Just a follow-up fyi on the heavy trigger. Mine was 7.5# out of the box and I couldn't find a schematic of the group (even Umarex reps couldn't find one in their system). Rounding the 1st stage travel screw lowered the pull to about 6.5# - still very heavy.Finally got up the nerve to take it apart. There are two springs in the trigger group (that I could see) - a heavy sear spring, which controls the tension on the 2nd stage, and a lighter trigger spring, which controls the tension on the 1st stage. I replaced the sear spring with a lighter one and now my trigger breaks at a repeatable 1lb 4oz. Everytime. The gun was good before, now it's great. I recommend doing this mod - the change from 6.5# to 1.25# on the trigger pull is huge.Info on the OEM and replacement springs:OEM sear spring: 0.6" length, 0.180" OD, 0.029" wire diam ==> 7.5# trigger pullRepl sear spring: 0.6" length, 0.156" OD, 0.016" wire diam ==> 1.25# trigger pull(the replacement sear spring I used was from Jones Spring Co (snip) and is stock # is 157-A. That's a 1" length which I just cut down and flattened the cut end. It was $0.40.Hope this is helpful to someone else.
Will- I have two of them set up identically, both have the lighter sear spring. One pulls at 2# even and the other pulls at 2.5#. I had them both under 2# initially but got worried about accidental sear slippage so I stiffened the sear spring up a little. I've hammered them pretty hard with a rubber mallet several times each and never got a discharge (never did under 2# either, but whatever). In fact, after hitting them 10 times with the mallet, the trigger pull was still 2# so there was no slippage that I could measure.If it's helpful, here are some pics of where the spring goes...Lillysdad- I believe the original Impact has the T05 trigger and safety up top whereas the Impact Max has the group shown in these pictures. However, I only have experience with the Impact Max so that may be incorrect. I really find this to be a nice, accurate gun out to 35 yds or so. Mine likes H&N Terminators and JSB 15.89s the most. BTW, this is the same trigger group as the .177 Umarex Forge.
Will- the oem spring is pretty close to a Jones Spring 156-C. Not exactly but very close. That one (the 156-C) has an 8.798 lbs/in spring constant. I originally replaced it with an actual Jones Spring 157-C which has a spring constant of 1.43 lbs/in, but I stretched the spring out a bit to get more compression. That's when I got the sub-2# trigger pulls. Even though I never got any accidental discharges, I decided it was too light and put in a Jones Spring 154-C which has a spring constant of 2.15 lbs/in. Again, stretched it a little to add some additional compression and now the triggers sit at 2# and 2.5# respectively on both guns. Also did this with my Umarex Forge which has a similar 2.5# pull now. Hope that is helpful. Here's a pic comparing the springs.You can get them at springsfast.com - just search for the above part numbers.
I bet these would work fine too, from Amazon with free Prime shipping:ClippedOr these:ClippedOr these:ClippedYou can stretch or compress any of them to get some range of stiffness. Also, hit the ends with a bic lighter until red, then press straight down on a flat metal surface to make the ends closed then just sand the ends to get them nice and flat.Sorry I don't have anymore or I would certainly send you a spare - I sent a couple out and used 3 of them (1 on the Umarex Forge, 2 on my two Impact Maxes). I had 5 of them from a collection I picked up off Amazon.
Hi Bill,Sorry - was away on a quick work trip. If you don't mind waiting until this weekend, I'll take one of mine apart and take a few pics. Can't remember if you need a spring compressor to disassemble or not. I *think* you don't have to remove the trigger group - just push out one or two of the pins that hold things together, but I'll have to look at it this weekend and post here. If I haven't posted by Sunday evening, just pm to remind me.