TheTrevor
03-11-2014, 12:06 AM
I'm not quite a full-blown HK fanboy, but you wouldn't know it by looking at the pistols I've owned in recent years. All of my "practical" (i.e. non-22LR-target) pistols in my safe over the last 15 years have been HKs, specifically USP-family guns. I wasn't a particularly active or skills-oriented shooter until I had both time and budget to get focused on improving my skills a few years back. Even then, I stuck with the USP for quite a while because I was certain I wasn't anywhere close to getting the full potential out of the gun, especially as I started to realize how I'd been fooling myself with the usual low occasional-shooter standards.
Fast forward to today. I've been intensively developing my skills with a LEM-converted USP40 since last year, and it's no understatement to say that the LEM conversion completely rekindled my love for the USP. In fact, just in terms of trigger feel and reset I'd have to say that the USP version of LEM is substantially, perceptibly better than the factory LEM setup in the P30 family. Shorter reset, cleaner break, better feel as you press through FPB engagement and sear trip... the whole thing.
That said... I'm in the process of making a fairly quick transition to the P30 in 9mm LEM, and I'm running into a couple of issues that I'd like to share and solicit feedback on. I need to be pretty much squared away on the P30 4 weeks from now, shooting at least at the level of speed & accuracy I can achieve with my USP.
The problem is that my POI keeps getting pulled to the right when I'm shooting right-handed, and to the left when my left hand is driving. Until I got good sights on the gun, I figured it was just struggles with the sight picture, but it turns out I'm actually having a bit of trouble managing grip and trigger on the P30. I paid extra close attention to this on my last range trip.
Trigger distance and trigger-finger geometry
I didn't realize it at first, but the P30 has a significantly shorter trigger-to-backstrap distance with the trigger fully depressed than the USP. My LEM USP40 with the trigger pinned back measures ~62mm, and the P30 shows ~57mm in the same direction, roughly 1/4" difference. When I take a strong master grip with my right hand wrapped securely around the gun, I get very different final resting angles for the distal end of my trigger finger comparing the USP and the P30.
On the USP, my trigger finger is darn close to perpendicular to the long axis of the gun with the trigger pinned, and is perfectly perpendicular as it breaks. On the P30... not so much. By the time the trigger breaks, my index finger is bent at a slightly acute angle which only increases as I press into overtravel.
Changing backstraps doesn't seem to help, because the "large" backstrap doesn't actually do anything to affect the backstrap-to-trigger distance. Seems like they weren't thinking about trigger reach when they were designing the modular panels.
Trigger shape
The USP trigger is reasonably wide and very gently curved across the face, just enough for comfort. The P30 trigger, on the other hand, is definitely narrower and has a more aggressive curvature across the face, with molded-in texture lines running vertically down the face of the trigger. I've grown accustomed to being able to apply pressure pretty much anywhere across the front face of the USP trigger and generate a straight-back press. This does NOT work on the P30.
Get to the point, already...
When I pull the USP trigger, it comes straight back and stops before the forces on my trigger finger start to deflect or slide the point of contact to either side.
When i pull the P30 trigger, I'm finding it quite difficult to keep my press focused on the front of the trigger all the way through and generate a straight-back pull. Once my finger bends past 90deg it rolls right over that rounded front face towards the far side, right as the shot breaks, steering the shot subtly towards the shooting hand side.
What's killing me is that it looks fine in dry-fire, because unless I'm watching very closely AND know what to look for watching the sights, that little bias to the left or right is oh so subtle and easy to miss.
Solutions
Obviously, I'm going to continue to work on trigger control and grip to see if simply retraining my trigger fingers will address this. There is a narrow range of acceptable fingertip-to-trigger contact points and angles that DO work for me on the P30, I just can't find them instinctively and consistently yet.
I'm also going to try a hardware solution to help things along. I ordered a spare trigger along with some other parts tonight, mostly TLG-spec springs plus spares. The plan:
* add an overtravel stop by drilling and tapping a 4-40 hole in the trigger and installing a set screw
* gently recontour the front surface of the trigger to flatten it out to a USP-like profile, eliminating the molded ridges
So.... Am I missing something here? I mean, I'm not flinging lead all over the target backer, I'm just consistently pulling left or right despite good sight alignment and a seemingly-good trigger press.
