Hw99 piston lightening?

[TonyL]

Glad you're happy with the outcome.

When you come to finally fine-tune the power output / pre-load, it may be worth considering running some Falcon Accuracy Plus / JSB Jumbo RS through it, as these very often produce the highest energy readings, to make sure you're safe and legal?

Maybe a little more piston bounce may be evident once the preload is reduced? It may be worthwhile conducting some of your own hold sensitivity tests once you have arrived at yiur final set-up.

However, if it's all to your liking, fantastic, job well done and something to take pride in. Everyone loves a trier and where would we be if nobody ever challenged convention?

And you're so right, a good 99 can be the only gun any shooter ever needs. Light and portable for fieldwork and, for many, just as accurate as the heavier, "more obvious choice" springers for target work.

Nice one.

[stiks]

Thank you.
I'll tell you how I work TonL.
By feel and feel alone. If I can shoot tight groups with ease at my maximum comfortable range, and yes have it as insensitive to hold as possible, then I'll be happy.
I would like to keep maximum preload against piston bounce, and I may tinker very gently with Piston weight and TP diameter as I feel. But I must keep away from getting stuck into it technically, I could but I won't.

There's a good reason for that......

When I was designing antennas for my HAM Radio hobby I would be up to the early hour's, 0300, 0400, 0500, until the birds were singing with a misty veil over my eyes, trying to get it absolutely bang on. Id even get out of bed in the early hours and start work, if i had a thought of how i could further improve it.

I had to sell my compound bow, same problem. Though I've recently bought one again, almost went down the same road until, unbeknown to him, a forum member said "I think you're over thinking this" and made me stop. I must thank him actually.

Same with computers, same with many other things.

I used to work to very tight tolerances and with great precision, not only physically but several mental disciplines, philosophy being one of the least obscure! ha ha.
Now, I've actually given up the carbon steel blade and gone back to using flint, so to speak. ... I do build knives as it happens, same approach, no plans, I have an idea and run with it. The result is generally much more aesthetically pleasing. If I went in with a strict design, well I'd still be in there now! ..... I wont have high precission machinery in my shed for that reason, plus i cant afford it!

It's called Aspergers Syndrome. .... Its only taken me 50 years to get it under control, mostly, ....

So basically, I go with my gut and do what feels right, otherwise I'd never be out shooting.

Thanks for the pellet recommendations for energy level checks. I'll be sure to be safe and legal.
I'll take some notes on hold sensitivity for you, ill be working on that. My 98 has come out great in that regard, but quite a bit more mass.

Challenge convention, my uni tutors loved me I can tell you. I'm the sort that will go my way around the super market, NOT the way they want me to go! ..... hahaha

[TonyL]

What a lovely post, stiks.

Many valid points there, and I know where you're coming from.

[stiks]

Ok folks,
Fitted my adjustable cheek piece, I need to finish properly as you can see. I might strip the stock completely.
I've used heavy brass bar, I wanted to increase weight a bit and bring it back towards the shoulder.

Regarding my modifications.
I'm extremely happy with the results, you might think "well he's going to say that" but I tell you honestly it's superb.
I've found it shoots and feels better with 15.9gn pellets. When I first shot it at range outside in my garden I was stunned by the fast extremely low recoil.
I can feel some piston bounce but it is very low, it was also very quiet. All this made me go inside after only a few shots to pop it over my chrono again thinking something must've gone wrong.
No still delivering 11.4 ftlbs and extremely consistent, great!
I'll be checking hold sensitivity soon, that will be very interesting.

Piston weight reduction from 221gr to 211gr .... A 10gr reduction.
Transfer port size was larger than I'd previously guessed. I was guessing about 3.2mm, it turns out to be 3.35mm. I think this is why it much prefers 15.9 PELLETS


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