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.177cal Crosman Optimus at 50 yards

July 14 2017 at 6:15 PM
TCooper  (Login t-cooper)
YF

This afternoon I did a bit of accuracy testing with my two .177cal Optimus rifles. These are the same rifles that I reported on before but at shorter distances. Nothing special was done to these rifles. One is a Canadian detuned model with a mid-power Crosman spring installed. The other is a full power version. Both rifles had the spring spacers shortened to reduce power. Moly paste to all friction areas and a mild polishing to trigger parts. Longer trigger adjustment screws. Factory guides & top hats, original crowns, OEM mainsprings, OEM triggers, no tube polishing, no barrel lapping.

--- Canadian Version ---
33 coils, .118" spring wire, 170mm non-vented piston
3/4" spring spacer for 1/4" preload
625fps with 7.9gr pellet

--- Full Power Version ---
36 coils, .122 spring wire, 150mm non-vented piston
3/8" spring spacer for 3/8" preload
800fps with 7.9gr

--- 50 Yard Accuracy - 5 shot groups ---

Canadian Version
8.44gr JSB Exact - 2.49, 2.12, 2.98, 2.45, 2.96, 2.22 -- Ave = 2.54" ctc
8.18gr H&N Sport - 2.78, 2.15, 2.54, 1.61, 1.90, 2.38 -- Ave = 2.23" ctc

Full Power Version
8.44gr JSB Exact - 2.10, 2.24, 2.35, 2.10, 2.05, 2.48, -- Ave = 2.22" ctc

The 10m accuracy was previously tested at approx. 1/4" and 20 yard at 1/2" ctc for both these rifles.

I'm happy with the 50-yard accuracy for these cheap springers. Fitted guides might tame them down a bit and give slightly tighter groups, or maybe not. There was a mild but annoying breeze today... so groups might be better on dead calm conditions.


 
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