I read through the FAQ several times and still got no clear cut answer.  

SPECIFICALLY, I am building a 9mm carbine with a CMMG complete 9mm Upper, and a regular lower fitted with a "9mm hammer" from CMMG.  From the FAQ it sounds as if I do not NEED to ramp the bolt, but would doing so increase the life of my lower?  I seem to be seeing answers both ways on this.

I have a handle on the buffer stuff and mag block, etc, but want to know if ramping the bolt will help me or not (or should I ask CMMG?)

you do not NEED to, but the ramped bolt is easier on the hammer pins. over the long run it is better

Quoted: you do not NEED to, but the ramped bolt is easier on the hammer pins. over the long run it is better

Easier on just the pins or the pin holes in the lower?

If it's just the pins. then why not just install a set of KNS Anti-Walk pins?

woops..double tap...

Quoted: Quoted: you do not NEED to, but the ramped bolt is easier on the hammer pins. over the long run it is better Easier on just the pins or the pin holes in the lower? If it's just the pins. then why not just install a set of KNS Anti-Walk pins?

It's easier on both, but more importantly it's easier on the holes.

It's a MUST do on a F/A.

i broke a hammer pin in 500rds w/o the bolt ramped, i feel better now that it's ramped one less thing to worry about

Ok, I have a Colt AR6450.  To me it looks like the bolt has already been ramped.  I have been told by some that it is not and it is by others.  I've read that Colt started ramping their bolts, so look at the pics below and tell me what you think.

Not ramped.

This is ramped

Ahhh HA!  Nice pics.  I've seen other pics of ramped bolts but yours shows me the difference better than any other.

If the ramped bolt is so much better for a 9mm AR, then why the hell doesn't Colt ramp their bolts like the one in your picture?  My biggest issue with modifying the bolt is that you would void the factory warranty.  Yes, it would keep you from "egg-ing" out the lower, but I would think that if it did do that then the warranty should cover it.  Once you modify a part like ramping the bolt, you would loose any future claim of any defective part for the complete rifle.

I would rather destroy the warranty on a bolt then destroy an SBR'd Lower.

GREAT Pictures!  My bolt is from my CMMG 9mm upper and it is just like the first picture (unramped).  Meanwhile since the initial posting of this thread I have learned just what has been said here, that it will provide reliability AND longer life of parts (of which I am particularly concerned about the lower being the serialized part and somewhat a pain to get).

My 9mm carbine is a "parts gun" (GT/Danny's stripped lower, RRA parts kit from Pete, 9mm hammer, KNS pins, Vltor stock, Hogue grip, CMMG complete upper), so the warrantee is not an issue to me (what warrantee, we don't need no stinking warrantee!).  By the way KUDOS to all these great shops for great parts at good prices and good service to this internet commando...

I do see your point on a Carbine purchaded as a complete rifle, but how long is it Warranteed for, 1 year? (I don't know).  I say run it stock until you are convinced it is fully functional (say a few hundred rounds).  If you notice any problems get it taken care of RIGHT AWAY.   When it come back test it again, then assuming the problems are gone ramp the bolt and put in the KNS anti-rotation stainless steel pins to protect that lower for a good long time.  That is my plan only I will only shoot it perhaps 100 rounds before ramping my bolt.

About Warrantees: Oval shaped hammer holes will probably not be concidered a manufacturing flaw and thus not covered until the carbine just won't run.  And you may or may not have to replace the stock hammer pin at 500 or so rounds, but to me hoping the carbine does not break is a lack of confidence that I cannot tollerate.  You can shoot it until it fails and it may never fail if you shoot a magazine full of ammo every year!  But if the pin breaks a couple times and then you notice the hole(s) are sloppy and "ovalled out" you can buy the oversized pins and have the hole reamed (more $).   For me I plan to shoot this 9mm carbine a lot, let my kids and buddies shoot it too while 223 ammo is expensive.  I don't want take a shortcut for reliability so I will have it ramped before round 200 goes down the tube.  

Thanks again for the replies and the very illustrative photos!

On the first picture the factory bolt is actually ramped the wrong way! My CMMG bolt is unfired and like this too.

As I understand it the goal of bolt ramping is to have the bolt push the hammer back over a longer portion of the bolt travel, thus slowing down the hammer reset and transfering less shock into the hammer pivot pin.

I really would expect CMMG (a custom builder) to perform this or at least clearly offer bolt ramping as a service.  One woud think fully built Carbines would have this feature as a matter of service claims reduction.  It should be part of the bolt without aftermarket tinkering and thus possible loos of bolt hardness.