I recently bought a Diana 350 Magnum .22 and due to Swedish gun laws it comes with a 492 f.p.s power setting. It has a different spring and piston in this version. As I keep it in Norway where the laws are different I also bought it with a so called export system containing the full power spring and a different piston. My problem is that with this installed it delivers only 600 f.p.s with HN FTT .22
Does anyone know what the problem might be? What should the size of the transfer port be on a proper/fullpower airgun?
Regards.
Thanks! That must be the problem. Never thought of that. Iīve been looking for a V-mach/Maccari FAC kit on the net but canīt find any. Does anybody know where to get a kit? Also looking for metal parts for it. Hate the plastic trigger and safety! Any suggestions?
Br.
To keep the Diana 350 at low energies, the piston is also exchanged.
See the link of this German vendor to find out. Even if you do not speak German, the picture will make it clear.
- he's tired of the goony birds buying springs thinking they will get some insane increase in power.
He briefly made an "Arctic"-designated spring specifically for the 350, which actually reduced the stock ft. lbs. output (unspaced); it also made for a more reliably accurate gun.
The spring in my link above exactly matches the physical dimensions of the defunct "Arctic".
Stepar, what will the three nine ultra spring produce? The dimensions are the same
but, is it the same lower output as the arctic? If yes, if it is spaced will it be
equivalent to the stock spring? I'm not a goony bird but I want to keep the power
level the same as stock.
Spaced up 0.5", 740 fps w/ 15.9 JSBs for 19.3 ft lbs. This gun has a snugly buttoned piston, which definitely scrubs off some speed. Tack driver, now as accurate as my 460, which is saying something.
Generally runs around .6" for 5 shotters @ 30 yds.
I bought an Artic spring in March and immediately put it my 350 in .22. I was disapointed in the MV at 710 fps with Crosman Premier HP 14.3gr. Although the gun shot smooth with the spring, it was not worth the trade off as I missed that punch delivered from the OEM. I never cronied the OEM but best guess it was close to 875 fps. I shot so many pellets through the OEM that when I finally did get a crony, the OEM spring was only doing 650fps. The OEM spring never broke, it just weakened from so many shots. Anyway, a fellow named Joe on this forum sold me a "Macarri Mongoose" spring that I was very satisfied with. Gave me 825 fps and very smooth. My gun loved it. Well I put a BUNCH (thousands) of pellets through her and that spring broke recently. I just re-installed the Artic and once again shooting 710 fps. I would really like to find another Mongoose but don't have a clue where to get it so I guess I will be purchasing OEM from Umarex. Does anyone know the story with the Macarri Mongoose and why is it apparently no longer available? I would definately buy another. Has anyone else gotten better results than I am with the Aritc?
I am getting 790fps with Cp's 14.3 grs. With my arctic on all steel monolith guides made by JM. I might try to get a bit more out of it next time in the gun by using a Tesla seal (harder than the apex) sized after having the tube checked for size issues as a local friend with machines can hone the tube to perfection.
The 'Mongoose' is JM's FWB124 spring. Look in the FWB124 Sporter section. Its very close in size to a stock 350 spring, but I am guessing the wire dia. will be smaller.