Wondering ?????
 

Watching Guns international I noticed a new listing for a Parker 16 Gauge that had occurred some damage... not to get specific (look at the listing) could someone please tell me what 16 gauge load (factory or reload pressure) would cause damage such as this.. I would just really like to know where this forum would draw the line with load pressure with the ability to do what is pictured.. I am asking this assuming barrel wall thickness is sufficient... I don't want to discuss that particular gun ,just the pressure that would cause that damage..

To be more specific... How much pressure would it take to do this to a good measuring everyday Damascus barreled Parker 16 gauge GH ?? With NO barrel obstruction...

I'm glad it was not me...

http://www.gunsinternational.com/gun...n_id=100736629

maybe more pressure than you are likely to fit in the shell

i would bet there was some debris in there


maybe - unless the seller knows and trusts the shooter - it would be a good practice to set a condition - yes - you can shoot it- here are two boxes of RSTs - $20 please - refundable if you buy it

Maybe a reload with more powder than should have been in there.

I want to know... Why pay the money to list an ad on GI just to publically shame an unknown, to us, party?

Give me a pressure number that would raise your eyebrow in a 16

Too-long, high-speed paper shells?

Avatar
 

I'm more puzzled by Allen's avatar.

I doubt the person even knew they did it.

Happy meter on 11
 

My JRT with a chipper down the hole...

Educate me.... does the location of the bulge say anything to what may have happened ??

maybe hot shells?
maybe long shells?
maybe long hot shells?
maybe thin barrels?
maybe any of these combinations?
maybe something else?

PML

I saw the listing this morning & got to pondering all sorts of questions about it myself.

Because I'm not an expert, I don't have the gun in hand to inspect & I wasn't there to see the deed done. I have to believe the poster of what his take is on the matter.

I just hope this doesn't grow a life of it's own and feed the Damascus blow-up myth's & legend's of using nitro powder. IMO: There is just too many possible variables in play here to truly speculate on what the cause may have been.

My guess is a base wad on a previous shell caused a partial blockage.

I also doubt they knew as it is subtle compared to this photo. The Damascus pattern makes it less visible. I would guess factory heavy 2 3/4 inch loads with standard 12k psi pressure in 2 1/2 inch chambers.

Here is a set of 12 GA VH barrels I purchased from Brian Dudley in this condition. I'm guessing on these factory 3 inch shells in the 2 3/4 inch chambers, as the bulge is four and a quarter inches out. Now whoever did this you would think had to notice the first one and you wonder why they did it again? Maybe the excitement of a gobbler in front of them?

p.s. I don't think the GH is worthless now. It still has some value although a fraction of the before value.

Possible for once but not twice. You may have not noticed he is showing both are bulged.

Well...I guess the old saying 'Never lend someone your car or your girl....' applies here. In fact, you could use 'hot load' instead of 'rod' and it would work for guns, too.

Depends what level he's at on GI . Generally a bigger dealer gets the higher priced deal and you can list all you want for one price . So if that's the case this listing cost him nothing .

I saw it yesterday ,what a shame and although I have never met Steve in person,the first 28 Ga. Parker I ever purchased was from him and he was a Pleasure to deal with and a Fine Gentleman , I think he is, as he said in the ad ,Boiling , maybe just beside himself and hoping the shooter will at least own up to it if they in fact knew about the damage ! At the least an apology would surely be in order ! Just my opinion , I haven't called to inquire of the gun or spoke with any one about it !

I think this is heavy load damage, not obstruction. Both bbls being bulged indicates that, and they look equally bulged. Just my guess. Nice gun; what a shame. I'd have a go at taking the bulges out were it mine and would feed it nothing but low pressure loads after that, but you'd be wailing on them pretty good to take them out in that location. It would be an interesting project to at least give it a try.

Thanks to Edgar for the post below. Sounds like taking the bulges out is not an option. A real shame.

I saw this gun at Hausmann's and both bulges are right at the forcing cones. Additionally, they go all the way around the diameter, right into both top and bottom ribs, which, to me, says the barrels would have to be taken completely apart to tap the bulges down. I am also of the opinion that they were 2 3/4" hot shells.

I saw the gun as well and doubt this set of barrels is salvageable. Another member here had a similar experience with a 16ga hammer gun. I don't know if he ever got the barrels repaired.

