So what is the big the deal about cutting feed ramps after anodizing.  What will actually happen to the aluminum if it is left un protected?  I have a upper that had the feed ramps cut after anodizing, and I just wanted to know what could happen, and should I be looking for another upper reciever?  I plan on shooting this one alot, and keeping it forever.  I'm looking forward to hearing from some of the experts.

Thanks...........

I also have cut in feedramps from CMMG. Whats the difference between ours and anodized ones?

The main difference is that some folks around the site will wet the bed just thinking about dremel cut feed M4 ramps.

I have both types of ramps.  They both run.  I also have ones with no ramps.  No worries.

Expect a visit from the DUPE police.  Hide your dog.

I have a Colt 1/7 barrel on an A-1 upper with M-4 feedramps and so far, I haven't noticed any unusual wear there. From what I can tell, the tip of the bullet only touches a very small part of the feed ramp before it goes into barrel extension and I don't think it will create enough wear on the receiver to cause any problems.

Anodizing will protect the aluminum parts by making the surface much harder than natural aluminum.  Aluminum oxide is grown out of the surface during anodizing and then becomes aluminum hydrate that is extremely hard.  The porous nature of the anodized layer allows the product to be dyed any color that is required.  Type II anodizing (room temperature) and gives an anodized layer of .0002" to .001" (half which is grown into the surface and half out of the surface). Parts anodized will become slightly larger by about .0005"  Type III (hard coat) anodizing is done at much colder temperatures and at higher current densities and can reach thick nesses of .002".  Type III anodized surfaces can typically only be dyed black or dark green due to the denser pore size.


To be in spec your reciver should be done to type III hard coat.

Quoted: Anodizing will protect the aluminum parts by making the surface much harder than natural aluminum.  Aluminum oxide is grown out of the surface during anodizing and then becomes aluminum hydrate that is extremely hard.  The porous nature of the anodized layer allows the product to be dyed any color that is required.  Type II anodizing (room temperature) and gives an anodized layer of .0002" to .001" (half which is grown into the surface and half out of the surface). Parts anodized will become slightly larger by about .0005"  Type III (hard coat) anodizing is done at much colder temperatures and at higher current densities and can reach thick nesses of .002".  Type III anodized surfaces can typically only be dyed black or dark green due to the denser pore size. To be in spec your reciver should be done to type III hard coat.

Ken at Specialized Armament told me that even Colt doesn't anodize the receivers after cutting the ramps, but before.

Quoted: Anodizing will protect the aluminum parts by making the surface much harder than natural aluminum.  Aluminum oxide is grown out of the surface during anodizing and then becomes aluminum hydrate that is extremely hard.  The porous nature of the anodized layer allows the product to be dyed any color that is required.  Type II anodizing (room temperature) and gives an anodized layer of .0002" to .001" (half which is grown into the surface and half out of the surface). Parts anodized will become slightly larger by about .0005"  Type III (hard coat) anodizing is done at much colder temperatures and at higher current densities and can reach thick nesses of .002".  Type III anodized surfaces can typically only be dyed black or dark green due to the denser pore size. To be in spec your reciver should be done to type III hard coat.

Thank you for your explanation, that's the info I was looking for.  Now if those surfaces are not anodized should I get a different reciever or will that are be ok with out that protection?

Quoted: Quoted: Anodizing will protect the aluminum parts by making the surface much harder than natural aluminum.  Aluminum oxide is grown out of the surface during anodizing and then becomes aluminum hydrate that is extremely hard.  The porous nature of the anodized layer allows the product to be dyed any color that is required.  Type II anodizing (room temperature) and gives an anodized layer of .0002" to .001" (half which is grown into the surface and half out of the surface). Parts anodized will become slightly larger by about .0005"  Type III (hard coat) anodizing is done at much colder temperatures and at higher current densities and can reach thick nesses of .002".  Type III anodized surfaces can typically only be dyed black or dark green due to the denser pore size. To be in spec your reciver should be done to type III hard coat. Thank you for your explanation, that's the info I was looking for.  Now if those surfaces are not anodized should I get a different reciever or will that are be ok with out that protection?

