Greetings,
Today, I finally got a chance to try an experiment with my 9mm AR (DDLES GSF lower). When I built it, I used the Slash 9Q ( xtra heavy) buffer and the higher power Wolf spring he suggested with it. A round guess would be 4000-6000 rounds since I got it going and with some minor exceptions at first it has been virtually 100% reliable with every ammo type I've tried (probably a dozen and a half at least). Prior to the actual build, I'd read about using the Endine "hydraulic" buffer specifically for 9mm. I'd been wanting to give that a try pretty much for the same reason as the OP in this thread. There is a lot of weight being sent back on recoil and subsequent scope movement. I was also interested to see if the felt recoil would be any different.
SO, I ran 2 mags of 10 rounds each S&B 115g. I wasn't sure at all what would happen, so the first mag was very slow fire. Actually, no issues whatsoever! The second mag, I semi-rapid fired (about 2 rounds/second), with the same positive results. Due to the gnats being just about unbearable and it looking like rain, I stopped at that point. I really can't say if I felt any difference in recoil, but the EoTech 'seemed' to be more stable on the rapid fire mag (I have a 3-9x scope on a "return to zero" mount that I swap on for target shooing; the EoTech is pretty much for HD). I had intended to swap back the Slash buffer, put the scope on, mark targets, etc. and try to do a more scientific test, but that will have to wait. I'm heading to the shop to clean up the carbine and closely examine the buffer for any problems. Hope to try a much more detailed experiment soon, but wanted to let you all know the old Endine did indeed work with no malfs.
Regards, Jim