QB foursome (late... gotta tell someone)

[ribbonstone]

Finished converting the old QB78 into a 5mm (MAC 1 25" barrel blank).
Which completes the standard calibers....AR2078 in .177, QB 78 converted to tanker and now in .20, QB79 in .22, and a Mountain Air QB78D in .25 converted to a tanker.

Haven't decided where to set the velocity on the .20...suspect I'll set it in the 630-650fps range (14,3gr. pellets)...will do some 25yard testing tomorrow and see what pellet it likes.

[Jaymo]

Sweet.  I like those QBs. I have an AR2078 in .22, a QB79 in .22, and a TF78 Gold Series in .177(got them all on sale for good prices). Lately I've been playing with bulking my 78GS with my Axsor hand pump.

[ribbonstone]

Some people want them fast, some want them slow,...will generally run them in the middle range...except for the last one, which is probably running as hard and as fast as it can.  

Left to Right:

AR2078 (.177):
 Outside: Stock refinish, stripple grip area, extend butt plate, adjustable butt plate, 10X44MM 30mm scope, brake.

Inside: Safety 1/4 turn modification, drastcially reduced hammer weight, adjusted spring tension to slow it down, poly transfer port, bulk fill adaptor, internal polish.

Results: Very quite rifle with a long shot count per fill.  10 foot pounds of energy.  
Kodiak @ 660fps.
Gamo Hunters @ 735fps
-- --------------
QB78 (5mm):
Outside: Stock refinish, 2-7X scope, brake added

Inside: Converted to QB79 gas block,  5mm barrel, brake, 1/4 turn safety modification, doulbe barel bands,  delrin valve seal w/o piercing stem, poly transfer port, reduced hammer weight, internal polish, spring tension adjusted.

Results: Quiet rifle.  12 foot pounds of energy.
 H&N Match @ 677fps
 CP’s @ 624fps
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QB79: (22)
Outside: Stock refinish, 3-9X scope, RWS brake added

Inside: Polished, barrel shortened to 17.5”, poly trnasfer port.  STOCK valve and spring.

Results: Quiet, 11 foot pound rifle.
Crosman Discovery HP’s @ 590fps
RWS Superdomes @ 585fps
-------------------
QB78D .25  Mounatin Air QB25
Outside: Brake and 3-9X scope added. Sooner or later will refinish the stock, but i want to get this one nice and scratched.dinged up before going to that trouble.

Inside: Converted to QB79 gas block, 1/4 turn safety modification.  All other modifications are from Mounatin Air.

Results:  23 foot pounds of energy (which impressess me for a co2 rifle).  Reasonably quiet for the power
Dina Rastatt (think “Mosquito”)@ 680fps
Kodiak @ 590fps
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Think I'm done, except for shooting and enjoying them.  have them where i want them for power; hope to only go back inside when something needs replacing or adjusting.

[DanoInTx]

Very nice collection.  I've gotta ask, where'd you get your barrel blank machined?  I have a .20 barrel on the way that I want to put on my AR2078A, and I have plenty of machinery at work, but I am a little hesitant to chuck the new LW barrel up in the lathe and go to town.  Actually the lathe work is no problem, it's doing the lead in that concerns me the most.  

You have a collection anyone would be proud to own, good stuff!

[ribbonstone]

Have a lathe, drill press, and various hand tools...so did it myself.

Steep learning curve (mostly on how to get it to seal the bolt probe but not cut the crap out of the o-ring).  Third try was the charm....first two were less than great, so cut off the offending section (about 1/2") and tried again....which is why it ended up at 23 1/2" long.

[adam h]

I'm a little new to this, so pardon the probably stupid question.  Where do you get barrels of different calibers?  Can you buy them or do you have to salvage them from other guns?  I have access to machine equipment and would like to get a little more into modding my air guns.

[ribbonstone]

Crosman .177 and .22  barrels are sold as parts (you have to call Crosman, they don't do on-line orders), skinny barrels, but inexpensive (and available in 24" lengths). Too thin for some uses.

