Xisico T05 saftey issue?

Xisico T05 saftey issue?

jke
Joined: November 3rd, 2001, 12:33 pm

September 28th, 2010, 7:41 pm #1

came across this on a T05 tune web page. made me think twice on a B28 a while ago.
"However on BAM B-28 the Chinese 350 clone, these sears and sear number one are not heat treated, and can be bend with pliers with force. Which is a major safety risk, in a cocked magnum springer like thus the main spring force pushing against the piston is said to be 300 pounds so by using not heated steel BAM endangers the owners of these guns. "

http://www.network54.com/Forum/644843/t ... +principle

fwiw joe
In the meantime.....I'm cleaning my gun.
Last edited by jke on September 28th, 2010, 7:42 pm, edited 1 time in total.
Reply
Share

Joined: March 3rd, 2005, 1:38 pm

September 28th, 2010, 8:14 pm #2

may be a case of nervous nelly.....the auther is known for not liking Chinese rifles so you can take it with a grain of salt...

mailto:flyingdragonairrifles@hotmail.com
Bestairgun.com
Last edited by mikeiniowa on September 28th, 2010, 8:21 pm, edited 1 time in total.
Reply
Share

Joined: October 10th, 2003, 5:24 am

September 29th, 2010, 3:59 am #3

came across this on a T05 tune web page. made me think twice on a B28 a while ago.
"However on BAM B-28 the Chinese 350 clone, these sears and sear number one are not heat treated, and can be bend with pliers with force. Which is a major safety risk, in a cocked magnum springer like thus the main spring force pushing against the piston is said to be 300 pounds so by using not heated steel BAM endangers the owners of these guns. "

http://www.network54.com/Forum/644843/t ... +principle

fwiw joe
In the meantime.....I'm cleaning my gun.
so much as how it holds up from repeated use. This is especially important in sear surfaces. Those two small planes must fit precisely to hold the gun cocked. It doesn't really matter what the rest of the sear bar or plate is made like so long as it can support the engagement parts. In order for the sears to maintain their engagement angles (which are what really holds the piston), they have to be of a minimal hardness. On powder burners, sears are often case hardened, although I have seen some older and cheaper guns where they are only surface-hardened. The latter are fine so long as you don't cut through the thin hardened surface layer when honing them. Do so and they will quickly wear. But that is for a powder burner, which has a different sear arrangement since it doesn't involve locking up a powerful spring, only the one for the firing pin.

As Mike stated, the B28 sear parts must be of sufficient materials quality to adequately serve their purpose since there seem to have been no reported failures. Bear in mind that the T05 clone has also been used in the Ruger Air Hawks and B25's, upon which there have been many, many posts and these have passed through the hands of a lot of tuners who would have spotted some flaw by now.

The biggest fault in most air gun trigger mechanisms isn't so much their designs (some are over-kill) as it is the modifications that owners have been made to them. It doesn't take much to over-do it when working sears, especially if they've been "fine tuned" with sandpaper and a Dremel. And it doesn't help that so many shooters seem to think they simply must have an eight ounce trigger in a field gun where 1.5 pounds is even a bit light. The quest for target triggers (which are designed around a light pull) has made many a safe gun just the opposite. IMHO.

Last edited by RedFeather on September 29th, 2010, 4:03 am, edited 1 time in total.
Reply
Share

Joined: October 21st, 2001, 3:36 am

September 29th, 2010, 4:39 am #4

came across this on a T05 tune web page. made me think twice on a B28 a while ago.
"However on BAM B-28 the Chinese 350 clone, these sears and sear number one are not heat treated, and can be bend with pliers with force. Which is a major safety risk, in a cocked magnum springer like thus the main spring force pushing against the piston is said to be 300 pounds so by using not heated steel BAM endangers the owners of these guns. "

http://www.network54.com/Forum/644843/t ... +principle

fwiw joe
In the meantime.....I'm cleaning my gun.
I'm going to disassemble it againg in the next few months, I'll make sure I put some pellets through it and check them for wear.

Reply
Share

Joined: October 24th, 2006, 5:38 pm

September 29th, 2010, 6:53 am #5

came across this on a T05 tune web page. made me think twice on a B28 a while ago.
"However on BAM B-28 the Chinese 350 clone, these sears and sear number one are not heat treated, and can be bend with pliers with force. Which is a major safety risk, in a cocked magnum springer like thus the main spring force pushing against the piston is said to be 300 pounds so by using not heated steel BAM endangers the owners of these guns. "

http://www.network54.com/Forum/644843/t ... +principle

fwiw joe
In the meantime.....I'm cleaning my gun.
I do a pretty fair amount of heat treating using high carbon steels. I can tell you that a fully hardened piece of carbon steel the size you talking about would be much more prone to breakage than a properly hardened and tempered piece would be.
On trigger parts they can be fully hardened to above 60RC and then easily drawn or tempered back to 43-46 RC while leaving the sear face around 55 Rc. Doing this will give the body of the lever the ability to spring and not break in weak areas like where the pin hole is. While the sear face is still appropriately hard to avoid wear.
A good example of this can be found in many of your early revolvers using a flat main spring in the grip area. To hard and the spring will break rather quickly, to soft and it just bends and does not provided the needed resistance. Done properly the spring will last for many many years of use. Still though you can take one that has been properly done and bend it with a pair of plyers past its point of return.
I have no idea if the parts in question have been properly heat treated and tempered or not, but just because they can be bent means absolutley nothing except they are not fully hardened.


Last edited by Guthook on September 29th, 2010, 6:59 am, edited 1 time in total.
Reply
Share

Joined: March 28th, 2002, 6:54 pm

September 29th, 2010, 11:46 pm #6

came across this on a T05 tune web page. made me think twice on a B28 a while ago.
"However on BAM B-28 the Chinese 350 clone, these sears and sear number one are not heat treated, and can be bend with pliers with force. Which is a major safety risk, in a cocked magnum springer like thus the main spring force pushing against the piston is said to be 300 pounds so by using not heated steel BAM endangers the owners of these guns. "

http://www.network54.com/Forum/644843/t ... +principle

fwiw joe
In the meantime.....I'm cleaning my gun.
on a blog presumably advertising his tune work. Not very professional...

He does downrate a lot of guns most guys like...
Reply
Share