It is my understanding that the reason for the deeper “M4 ramps” is to improve feeding reliability under full auto because of the M4’s higher rate of fire as compared to the M16. So my question is - how important are “M4 ramps” for semi-auto only rifles?
The reason I ask is that my BM M4gery does not have the M4 ramps, but has never failed to feed either. Is this a BM “shortcut” that isn’t worth loosing any sleep over in this case?
You can do a search on the subject as it has been discussed quite abit. If yours dosent have the M4 feedramps you dont need to worry. I prefer to have them 'just because" but I wouldnt lose sleep over not having them.
M4 cuts of course do help on FA. They also help when shooting heavier grain bullets.
You don’t need them, but if you can buy a weapon with them, then I would.
C4
Thanks for the replies - and clarification!
One other reason, softpoint bullets. It’s up to you whether or not you would ever use them, but many have reported problems with softpoints feeding in rifles with standard feedramps. I myself had problems with some GA Arms softpoints in a Bushmaster 16" HBAR.
Rob, that makes a lot of sense. Right now I’m pretty much sticking with XM193 or equivalent (55 grain FMJ) in that rifle.
Depends on the quality of the rifle. Our department purchased about 200 Armalites a few years ago and all of the rifles were put together differently. Some of them have suffered from feeding issues and I have had to cut M4 ramps on a few of them to get them to feed properly.
I have had soft point and hollow point hit at the point where a ramped barrel would have done the trick.
Whether you believe in them or not, i wouldn’t buy a carbine without them at this time.
They may not be necessary for all of the reasons listed above, but i truly believe that many of the feeding issues i see on a daily basis would be eliminated with those feed ramps.
Pat, thanks for your insight. No doubt the next upper I buy will have them.
BTW, do you have any carbine or AK courses scheduled for anywhere in New England? I’m moving to NH very soon and would be interested in any courses scheduled for 2008.
Thanks!
You’re welcome!
As a rule, i travel there only for mil/ agency classes. Too many issues and too small a student base. Sorry!
I used to have an Armalite carbine that wouldn’t feed worth a damn. My last three guns have M4 ramps and have never experienced feeding problems.
My Stag doesn’t have them, and today I had my first malfunction - a round hit below the feedramp and jammed. I put the round back in the mag and tried chambering it again and the same thing happened. The bullet was set pretty far back by then so I didn’t try to chamber it again. Ammo was Remington UMC 55 grain FMJ.
It might have been the mag, but I shot 120 rounds through two USGI 20 rounders today with no other feeding issues. The jam occurred only once (well, twice on the same round) on one of the mags. I didn’t keep track of which mag.
It might have been the round. That might explain why it only happened with that round.
It might have been because I didn’t seat the mag properly. But when I do that I get no feed at all, not a jam. And since I tried to chamber the round twice, I seated the mag twice.
But it would seem that a deeper reed ramp might have allowed the round to feed.
I also had another jam - a stovepipe caused by insufficient extraction. My Stag has a blue extractor spring insert and I already have a Colt spring & black insert on order (from Brownells), as well has a 10-pack of black inserts (from Brownells) and a 3-pack of extra power extractor springs (from Larue Tactical). I’ll find a combination that works best…
Its not the mag its the Rem UMC. Grab the projectile and move them around they arent in there very well. I had 2k rounds that I had to send back to Remington because these were so bad they were almost falling out of the cases on their own. Even there god ones arent very secure.
IIRC, this is nothing new with Remington UMC either. I’ve been using LC XM193 exclusively so far without any issues. I only wish there was some more around to buy!
A couple of my ARs have them. I’m somewhat indifferent since I’ve never had problems on the guns that don’t have them.
Although I have heard of the UMC issues that Shihan points out, some mags do indeed point the top round (left side, right side, or both) at a lower angle that will cause feeding problems. M4 feedramps will help if you have mags that have damaged or out of spec feedlips.
When given the choice you should simply get them.
The biggest thing about ramps is that if you assembling your own AR or having one assembled that isn’t a factory rifle you have to make sure that you don’t mix a M4 ramped upper with a rifle ramped barrel. This can create a lip of steel from the barrel extension and can cause jamming (it doesn’t always but it can depending on mags and cyclic rate). A M4 ramped barrel can be used in either kind of upper receiver.
That’s my experience as well.
I agree with Rob on the “Soft Points”. Awhile back I got soft points by accident when I wanted FMJ’s, and they had a little problem in my Non-M4 Ramped upper. The problem went away when I started using my LMT MRP upper with the ramps.
YMMV
Tack
what is the cause for that Remington ammo not being crimped good enough? Is it out of spec cases / bullets… or a lack of a quality crimp? 