Here's one to toss around and discuss. This could be fun.

[CharlieDaTuna]

A customer, Gregg, sent this e-mail and I thought it might be a good point for discussion, debate and/or evaluation.

An interesting case indeed. What happened???

(Quote from the e-mail) “I sent my Gamo 1000 to you in early Jan. for the Turbo tune. When the gun was returned to me I was very pleased with the guns performance, and your documentation of the pre and post tune performance.”

“I proceeded to break the gun in with a Gamo sample pack. I just switched to Crosman pellets (CPHP) when, on firing, the gun there was a loud detonation accompanied by a strong odor of burnt oil , the pellet had broken into pieces and, when I opened the barrel the spring had been re-cocked . Since then accuracy which had been good is worse than when i bought the gun. I tried using another sight and other pellets, including JSB's. There has been no improvement. What should I do?” (unquote)

Now, for some ground work here. Nearly five months ago, the gun was TurboTuned using a Tarantula spring, a fitted spring guide, fitted tophat and an Apex seal along with all of the normal procedures. As usual, no volatile lubes were used in the gun during the lubing process. There was nothing unusual or abnormal found in the gun internally.

The gun had detonated with such extreme volatility that it actually recocked itself. Note: This is something that I have seen only once and read about just a couple of times when several years ago a guy by the name of “Fast Eddy” was promoting using “Slick 50” in the compression chamber to increase power. In fact it did but to the expense of many gun owners.

So………….. what could have happened here to cause this to happen the, the extreme detonation, the loss of power, the loss of accuracy and consistency???

Gregg will be sending the gun to me to take a look at to see what may have happened and to repair it. What can I expect to find??? What kind of damage???

[Rixtrix]

Sounds like the pellet fell partially out of the breech when closing and blocked the port, causing extreme pressure and subsequent, detonation violent enough to recock the gun. Don't ust heavy pellets(as an aside). Just my idea.

Ric G

[Big_Bill]

Hello Bob,

First of all I will say that Fast Eddy still promotes the use of Slick 50 on the yellow pages, I have read some of his posts.

Next I freely admit that I know very little about the inside of springers, something I hope to correct with my B-3 project.

Going only on the information posted, that does not tell us/me very much: One thing that you point out is that the Crosman pellet broke apart, therefore it must not be made of lead, or the pressure was so extreme that it shattered the pellet but did not melt it ? And only an extremely hot explosive could cause that, and if so, I think it would have severely damaged or destroyed the rifle, and shooter. Perhaps excessive pressure caused the detonation of the lubes used ?

He may have used a very heavy pellet, or an over sized pellet, that caused extremely excessive pressure, causing the detonation. He also may have placed two pellets into the rifle ?

I thinkthis may have caused a bulge in his compression cylinder and/ or damage to the spring due to the heat and pressure of the detonation, and may have also damaged his seal...?

I believe that he was lucky ! This sounds like the detonation of 38 special target rounds, loaded with 2.7grs. of Bullseye Powder, it is believed that the powder totally detonated, not burned, causing the destruction of pistols and hands.

Just my thoughts.

[DanoInTx]

Someone cleaned their barrel with 50% 3in1 sewing machine oil and 50% gasoline maybe?  Hehe, definately sounds hosed!  

On a side note Bob, I have never had anything tuned by you, but I did have someone elses gun here a few months back for a barrel trade.  The owner asked me if I could chrony his gun prior to me sending it back to him, he claimed you had tuned it a year or so prior IIRC.  I chronied the gun and found the extreme spread to be something unreal, like <10 FPS in 10 shots....again, this is from memory.  So in 10 shots this gun shot a string that was so closely matched shot for shot, it was amazing.  I only wish I had more money and less of a "tinkering" mind, because I would definately be sending everything I own off for one of your tunes.  I kinda doubt you use any "Eddy's super springer lube" in your tunes, hehe!

Dan

[Gene_SC]

Sounds like that could explain the pellet he found in pieces.. hmmmmmmm

Gene

[Gene_SC]

I think the only area that woud get heat would be the expansion chamber in front of cylinder.. I would expect to find a very bad seal that may be burnt or even deteriorated from the pressure and heat. Not to mention the spring and guide.. hmmmm

Gene

[Gene_SC]

The first thing I thought was maybe this gentleman reached for some Goo Gone and forgot he had put a petrolium product in that bottle.. Hmmmm  It stands to reason that the probability for a spinger to cock it self from an extreme internal explosion like that, that there had to be some petrolium in the mix somewhere.  hmmmm... One thing I do know is that when CDT does a Lube Tune or even a Turbo Tune he uses non volitile lubes.. Non Combustible..........

Now as far as damage goes... I would expect to find a bad seal, collapsed spring, possibly a broken guide... I would bet that his barrel has some evidence of patroleum in it... And that his FPS is probably below average for that particular air rifle now...

