other tool to my receiver AFTER it was anodized. Is there a short term problem, no. Long term? Yes, otherwise the receiver wouldn't be anodized to begin with!!
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First of all let's all say thanks to ADCO for taking the time to reply numerous times in this thread and for the great pictures they took to explain all this. It is time consuming work and it was all done for free as a service to the members and guests on this board.
I am not a hobby gunsmith and neither is ADCO. The info we post is from working on hundreds of guns and years of experience with them. We take time to reply to these threads as a service to you guys. We are not here to argue, flame, just explain our experience. I would like to summarize some of this thread. Receivers are anodized to reduce wear. Removing anodizing on wear sufaces is not good. M4 barrel extentions have their own unique angle. Adding them to a non-M4 upper is not good. Rifle barrel extensions are used by every barrel manufacturer with the exception of Colt and LMT. They should not be used in uppers with TRUE M4 cuts and FTF can occur. The reverse is also true. If you want or need a true M4 feeding system you have some options. Buy a Colt M4 Upper and barrel. Buy a LMT barrel and upper. Have us or one of the other gunsmithing companies build you one. It is not cheap but many of us can do it. This involves getting a SS or chrome moly match barrel blank or at least an unchambered , unfinished barrel and having us fit an LMT M4 barrel extension to it and then cutting the chamber and fitting it all up. LMT will sell gunsmiths M4 barrel extensions. If you go this route you can get the exact barrel you want. Rate of twist, brand, length etc. I know some of you have had success with your dremel tool and have made guns that would not feed correctly improve. That is great and I am glad ya got the gun working. We have not heard from the guys who tried it and wound up with a hacked up barrel extension and upper as folks have a tendency not to post their failures. This is a good thread with good info and some great pics courtesy of ADCO and it should be saved. As to ADCO's comment on "marketing" it is right on the money. You want real M4 do one of the things I suggested above. Don't get conned into buying and "M4" that really isn't. The real deal is only available as stated above. |
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