GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: nervoustrigger on July 02, 2014, 03:15:19 AM

Title: groups with QB78 HPA conversion
Post by: nervoustrigger on July 02, 2014, 03:15:19 AM
The QB78 HPA conversion I put together a few months ago really seems to have broken in nicely.  GTA member Andrew (MEAT) put down a set of excellent 43 yard groups with it a few weeks ago measuring 0.25", 0.31", and 0.37".  That is the furthest I can shoot in my yard.  Today he suggested I try stretching out a little further to see how it does.  I have been doing some pesting for a neighbor and they have a good 60 yard shooting lane there so I decided to give it a try this evening after work.

Sitting at a picnic table with a front bag, the first group measured 0.69" and was biased to the right just a bit.  I gave the scope a slight adjustment and shot a second group that looked like a single hole through the scope, but when I reached the target I noticed a hole out to the right on the black line that opened the group up to almost the exact same size as the first group, 0.70".   Bearing in mind this is a stock QB barrel, a couple of 1.1 MoA groups at that distance is very encouraging.

The 4 shot groups measured 0.39" and 0.31" and there was a variable breeze today so maybe I can improve the results on a calm day...or with pellet sorting or with a rear bag or some combination.  If the weather holds this weekend, I'll see if I can get some more groups.
Title: Re: groups with QB78 HPA conversion
Post by: vigilandy on July 02, 2014, 03:35:57 AM
That's pretty amazing Jason!  I can't even shoot groups like that at 30 yards!
Title: Re: groups with QB78 HPA conversion
Post by: DR on July 02, 2014, 08:01:15 AM
Nice shooting!!
Title: Re: groups with QB78 HPA conversion
Post by: Yarp on July 02, 2014, 08:37:09 AM
Great shooting.
Title: Re: groups with QB78 HPA conversion
Post by: clgraham82 on July 02, 2014, 08:59:03 AM
Good shooting!
Title: Re: groups with QB78 HPA conversion
Post by: twith70 on July 02, 2014, 02:25:42 PM
Nice shooting? What velocity is the output on the QB?
Title: Re: groups with QB78 HPA conversion
Post by: nervoustrigger on July 02, 2014, 06:07:34 PM
Thanks guys!

Andy, man that QB is still not grouping for you?  I was rooting for you to get it sorted out.  Let me know if I can help.

Twith70, I have my 78 adjusted to shoot the JSB 18.1gr at 900fps (about 32.6fpe).  The 60 yard target was pinned to a piece of 3/4" plywood and the pellets were blowing out the back...not just the tightly-grouped ones but at least one of the flyers, maybe both.
Title: Re: groups with QB78 HPA conversion
Post by: vigilandy on July 03, 2014, 01:16:33 AM
Thanks Jason.  I actually haven't had much time to work on it.  Not that I have any new ideas!  More like debating whether to pull the tank block and use it on the FDPCP....