QB18 / TF49

[plateshooter]

I bought a QB18 a couple weeks ago to have a quieter, lower velocity air rifle for the summer garden pest eliminator. The reviews I have read compared it to the Beeman R7 in power.  

When I received the rifle, the trigger would not hold.  The gun was an accident waiting to happen.  I hate returning things so I took it apart.  I found many things wrong, and I will list them and what I did to fix them.

Trigger does not hold:

The "piston grabber" rod at the end of the piston was not made square to the back of the piston.  This was letting the sear slip off of the notch.  I took a bit of pressure, but using the compression chamber as a cheater bar over the piston, I got it aligned properly.

Accuracy sucks:

There was no machined crown on the muzzle of the barrel.  I used a Brownell's brass ball lap and some 320 and 600 grit paste to finish the crown.  There was no "chamber" in the breech end of the barrel.  Pellets had to be seated with a phillips screwdriver to get them flush with the breech.  A few very light turns with a tapered reamer have Gamo Match pellets seating flush with the breech.  The barrel had several thousand's of side to side movement.  I made an adjustment by pressing the forks together until I had a snug but not binding fit, covered the area with JM molly and reinstalled the barrel.

While I had it apart, I applied the JM lubes to the internals with the exception of the heavy tar on the mainspring.  I used a bit of white lithium as I didnt want to slow down the fps, and there was no spring twang anyway.

I trashed all the auto safety plastic parts and reassembled.  I hate auto safetys, and this gun is so easy to cock, I just decock it if I'm not going to shoot it right away.  (no bear trap etc)

I installed a BSA scope that I had.  I have put about 1000 pellets through it so far.  It will now wack steel 1.5" steel swingers at 35 yards with boring consistancy.  It chronys at 676fps with only 3 fps dev. for 10 shots.

It turned into quite a nice shooter for me.  OK rifle if you like completeing the work that the mfg didn't,  out of the box, not so good.

[JMG]

In looking at the pic of this thing I am seeing a reocurring theme. On a lot of the CHinese B series guns the ergonomics of the pistol grip to trigger seems like it is dismal. On my B3 there is no way for me to get a nice hold on the pistol grip and be able to pull the trigger. I have small hands but I have heard others say thesame the about other chinese guns. It looks like the QB18 has the same problem or am I wrong? How do you like the pistol grip positioning to the trigger?

John

[plateshooter]

John:
I just compared my B3 to the QB18.  I have to really reach for the trigger on the B3, the QB18 is much closer and feels just about perfect for me.  The QBs pistol grip is "straighter" and slimmer than the B3s as well.  I find the QB18 much easier to shoot than my B3, easier to load, and has a much better trigger.  Of course, it cost twice as much at $46.99

[Gene_SC]

Looks like you have done a great job on the your B-18 David. That is a nice project gun.. It is great to be able to work on these cheap Chinese guns and make them shoot like a $200.00 air rifle when you are all done with them.. And just think, you do not have to pay a fortune for them either.. hehe. Just like the B-3, we have had a great time messing around with them and moding them to our needs.. Ed, AKA "Shadow" got some of hooked on them and boy what some of the guys have come up with is very impressive, just like what you have done..

Thanks for sharing

Gene

[JMG]

Hehe we were joking about the reach for the B3 trigger yesterday at the shootout. Not saying anything against or demeaning about chinese people but I always thought they were kind of small like myself and I really dont see any of them being able to reach the trigger real comfortably on the B3 lol.

John