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Post by **Mac** » Wed Apr 03, 2013 8:55 am

That is downright scary. Also disgusting that someone would put a buyer in such danger.

Thanks for the post that should certainly speak to all of us to check over everything you buy before putting it into use.

Glad everyone escaped injury on this one, but what might have been sure sends a shiver up the spine.

Windrifle · Post by **Windrifle** » Wed Apr 03, 2013 6:21 pm

WOW!

Un-freakin'-believable!

I hope the guy posts the seller's name and circumstances associated with this gun around the forums so everyone can avoid this individual. A guy like that (seller) doesn't deserve to be a part of ANY forum, pawning off time bombs like that. I know it's a "buyer beware" world and all, but come on...

Len: Do you know if the current owner has a replacement frame? I have a couple MK I's here (not counting the "LJ" you made for me) and one is stripped down as I was going to clean it up and repaint it, but I would be willing to give him the grip frame so he could get his back in shooting condition. He could just transfer his parts over to the "new" frame. Just a thought...

Todd

Leonardj · Post by **Leonardj** » Wed Apr 03, 2013 7:35 pm

Windrifle wrote:Len: Do you know if the current owner has a replacement frame? I have a couple MK I's here (not counting the "LJ" you made for me) and one is stripped down as I was going to clean it up and repaint it, but I would be willing to give him the grip frame so he could get his back in shooting condition. He could just transfer his parts over to the "new" frame. Just a thought...

Yes, he now has a suitabkle replacement frame. I did a bit of digging and found one for him in my stash of goodies.
The only condition attached is that when he swaps out the parts, that I get the old, over-pressurized frame - to personally band saw in half.

I'd like to say thank you on behalf of the owner of the gun, for your very kind and generous offer of assistance.
He does not post on any of the forums, but he does lurk on a few of them, so he will see this thread.

Gippeto · Post by **Gippeto** » Sun Apr 07, 2013 12:18 am

Hiya Len...been a while.

Dave posted this on the other forum to spread the word (I'm guessing). Disabling a safety device is pretty dumb IMO.

What peaked my curiosity though was that the frame survived at all....3000psi is nothing to sneeze at after all. Wondering if you verified the reg output pressure?

Thanks,

Al

Leonardj · Post by **Leonardj** » Sun Apr 07, 2013 2:21 pm

Gippeto wrote:Hiya Len...been a while.
Indeed it has.

Dave posted this on the other forum to spread the word (I'm guessing). Disabling a safety device is pretty dumb IMO.
Thank you to Dave for spreading the word.
This is only the second time in around 20 years that I have encountered a burst disc replaced with a (set) screw.

What peaked my curiosity though was that the frame survived at all....3000psi is nothing to sneeze at after all. Wondering if you verified the reg output pressure?
I am absolutely amazed, that the frame had held together for the several hours that it was over-pressurized - I'd have never believed it possible.
Yes, I did verify the reg output, thus my comment above - "the regulator was essentially non-functioning and outputting 3000 PSI".

Thanks,

Al

Gippeto · Post by **Gippeto** » Mon Apr 08, 2013 1:09 am

Appreciate the clarification Len. Had heard stories of these frames suffering fractures at much lower pressures...had me wondering is all.

Amazing for sure.

Regards,

Al

blade57 · Post by **blade57** » Mon Apr 08, 2013 1:17 am

Thanks for the great post, Len. I was and remain to be absolutely flabbergasted that one person could have such a low regard for another persons well being. I guess it takes all sorts though

Please keep on doin' what yer doin', buddy

DaveD

Leonardj · Post by **Leonardj** » Mon Apr 15, 2013 3:44 pm

Just to update the thread, after swapping out the parts, the owner gave me the over-pressurized frame, so that I could permanently "remove it from circulation".
The frame was band-sawed in half, and scrapped.

Leonardj · Post by **Leonardj** » Sun Sep 07, 2014 12:45 am

It has recently come to my attention that Tim McMurray, of MAC-1, had performed a hydro-test on a Crosman Mark I/II frame. The frame was pressurized to failure, and the result was surprising.
For the benefit of those that questioned the credibility of my original post with regard to the pressure involved, the following quote in regard to the Crosman Mark I/II, from Tim McMurray, made on the Crosman forum, should provide you some degree of validation.

I tested it to 4500 PSI. It stripped the valve screws and moved the valve forward for a perfectly repeatable non-catastrophic pressure relief by design.

The link to the post that the quote is taken from:
http://www.network54.com/Forum/275684/m ... ol+Will+Do

The pressure that the Mark I frame tested to before failure was, IMO, nothing short of amazing. I would never have thought that the cast alloy frame could withstand that amount of pressure without being blown to bits, and in the end, it was the valve screws that failed - the frame itself remained intact.

While the above info is good to know, it should in no way encourage anyone to pressurize these alloy frame airguns to such pressures. I don't know if Tim hydro-tested just one frame, or several, but since these are castings, there is always the potential for a porous casting, which could be the statistical "fragmentation grenade" that could cause serious injury to the user if over-pressurized.

Always be absolutely certain of the output pressure of the regulator, and never disable the protective device.

FTCentral.com

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