One of the nightmares of airgunners, especially break barrel shooters, is getting a bad barrel.
Until now, the whole breechblock assembly had to be sent over to be replaced (with luck), or get a new gun altogether (again with luck).
Well, with the DIANA EMS it's a new experience.
Hope you enjoy the read:
https://www.ctcustomairguns.com/hectors-airgun-blog/an-unintended-coincidence-c
Keep well and shoot straight!
HM
@hector-j-medina-g
Wow! Thank you so much Hector for all your great work. I can't wait until my repaired rifle arrives.
I'm going to have to go to your blog now and re-read your advice about running-in the barrel. Also as per your advice, I store my gas rams muzzle down.
Thanks again,
DonC
Also as per your advice, I store my gas rams muzzle down.
Shaft down is the standard (read proper or ideal) orientation of gas struts, since forever. Keeps the seal wet.
If you're new car shopping and notice the rear gate gas struts have been installed shaft up (to catch rain) run, don't walk.
What about horizontal?
If this was directed at me, the idea is to keep the seal wet. The degrees from 90, required for 100% seal coverage, varies with diameter.
If we reverse this and orient shaft up, how many degrees off horizontal equals 0% seal wetting?
There are some exceptions like automotive suspension struts or shocks, but I'm not clear on why they're excepted.
That's everything I think I know about the topic. 😆
If Hector has some other rationale or info, I'd certainly be interested to hear it.
Addendum. When inspecting well pressure tanks or air-over-water contact tanks, I've noticed that air will leak profusely, though a hole which could not pass water. If the tank were laid over so that the hole fell below the water line, the leak would stop. I don't see the gas struts being any different.
There are several aspects to this:
1.- Airgun gas springs perform a MUCH FASTER cycle than any other application. So they are more sensitive to "dryness" (to go along with GWH's terminology).
2.- The stem (shaft) weighs MUCH less than the body. So, if you are planning on using extra heavy pellets in a breakbarrel, it is a good idea to put the body forwards, for most applications, the body rearwards yields a better shot cycle.
3.- Most seals are either ORings or "C/Cup" seals (variations of the automotive). Good quality ORings can stand one or two "dry" cycles. C/Cup seals cannot. SOME C/Cup seals have "felts" that retain SOME lubricant to provide a proper start for the first two or three cycles. SOME materials that ORings use also have some "capillarity/surface tension" to them that retains a little of the lubricant even if they are fighting gravity.
4.- There IS a difference between the innards of a $15 gas spring and an $80 gas spring. You guessed it: mostly in the seals and sealing architecture.
5.- From what I have been informed by the maker of the NTec units:
Vertical body up.- Preferred.
Vertical body down.- OK in temperate storage conditions.
Horizontal.- Not OK
Horizontal in a hot environment.- You're gonna kill the gas the spring in the first month of storage (and you can ask the Saudis).
The 34 EMS allows you to install the NTec gas spring both ways. PERSONALLY, I like the mid-weight pellets where most of the research and application on ballistics has been going on in the 0.177" cal, so the shaft to the front it is. BUT that does not mean that if you want to shoot the 18 grainers in 0.22" you cannot get the barrel changed in your LoA and the NTec installed with the body forwards.
The versatility of the 34 EMS design is just beginning to be realized (even by some in DIANA).
😉
HTH, Keep well and shoot straight!
HM
