Air Gun Home :: View topic - Cr. 18" .177 Barrel (13-XX/22-XX)

Doc Sharptail · Member

I ordered (from riflesope-shop.com) in a factory 18" .177 bbl as a replacement for a worn out 13-89 bbl. I wanted to test it on a known to me good platform, so I used a 13-77 pistol as a tester.

Scope is a 6-24X 42mm Bushnell Banner. Tube and grip frame usually see duty as a pistol, with the stock 13-77 bbl.

Barrel was completely free floated to reduce test variables, with no bbl band. It has a flat top piston.

5 Crosman Ultra Mag Premier at 12 M from bench rest. I yanked the one at top- it wasn't the gun. Ten pumps yielded an avg. of 588.5 fps over a ten shot string. Maximum deviation was 8.9 fps, and the minimum was 1.6 fps. Scope was set up for the Ultra Mags in another 13-77 with a 24" .177 bbl, and not touched adjustment wise. This bbl is a keeper.

5 RWS Meister at 12 M, 10 pumps. I yanked the 2 at left Rolling Eyes

Average velocity 643.8 fps over ten shots. Maximum deviation was 12.1 fps, and minimum was 2.1.

I'm in a bit of a quandary here. In order for this bbl to work in the 13-89 properly, the transfer port section of the bbl will have to be removed. It's such a nice shooter that I'm beginning to have second thoughts on the barrel cutting.

Regards,

Doc Sharptail

rsterne · Moderator

Doc Sharptail · Member

rsterne · Moderator

Doc Sharptail · Member

Bob-

I'll get some pix up soon of the breeching system. It's very sensitive to pellet seating depth.

Regards,

Doc Sharptail

Doc Sharptail · Member

Here's the loading gate open, with a pellet ready to shoot:

Loading gate from the right side of the gun:

I tried shooting the 13-89 tonight, with the new bbl. It worked a little worse than I had expected. Lead flakes started falling out of the action after the third shot. Air blow black from the transfer port hole was opening the load gate.

Lead particles at the bbl transfer port hole after 5 shots.

New bbl shows a steady velocity decline, with albeit, a much tighter group than the original bbl. I think some lead blew back into the valve...

I wonder if the quest/phantom bbls are the same diameter as the 13-XX/22-XX bbls? That may be an avenue to explore. I'm still hesitant to cut that bbl. I'm forming a scheme in the back of my mind to use it elsewhere....

Regards,

Doc Sharptail

rsterne · Moderator

The Phantom barrels are larger OD.... could be turned down, of course....

Bob

T191032 · Veteran Member

"Scope is a 6-24X 42mm Bushnell Banner. Tube and grip frame usually see duty as a pistol, with the stock 13-77 bbl."

Wow, and I thought a 4-12x40mm A/O was big on mine 1377 carbines.

Doc Sharptail · Member

After a bit of poking around, I found that the current SBK steel breech kit is a direct fit onto the backpacker's grand-dad 13-89. It's not the pot metal original, with loading gate, high rise breech, or the shot-out 14" original bbl, but the gun still retains much of it's "cool factor".

I like the separation of loading and cocking operations. Jury's still out on the plastic trigger. Shown wearing a new Dawn/Dusk Banner 4-12X 40mm A/O- still just as good, if not better than, the first one I bought over ten years ago. Burris all steel rimfire rings. That's the 18" bbl I ordered in from riflescopeshop.com. It shot so well on a 13-77 with the 10.5 gr ultra mags that I decided against cutting it for the original 13-89 rear flow breech. Gun is still on the original cup piston.

Here's a few groups with the Crosman 7.9 gr "milk carton" hunting points. This barrel isn't near shot-in yet. It has about 50-60 pellets through it.

As usual, with Crosman .177 pellets, a burp in velocity always helps:

20 pumps, and the gun starts retaining a little puff of air. Gun still has the original check-valve spring and spacer in the valve. A little spring search seems to be in order.

It still has some work ahead of it- a flat top piston and a breech band. Groups will tighten up once that 13-77 bbl band is gone. I can rest happy for the time being...

The way things are right now, I'm not all that anxious to get into bbl cutting- mostly because I lack the proper tools. If I was certain that I could cut that transfer port hole section out of the rear of the bbl, and get it flat and square, I'd go for it- but I'm not all that sure (yet) Mr. Green

Regards,

Doc Sharptail

broommaster2000 · Moderator

packrat · Senior Member

If it gets right down to it,,the barrel could be cut with a standard hack-saw, and the end made flat and square with a hand -file...not that hard to do..then just re-crown and you'll be back in business..as good as the barrel appears to be, I'd do whatever it takes to get it right Mr. Green

Doc Sharptail · Member

I couldn't ***stand it*** any longer. That bbl became an itch that I couldn't scratch over the last 48 hrs or so. I used a diamond wheel on a dremel, with the barrel slowly turning on a Ridgid pipe thread cutter- as close as I'm gonna get to a lathe. All squared up and nicely polished. I shot it out of the original 13-89 set-up, and got inch and a half 5 shot groups at 12 meters. Heck of an improvement over the original bbl, but I have a ways to go yet.

Turns out these bbls need a lead-in to the rifling. The original 13-89 bbl, and the current available transfer port hole bbls have a tapered lead up to the rifling that is a bit over a half inch long. That's a reamer I don't have. If anyone has suggestions on cutting that taper, I'd like to hear them...

Regards,

Doc Sharptail

Doc Sharptail · Member

Progress is slow, but it's still positive progress, all the same.

Lead in chamfer started with *1000 wet/dry paper. Polished with *2000 wet/dry paper, turning at about 30 r.p.m. in the pipe threading machine.

Gun will put 3 into less than 1/8" at 12 meters, then throw the next 2 pellets a half inch out of the group. I found the front breech screw seat to be pretty badly worn. I'm going to deepen that lead in chamfer a bit, and clean up the shank face- that's where the breech seal is made. As for that pot metal breech, I'll try making another breech screw hole- on the axis of the front trigger guard screw, and sink a screw into the valve. I'll get that pot metal breech back to usable yet...

I find the chamfering/polishing operations to be pretty relaxing- with the slow out-put of the pipe thread cutter. That relaxation sure helps for getting down to causes and conditions...

Regards,

Doc Sharptail

Doc Sharptail · Member

I have it shooting a lot better now. Mr. Green

It took a bit of work at the breech end of the barrel to get there, and the new breech screw mentioned above.

5 Crosman 7.9 gr Hunting point at ten pumps, 12 meters. Gun is still on the cup piston. Group was shot with a crappy little trashco 4X 18 mm scope. It's really getting close now! I'll shoot it a bit more with better glass. I'm not quite satisfied with the lead in to the rifling that I cut. I need to investigate some smaller polishing pads for the dremel.

Here's a quick look at part of that breech improvement:

That large, rough looking hole in the top of the breech is access to the 8X32 screw I put in opposite the trigger guard screw. No need for a breech band on this gun. Barrel is free floated, and needs a bit of shooting to tighten up- the bore is squeeky clean from my efforts to get the cutting residue out. I'll have a bit more on this later. I've gotta play around with scopes and mounts to arrive at something decent. I'm curious as to what's gonna show up on the chronograph before I go to the flat top piston and valve...

Regards,

Doc Sharptail