Would like to know the do's and dont's of a proper gsi j/m spring tune kit for my .177...it comes with I believe tar, spring and guide and was wondering what is the best/proper install along with grease/moly placement....awaiting kit...gun has been debured....also have new seal for install...Thanks...Happy Sniping....Mike......
I saw that You didn't get any replys as to what and how and where etc. as to the JM tune kit and seals and lube .
I am going to be in the same place in a few weeks as I have 2 .34's --- .177 and a .22 both new guns with about 1000 shots each so far .
If you have any tips and or do's or DONT'S PLEASE SEND THEM ALONG .
Hope it all went / goes ?? well for you .
Hope it made a BIG improvement and made an already fine gun even more enjoyable to shoot .
Thanks for any info that you might send along . If I get to it first I will send you what I come up with .
Due to the lack of forum response...I did my own research and everything turned out greater than I expected....She is better than when new as far as accuracy and spring vibration...Seems a little slower but not much....dont mind sacraficing a little fps. for tac driving accuracy and I know it will only get better after a few 1000 rounds...Mike./././/./././.
Maccari used to have some information on his website that I found helpful my first time around. The whole process takes quite a bit of time to type out, and you can search the forums and get most of that info anyway, so I'll hit a few specfic highlights.
1.) get the full blown kit, even if you have to wait to get a few extra bucks. Cuurenttly that means the GRT vice the GSI kit. It's a drop in install.
2.) There is about 80 lbs of pressure on the endcap when it's free when you're uncorking. The kit will install with considerably less force. It can be doone without a spring compressor. A bar clamp is helpful though.
3.) I's suggest you also order some Velocity tar. It's a great lube on the pivot bolt assembly.
4.) The biggest deal is the two back pins. it's easiest if you pull the rear pin first and re-install the opposite way. The pins fit around the safety spring, and if you understand how this works, you can do it in any order. The rear pin actually has the flat spring "clamp" across it's diameter, and the flat spring passes under the front pin.
The trigger can be easily "tuned" by a first time amateur. You'll need a bench grinder with polishing wheel and a dremel tool with polishing felts and some polishing compound. See my post below. If it looks like you want to tear into it email me & I'll send you a writeup on the modular trigger.
Any idea what the initials "GSI" and "GRT" stand for?
I just received a Maccari "GSI" mainspring for my 1968-vintage Diana MOD. 35 (not a kit, just a 34-coil .555" internal dia. top-quality product that I have yet to istall with some Maccari Black Tar and a nice "Maccari" black-and-gold sticker along) and I was wondering if you are referring to the GSI v. GRT springs and what the difference may be between the two.
I have the exact same 31-coil mainspring from JM (BSA Air-Sporter), as well on my 35. It works smoothly and it never gets tired for months on end. From the first to last Crosman Copperhead 7.9 grains, or its favoured Logun Penetrator 9.5 grains, pellet shot during the day, the POI never shifts (w/ a Shepherd 3-10x40 scope attached), since it was sighted-in last year. I just got the GSI as a spare. I may never need it, but I sort of keep it if I want more power (?), which is unlikely. In fact I also have a 30-coil one from JM, also for the 35, for less power in fact, aimed at using the 35 for some precision shooting with a diopter (so I can give a break to my Diana Mod. 60), at some point in the future.