Gamo CFX .17 Cheap Tune Up
Posted: Sat Oct 03, 2015 5:32 pm
So I have had the CFX for about 5 years and with the boys have probably put 4-5 tins of pellets through it. now wears a Nikko 6-24 scope. I put a Charlie deTuna trigger in it early on which helped but the trigger was creepy, inconsistent, but not heavy. The main spring went clang, twang, clang on firing. Not knowing any better we accepted it.
Well after attending the Newcastle FT day a couple of months ago I came away with an appreciation of what a good AR can do. The PCPs were incredible to shoot but the biggest thing was how smooth a tuned springer can be and a good trigger is so important in any firearm.
So I read a lot on the web about tuning etc. and decided I didn't want to put $ into the rifle but wanted it better. Only way was to pull it a part and have a look, nothing to loose. Found sharp edges and rough stamped metal on all parts including the trigger sears.
I started by smoothing all the edges where the cocking leaver slide runs in the spring housing and any other edges with emery paper. The main spring clanging was easy to help by putting a plastic sleave inside the steel tube so there is no metal to metal contact, a piece of drink bottle did the job.
Then I looked at the trigger for a while to see how it worked. The sears are as they come stamped out of the sheet steel, well if you can call a rough, round, off angle edge a sear. Since there was lots of sear engagement I took to both with a file and then stone to get a clean sear edge on both for a definite let off point. The steel did not seem hard, it is a cheap AR. ( when I have it all apart again I will do some more honing, there is still room for improvement and plenty of steel).
The trigger has a sort of sear adjustment screw that isn't long enough to do anything useful. It runs through a plastic moulding that is pressed into the housing and wobbles about. I glued the plastic in solid and used a longer screw so I can adjust sear travel and reduced creep dramatically. You would not want to do this without shaping the sears first as I don't think you would be able to safely adjust it with the original sear shape.
Finished by lubing and greasing moving parts.
The result is that trigger is quite good, cocking action is smoother, less spring noise and with the JSB Exact 8.4gn pellets Matt put me onto it shoots very consistently.
So a cheap tune up can be done with a bit of thought and research.
Bruce
- Gamo CFX .17
- DSC02652a.jpg (140.25 KiB) Viewed 586 times
So I read a lot on the web about tuning etc. and decided I didn't want to put $ into the rifle but wanted it better. Only way was to pull it a part and have a look, nothing to loose. Found sharp edges and rough stamped metal on all parts including the trigger sears.
I started by smoothing all the edges where the cocking leaver slide runs in the spring housing and any other edges with emery paper. The main spring clanging was easy to help by putting a plastic sleave inside the steel tube so there is no metal to metal contact, a piece of drink bottle did the job.
- drink bottle spring liner
- DSC02585a.jpg (81.43 KiB) Viewed 586 times
- trigger sears
- DSC02587a.jpg (138.31 KiB) Viewed 586 times
- sear adjustment screw
- DSC02588a.jpg (94.02 KiB) Viewed 586 times
The result is that trigger is quite good, cocking action is smoother, less spring noise and with the JSB Exact 8.4gn pellets Matt put me onto it shoots very consistently.
- 35 m
- DSC02595a.jpg (255.33 KiB) Viewed 586 times
Bruce