Archer sells Qb 177 and 22 replacement barrels...not too expensive, can be adapted to other guns.  Cutting the existing breech off can still leave 21" of barrel to cut on.

Can find just blanks, but are usually from more expensive makers....call it $90-110.  these are usually available in all 4 calibers (.177, 20,22,25) and in two thicknesses.

Once in a great while, can find a busted cheap rifle with a decnet barrrel...of which you can salvage at lest part.  Might be able to sell off some parts to off-set the expense, but the basic China-made bottom-end springer won't sell for a whole bunch once it's not shooting.  Barrel quality varies a lot, but have been some very nice barrels on some of those rifles that sold for $25-$35 new.  Have two cut off .177 China-made barrels in the shop taken from junk-guns (and now the .22 QB take off as well).  Sooner or later, will get used on something.

Big bore shooters often go to Track of the Wolf (they are on-line)....have barrel liners.  Liners are thin barrels that are used to reline worn out centerfire/balck powder barrels (they bore out the bad barrel and insert the liner, either bonding by solder or by specialized glues).  These they sell by the inch, and only come in certain bore sizes....will still end up paying about $85-$88 for a 20" barrel

[gunsup0331]

Beautiful collection there....I know I shouldnt be wandering over here on the Dark Side, lol.

[Jaymo]

Could always buy one of the 50 dollar.22 caliber MP512M  springers from the sportsmans guide. That gives you a good quality, accurate barrel that you can use as a barrel or as a liner for 50 bucks.
I really like your QBs. What did you use to refinish the stocks? Tung oil, varnish, etc? How did you get that nice shade of red on the AR2078A stock? It looks like mahogany stain under tung or teak oil. Did you use a Dremel to stipple the wrist area? It reminds me of the stock on an FWB 300S I was looking at recently.  I really like that stock and would like to do the same to my AR2078 thumbhole.

[ribbonstone]

That's pretty much the color of the wood I found under the factory finish on the AR2078.  Did get a litgh stain with "oak" stain, but  mostly it just brought out the wood's color rather than adding to it.


Strippling was done by hand, using a home-built tool.  Took an old philips screw driver, used the cross hatching as a guide, and cut it into a 4 prong strippling tool. Want pyramid shaped points, which you can file into the now seperate prongs.  Makes four "stipples" per hammer strike, just rotate it around between strikes.  Practice...but if you hold it tightly about 1/2" over the work, strike it smartly, and your hand kind of automatcially rebounds it back up. Can get into a rythem, sounding like a crazed woodpeker (I gotta spell it aht way or the forum will replace it with "*****'0....think it took 1 1/2-2 hours to do the stock. Once stippled, brass brush it to remove the highest points, and stain it with a dark stain (think this was "ebony").

[Jaymo]

Thanks, that was very informative. Wow, we can't even say *_*_*_*_*_* (peck-er)on here without getting censored?(Guess not.) I didn't really expect that.
That is one good looking piece of lumber on that one.

[London177]

An excellent collection you have Rib especially as you have them set up just as you like them. Congratulations :0
regards,
Alan

[ribbonstone]

Been playing with HPA on the newly converted20cal. in prep. for the winter hunting season (tree squirrels).

Rifle kind of looks like a pimp-magnet drug though a fea market...not real fond of the brass and gauges.  


Upper gauge does read the HPA tank pressure, the lower gauge reads the pressure in the rifle...at the start, the top reads 3,000PSi and the bottom reads 830PSI....the top chnages as the gas gets used up, but the lower one reads 830PSI for as long as there is over 850psi in the tank (it just takes a bit longer to cycle up to 830 as the tank's pressure goes down).


Shoots about as well on HPA as it does on CO2.  Think it can do better, but the state of my aim today limited results (and it's a bit windy as well).

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While a lot of posters rave about the Crosman Premiers in .20, this rifle has been the best at shooting them out of 4 5mm's...and they still don't impress me too greatly.