Yesterday's Weapons Forums

After installing the steel breech, on went the cheap Barska 3x9 scope.

Cros1 (2).JPG [ 83.65 KiB | Viewed 4324 times ]


Then it was try for groups. Put the target out 12 long paces and sitting in a lawn chair, used the lawn mower for rest. Scope on 4x - 8 pumps from a max of 10. It sure looks like the gun prefers the 17.1 grain pointed pellets over 14 grain round nose. 5 shots in each group.

I'm way happy with it! Now to order the flat face valve and piston. Those will bump velocity and muzzle energy in case I'm target shooting in the buttes, and a turk ignores safety rules, wandering in front of a shooter!

Since it's so hot and neighbors are staying inside with the a/c going, I can blast away with a happy heart right in my back yard. SW

14 grainers

Cros2.JPG [ 45.37 KiB | Viewed 4324 times ]


17.1 grains

Cros3.JPG [ 39.29 KiB | Viewed 4324 times ]

_________________
Slava Ukraini!!

After you've been at this for a while, you'll find your guns are prone to liking "brand specific" pellet types.

I have not had much luck with crosman domes out of the tins. Boxed domes are a completely different story.
I've gotten the best out of the 16 gr JSB domes in my crosman .22 pistols.
I've gotta get out for a shoot soon.
Grouse season opener is at about 7 week mark now, and the time is gonna go by fast until I have everything sighted in and ready.
I have some new pellets to work up to zero as well.
May end up carrying the .177 13-XX pumper rifle with the 24" bbl for the early part of the season.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

Messed around today shooting groups to see if there was a correlation between number of pumps and group size. Not really as far as I can tell. I did notice at 6 pumps (10 max) I can see the pellet in flight. So I'm staying with 10.

I went with this vendor for a flat face valve & piston kit. SW
https://alliancehobby.com/flatman.htm

_________________
Slava Ukraini!!

I had looked at that site earlier, and was debating putting up a link for it.
A bit on the pricey side.
I still have some brass stock left here for the latest 13-XX pistol.
Just having an inner debate about doing the "turning down" without a drill press.
I could probably do it with a new M/B file and the new electric drill I got for Christmas last year.
It's a cord model and does have significant torque.
I found about 3 feet of 1/4" X 20 drill rod in the back of the car.
I think there's some old 21/22-00 steel pistons around here that could be shortened as well.
I am almost certainly going to have to get a vise of some sort.
A trip to Princess auto may be in my very near future...

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

That's interesting. A somewhat long term goal is to get a longer barrel and "silencer"... for which the flat top kit could have applications. SW

_________________
Slava Ukraini!!

I've used the flat top pistons in pistols for quite a while now.
The reduced pumping is always a bonus.
I'd have to look it up in my chrony notes- IIRC, velocity maxxes out in the .22 pistols somewhere in the upper fives, with a 14.3 gr pellet. 18 gr JSB's are a lot of fun in the pistols though- their end results on the target get interesting, especially with soda can pull ring tab rivets as the bull.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

How far down the modifications rabbit hole can you go?
I'm not sure, but can tell you the only original part left on the 13-22 in the following photo's is the air tube.



These are mostly to show the extra machine screw modification to tighten up the "packer" style stock against the grip frame.
1701-P/P-rod (marauder pistol) grip frame and sear assembly. Note over-travel stop pin in the trigger guard frame. As issued by the factory.

RVA (rear velocity adjuster) made by me from discarded steam PRV (pressure release valve) parts. It adds tension to the hammer spring to deal with the retained air issue discussed in the post above.
IIRC, it tensions against a Benjamin Discovery hammer spring.

Note slightly protruding machine screw head at the bottom of grip.



There's a look at the problem solving screw, partially backed out.
The plastic on these "packer" stocks is a bit soft, and the screw head will sink into it a little ways- about 1/8" on my sample. Sources tell me the plastic on the current stock frames is quite a bit harder now.



There's a look at the screw through the frame. 8 X 32 x 1-1/4".
Note pull adjustment screw on the 1701-P grip frame.
I haven't touched this.
It came set from the factory with a roughly 2-1/2 lb pull weight, and I've left it alone.
It's fine the way it is for the type of shooting I do.
The hammer will have to be modified to a non-waisted style in order to cock properly with this grip frame's sear...