IMHO the obvious and least costly approach is to look for another set of barrels and would think fluid steel ones would be easier to come by vs Damascus.

I would be curious if anyone has seen the results of shotgun barrels that have failed proof testing. It would seem to me the opertunity to budge a barrel during the proofing is elevated. The data of guns tested would provide us with results in a controlled situation of what might happen to shotguns fired with proofing shells. My understanding is that these shells are loaded to about double the normal charge. I realize dents, wall thickness, and other variables would effect the results, but still there should be patterns of barrel bulges.

Rich, that was me, as you know, and Brad repaired my barrels and I shoot it all the time now. He told me that if it was anything but Laminated Steel he wouldn't even have attempted it. Something about Lam that makes it more resilient than the other composites...
I wrote about the gun in Parker Pages less than a year ago - "Shot to Destruction" is the article to look for.

I'll bet a dollar that a set of fluid steel barrels of that vintage would have suffered similarly (or blown out) under the same circumstances.





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I saw this gun before, and it was a great gun, and no the bores were clean. One of these two people shot this gun and returned it to Steve, and if you have ever dealt with Steve he will always say "go out and shoot it", bring it back set it back on the table. Say yes or no it didn't fit or whatever and he will say fine (I have seen him do it many, many times).
I cannot believe that the person that did this, did not have enough backbone and/or been man enough to say I'm sorry I screwed up your gun what can I do? If I know Steve he probably would have cut him some slack and said that happens and worked something out, but no, the guy just dropped it on the table and went on his merry way:cuss:. I know Steve has been steaming about this for a few months, the person that did this has no excuse :nono:

Phil, In proof testing, they use a shell of the proper length for the chamber.
I think the type of hull has something to do with what happened to Steve's gun. Many, but not all, plastic hulls are skived, and this tapered wall section of the crimp portion may blend with the forcing cones so that the wad doesn't meet with a strong resistance. I don't have to worry about what the chamber length is when I decide to shoot a particular gun that doesn't get much use, because I only load, and only buy 2 1/2" shells.
I think quality Damascus barrels, in good condition can easily tolerate higher than our normal pressures, but maybe not so well when a shell too long for the chamber, is thrown into the mix.

It would be interesting to know ALL of the circumstances involved.






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Just for the sake of asking anyone's non-committed and honest opinion... What would you guess would be the necessary generated pressure (without obstruction) in those barrels to cause them to bulge..
How about a ballpark ???? And would an off the shelf modern factory load generate that pressure ?? I am not trying to nail anything down here I am just trying to get educated on what is really the case here.. I have read of people shooting 2 3/4 hulls and Wal-Mart specials and I am now hearing the extra length may be an issue at the forcing cone.. I will only shoot 2 1/2 hulls because I just don't know and as such stay on the safe side, what say you ??

John good question, I don't think even a Promo load could cause that, maybe as was said before a base wad came off and then the gun was fired again.

Allow me to start this off... Would anyone think 15,000 PSI chamber pressure would cause a normal set of 16 bore Damascus barrels to bulge in this manner ?? I would like to get an opinion on a number to get an idea of a how much of a buffer zone I have between my low pressure loads and what would cause a potential situation.. I am not looking for the hairy edge zone....

I don't believe you would find any factory loads that would approach 15,000 psi. A crazy reload maybe. Possibly one with a double charge? Could 20,000 psi do it? I don't know.

My question is if this shooter bulged these barrels due to hot loads. What condition are the other guns in he was shooting that day? Surely he didn't just have these two hot loads with him. This was at the southern SxS shoot so his loads would have probably been shot in other similar guns as well.

The other question I have is about how common is it to have base wads come loose and cause obstructions? I've been around a lot of guns and shooting & can honestly say I've never seen or experienced it. What are the odds of having two base wads come loose in two different barrels on the same gun & bulge both barrels at approximately the same place in each of them?

Personally I think there's more to this story. I want to believe Steve, it's his gun and he was the one that experienced it in real time. I'm thinking that it's a mystery that will never be solved without more concise information.

There's a LOT more to this story that we will probably never know. I don't think we can learn anything from this exercise.





