Shotshell Pressure Question?

[ED J, MORGAN]

The 2010 raffle gun has nitro proofs.

[TARNATION !!!]

Originally Posted by Mark Ouellette

Drew,

I have a Parker GH Damascus 10 GA that is proofed to 3 & 1/2 tons or 10,500 PSI. Mark

I recently acquired a GHE in 12GA from a gentleman who grew tired of some of his hunting buddies concerns over his use of a damascus barreled gun. He sent it to Birmingham for proofing and a clean up of the damascus. (Came back brown, not black) BNP 3 1/4 Ton. His buddies got over their concerns. He shot many migratory and upland birds with that gun. Unfortunately, health no longer lets him enjoy the hunt and thus the passing on of some of his guns. I intend to use that GHE for opening day pheasants and hope to post some pictures of a successful day (that might mean some nice scenery shots and a sunset but a rooster or two with the GHE would be a bonus)

Tomorrow, my wife, the dogs and I drive to Montana to pick up the plain twist under lever. While roosters don't open here until October 1, I will force myself to take a hike on our return trip looking for huns and sharptails with the .410 (not a Parker). I want to have a good look at the lifter before pressing into service.

Cheers,
Jack

[ch]

Bruce, 1st what's an SL. When you tossed the shell in the fire was the expected result your pappy found out and had a talkin with you ch



Jack, I used to take a lot of pictures years back slr under stood it film speed f stop yahda yahda, then they made them into computers I kept shooting the slr (I don't need 1 of thoes goofy cameras) well here I am I want to put pictures on here so I go to wally world to get me one or use my daugthers what are the guidelines to get a good picture the pixles or what ever. Thanks ch

[Bill Bates]

Originally Posted by calvin humburg

Bruce,

Jack, I used to take a lot of pictures years back slr under stood it film speed f stop yahda yahda, then they made them into computers I kept shooting the slr (I don't need 1 of thoes goofy cameras) well here I am I want to put pictures on here so I go to wally world to get me one or use my daugthers what are the guidelines to get a good picture the pixles or what ever. Thanks ch

this is a bit of a wander from the OT.

The rules haven't changed when it comes to photography iso (film speed and grain), f/stop, shutter speed and such, it is still the same. If you have a good film SLR with decent lenses you may want to see if there is a digital body that will use them. Don't get to hung up on mega pixels when it comes to posting pics on the web. There isn't a current digital camera that doesn't have way more than needed when it comes to pixels. If you want to make wall size prints maybe more pixels matter and maybe not. Once we passed 3 mega pixels it just became a number for the marketing boys. The quality of pixels maybe another thing but that is a discussion for a good digital camera techno geek forum like DPReview.

Go with a digital SLR with a few decent lenses. Point and shot digitals most older film photgraphers find slow and frustrating.

[Austin W Hogan]

Jack, Mark, Drew; I think Jack's recent post frames my concerns rather precisely. Jack and Mark cite British proof of 3 1/4 and 3 1/2 Tons. If those are tons made of English pounds, and expressed as the force on English square inches, they are pressures of 6500 psi and 7000 psi. Metric tons and English square inches raise those numbers 10%. If they are metric tons and metric centimeters squared, they are about 15000 psi, comparable to SAAMI proof loads.
Measuring transient pressure, especially when the total event occurs in milliseconds, is not a precise experiment; the numbers quoted always have to be referenced to the time that the pressure is averaged and the measuring instrument.
That is the reason I prefer to choose a gentle load from a simple shot column length and shot speed. I know that a shot column 1 inch long leaving the gun at 1300 ft/sec is pretty hot irrespective of gauge; a shot column 3/4 inch long leaving at less than 1200 ft /sec is pretty mild.
I think RST tables back me up on this; 10 ga 1 1/8 ounce (.686 inch), 12 ga 7/8 ounce (.603 inch ) and 3/4 ounce (.520 inch), 16 ga 7/8 ounce (. 732 inch) and 3/4 ounce (.626 inch), 20 ga 3/4 ounce (.672 inch)and 28 gauge 5/8 ounce (.756 inch) all at less than 1200 ft/sec are without a doubt very gentle loads, and it is not necessary to quote pressure to verify this.
Incidentally, Parker, prior to the formation of the interindustry for runner of SAAMI in the 1920's, proofed by lengthening the shot column (adding more shot weight, not powder weight) according to TPS.

