Terminator Tuner Testing on the CZ 457

ShawnCarlock said:

05-25-20

Tuner testing today with the CZ 457

Tuner: DE Terminator Tuner

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ShawnCarlock said:

05-25-20

Tuner testing today with the CZ 457

Model: Varmint
Serial # D187927
Barrel Length: 20.5"
Barrel Twist: 1-16"
Barrel Profile: .862" straight
Stock: factory pillar bedded
Trigger: factory, tuned to 8 oz.
Bedding: Epoxy recoil lug into stock
Base: DIP Inc. 20 moa 11mm adapter to Mil Spec rail
Rings: Warne VS rings 1"
Scope: Weaver T36 - 36x
Tuner: DE Terminator Tuner

Testing flow chart:

• Starting bottomed out, shoot 3 shot groups in 1 revolution increments
• Find best group and shoot 3 shot groups starting at -1/2 revolution and ending at +1/2 revolution in .10 revolution increments.
• Identify best group and shoot it again, also shoot +.10 and -.10 revolution again but all in 5 shot groups.
• Write this setting down and log atmospheric conditions

Model: Varmint
Serial # D187927
Barrel Length: 20.5"
Barrel Twist: 1-16"
Barrel Profile: .862" straight
Stock: factory pillar bedded
Trigger: factory, light spring, adjusted 8 oz.
Bedding: Epoxy recoil lug into stock
Base: DIP Inc. 20 moa 11mm adapter to Mil Spec rail
Rings: Warne VS rings 1"
Scope: Weaver T36 - 36x
Tuner: DE Terminator Tuner

All tuner testing conducted at 50 yards outdoors, benchrest, front mechanical rest and rear bag.

Baseline target with no tuner fired with Lapua Center X ammunition

View attachment 218615

I fired targets at all tuner settings on the whole revolution. Clearly there were two nodes that appeared on at 2 turns out and another at 11 turns out. I decided to work the first node by itself. I shot from 0 revolutions to 3 revolutions with very similar results.

View attachment 218619

Clearly 2 revolutions out was the best setting, cutting the baseline bottomed out setting down to a group 1/3 of the size. This was a significant reduction in group size. Now it is time to fine tune the setting. I shot groups at 1.75 revolutions, 2.0 revolutions and 2.25 revolutions. Each ¼ revolution moves the tuner approximately .010". The difference .010" makes is impressive and only goes to prove the sensitive nature of tuning .22 rimfire rifle.

View attachment 218617

There is further testing to do as I can see that when we get out to 3 revolutions accuracy started to open up. There is the potential for slightly better accuracy between 2.00 and 2.75 revolutions. I will break the next groups down to 1/10 revolutions and shoot 10 shot groups conditions permitting to see if there is a slightly better setting to be found.

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Hi-NV Shooter said:

Shawn, Question on the target and groups you got. was your POA center of the bull ? if this is correct your POA was center, where did your first and last shot land in correlation of POA

I am asking because the 1-Rev out group, if the first shot was the one at about 11-o'clock and the next two were centered. IMO the setting is below 2-rev out
probably between .75-1.50 out
one last thing you don't want shots to go left of POA at anytime when tuning.

Lee

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ShawnCarlock said:

Here is the newest version of the Terminator Tuner, we have been doing a ton of testing on several rifle so that the production run is perfect when we make them.

View attachment 235803

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