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The current SAAMI maximum pressure for a 16ga 2 3/4" cartridge is 11,500psi regardless of shot and powder loading. At 80 percent of proof pressure, this requires minimum SAAMI compliant proof of 15,365 psi for a 16 ga gun, manufacturers may exceed the minimum standard .

Current production cartridges may be at or below the 11,500 pressure, particularly 1 1/8 loads.

At the time the Parker in question was made, the normal max pressure for 16 cartridge was 10,200 if I recall correctly, this gives a minimum proof load of 12,700 that the gun would have been tested with.

Tests have shown that chambers 1/4 " short increase pressure over nominal 2 3/4 by about 5 percent. Therefore assuming it was short by 1/4 " ( which may or may not be true) , a possible pressure could have been 11,500 plus 575, 12,075.

Therefore, the maximum pressure that factory shells loaded to maximum SAAMI specifications would have provided exceeds the load pressures the gun was intended for but remains less than what the gun was proofed with. The few tests done and reported in DGJ have demonstrated that the tested composite steel barreled guns withstood at least 4000 to 5000 psi above proof before they experienced non elastic deformation.

Neither the bore ID nor wall thickness has been disclosed for the gun in question. That information is critical to any informed analysis. O framed 16's , which this may or may not be , often do not have much wall thickness to spare.

We saw a fairly new Italian over under rupture forward of the chambers at the Southern about ten years ago. He was using Winchester trap handicap gold loads that would have been loaded to SAAMI max.

I have an acquaintance who had a Guerini rupture halfway down with factory handicap loads. He saw the shot cup fly out on the previous shot so it was not a squib and stuck wad issue. He later had the barrels measured, bore ID was standard but the wall thickness was less than .020, how far less I don't recall but they were made surprisingly thin.

It's possible that the offender didn't even know the barrels had swelled. I could easily see myself shooting a gun at an event where there were lots of people and commotion and never paying that much attention to the gun. Keep in mind the swells are just that - gentle swells - and not ruptures or jagged edged. The Damascus pattern helps hide them, too.


I'm not taking sides....but I gotta say whenever I let someone shoot one of my guns I am very specific about what shells they use. Very specific.

It appeals to the ego to be a laid-back gun dealer who jauntily hands someone a multi-thousand dollar, 100 year old gun while casually saying "Bring it back when you're done..." But I think the dealer in this case has learned a lesson the hard way and will be less magnanimous from here on out.

"Don't lend someone your car or your girl...someone might throw a rod in 'em."

Whenever I let someone shoot one of mine, not only will I insist on what shells they will use - I will hand them a box or two of MY shells.





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Couldn't agree more

All the commonly available factory loaded 1 oz 16ga cartridges I am aware of generate chamber pressures below 10,200, or the design max working load for the gun. 1 1/8 loads are over that to the full current limit of 11,500. It seems implausible that a person would come to shoot targets with 1 1/8 oz 16 ga loads.

We have yet to be told the bore or wall thickness of the bulged barrel gun.

At the time this G grade 16 Parker was made, the Parker recommended load was 7/8oz at 2 1/2 drams. How do you know the shooter did not go to the RST tent 75 yards away and get a box of shells with exactly that load? Why would that not be the most likely scenario?

Very true. That way if something goes wrong, you have no one to blame but yourself. At least you know what shells are being used and if you reloaded them, then you know who may have made the mistake.

I highly doubt someone bought a box of RST just to shoot a gun a couple of times. More likely they had 16ga ammo and used that. It's not out of the realm that someone used 1 1/8th loads for shooting targets either.

I believe this gun is a #1 frame.

http://pic20.picturetrail.com:80/VOL.../412718116.jpg

"I don't think we can learn anything from this exercise."

Few more insightful words have been typed :)

HOWEVER, having participated in a number of barrel bulge/burst and shotgun blow-up discussions I'll babble anyway ;)
I believe a 2 part barrel burst failure analysis and metallurgical study will appear in the DGJ Fall issue.
Lots of information, and scary pictures here, along with some anonymous sniping :(
http://www.shotgunworld.com/bbs/view...p?f=5&t=366087

1. A Parker Service and Proof Load table was published in the 1930s and reproduced in The Parker Story p. 515. 12g 2 3/4” shell Service Pressure is 10,500 psi. Definitive proof used 7.53 Drams (no doubt) black powder and 2 oz. shot with a pressure of 15,900 psi. The pressure was (likely) measured using LUP and modern transducer values would be 10-14% higher, or more than 17,500 psi. I am not aware of any definitive information as to turn-of-the-century Parker proof pressures.