Open to suggestions. I'll have a couple of days of dry-fire and 1-2 range sessions before I get the new (spare) trigger modified and installed, glad to try whatever diagnostic or corrective drill the PF Hive Mind can come up with...
Fast forward to today. I've been intensively developing my skills with a LEM-converted USP40 since last year, and it's no understatement to say that the LEM conversion completely rekindled my love for the USP. In fact, just in terms of trigger feel and reset I'd have to say that the USP version of LEM is substantially, perceptibly better than the factory LEM setup in the P30 family. Shorter reset, cleaner break, better feel as you press through FPB engagement and sear trip... the whole thing.
That said... I'm in the process of making a fairly quick transition to the P30 in 9mm LEM, and I'm running into a couple of issues that I'd like to share and solicit feedback on. I need to be pretty much squared away on the P30 4 weeks from now, shooting at least at the level of speed & accuracy I can achieve with my USP.
The problem is that my POI keeps getting pulled to the right when I'm shooting right-handed, and to the left when my left hand is driving. Until I got good sights on the gun, I figured it was just struggles with the sight picture, but it turns out I'm actually having a bit of trouble managing grip and trigger on the P30. I paid extra close attention to this on my last range trip.
Trigger distance and trigger-finger geometry
I didn't realize it at first, but the P30 has a significantly shorter trigger-to-backstrap distance with the trigger fully depressed than the USP. My LEM USP40 with the trigger pinned back measures ~62mm, and the P30 shows ~57mm in the same direction, roughly 1/4" difference. When I take a strong master grip with my right hand wrapped securely around the gun, I get very different final resting angles for the distal end of my trigger finger comparing the USP and the P30.
On the USP, my trigger finger is darn close to perpendicular to the long axis of the gun with the trigger pinned, and is perfectly perpendicular as it breaks. On the P30... not so much. By the time the trigger breaks, my index finger is bent at a slightly acute angle which only increases as I press into overtravel.
Changing backstraps doesn't seem to help, because the "large" backstrap doesn't actually do anything to affect the backstrap-to-trigger distance. Seems like they weren't thinking about trigger reach when they were designing the modular panels.
Trigger shape
The USP trigger is reasonably wide and very gently curved across the face, just enough for comfort. The P30 trigger, on the other hand, is definitely narrower and has a more aggressive curvature across the face, with molded-in texture lines running vertically down the face of the trigger. I've grown accustomed to being able to apply pressure pretty much anywhere across the front face of the USP trigger and generate a straight-back press. This does NOT work on the P30.
Get to the point, already...
When I pull the USP trigger, it comes straight back and stops before the forces on my trigger finger start to deflect or slide the point of contact to either side.
When i pull the P30 trigger, I'm finding it quite difficult to keep my press focused on the front of the trigger all the way through and generate a straight-back pull. Once my finger bends past 90deg it rolls right over that rounded front face towards the far side, right as the shot breaks, steering the shot subtly towards the shooting hand side.
What's killing me is that it looks fine in dry-fire, because unless I'm watching very closely AND know what to look for watching the sights, that little bias to the left or right is oh so subtle and easy to miss.
Solutions
Obviously, I'm going to continue to work on trigger control and grip to see if simply retraining my trigger fingers will address this. There is a narrow range of acceptable fingertip-to-trigger contact points and angles that DO work for me on the P30, I just can't find them instinctively and consistently yet.
I'm also going to try a hardware solution to help things along. I ordered a spare trigger along with some other parts tonight, mostly TLG-spec springs plus spares. The plan:
* add an overtravel stop by drilling and tapping a 4-40 hole in the trigger and installing a set screw
* gently recontour the front surface of the trigger to flatten it out to a USP-like profile, eliminating the molded ridges
So.... Am I missing something here? I mean, I'm not flinging lead all over the target backer, I'm just consistently pulling left or right despite good sight alignment and a seemingly-good trigger press.
Open to suggestions. I'll have a couple of days of dry-fire and 1-2 range sessions before I get the new (spare) trigger modified and installed, glad to try whatever diagnostic or corrective drill the PF Hive Mind can come up with...