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Proof marks/choke


PotHunter96
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11 minutes ago, PotHunter96 said:

I can’t make anything out apart from the 2.5 inch, it’s just I have some 34 gram 67mm cartridges and I’m wondering if they’d be a bit much for it 

Have they got any pressure limits given on the box?

 The 67mm is OK and your working pressure limit is 3 tons/sq". Just in case you're not aware this is not the proof pressure which would be some 25 to 30% ISH above that and you're looking for 850 bar minimum.

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Looks like the gun was originally proofed at 13/1 (.719) or 13 (.710) under the1925 rules of proof, was reproofed in 1966 under the 1954 rules of proof at .729, for 2 1/2inch (65mm) cartridges, I wouldn’t use more than 32g game loads through it (28 or 30g would be my choice) I don’t know what the obscured marks were originally showing? be careful using 67mm HV cartridges, they can be uncomfortable to shoot due to excessive recoil, I imagine it was originally choked for game shooting.

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The gun has at some time failed proof and the marks were defaced by the proof house. It was later repoved at 2&1/2" which equates to 1&1/8 oz load. 

The 30 and 36 are meaninless marks put on by some gunsmith to identfy the gun for his records , it was common practice in the Birmingham trade as the shop that had the gun may of had 50/60 guns in at a time and parts of it may have been with several diferent people at various times . . As to "choke"  this relates to earlier proof and is irrelevent . What chokes it had originally and what it is now may be two diferent things and the only way of knowing is to measure it .

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If you do not have a chamber gauge, then your best bet is to take it to a local gunsmiths/shop and get the chamber length and chokes confirmed, having said that and looking at the proof marks of 3 ton per square inch and chamber length marked 2.1/2 inch you will be good with anything at that length and up-to 1.1/8, it will shoot nice all day with something around the 1oz mark.

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If you look carefully at the photo you will see what appears to be  the word sleeved stamped on the side of the barrel above the bar . This was the practice in the earlier days of sleeving .The Proof date RB is 1966 .

Not quite sure when they started to stamp on the flats but it was in the mid 70'sas far as I remember .

At one point in the 90's London stopped stamping sleeved for a couple of years  adding a reproof mark for some reason but started again soon after .

Proof houses sometimes missed marking sleeved if the joints were so good as not be seen and the submitter did not declare it as so , in an attempt to pass the gun off as original . 

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