Brass dents revisited

[LRRPF52]

I de-edge, blend, and polish my feed ramps unless the barrel extension has already been tumble-polished, like on the ones I’ve gotten from Precision Firearms.

My brass ejects looking new unless shooting suppressed.

There are 2 major types of barrel extension designs for the AR-15 when it comes to feed ramp geometry:

1. Original rifle extensions

2. Colt 727/M4 extended feed ramps, that require a matching upper with lowered feed ramps (rifle uppers never had extended feed ramps). This was a band-aid for cyclic rate issues in the Colt carbines shooting high volume full auto in certain units.

The serendipity of the extended feed ramps was that they provided a nice feeding geometry for larger cartridges like 6.5 Grendel.

The central divider can be harsh on your brass if the edges are sharp, which is why I de-edge, lightly blend, and polish them.



I also polish pistol barrel feed ramps to aid in reliable feeding.