Ever since I got into PCP's I have admired the look of the AA/CZ S200 with 2 piece stock. Never could find one when I was looking. Well I picked up a Compatto .22 and then an FX Wildcat .177 and swore I was done buying. Then along comes this .177 AA S200 T on a forum at a good price so I have to get it.
When it arrives I take some shots. Since it's the Target model it's tuned WAY down (but it is the 16j version)- 8.44's are in the mid 500's.(5.5FPE) I turn the port screw out and they get up into the 600's. Everybody says these guns can be tuned up to about 14fpe in .177 with some twists and turns, but "major mods" are needed to get anything else. Well I can tell you they are dead wrong. The hardest part is getting the firing valve out of the cylinder. Apparently at the factory the torque these things to 100FTLBS so that those countries with restrictions can't easily "tamper" with them. I tried all my strap wrenches and it wasn't budging.
Well I picked up a 1" pipe clamp that I drilled and tapped for opposing 8/32 screws to fit into the firing valve holes. I also picked up a 3/4" pipe "repair" clamp that fit the tube perfect. It has a rubber piece inside that would seal when clamped around a leaky pipe so it grips the cylinder really good. I put a wrap of "horse bandage" tape (a couple $$ at TSC) on the cylinder to stop any marring and then tightened the clamp down. I then put the clamp into my vice to hold it. I then used a 24" still-son wrench (wouldn't move with the 18") on the clamp and with a "jolt" broken the valve free. I then removed the "pot" and turned out the poppet spring retainer until there was just barely and pressure on the spring.
I filled the cylinder up to 180bar, cranked the hammer spring all the way in, replace the TP adjuster with a 3mmx8mm bolt (max opening) and started a string. (Even with the HS at full preload I can still cock it with my pinky) When I got to 161 bar the 10.34 jbs's were moving at 905FPS. That's 18.8FPE! I wound up getting a string from 870 to 905 back to 870 over 23 shots. 895 avg for over 18FPE
Now since the gun I picked up came with 2 cylinders I left the HS the same and put the other cylinder in without modifying it. Starting at 185 bar I am getting 870-905-870 with 8.44 JBS"s for 14.9 FPE over 30 shots.
Next I took the original TP adjuster and maxed out the adjustment on the low end. It's about 9.5mm overall. I replaced the 8mm screw with this and ran a string with the unmodified cylinder. Starting at 190 bar I get a 35 shot string with 8.44's from 800 up to 826 and back to 800 for avg of 12.4 fpe.
While I could probably get more shots at the lower power level by using lower pressure and less spring, I am still getting decent efficiency (1.32 fpe/cuin) at the lower levels. I'm just not able to use as much of the air. With the higher tune I'm shooting down to about 120 bar and with the lower tune I'm stopping at 135 or so.
So basically I have a 12FPE gun that I can change the TP screw to change it to a 14.9FPE gun. I can then change the air cylinder and it's an 18.5FPE gun.
I have no need for a 5fpe gun, but I'm pretty sure I could put a 3mmx10mm screw in the TP and easily get a 5fpe tune.
Here it is with my MTC Viper 3-12 - it weighs in as shown at 8lb 1oz. Nice little hunting carbine.
When it arrives I take some shots. Since it's the Target model it's tuned WAY down (but it is the 16j version)- 8.44's are in the mid 500's.(5.5FPE) I turn the port screw out and they get up into the 600's. Everybody says these guns can be tuned up to about 14fpe in .177 with some twists and turns, but "major mods" are needed to get anything else. Well I can tell you they are dead wrong. The hardest part is getting the firing valve out of the cylinder. Apparently at the factory the torque these things to 100FTLBS so that those countries with restrictions can't easily "tamper" with them. I tried all my strap wrenches and it wasn't budging.
Well I picked up a 1" pipe clamp that I drilled and tapped for opposing 8/32 screws to fit into the firing valve holes. I also picked up a 3/4" pipe "repair" clamp that fit the tube perfect. It has a rubber piece inside that would seal when clamped around a leaky pipe so it grips the cylinder really good. I put a wrap of "horse bandage" tape (a couple $$ at TSC) on the cylinder to stop any marring and then tightened the clamp down. I then put the clamp into my vice to hold it. I then used a 24" still-son wrench (wouldn't move with the 18") on the clamp and with a "jolt" broken the valve free. I then removed the "pot" and turned out the poppet spring retainer until there was just barely and pressure on the spring.
I filled the cylinder up to 180bar, cranked the hammer spring all the way in, replace the TP adjuster with a 3mmx8mm bolt (max opening) and started a string. (Even with the HS at full preload I can still cock it with my pinky) When I got to 161 bar the 10.34 jbs's were moving at 905FPS. That's 18.8FPE! I wound up getting a string from 870 to 905 back to 870 over 23 shots. 895 avg for over 18FPE
Now since the gun I picked up came with 2 cylinders I left the HS the same and put the other cylinder in without modifying it. Starting at 185 bar I am getting 870-905-870 with 8.44 JBS"s for 14.9 FPE over 30 shots.
Next I took the original TP adjuster and maxed out the adjustment on the low end. It's about 9.5mm overall. I replaced the 8mm screw with this and ran a string with the unmodified cylinder. Starting at 190 bar I get a 35 shot string with 8.44's from 800 up to 826 and back to 800 for avg of 12.4 fpe.
While I could probably get more shots at the lower power level by using lower pressure and less spring, I am still getting decent efficiency (1.32 fpe/cuin) at the lower levels. I'm just not able to use as much of the air. With the higher tune I'm shooting down to about 120 bar and with the lower tune I'm stopping at 135 or so.
So basically I have a 12FPE gun that I can change the TP screw to change it to a 14.9FPE gun. I can then change the air cylinder and it's an 18.5FPE gun.
I have no need for a 5fpe gun, but I'm pretty sure I could put a 3mmx10mm screw in the TP and easily get a 5fpe tune.
Here it is with my MTC Viper 3-12 - it weighs in as shown at 8lb 1oz. Nice little hunting carbine.