Theoben Rapid Forum

Hello all, hoping for some info on an FAC mk2 hammer pip.  There doesn't seem to be a definitive length out there, as I have read between 8-11mm for an FAC MK2 with Mk4 trigger. The pip length on mine is around 11.4mm. Would there be anything to gain by shortening the pip to 8mm? I am currently running this as a .25 cal. Should this question be moved to the FAC forum?  Thanks,

Kevin

My .22 R7 has run well regged or fastflow with 9mm.
Depends ..I guess...if the guns hitting its peak at 11.5mm, might be able to get away with less spring

Quote from: kevin10 on December 14, 2022, 02:06:04 PM
Hello all, hoping for some info on an FAC mk2 hammer pip.  There doesn't seem to be a definitive length out there, as I have read between 8-11mm for an FAC MK2 with Mk4 trigger. The pip length on mine is around 11.4mm. Would there be anything to gain by shortening the pip to 8mm? I am currently running this as a .25 cal. Should this question be moved to the FAC forum?  Thanks,

Kevin

As I understand it, the short FAC pip allows the hammer to build more momentum compared to the longer sub 12 pip,
the previous owner of my .20 had obviously run it "hot" as it was a struggle to keep it sub 12 when I first bought it, that had a 6.2mm pip  :o
now using 17mm & it's much better behaved.

Dr Bobs short pip is 8mm

Thanks everyone, good info. I'm a little reluctant to run out and chop the pip down, but its an option. I have read that aside from lowering the power, a longer pip creates a faster lock time, leading to a cleaner shot cycle.  I'm good with the current power level, but I have plans to shorten the barrel so I'm on the lookout for any place to squeeze a little more power out of it.