
The APS IISV is a piece of work. The receiver, bolt handel, outer barrel, and the flash hider is metal. The stock is adjustable for pull. The trigger is crisp and the action is lightening. So why am I trying to modify a good thing? Well... Because I can.
Here's a list of modifications I plan to perform when I have time.
Mounting Optics : The base that came with the gun is not weaver. Which makes fitting a pair of rings difficult. My plan is to mount a weaver style base to the gun so I can install the Bushnell SportsView scope. Solution : I found a cheap old pair of rings that I filed off the weaver notch. I put tape on the base so the base don't scratch it. I put another couple of layers of tape just so the ring will mount firmly and that seems to work well enough. I also found that Millet rings will also work if you make plastic spacers to level out the Weaver notch.
Mounting Bi-Pod : The forward sling swivel is on the front on the stock which is the wrong place to mount a Harris Bi-Pod. I need to drill and install a sling swivel on the bottom of the stock so I can mount the bi-pod. Solution : Went to a gun show last weekend and picked up a Harris Bi-pob, the LM model, and a sling stud. I drilled a hole and screwed the stud in. The bi-pod mount with no problem.
Power Upgrade: This involves replacing the spring guide and piston with aluminum ones and installed a more powerful spring, .
Sound Suppressor : Not much of a modification. All I need to do is to unscrew the flash hider and screw on the suppressor. That's it!
Range Time (Pre-Mod):
It gets dark too early now a days. I had to play hooky from work, took off work an hour early just so I have some time to play with the APS IISV.
Chrono Reading:
286fps with .20g bb
235fps with .36g bb.
Accuracy: My scope is sighted in at 10 yards and it shoots 4 inches high (I cranked the cross hair as high as it'll go and it still shoots that high. Guess I have to modify the scope rings.). I set up a target, an orange 2'X3'poster board, at a range of 20 yards then 30 yards and had a go with the .2g bbs.
At 20yards it shoots about 12 inches high. Grouping is around 4 inches.
At 30 yardsit shoots 2 feet to 2.5 feet high. Grouping is around 2.5 to 3 feet.
The back spin caused by the hop is amazing. shooting almost parallel to the ground at a height of 10 inches, the bb goes flat for around 15 yards then curves up so it'll pass over a 8' tall hedge at 45 yards. However, it does this consistently so a long range shot is not impossible. But this does make the 9X scope I put on the gun pretty much useless.
Next I'll try the .36g bb to see if the heavier bb can tame the back spin caused by the hop-up.
Modification:
I Finally found some time to my self to perform the modification. I took the gun apart with help of the SeiBiDo Airsoft Catalog from 1996.
Using hex keys that came with the gun, I removed the two bolts that holds the action to the action. I drilled a hole in the stock and screwed in the swivel stud so I can mount the bi-pod. The plastic the stock is made of is pretty soft so the bi-pod was mounted in 20 minuets.
I then unscrew the flash suppresser and screw on the sound suppresser.
The barrel is unscrewed from the receiver. The bolt handle is removed by unscrewing the retaining screw. Watch out for the little tab that slips in at the base of the bolt handle. don't loose it. The rear of the bolt is slid out and the bolt handle is extracted. The bolt retaining lever is then removed and the bolt slid out of the receiver. A special nozzle tool is needed to remove the nozzle. Since I don't have this tool I jerry-rigged one and the nozzle pops right out with the piston. The spring and the spring guide is removed by tilting the bolt upside down. The old spring is much thinner and shorter than the new. After the piston gasket is transferred to the new piston I sprayed the new spring, spring guide and piston with silicon grease. the spring, guide, and piston is inserted back into the bolt. Care was needed to re-screw on the nozzle. The rest of the assembly is pretty much the above in reverse. Oh, be careful when putting the bolt handel back. There are three spring loaded retents that may bend if the handel was in inserted straight in.
Result:
Range Time (Post-Mod):
Had some time before it rained to ran some tests outdoor. With the new spring and piston gives the rifle a sharp crack instead of the old whoomp. Shooting the stock rifle can be described as mellow. It's got a such a big cylinder that a stock spring can achieve 235fps without breaking a sweat. With the super charged spring the velocity is almost doubled and the trajectory is more flattened.
Chrono Reading:
486 fps with .20g bb
415 fps with .36g bb.
Accuracy: I used the same target as last time.
With .36G BBs
At 30 yards it shoots about 6 inches high. Grouping is around 3 inches.
At. 47 yard it shoots around 12 to 18 inches high. The grouping is around a foot.
Conclusion:
The upgrade made a good grifle into a kick ass rifle. The APS2 can now hit a man size target at close to 50 yards consistantly and pretty quietly too. However, At 415 fps I can not use this gun in a game least I shot someone at close range. But it does look mean though.