Cheap Hatsan PCP (parts 2 and 3)

[Ribbonstone]

Part 1:

http://www.gatewaytoairguns.org/GTA/index.php?topic=62285.0

Part 2:

Decided NOT to change anything, just shoot the gun as it came until it’s broken in. 

Burned up most of a tin of old .24.2gr 25 Ram Jets that never did shoot great in any other .25 tried but at least could be put to good use in breaking this one in.

So with +140 shots taken (8 fill ups),  shot a new shot string with  Benj.Domes (27.8gr).  Really no change in count  or sweet spot pressure (still running  16-17 shots inside of 4% but the velocity increased by 21fps (from an average of 790 to 811FPS (or from 38.5 fpe+ to 40.6 fpe+).

Just guessing that the moving parts are smoothing out a bit.

Did change to a more “heads up” scope mounting. Has that Weaver base, so may as well use it.  Hunting gun, so a good part of my shooting will be offhand (or at least standing supported by the side of a tree), so the higher scope mount works well with that stance.




CHANGES:

Now that the gun is wearing in, decided to go after the trigger before doing any accuracy testing. Adjusting the trigger before breaking the gun in a bit just leads to re-adjusting the trigger.

Can get to the 3 screws, awkwardly, through the trigger guard.  But to really get at it to both adjust it and lube it (white lithium grease works) will need to do the following.

1. Flip the rifle “belly up”.

2. Take out the two screws from the pump fore end.

3. Slide the fore end off to the front (it rides in a dovetail).




4. Remove 4 screws:  One for each barrel band and two for the action.

5. Stock lifts right off.




6. Trigger has 3 adjustment screws.  Manual refers to them differently, but this is what they do:




7. Reassemble in reverse order.

BTW: Weird little lever inside the trigger guard is NOT A SAFETLY.  When the gun is  pump cycled, the pump locks forward.  That little lever in the trigger guard lets you unlock the pump, so you can pump it back and remove the pellet cylinder.  BEWARE: if the cylinder held pellets, there will still be a pellet in the barrel ready to go even if you do remove the magazine.

Trigger ended up as a “kinda” 2-stage, with the break taking about 1.8 pounds by my measure (trigger hanger and weights rather than a digital gauge).

Given time, will do some initial accuracy test tomorrow. Still waiting for the TKO attachment to arrive, so will be limited in range for the initial tests (so I will be able to tell what pellets it HATES, but not tell which pellet it LIKES best until getting that TKO and then out for more range),


Hatsan 3:

Start off with a safety concern for owners of older Hatsans.

The brass thread protector for the older guns is a solid cylinder of brass.  It screws onto the valve end of the cylinder to protect the threads when the cylinder is removed, and the cylinder is o-ringed.

Screwed on, the old thread protector is 0-ringed. So if the valve leaks, the thread protector contains the pressure.  Which means, if it leaks, you either can’t get it off (as it’s holding 3K pressure inside) or you do get it off and have a nasty 3K surprise.


The new thread protector is vented between where the valve’s o-rings would seal.  So if there is a leak, the leak just vents and doesn’t build up.

Old on right/new on left:




Also the new thread protector has an allen screw at the top.  Idea is you can use this to degas the cylinder: back the allen screw up, screw on the thread protector, and screw the allen screw down until air hisses out the vent.




So if you have one of the old ones, do yourself a favor and DRILL IT FOR A VENT.  If you are worried about dust getting in through the vent hole, seal it with wax (the wax will blow out of the hole at low pressure if there is a leak).




Still no LDC, so still no serious accuracy tests. Know enough from shooting +200 shots that it will shoot well, just can’t prove how well until it tones down a little.

Did go back and retest after +200 shots and a cleaning.  Rather than “waste” the best pellets, have been using some old Beeman Ram Jets (24.2gr.).

Also borrowed a modded Pneuma cylinder with 4 of the 6 valve ports plugged (leaving just the two aligned to the transfer port open).


As issued Cylinder with all 6 of the ports open:




Modded Pneuma cylinder with just two ports open:




Results:




THOUGHTS:

Breaking in gained  a little energy and upped the best fill pressure by 100PSI.

Certainly got slower with 4 ports plugged, but bare-barreled it is still loud (although quieter than the high power version). With an LDC, suspect the slow version to be considerably quieter.

Interesting that the Pneuma .177 gets 16-17 foot pounds with that cylinder and the .25 gets about 50% more energy. (Or you can reverse that and think that the plugged tube got  100% more shots).

Efficiency and total energy per fill doesn’t really change much, it’s just divided into more little bites.

Happened to have an old Pneuma air cylinder (had replaced it and kept the old one). Resealed it and got the ugly (has  few blemishes) tube working again.  Was also port plugged.

Thinking that even if I don’t do any tuning (which I will do, but just thinking), could have a +40 foot pound tube and a +20 foot pound tube.

[Rescue35]

Are you sure that the 4 port bloked valve is lining up with the transfer port ob this rifle. Im just thinking the reason they make them that way is so they do not have to be precise on there thread engagement.

[Ribbonstone]

Actually, it ended up pretty much in the middle of the two open ports. Figured with two ports open, that would be the best choice.


Striker has more than enough travel to work, so if you ant to try one port, could shim the tube so that that one port lines up dead even with the transfer port in the receiver.  Set up the .177 Pneuma that way for a time as a 12 foot pound gun with a whole lot of shots per fill.

Also filled in the groove over the plugged ports with epoxy putty, figuring having the air run around in a circle before finding its way up wasn't going to do any good.

edit:


A little accuracy test teaser.


DISCLAIMER: If it ain’t legal to shoot an airgun in your location, DO NOT DO IT.  It is legal (on your own property) in mine, but I also don’t want to test my neighbors patience.

Find it interesting in a philosophical sense that I can make MORE noise with something else and not have them bat an eyelash, but prefer not to test them with the sound of shooting. Guy across the street can fire up his hot rod to tune it, guy next door can work on his Harley, and the  guy down the block shoots fireworks when the home team wins a game.

Had to resort to suburb-camouflage to get a few shots in on targets at short range (20 yards).

1. Got out gas chain saw.
2. trimmed a few tree branches.
3. Left it running with the choke slightly engaged (it would sputter a little/back fire now and again).
4. Between groups, go out and cut one of the limbs into fire wood lengths so it sounds like you’re working.

Anyway, here’s a quick 20 yard test of what I thought would be one of the worst and one of the best (just from the break in shooting/chronograph sessions). You’ll notice I’m still using up old stock.