doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com AyA Proofmarks

Happy new year to all.

I would be very grateful if someone would point me in the right direction regarding the proof marks on the gun shown below:





My apologies for the quality of the pics.

My question is: Is that marked 1200 Kp/c (which seems to be low for a magnum proofed gun) or is that supposed to be Kg/c?

The question is in itself moot as I use it with magnum shells and was told when I bought it that it would handle any known 12 gauge shell upto 3". I have always wondered about the marking.

Any other info would be much appreciated.

The gun itself is marked "Super Solway" and was bought from Elderkin and Sons, Gunmakers in the UK in 1984. It is just a non ejector wildfowler with thirty two inch barrels and three inch chambers made by AyA.

I use it for ducks (lead shot, I do not live in the USA or UK and am not required to use non-tox.)and it spends much time in boats and saltwater and looks it. The bores are mirror though!



All the best

Skeeterbd

Skeeterbd

This should be of help

http://www.shotguns.se/html/spain.html

Gun made in 1979 for the 3" Magnum shotshells

Notice the CH proof with Shield and Swords which
is on your shotgun

Re-inforced smokeless proof for shotguns barrels with proof pressure of 12.801 psi

PLUS my normal 2 3/4 AYA was struck at 900 KGS and not 1200, you sould be set to go

Mike

I read the 1200 as being 1200 bar proof. Multiply that x 14.5 to convert to psi and you get a proof pressure of 17,400 psi, which is in the CIP magnum (or superior) proof range. If the proof pressure were only 12,800 psi, then there's no way one should be shooting American factory 12ga loads through that gun, since those shells have a maximum service pressure of 11,500 psi.

Thanks skeettx and L. Brown.

I originally read the Kp/c as kilopascal without a clue as to what a pascal was! When I looked up the conversion to Kgs and bars I realised at once that I was way out of line. However I think that there has been some loss in translation from the Spanish in the proof marks table kindly provided by skeettx. At the same time I am not sure the 1200 Kg/c (it must be kgs per centimeter squared)refers to the proof pressure viz:



From that packet it appears the proof pressure for CIP Superior Proof is 1370 bar. This is approx. 19870 psi which sounds more like it.

The markings on the cartridges for these and other European 3' magnum cartridges say max pressure 1050 bar as do US cartridges. 1200 Kg/sq.cm is approx: 1176.8 bar which is near the 1050 bar max pressure for 3" cartridges. So I suspect that the 1200 kg mark is max service pressure and not proof pressure although I may well be wrong!



Funnily enough the the Remingtons obviously do not exceed the SAAMI limit of 11500psi which is approx. 792.9 bar (say 800 bar) whereas the RC Magnums are advertised at 900 bar!

http://www.rc-cartridges.com/rc50_magnum_hp-231.html

Its the European load which is stouter and of course none come near the advertised 1050 max pressure limit which is a fearsome 15228.956 psi!

I hope I haven't put you all to sleep!

All the best

Skeeterbd

1200 Kp/cm2 is actually 1200 kiloponds which is 1200 kg-force/cm2 which is equal to 1177 bar. It is interesting to note that the only time I ever see the term "kilopond" is in reference to proof pressure in European guns.

Well, that has cleared that up!

Thank you Ian Forrester!

All the best

Skeeterbd

Sorry, double post!

Skeeterbd

The 1050Bar max marking is basically worthless. German slugs in 70mm case have similar marking. The gun up there is suitable for 76mm CIP shells (not ammo for the T-34 of course That makes gun very suitable for stiffer US-made 70mm shells which is exactly what American nimrod should want to own.

My bad on messing up the 1200 mark on the barrel flats. That is indeed the proof pressure. However, that gun is old enough that at the time it was proofed, CIP countries were still using the old crusher method. I have an email from the master of the Birmingham Proofhouse explaining the same mark previously found on magnum/superior proof British shotguns, when they were still using the crusher method of measuring pressure. (The more typical mark seen back then was 850 bar, which was the standard--versus superior or magnum--proof pressure.) From that email for a gun marked 1200 bar: " . . . the transducer values are 1050 bar service and 1370 bar proof." So skeeterbd, that box of Italian shotgun shells marked "1370 bar" are for guns of the same proof as yours--simply measured by the current (electronic transducer) method versus the old lead crusher system. You cannot convert directly to psi from crusher bars, as I did in my earlier post. You'd need to multiply 1370 x 14.5 to get the proof pressure in psi.

L. Brown

Thank you for clearing up my confusion.

I have so many questions regarding the higher levels of proof but they can wait for another thread.

Again I wish you and all the forum members a happy and prosperous new year and the best of health!

All the best

Skeeterbd