Guest cookoff013 Posted May 1, 2013 Report Share Posted May 1, 2013 the cip regard 65 and 67.. the same. but this is where the kicker really is, if you measure new unfired cases, you`ll find most ~1.5mm shorter than advertised. 70mm, being 69-68mm. 65mm - 63.5mm 67mm - 65.5mm or so. so the cip recomending 67mm hulls for 65mm chambers spot on. Quote Link to comment Share on other sites More sharing options...
WelshAndy Posted May 3, 2013 Report Share Posted May 3, 2013 This is what you need http://www.justcartridges.com/xtreme.html Quote Link to comment Share on other sites More sharing options...
JohnfromUK Posted May 3, 2013 Report Share Posted May 3, 2013 (edited) I have several 2 1/2 chambered guns, including two with (nitro) Damascus barrels. I was advised by the maker of two of my guns that the chambers are actually approx 2 5/8" and that 67.5 mm, 67mm and 65mm are all OK provided the load is below the proof load (often 1 1/8oz). 70mm is NOT alright and nor is anything over 1 1/8oz, whatever the case. The thing to look out for is that if the gun has short chambers AND abrupt forcing cones, the opened cartridge can sometimes just not quite clear the cone. You see this as damage on the fired case - like a chewed edge to the opened end and pressures are raised. Long term damage due to raised pressure (the gun shooting loose) can occur if done regularly - and there is a (small) risk of short term damage (bulge - or very rarely worse). I knew someone who went on a simulated game day and fired a lot of the cartridges provided through a fine old English gun without realising they were 2 3/4" He ended up with a sore shoulder, a headache, but when cleaning the gun, he thought it was a bit loose. Took it to a gunmaker and ended up with an eyewatering bill to rectify the situation. What we don't know was the state of the gun before this all happened (slightly loose guns with rapidly loosen if overstressed) - and what the loads fired were since 2 3/4" (70mm) cartridges often carry a heavier load. Edited May 3, 2013 by JohnfromUK Quote Link to comment Share on other sites More sharing options...
brent52 Posted May 3, 2013 Report Share Posted May 3, 2013 if it says 2/12 on the box thats what it's for, whats the problem ? Quote Link to comment Share on other sites More sharing options...
Wildfowler325 Posted May 6, 2013 Report Share Posted May 6, 2013 Aaa just hold them through Quote Link to comment Share on other sites More sharing options...
simmans Posted December 31, 2018 Report Share Posted December 31, 2018 just to further confuse the picture , I use gamebore super xls no 8 in my damascus barrelled hammer gun .. case says 65mm with arrows indicating the unfired length my callipers measure 63.70 mm overall fired length 55.67mm unfired more confusion... these are subsonic and sound like a **** in a cullender. BUT the vintagers club here t in melbourne say it is fine to use 67mm thanks george Quote Link to comment Share on other sites More sharing options...
DUNKS Posted December 31, 2018 Report Share Posted December 31, 2018 What I would suggest is that you get a couple of the cartridges shot in a gun with 70mm chambers. Then measure the shot cartridges accurately. Put a well fitting hardwood or steel plug in your chamber and also measure. I think you may be surprised I have several old guns with 65mm chambers and they are all 67.5 at least. Only one a 1885 SXS is exactly two and a half and the forcing cone is very sharp. Also I have measured a lot of fired cartridges and nearly all are shorter than stated 67s are usually only 65.5. I have some Eley first which are 67.5 and fired they measure 66.25. Quote Link to comment Share on other sites More sharing options...
Lloyd90 Posted January 2, 2019 Report Share Posted January 2, 2019 Seems a bit all over the place. Before I know any better I went to get some carts for fox in a gunshop, I told them the gun I was using and they sold me some 3” SG carts for my gun with 2 3/4” chamber ... I fired a couple with no issues although recent noticed this and wasn’t impressed to find out... How many newbies about there would be as aware of such an issue? I always thought if the cart was too long then it would stick out and the gun wouldn’t shut. Quote Link to comment Share on other sites More sharing options...