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

Doc,

By chance do you know of a forum tutorial for installing the flat face valve and piston
kit? There's one on YT, but the Brit guy is hard to understand. The kit should be here today - next move is get my chronograph and record velocities so I can measure the flat face improvement. SW

_________________
Slava Ukraini!!

I'll take a look around.

What's your search engine?

Some bury gun stuff intentionally.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

I'm going with duck duck. SW

_________________
Slava Ukraini!!

You're gonna need a few things to deal with that roll-pin.

A pin-block: I use a six inch length of fir 2" X 4" with a 1/4" hole drilled straight and square all the way through.

A roll-pin punch. In a pinch, a length of garage door motor chain pin will work. A real roll-pin punch is a heck of a lot easier to use.
It's gonna take a bit of a whack to get that pin moving.
I'll have to dig through my stuff to come up with the correct dimensions and sizes.
The pin punch comes in handy if you plan on re-using that pin.

More in a bit...

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

https://www.youtube.com/watch?v=xVI5owkEPAc

Give this a try.
It's the parent guns, but the principles are all the same.
Use sub-titles if the cockney accents are a bit steep.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

Thanks! I hadn't seen that one. Harbor Fright has a roll pin punch set for $10 so in the morning I'll wander over and do the deal. SW

_________________
Slava Ukraini!!

I have two sets here- one bought in the equivalent to harbour freight, and the other from a a machine shop.
The machine shop kit is in brass, the harbour freight in hardened steel.
Both are equally up to the task.
Much better than marring up the pin ends to where the inside of the air-tube gets burred.

Speaking of which, sometimes the factory leaves burrs inside the tube at the pin-holes.
A bit of work with a round file, and some wet-dry auto body paper clears that right up.
Those un-corrected burrs are hard on o-rings, which there are at least 2 of in a flat top piston installation.
We don't want to cut them on burrs.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

Got the Chrony out and discovered 10 pumps with the 17.1 grain pellet gives me 425 fps.

Tried for a finer sight in. 5 shots in each group @ 10+ a little yards. Maybe 10 meters. The spot is roughly 3/4 inch in diameter. Not exact, but since I don't plan on shots at turks past this range, I figure I'm GTG.

Head shots only, of course. Instant kill or the turk shuffles off muttering to itself. SW


Cros3.JPG [ 46.07 KiB | Viewed 4260 times ]



Cros2.JPG [ 61.26 KiB | Viewed 4260 times ]

_________________
Slava Ukraini!!

You're doing fine for .22 on a cup piston at 10 yards.

After the flat top piston and valve are shot in a bit, shoot again for group at 10 pumps.
The curve should tighten the groups to the point where it's a measurable improvement.

I found my crosman pistol bbls in .22 to like the gamo pointed 16 grain hunter.
There's also a 16 gr Gamo with a b.b. set into it's head that have decent accuracy as well.
They are the Gamo Rocket, and pack a bit of a punch as well.
Best peformer for me in the crosman .22 bbls has been the JSB Predator at 16.0 gr.
I have not tested the short Predator version for rotary magazines, and have been able to find little in the way of reviews.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

More accuracy testing. Scored a tin o' Crosman 14.3 grain "Piranha" with sinister-looking hollowpoint. They seem to shoot a little tighter than the 17.1 grain pointed pellets. For sure tighter groups that the 14.1 domed variety. Also shoot closer to point of aim, and I changed nothing on scope adjustments.

Same range - same 10 pumps. Today's groups are to the left of the lighter blue color from yesterday. Forgot to get the chronograph out. SW


Cros5.JPG [ 43.92 KiB | Viewed 4249 times ]

_________________
Slava Ukraini!!

I had tried the pirhana's in .177, and was un-impressed with accuracy.
They were first run batch though, and had serious variances in head diameters.

Shot my first one-hole a/g group with the crosman Competition 14.3 gr wad-cutters.
I still have a bubble pack of 500 left yet.

RWS is worth a look too. The .22 meisterkuglen w/c are very good.

Pellet pricing has gotten really bad around here- prices are up 60-70% over last summer.

Regards,

Doc Sharptail

_________________
"Ain't no Half-Way" -S.R.V.

"Oh Yeah!.....All Right!" -Paul Simon

Set the chronograph up and clocked the 14.3 grain pellets at an avg of 450fps. This being a small town, my sources for pellets is limited. I've got mail coming from Hungary... I should see what obscure brands are available for inclusion in the box. SW

_________________
Slava Ukraini!!