Sierra-Pro lives again!!!,..but not without a self taught.....

[tjk]

amatuer tuning lesson.Note to self,...Count the dang coils you idiot!!!!! Well today I received two packages in the mail,....parts!!!!!! Maccarri and Crosman. Another good excuse to toss the shovel and mattocks aside and have some fun!!! But it wasn't alll that fun for a while.Anyways, I've had my hot-rod shooter laying in pieces for some time anxiouslyawaiting on some fresh parts. The old Tarantulla spring was spent,...and all I needed was to put her back together. Now CDT TT'd this shooter, so all I thought I needed to do was drop in a new spring and seal and everything would be hunky-dory!!!!!!....NOT!

Everything went back together like patchwork until I gave her a cocking test,....wouldn't catch,...so I spent most of the day modifying the trigger housing to make it work,...to no availe.Good thing I bought two trigger assemblies from Crosman!!! LOL's. So I finally gotan idea andremoved thetop-hat,..and she cocked!!! Hitting in the 850's,..but that wasn't enough!!OK, it ain't the trigger group. I kept thinking the trigger wasn't close enough to engage the sear,...fact of the matter,...the spring had two extra coils more than the old Tarantulla spring,...about a .254" difference, but I discovered this later in the day!!

Any how,...After a shower and a walk to the store with my daughter for someice-cream,..And I needed some down time to get my mind off of "things",....I went back to work and "COUNTED THE COILS" and discovered this differenciation!!! Can I get a "John-Boy and Billy 'duh-huhhhhh' please"?!?!? It was the spring the whole time,...not the trigger,...not the guides. Somebody slap me for being a bone head!!! I ended up tapping out the custom rear spring guide out of the bolt block, removed the spring seat and sawed of about a 1/4" off of it. Slapped her back together, and everythings'Peachy'!!!!

Now here's whereBob and Gene are really going to chastise me!!!!! Since the Apex seal (the red one)thatBob installed looked fine,...I decided to stick with it and save the other three new seals for future use.Re-installed the top-hat,...and comenced to testing,.....started out in the 850's,..OK I thought,...not the power jump I exspected,...but as the lubesstarted migrating out of the compression chamber and thinning down with the dieselling,...low and beholdshe's now hitting the high 800's to low 900's,...when I saw 922 on the chroney,...I about wet my pants!!!!! LMAO!!!!!! My ideal .177 cal "BT" huntingvelocities (high 800's),...and these were with RWS Super-Domes!!!! Oh Yeah,...I got my Hot-Rod back,...and she's hungry too!!!!!.Now that that problem is solved, I plan to break her down (trigger wise)tommorrow for a thourough cleanning and tweeking!

So Let this be a lesson to other home tuners,...Count Your Coils so you won't waste an afternoon on DA'd BS theories like I did!!!None the less, the lesson was learned,..and won't soon be forgotten!!!! Happy shooting,...and Tuning!!!! tjk

[gamo2hammerli]

Hey tjk....when you count the coils...does that include the ends too?  Good job in your repair with your Sierra Pro.  I wonder if all SP's are finicky....mine sure was until I cocked her and let her sit for 10 hours.....2 times....now I can shoot her good....I use mine in the 25 Yard Open Sights match....any misses is MY fault.

[tjk]

Thanks Stan, I start counting at the end half way between the the first full bodied part of the 'un-sanded part' and start from there. Still having a time smoothing things out, and may break her down completely and start from scratch. Good news is that the seal and spring are doing fine,..but the cocking still feels scrunchy at sear catch, and the trigger still feels a bit sandy. But it's been fun getting her back into shape! Updates Later!!!! tjk

[Gene_SC]

LOL Thomas, that is on of the most important steps of tuning.. Ya gots to use the calculator.. Wire dimensions, coil count, I/D and O/D is the key to tuning a springer. You can figuere right down to the thousandth if it will go or no go.. I gained a lot of knowledge on my own moding the Chinese springers with different types of springs ect.

Glad you figuered out the problem but cutting a spring is... Yikessssssssssssssssssss

But you got er done and that is what counts with a home tune. Getting her done and learning..

[tjk]

No No Big Daddy Gene!! I cut the rear spring guide seat (the black plastic part), not the spring...I ain't even dumb enough to try that!!!LMAO,...ok the thought did come to mind I admit,...but I opted for the plastic instead!!!! Reworked he trigger and all that's left is to get her zeroed in!!!! Thomas