Gunman Posted January 2, 2019 Report Share Posted January 2, 2019 A lot will depend on the profile of the chambers in your gun. Many older guns had what can be called "roll over " chambers , that is a very short cone into the barrel that on view looks more like a step . If so I would try to avoid cases that when fired open up to over 65 mm . This may depend on the cartridge and the crimp and not all gases are the same . If the chamber has a "normal" tapered cone then there is no real problem . It may be wise to have the chambers plugged , that is correctly measured , as again older guns often had tight chambers , so may need to have be slightly opened up or re profiled to modern profile . I have done this on numerous occasions usually to help with extraction problems and providing the chamber is not deepened beyond the specified depth it will not affect proof status . Quote Link to comment Share on other sites More sharing options...
wymberley Posted January 2, 2019 Report Share Posted January 2, 2019 Sometimes an indication that something is not quite right is that the cartridge mouth is tatty or 'feathered'. Quote Link to comment Share on other sites More sharing options...
Dougy Posted January 2, 2019 Report Share Posted January 2, 2019 5 years old +, i bet the cases have shrunk since this thread was started. Quote Link to comment Share on other sites More sharing options...
simmans Posted January 3, 2019 Report Share Posted January 3, 2019 yes well shrunk bit like me really! My westly richards hammer gun is chambered for 2 1/2 but when measured with a 20mm dowl shows the chambers to be 67.98mm B&P sub sonic 1oz loads are 67mm when fired despite the packet saying 2 3/8 inches so guess ok and should be within my three tons pressure limit, or close. the only problem that arises is there aint no pigeons in Oz!.. good for all varieties of snakes though cheers george Quote Link to comment Share on other sites More sharing options...
simmans Posted January 3, 2019 Report Share Posted January 3, 2019 14 hours ago, Gunman said: A lot will depend on the profile of the chambers in your gun. Many older guns had what can be called "roll over " chambers , that is a very short cone into the barrel that on view looks more like a step . If so I would try to avoid cases that when fired open up to over 65 mm . This may depend on the cartridge and the crimp and not all gases are the same . If the chamber has a "normal" tapered cone then there is no real problem . It may be wise to have the chambers plugged , that is correctly measured , as again older guns often had tight chambers , so may need to have be slightly opened up or re profiled to modern profile . I have done this on numerous occasions usually to help with extraction problems and providing the chamber is not deepened beyond the specified depth it will not affect proof status . Many thanks your comments Gunman. you are correct on the roll over chambers , they look just like a ridge I have just noticed on the B&P packet "do not use in damascus barrelled guns , but my westley is damascus and is nitro proofed to 3 tons so should be ok. Quote Link to comment Share on other sites More sharing options...
tonyshotgun Posted October 28 Report Share Posted October 28 67mm is the final length of the cartridge once it has been shot. I’ve got 5 beautiful old side by sides and I have never had a problem with 67mm’s 👍🏼 Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted October 28 Report Share Posted October 28 WOW! GB again...................................... Quote Link to comment Share on other sites More sharing options...
Fil Posted October 28 Report Share Posted October 28 (edited) On 28/09/2011 at 09:25, Montefeltro said: Hello all, I recently purchased 250 Eley Firsts in size 8 fibre to shoot in my 2 ½ inch chambered hammer gun. On the cartridge box is says 67mm long to suit 2 ½ inch chambered guns, but I thought 65mm was the maximum size for 2 ½ inch chambers? Is it safe to shoot a 67mm long cartridge or should I stick to exactly 65mm? If you can only use 65mm in a 2 ½ inch chambered gun then why are Eley selling 67mm cartridges and saying for use on 2 ½ inch chambers?? I know its only 2mm but Id hate to damage the barrels or the forcing cones Regards Gary Oops it's an old thread. lol Edited October 28 by Fil Being a dummy Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted October 28 Report Share Posted October 28 GB................................... Quote Link to comment Share on other sites More sharing options...
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