On all my M4’s I run a auto carrier, a “H” buffer and a heavy extractor spring with a black bumper. I pretty much shoot Federal M193, which I know is a fairly warm load. On the last few factory built M4’s I have looked at the manufacturers use a Carbine buffer and a lighter extractor spring with a blue bumper. Do manufacturers do this so the guns can run more differant brands of ammo that may be loaded on the “Cooler” side? Am I doing this right?
Also I recently purchased a Stag upper and noticed no M4 feed ramps. Are they neccessary or just “Nice to have”
The reason for no feedramps is because they like to cut corners and don’t think they are necessary. The extractor spring issue goes like this. The M16A1 and A2’s, A4’s, etc… only need a standard extractor. The M4 requires a more stiffer spring. Colt and most other well known properly constructed M4’s have this.
Other companies prefer to cut corners and put a regular one in their.