Best, Austin

[Bruce Day]

TPS, Fig 12.16 , p. 515. Jack's gun, assuming 2 5/8" chambers, would have been proofed by Parker using charges that generated an average of 6.1 long tons and 13, 700 pounds and a maximum of 6.7 long tons and 15,000 pounds. Actual and theoretical service limits for ammunition intended for use in the gun are also provided. So if Jack goes down to the local gun shop and buys a flat of Winchester AA Xtra Lights ( 8500psi ) for example, he is 1000 pounds under the average factory load pressures (9500) for which the gun was built.

As another example, say that I want some 16ga shells to go pheasant hunting. I can handload, buy RST's ( which are great shells) or I can get Federal 1 oz Game Shoc loads at my local hardware store. These are 1oz, 2 1/2 dram, 1165fps loads and develop 7, 400psi. From the Fig 12.16 table, I know that my 16ga with 2 9/16" chambers was intended to shoot ammunition that averaged 10,100psi, so they are 2,700psi under the service working limit average. But these Federals are marked 2 3/4" on the box, yet only 2 11/16" when I measure the expended shell. So these shells are 1/8" over the gun chamber length, and precisely as Parker intended for good sealing.

[Big Friend Ten (BFT)]

Austin,
I've been studying this subject but for a while. I don't know enough to teach but for what it's worth:
- During the period when the British proofed in Tons (Long Tons) it was by the Lead Crusher Method. That was by a Government approved proof house. One would imagine that if for the British Gov't it would err on the side of caution.
- SAAMI uses the piezo-electric method which can be measured and recorded in micro-seconds if one has the equipment.

So... Shooting a higher pressure load than 8000 PSI in Parker Damascus (or LC Smith) is a personal choice. My daily shooting is with 6000 PSI in 12 and 10 ga which break targets just fine. I know the barrels will however withstand modern loads but I still reserve those for when I can't load a low pressure to do the job.

A good friend and member of this board made the classic mistake of loading shells with PB instead of the black powder which he thought was in the MEC powder bottle. PB looks like black powder. His barrel blew on the 4th shot. He later had the remainder of those shells tested. They were all far above 20,000 PSI and one was somewhere around 34,000 PSI. After that my friend now keeps all black powder loading equipment in a seperate room from his smokeless loaders and supplies. In life things happen... Then the rumors start which are always much, much worse than the actual event. Oh, my friend's blown gun is pictured in "Shooting Flying" by Murdelack (SP?).

I believe in moderation to preserve and only push to the limit when necessary!

[Drew Hause]

Jack: could you please post an ultra close up of the barrel flats of your BNP GHE and thanks!

Bruce: in 2002 Tom Armbrust tested and the 16ga reloading group reported two batches of the old 16g Federal Game Load 1 oz 1165 fps at 9160 and 9633 psi. All I could get Federal to tell me on inquiry was "about 10,000" in order to assure funtion in autoloaders. It's called Game-Shok Game Load now http://www.federalpremium.com/products/shotshell.aspx

LTC Calvin Goddard writing in Army Ordnance in 1934, stated that Hunter Arms proof tested 12ga 2 3/4" chamber barrels at 14,300 psi.

[Bruce Day]

Drew, I suppose that's possible. I got "about 7500" when I talked to the Federal people in person at Pheasant Fest and matching fps with the published drams. But the Fed hull is a straight hull noted for low pressure, they use Fed primers, and even with fast burning powder like Hodgdon Universal at 1165 fps the pressure is only 7500 and less with well known slow burning powders like SR 4756. So what powder Federal would use to push faster than a fast powder like Universal is unknown to me. Universal has the fastest burning rate of any powder made by Hodgdon that is suitable for 16ga.

I got a list of pressures from Federal years ago, I'll see if I can retrieve it, but I don't think their "above 10,000" is correct and may have been only to placate the autoloader bunch. I remember they told me that their 12ga 1 oz Gold Medal papers are at 8300 psi, also a long way from 10,000.

[Bill Murphy]

Maybe someone would send a Damascus Parker ten to Birmingham to have it proofed for 3 1/2" shells at 4 tons. I can't remember the shot weight of that proof, but I have seen more than one Damascus Brit gun marked with that particular proof. I think the shot weight may have been 1 3/4 ounces. Phil Futrel once had a hammer Purdey ten with that proof stamped on its Damascus barrels.