Canadian Airgun Forum

Hi everyone, I recently bought a benjamin classic .22 495 fps from a friend who was moving away and having shot it a little bit I want to do some work to improve it. My first issue is velocity. I have my PAL so no issues with upgrading there. My question is which spring I should order for it and whether the piston also should be swapped out? The piston is about 6in long and the barrel comes back to about a 35-40 degree angle when cocking so I dont think it has a long piston? The spring is only 9.5 in long and had very little preload at all. I added a 1/2in shim behing the spring and lubed everything which quieted the gun down and added some velocity but I would like to get it around 600-700 fps if I can.

I've owned one of these myself -it was the rifle that got me back into the sport and down he road to PCPs.

Haven't any experience with increasing power on this model, but the trigger action can be vastly improved by installing a roller bearing. https://www.youtube.com/watch?v=L7QimswXxsw

Cheers!

Avianmanor

_________________
*Air Arms S510 Extra*Artemis M11 MK II*CZ 200S*Benjamin Marauder*Brocock Concept*Cometa Orion*Daystate Huntsman*Daystate Revere*FX Dreamline*FX Streamline*Hatsan BT65*Kral Puncher*Reximex RPA*QB78D*Weihrauch HW100S*Artemis PP700SA*PP750*Snowpeak CP1-M*

I have one of the original ones with the "stainless" finish. Great rifles except for the usual crappy Crosman trigger. A nice GRT-3 replacement solved that...

_________________
Air and springs and CO, too

Go for B18-00-4D should get you the velocity you are after. Gravel Agency sell it for around 14 dollars.

通过我的 ALP-AL00 上的 Tapatalk发言

_________________
AirArms TX200HC
AirArms S400F
Diana Outlaw
Feinwerkbau 300S
FX Dreamline Classic
Weihrauch HW100KT FSB
Weihrauch HW97KT
Weihrauch HW50S
Artemis M16
Artemis PP700
Weihrauch HW40
Beeman P17
Stoeger XP4

Thanks for the input everyone, I shot it over a chrony last night and with the 1/2" shim it now shoots an average of 470fps with 14.3gr crosman premier hollow points. And about 520 with 11.9gr rws hobby wad cutters. Both pellets make about 7 ft lbs . I also purchased a bearing to mod the trigger today. I may order a spring soon as well but I am pretty happy with the shooting characteristics I only want to increase velocity to the 600 fps range so I'm wondering if a longer shim might do the trick ... although I may be better off putting in a full power spring and trimming it to detune to the power level I want. I have seen several references in this forum to a springer tuning guide by chevota but cant find it on the forum, Can someone point me in the right direction?

Private Message chevota. Spring listed above will give you 713fps with Crosman HP 14.3g. 663fps with JSB 13.43g. 642 with JSB 14.35g. 642 with JSB 15.89g.
That's what I experienced with my Benjamin Classic. Seal was bad, replaced that and spring, shot the 15.89g JSB the best, that's what I choose.
Roller bearing only helped slightly, still a garbage trigger.

Sent from my LG-H873 using Tapatalk

I have had this rifle for about 8 years and I am getting between 700 and 715 with the piston mod and spring upgrade, I really like it a lot and am now in the process of entering the PCP world. PM me if you like and I can give you the details