Sunday, July 29, 2018

The QB77 Continues to Change

This QB77 rifle in stock form has always overlapped too many of my other airguns.   The .177 caliber also doesn't help as the small pellets are difficult to load compared to the .22 variations.  The loading trough is too wide relative to the .177 pellet diameter and it's common for the pellet to flip 180 degrees and load backwards.  I've had a few occurrences where the pellet turned sideways and was mashed into the breech with the loading bolt.  Took a rod from the muzzle to knock it clear.  To be sure, part of the problem is me.  With the contact lenses in, I'm over-corrected up close so that little pellet is slightly blurry--as well as partially obscured by an overhanging scope.   I should just rebarrel it to a larger caliber.  I expect that would end the pellet flipping problems as the loading trough seems originally designed for the larger .22 size.

Anyway, that's a project for another day.  I enjoy having variety in my airguns, so this rifle continues to evolve.



















It's currently wearing an AR2078A match-style stock.  As a departure from its similarly stocked brother, it got sprayed with truck bed liner.


























The texture makes the stock feel like one of the new tactical precision rifles. 





















Cut and installed a picatinny rail to the underside of the forearm.





Made an aluminum screw cup to bring the stock mounting bolt flush.



 



















All the various AR-style under-gun rail options plug right in.  Hand stops, barricade rests, bipods, AFGs, sling mounts, vertical grips...




















At the toe of the stock, rather than use a simple sling stud, I fit a QD socket.  The socket began as a KeyMod fitting.  Cut the bottom flush and used deck screws in the mounting holes.




























































 

 

Been trying a couple scopes and red dots.  Just figuring out where it fits in.  There's a UTG 6X Bug Buster on it right now.  Subject to change--or whim, or whatever.  

Thanks for checking in.  More soon.

Wednesday, July 25, 2018

Some Help for Slipping Scope Mounts?


Spring piston air rifles are notorious for their ability to move scope mounts rearward on their dovetail from recoil. The dovetail is typically 11mm wide and offers little surface area for ring clamping  To address the problem, many if not most such rifles come with a stop hole (or three) drilled into the top of the compression tube at the rear of the dovetail.  And most of today's scope mounts have a requisite recoil arrestor pin to fit into the hole.

But what if your rifle doesn't have a stop hole?  Or maybe it's not in a convenient location for your chosen scope mount?   Maybe your scope rings won't accommodate a stop pin?

























Maybe this will help.


Backstory:  The cycling industry had a problem a few years ago when carbon fiber became common place.  The smooth surfaces and relative fragility of lightweight carbon parts presented a clamping and fixturing challenge. Carbon seatposts, stems and handlebars would often slip under rider weight.  Parts wouldn't stay in place.  Torquing the fasteners beyond spec was an all too common (and bad) solution as it deformed and crushed the carbon fiber ruining the expensive components.   The cycling industry's earliest and simplest fix was to have mechanics add a friction paste to the clamping surfaces of parts.  The paste contains fine silica that provides bite or "tooth" to the mating surfaces and substantially increases grip for the same amount of fastener clamping torque.  The cycling industry calls it "carbon assembly paste".  It's  available at any halfway decent bicycle shop or through the internets.

Finish Line Fiber Grip, Tacx Carbon Assembly Compound, Park SAC-2, FSA,  Whatever.  It's all silica in an inert carrier. 




















OK, so there's all that.  What's that got to do with me?  I've got this hard kicking Hatsan Manufactured Webley Patriot.  It's a known scope mover and breaker.  I've heard of several now that have even broken the stock mounting bolt--including this one.  There's no conventional stop hole on this rifle.  Webley uses shallow cross grooves as the scope stop and that requires a special mount. 





I really don't want to try to find one--especially for a 30mm scope tube.  Just wanna use this cheap Walther red dot and mounts I already own.  Without a proper scope stop, figured I need to get as much grip on the dovetail as possible.  To increase my chance of success, I used an 11mm to picatinny adapter that has about 4" of clamping surface and four clamping screws.  The picatinny cross slots ensure the rings won't move.




















