Go to www.airrifleheadquarters.com and click on tune kits.Scroll down till you get to the GRT kit for Diana 48, etc. This fellow makes and sells the finest springs and guides anywhere.The GRT kit will lower the velocity of your 48 a bit and make it considerably smoother.The heavy tar that comes with the kit goes on the outside of the spring(about one third to one half of the sample enclosed will set it up perfectly.
"The Almighty grants us rights, men restrict them".
I have one of his grt kits in my 48, but its still not 'easy' to cock. I'd send an email to Maccari at that site to see if he has a 12 ft. lb. kit for that gun. If he does, it should make cocking it quite a bit lighter, although velocity would be significantly reduced also.
JM (Maccari) has a regular spring kit for the 48/52. I 've read that cocking effort does improve plus power is maintained and the guns are smoother shooters. I would try that first unless you 're set on a 12FPE gun.
I recieved my shipment notice for my GRT kit this a.m. . I emailed for info Friday a.m. ,before I even finished checking the mail I had a responce in the inbox (or about 10 minutes later LOL ) . I'm really hoping for decent improvements for this already sweet "R" code 48 .
I checked with JG airguns and he told me his Titan no.1 mainspring will take the power of a 48 down to 12fpe that might be also something you can consider.
Hey fellas, remember there's a FACTORY reduced velocity Mainspring that's legally mandated to be used in several Countrys with Power restrictions (ie: Germany).
Diana sells a 700fps (.177), Low Joule, Spring that's available for most rifles thru Umarex now. I just checked on the Model 34/36/38/40/late 45 spring and they have em for under $20!
SUre JM makes a wonderfull piece of wire but Diana Factory Springs are pretty decent too.
Just a suggestion, it might be another way to go...
I worded that all wrong I meant to ask about the part# on the spring that Umarex has, a mainspring for around 18.80 to take the power down on these guns is a perfect deal less expensive than the Titan springs and will keep the gun all factory good deal.
I just took 4 coils off(1.55") a 48/.177 last night. Actually a brand new gun and only shot it once with the original setup. SPROINNNGGGG!! The cocking effort WAS a bit stiff but I had been reading all the posts about de-tuning and wanted to go through the gun before shooting it anyhow. Found a bunch of debris in the cylinder port that seemed to be part of the seal. Easy to remove and everything else in the gun looked just fine.
Don't have a spring compressor and it isn't really needed with the 48 but it was a LOT easier to get the pins in with only a couple coils worth of preload vs 6. Cocking effort is now 29lb max measured with the lever @ 90deg.
I cleaned the piston/seal front and wiped out the chamber but didn't change the lube. Will change over to the JM products when they arrive. NO dieseling and the gun shot nicely at this level of spring pressure.
Velocity was 725 fps ave. with Crossman Premier Ultra 10.5grn which makes it around the 12.5ft/lb level. Easily put them in the same hole @ 10yds so my accuracy worries are gone. I'm liking it a lot!
just clipped about 1.5 inches off my m48 spring and it did help lower the effort needed to cock this rifle. It lowered the speed too but this is not an issue with me. After reading a few posts on detuning these rifles it sounds like piston recoil is a issue which this rifle has compared with my HW 50S. So maybe a lighter piston, aluminum or titanium...