2. Under the 1896 British Rules of Proof, 12g 2 1/2” and 2 5/8” chambers (bore .710-.740) maximum service load was of 3 1/4 Dram Eq. with 1 1/4 oz. shot.
https://books.google.com/books?id=in...AJ&pg=PA296&dq
Definitive Proof – 6 1/2 Drams Proof-House Black Powder with 1 2/3 oz. No. 6 shot = 10,100 psi + 10 - 14%
Supplementary Nitro Proof with 4 1/2 Drams of C&H No. 2 T.S. powder and 1 2/3 oz. shot = 16,400 psi + 10-14%

3. 16 bore British Service charge was 1 oz. 2 3/4 Dram Eq. = 38 gr. Bulk Nitro powder. Published pressures + 10-14%:
C&H No. 4 - 7,480; “Schultze” - 8,250 psi; “E.C.” - 8,960 psi
The U.S. 16g standard was 1 oz. with 2 1/2 Dr. Eq.; likely about 7500 psi with Bulk Powder by modern transducers

4. There are a number of bursting pressure formula; Burrard used the Alger Burst Formula:
Burst pressure = Ultimate tensile strength x 3(OD – ID) / OD + 2xID

There is also Lame, Boardman & Lame, American Standard, and Barlow's:
P=2 S t / D
P=Bursting pressure in psi.
S=Tensile strength of material in tube wall.
t=Wall thickness in inches.
D=Outside diameter in inches.

Barlow’s refers to a pipe capped at both ends with a static pressure (a pressure cylinder). Shotgun barrels are not designed to be pressure vessels as one end is open and the pressure rises and falls quickly. I've discussed this issue with a mechanical and a metallurgical engineer, and there is essentially NO formula that can be used for shotgun barrels. Nor can the Hoop Stress Formula be reliably applied.

NOTE: every formula requires knowledge of the tensile strength of the metal AND the wall thickness. Without that information any speculation is at best a guess.

Wallace H. Coxe, in "Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics" published by E.I. du Pont de Nemours & Co. in 1931 cites a study in which a fluid steel barrel was cut to 9” and capped, then a series of progressively increasing pressure loads fired. The barrel cap was blown off and barrel burst at 5,600 psi.

4. From Major Sir Gerald Burrard, The Modern Shotgun, "Volume 3, The Gun and The Cartridge", 1948:
“In the case of an obstructional burst the really essential evidence is the ring bulge. If there is a ring bulge, there must have been an obstruction…”
Odd to have obstructional bulges at the same place in both barrels, and Burrard also makes the point that "rib lifting" almost always occurs with ring bulges. which I do not see.

5. A study by the Royal Military College of Science, sponsored by the Birmingham Proof House and the British Association for Shooting and Conservation, showed that an obstruction by 2 fibre wads (total weight of 4 grams) was sufficient to bulge or burst a 12 gauge barrel shooting a 28 gram (slightly less than 1 ounce) load. Peak pressure occurred 22mm (.866”) past the leading edge of the obstruction.

6. This is a 1902 16g No. 0 L.C. Smith with chambers extended to 2 7/8" with wall thickness at the end of the chamber of .096". Likely the victim of 16g "short magnum" shells with 1 1/4 oz shot

http://pic20.picturetrail.com:80/VOL.../408859003.jpg

Radiography thereof

http://pic20.picturetrail.com:80/VOL.../408857932.jpg

7. So what happened to these barrels?
My opinion, which is of no greater validity than anyone else's, is that this was NOT obstruction but inadequate wall thickness from previous honing.
"Mirror bores" in any vintage double should be huge red flags.

8. It might be relevant that some "low pressure" loads use powders with a slower burn rate, producing a lower peak pressure BUT slightly MORE pressure further down the barrel. Note the DuPont Oval curve below

http://pic20.picturetrail.com:80/VOL.../410772139.jpg

Red Dot vs. PB (no longer available)

http://pic20.picturetrail.com:80/VOL.../406243470.jpg