The Original CZ Forum
CZ LONG ARMS => CZ Scorpion EVO => Topic started by: Oldnslow on December 02, 2017, 11:48:35 PM
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Once upon a time I bought a new CZ Scorpion carbine (with the muzzle brake). One of the first things that I did was to measure the trigger pull. This was done before cleaning or lubricating the weapon in any way. The result was an average trigger pull weight, after 10 test pulls, of 9.63 pounds. [#1] Ouch.
Then I cleaned and lubricated the weapon and tested again. [#2]
Then I took it to the range for a 300 round break in and tested it again. [#3]
Then I cleaned and lubricated the weapon, post range trip, and tested it again. [#4]
Then I did a light polish of the trigger group parts and tested again. [#5]
Then I did a light file job on the trigger group parts, followed by another light polish, and tested yet again. [#6]
Finally, I installed the HBI spring kit and tested it one last time. [#7]
Whew! And here are the results.
#1 9.63 pounds :(
#2 9.10 pounds
#3 8.62 pounds
#4 8.26 pounds :)
#5 7.98 pounds
#6 7.38 pounds
#7 4.66 pounds ;D
In theory installing an HBI Delta trigger will reduce the trigger pull by up to an additional 12%, but I was unable to verify this because my trigger pull tester self-centers on the trigger being tested. Since the Delta trigger is at a steeper angle than the stock trigger the tester self-centers higher on the Delta trigger and actually produces higher values, not lower. Since the point on the trigger should be where your finger rests, or at least on the same relative location on all tested triggers, this makes using the normal testing procedure invalid.
Changing the angle of pull during the test so that the contact point of the tester is on the same relative location on all tested triggers is one option, but may not be valid, either. I tried this with mixed results.
Another fix would be to set up a block either on the trigger or some other way so that the location of the contact point on the trigger is consistent between triggers and also maintains the correct pull angle. (I test with the pull angle parallel with axis of the barrel bore.) However, I was not able to setup such a block that I thought was truly valid, but I did the test anyway. The results were not, as I had suspected, valid.
Bottom line on the Delta trigger is that I think it makes an improvement in the trigger pull weight via an increase in leverage, but I can't really prove it.
Finally, I did a medium to heavy file/grind/polish trigger job, followed by a full lubrication, which now yields something less than a 4.5 pound trigger pull with the Delta trigger. That's using a standard test without any correction methods applied. I suspect that if I could do a valid corrected test I would see a final trigger pull weight of just over 4 pounds.
Yes, that was a lot of work. Thank you. ::)
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I am also using a delta, it does feel slightly reduced on my trigger pull weight as well maybe its becsuse it sots dlightly forward so I get more leverage?. The shooters element might be a little better but I'm well under 4lbs and I like the looks of the delta alot better. 8)
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Great info for new owners, HBi gave me similar results with the spring, polish, and shoe swap... 4.5# pull.
I have my 2 friends with new Sig MPX's (we all bought PCC's together) jealous, they are now complaining the scorpion trigger is so much better than theirs O0
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I have put the HBI flat trigger and spring kit in my EVO and it makes it the gun it should be. Love the trigger now. HBI makes some really nice stuff for the EVO. I have their red charging handle as well and couldn't be happier.
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Great info for new owners, HBi gave me similar results with the spring, polish, and shoe swap... 4.5# pull.
I have my 2 friends with new Sig MPX's (we all bought PCC's together) jealous, they are now complaining the scorpion trigger is so much better than theirs O0
Install shims in the trigger and remove most of that long trigger travel. Then they will be very jealous!
- DanT. Phoenix, AZ
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Great info for new owners, HBi gave me similar results with the spring, polish, and shoe swap... 4.5# pull.
I have my 2 friends with new Sig MPX's (we all bought PCC's together) jealous, they are now complaining the scorpion trigger is so much better than theirs O0
Install shims in the trigger and remove most of that long trigger travel. Then they will be very jealous!
- DanT. Phoenix, AZ
Shims you say? I?m intrigued! Link or pics for a ?how to? ?
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Also interested in the use of shims. Ive already reshaped the trigger spring and am happy with that, but low/no cost improvements are always welcome.
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There were several threads. Do an advanced search for trigger with DanT as the author.
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Also interested in the use of shims. Ive already reshaped the trigger spring and am happy with that, but low/no cost improvements are always welcome.
Wouldn?t trigger reset be softer and slower with a reshaped ?weaker? trigger spring?
The way this trigger is designed there doesn?t seem to be a way to reduce trigger pull without making reset weaker and potentially less reliable.
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I would say that yes the reset would be weaker based on a spring that isnt pushing as hard. However, the reset is still noticeably positive. The sear tabs are halfway over the hammer before the disconnect releases it.
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There were several threads. Do an advanced search for trigger with DanT as the author.
I second the above.
Do want Dan says. You will be glad you did! Extremely short take up and reset with a very distinct reset.
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