I heard M4 feed-ramps came about because M855 behaves SLIGHTLY different from M193 when feeding in full-auto fire. THe M855 is slightly nosing lower, just hearsay though.
I am planning on buying 2 black PMAG’s w/window. You guys have convinced me to try them. Anything worth buying once is worth buying twice, so I shall get two.
Just for fun I tryed the P Mags in a FA M4 and they worked as well as a USGI mags.
Well yeah, that’s pretty much it.
I’m sure Pmags do work well in FA. They were probably tested in FA extensively unlike how some other companies test their mags and then don’t produce 
This is why there’s a debate over the need for M4 ramps in the first place.
My point is simply that if the mag won’t allow a bullet to leave low enough to hit a ramp then they weren’t designed to work well with them- whether they are needed or not.
This is some of the most f00ked up internut logic I’ve ever read.:rolleyes:
But on the upside… I now know to ignore every post I ever see from you from NOW on! 
I just wanted to see it on the screen again 
I would appreciate it if you did NOT edit what I said and put words in my mouth. Please re-read the past 3 posts above your inaccurate quotation for clarification. Thankyou.
Saying any mag, PMAG or otherwise, introducing a round closer to the bore axis is bad is…well, ridiculous. The AR design does not require a “stall” prior to feed. Hence, no benefit to a round being introduced to the chamber lower than the axis. Similar to the 1911. I digress…
I don’t drink Kool-Aid, but I am all about science. Some people on these forums…:rolleyes:
6920
pmag
standard mag
I don’t see much difference in where the mags sit in relation to the feed ramps.
One difference I do notice is a tighter fit, there is very little forward/rearward movement with the pmag once inserted into the magwell. With a standard mag there is some play which affectes where the tip of the bullet ends up. Both feed fine though.
pmag
standard mag
I don’t know if it’s the camera angle or not, but it looks to me like rounds presented from the left/port side of the mag are presented lower to the feedramp than rounds presents from the right side. Is this the case? It definitely looks like th extended ramps help on that side, but not on the other.
I think it is the camera angles. The bullet tips when pushed forward both contact the feed ramps just above the cut outs left and right and with both style mags.
I figured by looking at a mag that the presentation of each round, regardless of which side it’s being presented from, should be the same. The lips are formed at the same height. But looking at those pics it definitely looks like there’s a difference. The only logical explanation is the camera angle.
You honestly didn’t get what I said? M4 feedramps were designed because longer rounds COULD have a tendency to smack into the receiver too low. The ramp is there so the bullet can be guided upwards.
In the same scenario which this would occur, whether it happens often or not, would not be able to happen with a PMAG. The bullet tip would hit the front of the PMAG.
M4 feed ramps were implemented to cure feed issues caused by worn out magazines used in carbines fired full-auto. The PMAG may negate M4 ramps but so does a brand new aluminum magazine with an anti-tilt follower and new spring.
No, the bullet noses down AFTER it is free of the mag from what I have seen on slow-motion videos of full auto fire. The PMAG from what is being said, introduces the round higher in the breech so as to allow a straighter path into the chamber.
Right. Now I’m no engineer, but from what I can see by just looking at the design… the top round would need to do a JFK magic bullet to even hit the bottom of an M4 feedramped upper.
The various slow motion videos I’ve seen of M16s and M4s shows that the rounds in the mag bounce up and down within the mag body as the gun is cycling which much more pronounced in M4s due to the more violent higher cyclic rate when fired on auto. This can become a problem if the rounds aren’t all the way up against the feed lips as the bolt begins to push the top cartridge forward. If not all the way up the top round could dive nose down and hit the upper receiver and jam the rifle.
Stronger mag springs helps, slowing the cyclic rate helps (heavier buffers), M4 ramps helps, and better followers like Magpul anti-tilt followers helps (an upgrade from USGI green anti-tilt followers) and now PMAGs help even more.
A side effect of the M4 ramps is that they also allow for a little more positive feeding with different projectile ogives.
Do PMAGs negate M4 feed ramps? IMO no.
But if the round can’t physically even touch that part of the ramp?
Granted, there’s no guarantee that you’ll always have a Pmag in the weapon… And my point certainly isn’t to opt out of the M4 feed ramp design. It’s just that from what I see, it looks like the round would have to go through the front of the mag body to hit the bottom of an M4 feedramp.
(none of this discussion is monumetally critical in the grand scheme, I know 
)
I thought about the magpul followers while at work today- yeah, those pretty much keep the rounds from being able to nosedive due to a nosediving follower as well…
I’m still thinking there may be a little too much material at the front of the PMAG extending too high. It wouldn’t hurt to not have that little bit that will block the tip of a lower round from hitting a ramp, would it?
That is not possible with the M16.
M4 ramps aren’t there because bullets normally sit in USGI mags too low. The PMAG doesn’t let the rounds start higher. Remember the carrier keeps them from sitting any higher no matte what mag you use! During cycling when the carrier is moving, they can become succeptible to nosedives just the same.