Before installing the 11mm to picatinny adapter, I degreased, then gooped up the rifle's dovetail with Finish Line carbon assembly paste.  Tightened the bolts, then installed the rings and red dot. 


 

 

Gritty!

It's been a week and a hundred shots and it hasn't moved at all.   Obviously not a definitive test, but it's a good start.  This would probably also be the ticket on scoped IZH-61 rifles that have that plastic receiver and dovetail with no stop pin hole.  It promises extra grip without crushing that plastic rail.

Will this work?  It's definitely going in the right direction.  Without a mechanical stop, increasing the friction between the dovetails of the rifle and scope mount is the only other option to end recoil induced movement. 

I'm not exactly sure what constitutes success.  Guess it's going to be subjective.   For me, it'll be a success if the red dot stays zeroed for five hundred shots with no apparent shift. 


Monday, May 28, 2018

More Morgan recoil pads

Despite the lack of posts, there are often many airgun projects going on.  They don't get blogged because they're something covered previously.

Nick recently set me up with several Morgan adjustable recoil pads.  We've both blogged about how to install them before, both the aluminum and plastic style bases. It takes a bit of time and can seem daunting at first--especially if one is fitting the aluminum model.  Over the last three weeks, I've installed three of the plastic base models averaging about 90 minutes each.   90+% of the fitting was done with a 4x36 belt sander from Harbor Freight.


Anyway, here are the results.


Beeman (Weihrauch) R1 Laser.  



























































Another Weihrauch.  A 97K model. 




































 And finally, a generation 1 Benjamin Marauder.


















The vertical adjustability allows for a more comfortable (and quicker) position behind the scope. 


More soon.

Friday, May 18, 2018

FB Record Mod. 68 and Gamo Center Pistol Finds

Finally made some time to post all the stuff that came home with me from the Findlay airgun show.














I know!  Like I need more pellets?  Well, the Crosman/Benjamin tins were 3 tins for $5.  The others were $5 per tin.  Aside from the pellets, I also snagged two air pistols.





















I'm a sucker for cool airgun boxes.  Though, this hasn't always worked out well.





25 or so years old and still new in the box.  FB Record Model 68.  It's a decent, inexpensive break barrel spring piston.  The shroud/front sight is some kind of casting with a steel barrel insert. Compression tube is also non-ferrous. (???)  The seller said it had some "cosmetic issues".  I assume he meant that the color of the shroud had turned a plum color over the decades since it was made.  I was OK with that.  Its still is great shape and has some really interesting mechanical details. 






















Gotta love knurled rear sight adjustment screws like this. 





















And they carried that adjustment design to the trigger, too. 












The second pistol was one that was actually on my hit list.  A Gamo Center target pistol.




















I believe this design goes back to the late 1970's, though I doubt this particular gun is that old.  Maybe mid 1980's?  I vaguely recall this particular model being somewhat in demand from a small group of club level target shooters in England just few years ago.  They thought it was an underrated diamond in the rough.  Apparently, that made an impression. 
















Underlever spring piston design.






With a swing out loading port. 



































The rear sight elevation is a completely vertical adjustment from underneath--




















via this large screw.    The grips swivel on the frame with five adjustments settings.


























The locking screw is at the bottom buried in the grip frame.   Expect I'll be revisiting this one.   The plastic grips have to go. They don't match the build quality of the rest of the design.  So, new grips are a go, though I know I'm still off the back making grips for that Hammerli Master from last year's show.  There's some really nice figured walnut in the basement waiting...


Appreciate everyone checking in.  More soon.



Saturday, April 14, 2018

13th Annual Toys That Shoot Airgun Show Findlay, Ohio 2018

The 13th annual Toys That Shoot Airgun Show happened this morning in Findlay, Ohio.  There were incredible deals EVERYWHERE.  I managed to buy a couple air pistols and another 20 or so tins of pellets.  Had a great time as usual.  Here's a bunch of pics.  Enjoy!