The way I look at it, the receivers ramps are for clearance purposes only... The bullet tip should only be hitting air when traveling past the receivers ramps, not the receiver itself... The tip of the bullet should only come in contact with the barrel extension ramps before entering the chamber...

If your receiver shows signs that the bullet tip is hitting the receivers cut ramps, then you should be wondering why and do something to correct it...

IMO,  if its already working ok, use what you have because it really doesn't matter when the ramps were cut...

chemical restinance  would be the only reasone to see if anyone does the cuts before anodizing.

For function. the bullet does not care if it is hitting "raw" Al or type III hard coat.

Quoted: The HC anodizing is where the aluminum gets much of its strength wear resistance.

Quoted: Ken at Specialized Armament told me that even Colt doesn't anodize the receivers after cutting the ramps, but before.

That is only partially true.

Until I see proof that cutting the ramps before or after makes a real difference I'll worry about it.

Till then it's a non issue.

Quoted: Quoted: Ken at Specialized Armament told me that even Colt doesn't anodize the receivers after cutting the ramps, but before. That is only partially true.

Would you please elaborate on this.

Does anyone know if US Military specs allow for feed ramps to be milled in and left unanodized on issued rifles?

I don't doubt that they are largely unnecessary on semi-auto rifles; and the logical argument does hold that if that area is never struck by the bullet during feeding, hence the argument against the ramps, then why would it matter if they are not anodized, if they will never be struck anyway.

But if I choose to have feed ramps, I would much rather have them factory anodized as opposed to milled after anodizing.  The anodizing obviously serves a purpose, so I would rather have it than not.

The military spec question would go a long way in swaying my opinion to one side or the other though.  If they are allowed to be left unanodized as per military specs, and this practice has caused no problems leading to a rescinding of this specification, then I would have to conclude that lack of anodizing on feed ramps is nothing to give the slightest worry to; aside from users who exclusively use exotic, non-military rounds which have specific feeding issues.

Quoted: Does anyone know if US Military specs allow for feed ramps to be milled in and left unanodized on issued rifles? I don't doubt that they are largely unnecessary on semi-auto rifles; and the logical argument does hold that if that area is never struck by the bullet during feeding, hence the argument against the ramps, then why would it matter if they are not anodized, if they will never be struck anyway. But if I choose to have feed ramps, I would much rather have them factory anodized as opposed to milled after anodizing.  The anodizing obviously serves a purpose, so I would rather have it than not. The military spec question would go a long way in swaying my opinion to one side or the other though.  If they are allowed to be left unanodized as per military specs, and this practice has caused no problems leading to a rescinding of this specification, then I would have to conclude that lack of anodizing on feed ramps is nothing to give the slightest worry to; aside from users who exclusively use exotic, non-military rounds which have specific feeding issues.

I would assume the specs call for anodizing after ramps are cut.

It has nothing to do with full auto.  The gun cycles the same as in full or semi auto.

It has to do with carbine cycling more violently than a rifle and increasing reliability if out of spec or damaged mags are used.

Quoted: Quoted: Does anyone know if US Military specs allow for feed ramps to be milled in and left unanodized on issued rifles? I don't doubt that they are largely unnecessary on semi-auto rifles; and the logical argument does hold that if that area is never struck by the bullet during feeding, hence the argument against the ramps, then why would it matter if they are not anodized, if they will never be struck anyway. But if I choose to have feed ramps, I would much rather have them factory anodized as opposed to milled after anodizing.  The anodizing obviously serves a purpose, so I would rather have it than not. The military spec question would go a long way in swaying my opinion to one side or the other though.  If they are allowed to be left unanodized as per military specs, and this practice has caused no problems leading to a rescinding of this specification, then I would have to conclude that lack of anodizing on feed ramps is nothing to give the slightest worry to; aside from users who exclusively use exotic, non-military rounds which have specific feeding issues. I would assume the specs call for anodizing after ramps are cut. It has nothing to do with full auto.  The gun cycles the same as in full or semi auto. It has to do with carbine cycling more violently than a rifle and increasing reliability if out of spec or damaged mags are used.

Alright.  I had read somewhere that it had to do with the last few rounds fired in full auto from an M4.  I am not certain about that though.  It makes sense that it has to do with the M4's cycling as opposed to just full auto though.  It is just more of a fix for an isolated feed problem in M4s then correct?

