The Mystery Hy-Score/Hammerli/Puma Disassembled.

[cartertools]

Ok, not a total mystery, but there are a few odd things, like the possibly missing anti-beartrap, the model number and the odd trigger housing...

http://anotherairgunblog.blogspot.co...le-part-1.html

http://anotherairgunblog.blogspot.co...le-part-2.html

Any and all enlightenment appreciated.

Nick

[Phil G]

Any and all enlightenment appreciated.

Nick

Don't have a clue but a good posting and fully illustrated. Better than one of those diy car manuals. The experts will be waking up soon (06.30 am here) and will be posting Phil




=

[Hsing-ee]

That trigger on the mystery gun is definitely home made, it is only half the length of the original one, and is missing the part of the housing that held the anti-beartrap. Besides, it seems to be made of aluminium alloy.

[I. J.]

That trigger unit looks very similar to the one on my rifle. and this is were the anti bear trap should be.

ATB
Ian

[Hsing-ee]

I take it back. It is a factory job clearly.

[cartertools]

Yes, it seems that the trigger housing is stock. On the American vintage forum another person had a Hammerli that while it had the anti-beartrap piston and the slot, it did not come with the beartrap. So possibly it was an option that Hy-Score decided wasn't worth the extra cost.


Anyone have an idea of the velocity/ft-lbs a stock gun is supposed to achieve?

[Hsing-ee]

Anyone have an idea of the velocity/ft-lbs a stock gun is supposed to achieve?

My recently re-sprung .177 Mk 3, which is the same basic rifle, does 7.5 ft/lbs with Air Arms pellets. I think this will improve once the piston seal beds in (I gave it a long soak in SM50 and it got rather plump) by 0.5 ft/lbs. So about 8 ft/lbs for the .177. The .22 should give about 1 ft/lbs more, so I would say about 9 to 9.5 ft/lbs for your rifle.

This would be about 530 fps for a standardish 14.4 grain .22 pellet. They are very accurate rifles, so if you keep ranges short (about 30 yard max) and rangefind accurately, they make good hunters from a static position.

I used the very long original spring which I got from Chambers (http://www.gunspares.co.uk), but I have heard that the shorter but stiffer HW77 will also fit, and it may be the Feinwerkbau Sport spring fits as well. They are very sweet-shooting rifles, so it might be worth experimenting to get the best power/recoil balance.