Installed my tune kit & muzzle break on my qb79

[p8ntballernwpa]

Easy install, everything works great except for two things. After installing the muzzle break the pellets topple now and give the impression of smaller groups because of the bigger hole, but in reality it is less accurate in my situation. Also the new clear o-ring to replace the orange looking one doesn't fit right and leaks gas when the rifle is reassembled.

Hopefully someone can chime in and help me out with the installation of the clear o-ring.

thanks

[Bentong]

Are you talking about the gas block or valve seal?

[p8ntballernwpa]

breach seal is what it is called

http://www.archerairguns.com/ProductDetails.asp?ProductCode=AAQB79SEALKIT&Show=ExtInfo

its the clear ring thing in the picture.

thanks for the help

[Bentong]

Ok..that's the transfer port seal. That's suppose to be pre-measured already and  drop in fit. Just need to make sure before you tighten up the breech screw, get it straight so when you tighten it..it doesn't get pinched.  On my QB78d & QB79 I just use the poly tube I got from Home Depot used for ice maker and got a foot for $1.00 IIRC.

* What do you use to power her?

[fisherdude]

If the pellets are the proper caliber, they shouldn't tumble.  They are likely hitting the break somewhere  or are geting deformed somehow.

[p8ntballernwpa]

The hole for the transport seal isn't the same size between the metal tubes. The top is smaller than the bottom.

I use co2

[p8ntballernwpa]

They stopped tumbling after I went back out to shoot after dinner, and was shooting great.

Must be it just needed sometime warm or something.

Never doubted Archer's stuff, I just like it better when things work the way they are supposed to right off the bat.

[Bentong]

p8ntballernwpa - 5/25/2010  11:16 AM  

The hole for the transport seal isn't the same size between the metal tubes. The top is smaller than the bottom.

I use co2

The poly tube seals when it's wedge flat to the breech and valve that's why it's a must to get the right length of seal. Too long and it gets squeezed and deformed that restrict the flow and cause leak. Too short and it's not wedged to seal. The seal you got don't need to go in the breech hole, it just get pushed against the outside breech hole then sealed by the the 3 o-rings on the barrel.

I have a modified 1377 carbine and from what I observed, provided there is no restriction where the pellet spits out the barrel like clipping from muzzle brake or burr/poor crown...each type of pellet will be affected from the MV when it leaves the barrel. I can vary the pump to get higher or lower MV to get the pellet shoot true to target. Some pellets tumble with low power then punch clean holes with higher power.

[p8ntballernwpa]

So what I need to do is cut it to the correct size i need and it should work then, right?

[Bentong]

The length should be 1/8" and both end square or it will not seal. I had to vary the length to come up with a leak proof seal. If it leaks, look at the way the seal is squeezed..if you see restricted hole it's too long and if no mark it's too short..got to go in between like 1/8 inch. The key is to cut both ends flat. I used a 1/4 ID tube and slide the tubing and measure it then slice it with my xacto knife. Try this old thread for guide >  http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=1444&posts=6&highlight=qb78%20poly%20tube&highlightmode=1#M7949
FOR TUNING >>  http://charliedatuna.com/CO2TuneByCharlie.htm

[p8ntballernwpa]

I am going to have get some of that tubing cause I messed up the two pieces that came with the kit.

[Stephen Archer]

Glad you have it sorted out and are happy with Tune Kit and Muzzle Brake (I think!).

I find that accuracy is normally improved by the muzzle brake, although the point of impact is usually a little different from "pre-brake" shots. Let me know if you have any issues and we'll help resolve them.

Stephen Archer
Archer Airguns Inc.
Store: http://www.archerairguns.com
Blog: http://www.archerairguns.info
Video: http://youtube.com/archerairguns

[p8ntballernwpa]

The break and tune kit work great except for the poly tube. It was too long when I first put it on, so it was crushed when I put the rifle back together. With the next tube I tried making it little smaller so when the rifle gets put back together it doesn't get crushed, didn't cut exactly straight all the way around and so that one leaked too. I'm back to the original orange colored one, which is fine. Just wish I could have got it right see the difference in performance. But overall the break and tune kit is a great buy. Pellets hit harder even just with the different bolt.