Started my QB78 reverse bottle build - Finished!

[SpiralGroove]

Yeah Guys,
After the latest HPA explosions ....................... Did we ever get to the bottom of "that" .

Anyway, the next time I have my (2) QB78/79 HPA conversions taken down, I will add a stronger valve retaining screw (replacing the OEM screw, currently in use)





I've got enough problems on my hands, to add the worry about losing a hand or a Son

[aPpYe]

aPpYe.... That is a Crosman, likely a 2260 tube, 2240/50 grip frame and skeleton stock.... modded to accept a regulated bottle....

Hi rsterne,  yeah, I have been reading about how people are just getting fittings at the hardware store.  I plan on building everything with known pressure ratings...  About the stock though, is anything like that available for the QB family?  I don't mind having to modify something to fit if I have to, but I have never tried anything like that.

[rsterne]

It seems, IMO, that a combination of embarrassment and commercial survival for the companies.... and on the other side, complacency and/or the fear of getting sued for saying what you really think.... have allowed the threads concerning the three recent failures to die a quiet death.... Hopefully that will not result in another tragic injury or worse, a real loss of life.... I am saddened, but not surprised, that the companies involved have not been directly involved in the discussions.... Perhaps eventually they will present their findings publically, good or bad.... but I won't hold my breath....

Conversely, in both cases here on the GTA, owners have been given the information about suspected modes of failure, and the opportunity to disassemble their own guns and measure the parts of concern, and for the most part either have been so complacent to not do that, or chosen to keep that information to themselves.... Sadly, IMO, that means they will share, if not the blame, at least the shame, should we have a repeat incident.... You don't even need to have, or present, an opinion, to present the dimensions of the parts in question on your guns.... If nothing else, the manufacturers need to know if there are some of their guns/components out there that don't meet their own specifications.... even if they won't tell us what those specifications are.... Silence, in this case, serves no one....

Bob

[aPpYe]

So what kinds of failures have occurred recently?  I am literally less than one week into my discovery of these regulated guns. I know I have seen people saying that regulators wear out rather quickly, and I want to make sure that component is as solid as possible.  Is that what the burst discs are for, to make sure that the air exhausts safely upon failure?  Obviously I am a total newbie.

[rsterne]

Two of the failures involved Disco valves that were installed with only one screw instead of three.... One of them also involved the failure of a HiPac at the thinnest point, an O-ring groove.... The third failure was the pressure tube on an FD-PCP departing from the receiver.... All have been well discussed, but no conclusions reached....

A burst disc prevents the output from exceeding the pressure of the disc rating.... so a 1.8K disc will prevent the gun from ever seeing more than 1800 psi.... If the gun is built with a 3:1 safety margin over that figure, which is standard engineering practice, it should withstand over 5000 psi (once) without catastrophic failure....

Bob

[grand-galop]

Can we have updates on this rifle???
I love qb platform and what the thinkers are doing with it..
I would like to know if it sits in a closet collecting dust or a daily shooter..

Thanks

[nervoustrigger]

The OP is no longer on GTA so we shan't be hearing from him

[grand-galop]

The OP is no longer on GTA so we shan't be hearing from him

Thanks Jason!!

When i stumble on nice setup like that, i want to compare performance  and maintenance to what i have..

Tha valve seal and end cap seal are frequent care in my setup and was wondering if others are encounting the same..

My QB 78 hpa is still one of my preferate..