M4 feed ramps?

[6.5 Grendel]

Starting a new build my first 6.5 and was wondering if I should open up the M4 split ramp to make it just one ramp. My 7.62x39 AR would not feed for anything until I opened up the M4 split ramp, now it feeds anything even with cheap magazines. Would the Grendle feed better with just a single ramp?

[NugginFutz]

There was a saying by a wise man who went by the name of Murphy - "If it ain't broke, don't fix it." No-one I know has ever recommended this, and I personally can't see the need or advantage.

I have, on the other hand, seen several posters mention that they routinely polish the feed ramps to aid in feeding and reduce trauma to the bullet and brass, as explained in the below thread.

http://www.65grendel.com/forum/showthrea...h-M4-ramps

[6.5 Grendel]

This is what I had to do to the 7.62x39 ramp.

[ah1whiskey]

yea i just came from building 7.62x39s and thought i would have to do a "mono-ramp" for the grendels. --but decided they ran fine without it.

of the three i have one AA upper, one 264LBC and one saber m4 upper they all have just the standard m4 style ramps and so far not a hiccup.

the standard m4 set up is fine for the grendels .

getting good mags i think it the deal to making these things run. i am running the ASC 30 round 7.62x39 mags with no problems with the 6.5

my old C-products and ASC mags do work but have to be short loaded due to the tops swelling--

if you have the 7.62x39 30s try those and the e-lander mags if you don't have the 30s-7.62s.


no the 6.5 don't need a monoramp--

you will find the 6.5 is a joy to work with in the AR-15 compared to the 7.62x39--- no issues with deep set primers, or any need for XP-hammer springs or special firing pins--

the recoil on these things is soo smooth and the report is also very light--

[LRRPF52]

The only thing I do is troubleshoot the fit of the extension to the upper. Often, you will see ramps that hang back over the upper ramps, which causes a point of contention for the meplats of Boat Tail Hollow Points, and they will hit that ledge, and you get a FTFeed malf.

I de-edge, blend, and polish the ramps so that they match the upper receiver M4 ramps, and you get a nice, smooth transition from the mag through the ramps and into the chamber, without your brass getting scratched and dinged as well.

With the Grendel, there is no need to make a mono ramp like some manufacturers have done with the 7.62x39.