I am anxiouse to find out what happened and see it first hand...... Maybe CDT will let me bring my camera...

Gene

[SDale]

Pellet Wise, maybe he tried to shoot a half swaged .22 or an over sized pellet and it was just small enough to fit, but too big to be fired?

As far as the Extreme detonation... I remember someone mentioning the use of Carmex as a "Power Adder" .  Maybe this is the case? He also could have used Kerosene or the like to Lube the Compression Chamber. Or he used Hoppe's No.9  for Cleaning.

Another Idea is maybe he got the pellet into the transfer port somehow. The Transfer Port and Breech might not be perfectly aligned and when he tried to fire it, the stuck pellet caused enough pressure to build causing the detonation which in turn caused to pellet to exit the transfer port, shear into 2 pieces while on it way out into the breech only to come to a rest mid barrel.

The power loss could be caused by a compression chamber bulge, broken spring, burned piston or a combination of the three.

[Big_Bill]

Just a thought ?

Non volatile means not explosive ? Under normal conditions and by itself. Compress it under high heat and pressure, mix it with other chemicals, and only God knows what the reaction would be. Heck it could turn to gold, or start a fissionable reaction.

High pressure and heat are the cause, but what caused a reaction so much more violent then normal.

I believe that Greg screwed up, big time, and is telling you that "I didn't do nothin at all, and I didn't put acetone in my rifle, it must have been Charlie's tune. So I don't think I should be charged to fix my rifle or my eye and left ear. If it sounds like BULL S_IT, SMELLS LIKE< JUST MUST BE B.S. George might have sprayed starter fluid in it for all we know. IMHO

The answer is that the tune was done 5 months ago, who knows what he used on/or in it, where he kept it, and what he used it for That's like wanting to sue Browning cause you kept your shotgun in the barn and a mud dabbler wasp built a mud nest in your barrel, and it blew up when I shot it ! DA!!

Sounds pretty fishy to me.  Who knows he could have had a few too many cocktails and his buddies talked him into trying to make a flame thrower by filling it with lighter fluid and seeing if it would light when fired.  I think most of us have done some pretty stupid things growing up but hopefully he is not trying to get Bob to pay for it.

PS, Bob I will be sending you an email but wanted to let you know that I installed your trigger last night and must say that based in the minor cost of your trigger vs the dramatic improvement one would be crazy not to make the change.  I do a lot of firearm tuning for friends and wish it could be so easy.

Thanks Tom

[Gene_SC]

SDale - 4/26/2007  11:36 AM

Another Idea is maybe he got the pellet into the transfer port somehow. The Transfer Port and Breech might not be perfectly aligned and when he tried to fire it, the stuck pellet caused enough pressure to build causing the detonation which in turn caused to pellet to exit the transfer port, shear into 2 pieces while on it way out into the breech only to come to a rest mid barrel.

[/QUOT)

There still has to be a petroleum product somewhere.. Assuming that no petroleum product was pressent can a mere blocked breech cause the air rifle to cock itself??

Just a thought..

Gene

[SDale]

There may have been just enough lube left from his last few shots to make it detonate so badly.


EDIT: A blocked breech would DEFINITLY cause an extreme jump in pressure over just a rifle dieseling with a properly seated pellet. Could it be possible that the Extreme Pressure also caused enough heat to melt the piston seal edges and break it down into it base materials? ie. Oil???   Just a theory I pulled outta my butt. Don't listen to me, it's the voices talkin again. hahaha I dunno.

Maybe the guy is doin JUST what Bill said. Did the damage himself and wants it fixed Gratis

[JMG]

I think I am inclined to agree with Rick's take on it. I know of the same thing happening to me with one of my B3's... where I put the pellet in the load hole and then pushed the compression cylinder back up to get it ready to fire.... there was a pop from the gun, no patang from my steel backed pellet trap. and when I pulled the cocking lever back half of the smashed deformed pellet was sittin inside the loading port. The gun was not damaged nor did it recock itself lol. But the pop was very similar to a rimfire .22 report. The gun was also diesaling but not too bad from a bone stock B3.Thank god for lousy tolerances in B3's right guys? hehe Yep I think the pellet got pinched between the barrel and breech and the air had no where to release to and since the gun was tuned and performing optimally the pressure made the bang.

John

[shadow]

I wonder if the guy didn't tell the whole story and there was a additive put into the gun causing the death of a good shooter. It probably stressed out and broke several part's. I don't know if I would trust anything in the gun now, bent or broke. :0 Ed

[Silo]

yeah, Ric that sounds like the most likely scenario.... plus volatile oil in the barrel, I've been
guilty of forgetting to "de-oil" a stored air rifle barrel and had it go rim fire on me with the first shot  :p