new HW95/R9 barrel pivot block design.

[nced]

I may have made a wrong assumption concerning how the new HW95/R9 barrels are secured to the breech blocks.......
I thought that perhaps the new design barrels were screwed into the breech blocks instead of pressed because the breech now has a "star shape" form instead of the end of the barrel being flush to the breech block.
New style HW95/R9 pivot block breech..........

Old style R9 pivot block breech.......


From this pic after removing the rear sights I can see that the barrel is actually splined and either pressed or pulled into the pivot block......


Hummmmm......perhaps that torx looking breech of the new design HW95/R9 is simply a nut used to pull the barrel into the block.......I don't have a clue and I'm not about to destroy a HW barrel to find out for sure. 

I also found it interesting how the alignment of the rear sight is maintained with the new design vs the old......
New design uses a separate removable dowel in the pivot block to help maintain rear sight alignment.......



The old design used a milled "slot" to align the rear sight...........


Simply mulling over minutia! 

[grauhanen]

As a point of information, that new style breech is now at least two years old.

[MikieG]

Yup. I ordered a new .22 barrel from SSSO last year and it was the new style.

[wimpanzee]

My R9 from early last year uses the new design.

[nced]

HW95 spring loaded detent issue, and a nced home tune.
Looking at my disassembly pics the appearance of the brand new spring loaded detent looked worn as seen in the pic. Notice the appearance of the spring loaded detent of the decades old R10. While the HW95 cocked smooth after a previous installation of an unused spring kit and relubing with Krytox the barrel latching was kinda "ratchety feeling" after loading a pellet. Well.....I simply replaced the new HW95 detent out with the old R10 detent and the latching is considerably smoother. As a side note, after removing the spring loaded detent and spring I found a bit of "grit and swarf" in the "detent hole". I guess not a biggie since there was none anywhere else in the gun but I cleaned out the detent bore anyway before reassembly.
New detent........

Old R10 detent.........


I also installed one of my oring sealed piston caps in place of the factory seal (now I have two almost unused new design R9 piston seals), made up a TIGHT fitted guide and top hat on the factory R9 spring. I'm curious to see just how many shots I can expect from the "factory jobby". I have a couple factory R9 springs in my "parts bin" that are practically unused since they were replaced with aftermarket springs before even using the guns.........I'm thinking of "using them up" if I can get at least one year of service from each spring!

After reassembling the HW95 with real tight fitted guide and top hat, piston fitted with an oring sealed piston cap and shot a few "real snug" fitting CPLs (heads sized to 4.52ish mm) few shots over the chrony sensors read about 870fps. this is only 15fps less than I was getting with the HW95 in "factory twqang mode", loose fitting guide, and new design HW piston seal. LOL...again it seems that the new design factory HW95/R9 piston seal performs very favourable with my oring sealed caps....well, as far as velocity goes.

Tomorrow I'll be fitting the stock with some screw cups and steel screw posts to provide some "rock solid" screw torquing without concern about "crushing stock wood" under the screw heads.

Still haven't done any semi-formal accuracy testing yet but that will follow in a couple weeks.

Anywhoo......I forgot to take some more HW95 pics but a friend of mine also ordered a "$299 HW95" after he receives it (backordered) he wants me to do the same mods to his gun and I'll take a few more pics of what I find with his gun.

Oh...I almost forgot......
I usually have to do some rather tedious "receiver tweaking" with a home made hone to prep for an oring sealed piston cap, but not this time since the receiver was pretty good to start. Here's a pic...........

Notice it came with none of that "cross hatching" that most of the airgun gurus claim is needed and I really haven't found to be beneficial either!

[nced]

As a point of information, that new style breech is now at least two years old.

Yep....for sure because the R9 I bought over two years ago also has the "star nut pivot block". I actually think that my R9 was a "transition gun" because it had no piston liner but didn't really need it with the current cocking shoe design, however the new HW95 did have a piston liner.