Well, could you then say that if you want the most reliable M4 for SHTF, you would want a rifle that is capable, should the need arise, of using damaged or out of spec mags, without the heightened possibility, however remote, of damaging the feed ramps if this need to use damaged or out of spec mags should arise.  Such a rifle would necessarily have anodized feed ramps to reduce the possibility of damage to the receiver in this vulnerable feed area.  

It doesn't really matter how great the possibility of damage is without anodizing.  It is simply a matter of its possibility.  If it is possible, then necessarily a more reliable rifle would have anodized feed ramps.

Again, I want to stress in hopes of preempting certain comments, that I am not at all referring to rifles used to punch paper on the line.  I am only referring to SHTF rifles, regardless of SHTF's possibility of occurring, that are the most reliable in any given situation.

Edited for spelling.

Quoted: Quoted: Quoted: Does anyone know if US Military specs allow for feed ramps to be milled in and left unanodized on issued rifles? I don't doubt that they are largely unnecessary on semi-auto rifles; and the logical argument does hold that if that area is never struck by the bullet during feeding, hence the argument against the ramps, then why would it matter if they are not anodized, if they will never be struck anyway. But if I choose to have feed ramps, I would much rather have them factory anodized as opposed to milled after anodizing.  The anodizing obviously serves a purpose, so I would rather have it than not. The military spec question would go a long way in swaying my opinion to one side or the other though.  If they are allowed to be left unanodized as per military specs, and this practice has caused no problems leading to a rescinding of this specification, then I would have to conclude that lack of anodizing on feed ramps is nothing to give the slightest worry to; aside from users who exclusively use exotic, non-military rounds which have specific feeding issues. I would assume the specs call for anodizing after ramps are cut. It has nothing to do with full auto.  The gun cycles the same as in full or semi auto. It has to do with carbine cycling more violently than a rifle and increasing reliability if out of spec or damaged mags are used. Alright.  I had read somewhere that it had to do with the last few rounds fired in full auto from an M4.  I am not certain about that though.  It makes sense that it has to do with the M4's cycling as opposed to just full auto though.  It is just more of a fix for an isolated feed problem in M4s then correct?

As already mentioned, that is a magazine issue...

The M4 carbine cycles harder due to the shorter gas tube...

Correct... They only play a role when the magazine feed becomes an issue...

As mentioned earlier, the bullet tips SHOULD NOT be hitting the M4 feedramps on a regular basis. They are there to help chamber the rare round that feeds slightly low from a bad mag for example. If you are getting wear on your dremeled feed ramps, then you have some definite mag problems, and the same mags probably would jam a standard extensioned receiver. The M4 ramps are a slight improvement when feeding from bad, or dirty mags, and will chamber some of the rounds that would jam a normal rec/bbl ext(which doesn't happen very often).  They are NOT there to feed every single round, so wear on that part is a mute point. Also, as mentioned earlier, the only real draw back to having demeled feed ramps, is chemical resistance/oxidation, which for most of us is a mute point as well.

Having said that, There are planty of good upper receivers out there with the ramps cut before they are anodized, so why not purchase one of those? Mine is a CMT upper with the ramps purchased from Denny, and i installed a CMMG barrel with the M4 extensions and they lined up beautifully. Best of both worls and for a great price.

Quoted: Quoted: Quoted: Ken at Specialized Armament told me that even Colt doesn't anodize the receivers after cutting the ramps, but before. That is only partially true. Would you please elaborate on this.

Sometime Colt cuts them after anodizing because they don't have the correct parts.  Mostly on commercial products.

I have a mt6400 that had the feedramps cut after anodizing.  The aluminum is still a little bit proud of the barrel extension feed ramp so there is some room for wear.  The only time they have been used (AFAIK) was when shooting silver bear hollowpoints.  This ammo has a fairly blunt end on the bullet and was hanging up on a standard barrel extension with good mags.  Fed fine in the m4.  There was some minor wear of the receiver feed ramps after shooting about 300 rnds through the upper, but not enough to be a concern.  Have heard that the steel british mags are good to use with the silver bear ammo since they ride a bit higher than USGI mags.