[johnpe]

There are several current threads on gun blowups. Some time ago, probably three years or so, there was a quite lengthy thread about Mr. Bowen trying to blow up an H&R Topper and his trials and tribulations of trying and failing. The last I heard was that he was leaving for the Grand and Africa and would pick up where he left off. At the time, he tried everything anyone suggested to blow up that H&R Topper and all it did was digest everything without a serious hiccup. He posted pressures and velocities of each trial. I never did hear of the final outcome of his efforts. If someone out there has the information please post it. I think it will put to rest a lot of the stuff being batted around about what it takes to blow up a shotgun.

John Petty

 

[BBowen]

mr. petty

first of all let me state that what we did here with the h & r was not meant to prove anything. we have been skeptical about reloads being the cause of catastrophic failures in shotguns and were just trying to shed some light on that issue.

we did try every recipe for dangerous reloads that people gave us and the h & r held each time. it did get loose and is off the face but still shootable and we use it from time to time for some more tests. it was a new gun when we started.

we were unable to develop pressures much over 20,000 psi with reloads. that is well within the range of sammi proof load pressures. the highest pressures were with 2 charges of powder and 1 charge of shot. (that will work with the right wad, powder, and case combination and the pressures were slightly under 20k)

it is my humble opinion that reloads are not the cause of most catastrophic shotgun failures. barrel obstuctions immediately in front of the chamber would have to be solid as well to cause failures of the type described recently on ts.com. we tried at least 10 20 ga. live rounds in front of the chamber and they just shoot out with out going off. obstructions farther down the barrel can cause barrel ruptures. however, we tried base wads that we manually removed from winchester shells and it just shot them out as well. they could cause ruptures in thin barrels however and i would be cautious about them.

as i have stated many times, do not try overloads in your shotgun. i think that the h & r is no more or no less "strong" that most trap shotguns but conditions vary and it is dangerous business to try overloads.

i think the cause of most catastrophic failues is a high velocity gas leak. what allows that to happen is always the hard thing to figure out. i think in most cases, it comes from a stress crack that develops from many rounds being fired through the gun.

bruce bowen www.bbguns.net

 

[johnpe]

Mr. Bowen

Thank you very much for the enlightened reply and update on the status of your testing. I'm glad to see the Topper is still somewhat functional.

John Petty

 

[mrskeet410]

BB - Ever try a 12 gauge volume, say a #30 MEC bushing of .410 powder, in a 12 gauge load?

 

[BBowen]

mrskeet410

we did try your suggestion using both bullseye and h110. pressures were high but not beyond a saami proof load pressure.

bruce bowen

 

[SMITH47]

Mr Bowen

Please explain what a high velocity gas leak is ?

thanks,
ernie

 

[BBowen]

ernie

a high velocity gas leak occurs when there is a small opening in the chamber or the cartridge that allows gas from the powder combustion to escape. the most common example is a pierced primer or in rifles, a case head separation. if for example, there was a crack in the chamber wall of a shotgun, gas could escape and it would be like a nozzle on a garden hose, i.e. high vel.

bruce bowen

 

[SMITH47]

Bruce

i mainly shoot sub gauge briley tubes in a recently made MX8.

what would you recommend i do to be as safe as possible ?

that is reduce the risk as much as practical the risk of a catastrophic failure ..

ernie

 

[BBowen]

ernie

i have never heard of a problem with briley sub-gauge tubes but i would inspect them from time to time just to be safe.

bruce bowen

 

[SMITH47]

thanks Bruce


ern

 

[Quick 1]

Mr. Bowen,
I have a racing background and have a question concerning the hairline cracks you mention above. In racing, we had many components (crankshafts,ring gears,etc.) that were prone to failure checked for stress cracks by magnaflux,eddie current, and other methods. Would any of these methods catch the barrel defects in time to prevent catastrophic failure.
Mike McGee

 

[BBowen]

mike

i am sure that the crack would show up with the methods you discussed. i have seen some x-rays that show good detail as well. the problem is, on inspection there may be no cracks appearing but it may develop on the next shot and cause a problem.

i think stress cracks can occur when the barrel is silver soldered into the mono bloc and there is a void in the solder joint. when the shell goes off and develops radial pressure the barrel expands into the solder void. after many shots fired the barrel becomes fatigued and a crack possibly develops and there is a gas leak and a catastrophic failure could occur.

this is just a theory to consider.

bruce bowen

 

[JerryP]

It's refreshing reading to see actual numbers and test results. Especially after hypothetically blowing up guns for a week with AA basewads and then to read the H&R digested them without a hiccup. The stress crack theory seems most plausible. Bruce, thanks for taking the time to share this.

 

[Savage99Stan]

I have several single H&Rs and NEF's..normally for the kids to use or for loaners to relatives who visit. One in particular has a rifled barrel I was going to use to test Lee and Lyman "sabot" slugs using various plastic wads. With my Hastings and Remington slug barrels, the wad is a fairly snug fit in the bore, even before you put the slug in. With the NEF you can almost drop the wad down the bore...much looser. Would this in any way affect the results of the 20 ga in a 12 scenario? Just wondering if the larger bore would decrease the pressure keeping things from coming apart.

I've seen two barrels which were blown out at the breech from a 20 in the 12 thing and more than two with banana peel midsections or muzzles from barrel obstructions. I guess if you're careless you'll either get lucky or unlucky. Most of the ones I've seen were rather thinwall....M12's, an old Stevens pump, etc.