QB78 on air newbie all in ?s

[cclingma]

I say all in bacause I cut the threads off the tube recently to accomidate tank block and 13ci Ninja. I'm a slow learner so even with all the great post on here I still have a couple questions

1.  I cut my tube long enough to keep from having to mod stock to fit tank block.  I also intend to pin the block in case I decide to adjust regulator for higher pressure.  Question is , should I cut a little more tube off and inlet stock for tank block?  Pretty much hide block?  I thought I wanted to try to keep factory barrel band in oem location but maybe that's not all that important.  Of course if the block moves back the band goes too.

2.  Will I have to add a spacer to hammer spring if I do cock in opening mod by cutting rear down slot and removing rear pin?

Thanks

[sr1sws]

I say all in bacause I cut the threads off the tube recently to accomidate tank block and 13ci Ninja. I'm a slow learner so even with all the great post on here I still have a couple questions

1.  I cut my tube long enough to keep from having to mod stock to fit tank block.  I also intend to pin the block in case I decide to adjust regulator for higher pressure.  Question is , should I cut a little more tube off and inlet stock for tank block?  Pretty much hide block?  I thought I wanted to try to keep factory barrel band in oem location but maybe that's not all that important.  Of course if the block moves back the band goes too.

2.  Will I have to add a spacer to hammer spring if I do cock in opening mod by cutting rear down slot and removing rear pin?

Thanks

My $.02, and probably not worth that.  I have a QB79 so I understand where you're going, but don't know specifics.  I'm sure someone else will jump in... there's a lot of knowledge hanging around here. 

I think you'll want to leave the gas tube as long as possible.  This will give more HPA available for each shot, makes for higher power and less variability - at least that's what I've gleaned from lots of reading.

I suggest drilling a 2nd hole behind the front hammer pin hole and use it without the rear pin for cock on opening.  You'll have to grind a flat through the case-hardened exterior.  You'll also need a spacer between the rear gas tube plug and the cocking block.  I saw one article where this was made from an empty CO2 cartridge - a 1" length.  You can put washers over the spring guide part of the cocking block to adjust striker pre-load - or make an RVA.

See: http://www.network54.com/Forum/79537/thread/1279373919/Is+this+the+cheapest+and+easiest+QB78+cock-on-open+mod+ever

I'm sure you'll have more questions.  There are lots of answers on here, the Yellow Forum and several others.  You should have lots of fun.  I've had my QB79 just about 2 months and have found it fun and easy to tinker with.

Good luck!
Steve