I selected several brands of ammo to see first hand what their ROF would yield with the Lage MAX-11 slowfire upper. I started with a beautiful 75 degree spring day in the desert with a clean and lubricated M11/9, using a single magazine for the entire test. This magazine is an aftermarket metal one I purchased from CDNN and was loaded with 25 rounds of each ammo I tested. I have other brands and bullet weights on hand I've yet to test, and I will post those results when I have an opportunity to run that ammo with the PACT MKIV XP timer. This is about as non-scientific a test as you can get, and is merely my assessment of various 9mm ammunition's performance in the M11/9 with the MAX-11 based on my very limited experience. This in no way constitutes an endorsement for any of the ammo used in this test. As always, YMMV.
FNM 147 grain (subsonic) ROF = 622 rpm
Sellier & Belliot 115 grain ROF = 621 rpm
Speer Lawman 115 grain ROF = 612 rpm
Winchester 147 grain JHP ROF = 615 rpm
Federal American Eagle 115 grain ROF = 632 rpm
Remington 115 grain JHP ROF = 613
Sampson / IMI blue tip 158 grain (subsonic) ROF = 632
**Hirtenberger 115 grain +P+ ROF = 598
This had to be the suprise of the day! Some people had told me this ammo was HOT, while others said it seemed "normal".
Armscor 124 grain ROF = DNF
We couldn't get more than two rounds to fire and it was usually just the first shot. Very underpowered ammo that barely cycled the bolt on the MAX-11 upper turning it into a semi auto gun.
WWB MAX-11 & MAC JACK 115 grain ROF = 787
Nice way to speed it up....
WWB stock M11/9 115 grain ROF = 1484
WWB stock M/11 & MAC JACK 115 grain ROF = 1856
Total waste of ammo and a real handful of fun!
*Winchester White Box 115 grain ROF = 609 rpm*
* I'd previously tested the 100 round Winchester White Box, (WWB), bulk pack and got a ROF of 610. I re-tested again just to ensure my baseline ROF was holding constant.
** After considerable back channel dialog with two people I highly respect as being much more knowledgeable than myself, we feel the slower ROF is almost certainly due to the longer dwell time of the bolt being forced further back by this hotter ammo. However, at no time did the Lage bolt ever contact the rear buffer! Even though the MAX-11 slowfire utilizes 4140 steel for the barrel as opposed to softer 1018 steel found in many after market M11 barrels, use Hirtenberger at your own risk. I did so as part of an ongoing ROF test and you risk damage or serious injury to yourself and your gun should you decide to use Hirtenberger +P+ ammo in any MAC type weapon, especially a stock gun or one with an aftermarket barrel. Please contact any upper receiver manufacturer for their specific recomendations PRIOR to using this high pressure ammo.