Tuning a cheap Chinese airgun - Part 1
by Tom Gaylord
This "deluxe version of the TS45 sidelever was supposed to be an 800 f.p.s. gun. I tested it thoroughly to discover if it was a diamond in the rough.
B.B. Pelletier turned the blog over to me today to address tuning an inexpensive Chinese spring-piston air rifle, because I did just that for The Airgun Letter, my monthly newsletter that ran from 1994 to 2002. I had a lot of inquiries asking me to test Chinese rifles, but I had owned several and found them to be unsatisfactory, so I was reluctant to put them into my newsletter. My readers pestered me until I finally gave in and ordered one - a TS45 sidelever. I had owned an older B3, but I knew that one was too primitive to work on safely, so I took the advice offered by Howard Montgomery of Reno Airguns and went with the 45.
What my readers said
My readers said that Chinese airguns were wood and steel and represented a good value for less than $40 - pretty much what people still say about the cheap ones today. The importer advertised that the rifle was capable of 800 f.p.s. in .177, which mine was, so the first thing I did was put it on a chronograph. Beeman H&N Match pellets (7.6 grains) delivered an average of 467 f.p.s. with a 43 f.p.s. spread over 10 shots! I figured I would hear all sorts of excuses as to why my gun was so slow, but I never heard a single one! The Chinese gun lovers were a forgiving lot! Well, they would have to be, wouldn't they?
My rifle (if it was rifled - I never knew for sure) shot H&N Finale Match pellets into 2" groups at 10 meters. That was the best it did. Other pellets grouped 3" to 6" at that distance. The bore was so large that pellets fell out of the breech after being seated flush. I had to hold the rifle level until the sliding breech was closed to keep the pellet in the barrel. I don't know what your criteria is, but my expectations for a pellet rifle run higher than that.
Never stopped dieseling
That rifle smoked like a teenager at the mall! Every shot produced a cloud of smoke that smelled like bacon frying. Before chronographing, I shot 600 shots to break it in, but nothing changed, and it still smoked with every shot.
Huge transfer port!
The air transfer port was far too large for the power of the rifle, with the probable result that the piston was slamming against the end of the sliding compression chamber on every shot. The pellet offered no air resistance because of the oversized bore, so it's a wonder this rifle was able to shoot at all!
Fit and finish
Ever see a grade school craft project done by some disinterested kids? That's how this rifle looked. The "stock" appeared to have been gnawed by a rabid beaver, and the metal parts were left as they fell from the punch press and screw machine, where they don't sharpen their bits very often. Nothing to be proud of.
The sights were pretty conventional, but the rear sight was placed inches from the shooter's eye. That works with an aperture sight, but this was a notch and I couldn't see it that close, which is probably the reason for a lot of the inaccuracy. It also told me that whoever was making this gun was not a shooter and had never tried to shoot with his product.
A formal dinner at the Munsters' was my description of the trigger. It was both stiff and creepy. Not as heavy as I'd expected, but it made it impossible to do my best.
My suggestion was to use the gun in lieu of a fence post, but I had a few readers who thought differently, so we soldiered on. I had purchased a Lothar Walther air rifle barrel for $20 (this was 1996, and the barrels were left over from when Benjamin stopped making the Sterling spring rifles), so after this introduction we were poised for part two - where the rifle got tuned. I know this is what you've been asking for, so stay tuned!