wymberley Posted October 8, 2014 Report Share Posted October 8, 2014 (edited) the 3.5" 12gauge runs at an MAP 14,000 psi, thats nearly 1/3rd more than standard cip 12gauge (740bar 10,770psi or thereabouts) By my reckoning, that's inside the HP steel max service pressure. http://www.fabarm.com/web_eng/dettaglio-prodotto.asp?i=71 The answer to all problems, a gun proofed to 1630 bar... Just as well it's a 'fowling piece; putting out 13/8oz at the afore-mentioned 1700ft/sec it's going to kick like a mule at under 71/2lbs as momentum-wise this equates to a normal 8 bore lead load. Edited October 8, 2014 by wymberley Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted October 8, 2014 Report Share Posted October 8, 2014 By my reckoning, that's inside the HP steel max service pressure. Just as well it's a 'fowling piece; putting out 11/2oz at the afore-mentioned 1700ft/sec it's going to kick like a mule at under 71/2lbs as momentum-wise this equates to a normal 8 bore lead load. _in 12gauge_ yes it is within the HP criteria, whereas 1050bar is about 15,220psi so HP criteria has alittle more room to wiggle. although in the grand scheme of things its not that much. i like to use a max of 11500psi MAP if i was ever to go in to HP criteria. its just the stats that really make loads fail, the american standards are 2 standards above MAP which is a fancy way of working out the maximum upper range of one of the figures for the calculation of the MAP. ie how much over a few shots go, (of course that means there is a shell that is low enough to drive down the MAP for a statistic run.) there is no reason to avoid the 1050bar average if your gun can handle it. that is probably used as a criteria to squeeze out to the ~11500+psi or 790BAR+ where in alot of cases (ie documented homeloads) the 11500psi or 790 would clean up the loads, make them run right real tight data and in most cases make a MORE this is due to the phenomenon of pressure. due to the inherent decisions to use slower and slower powders, alliant steel comes to mind and certainly the newer generation of powders that these need even more pressure than normal to burn cleaner and get better performance. whereas shell manufacturers use the HP criteria to produce 1400fps or 410m/s shells with faster powders (ie cheaper powders) Quote Link to comment Share on other sites More sharing options...
DerbyshireDale. Posted October 9, 2014 Report Share Posted October 9, 2014 I think my 10 is only proofed to 1040 Bar. I put any shells through it (1600 fps steel homeloads etc) and it is fine. I think people worry just a little too much about proof pressures. I'm with you on this one Motty, things tend to get a little bit overkill on this forum at times, I personally dont know anyone who's had a gun Barrel blow to bits through using a fast cartridge or any homeloaded one, obviously, I've heard of Guns bursting through obstructions etc but I've never seen it done! Just recently, I loaded some proven recipe carts for "Shakin Stevens" and they kicked more than a 10G we were trying out at the same time!! and there was even another proven recipe from the same manufacturer for a further 2 gns of powder!!!!... we never at any time felt we were in danger, they just kicked like a mule!!! I suppose this is an interesting topic for many but I think most people just quote stuff from books they've read, after all, we all have to learn from somewhere but lets keep it real!!....this is not meant to be a put down towards anyone, just my thoughts thats all. atb...Dale. Quote Link to comment Share on other sites More sharing options...
wymberley Posted October 9, 2014 Report Share Posted October 9, 2014 I'm with you on this one Motty, things tend to get a little bit overkill on this forum at times, I personally dont know anyone who's had a gun Barrel blow to bits through using a fast cartridge or any homeloaded one, obviously, I've heard of Guns bursting through obstructions etc but I've never seen it done! Just recently, I loaded some proven recipe carts for "Shakin Stevens" and they kicked more than a 10G we were trying out at the same time!! and there was even another proven recipe from the same manufacturer for a further 2 gns of powder!!!!... we never at any time felt we were in danger, they just kicked like a mule!!! I suppose this is an interesting topic for many but I think most people just quote stuff from books they've read, after all, we all have to learn from somewhere but lets keep it real!!....this is not meant to be a put down towards anyone, just my thoughts thats all. atb...Dale. Under contract, Tom Roster tested some Remington Model 870 12 bore barrels to destruction. When he got to 25,000psi and nothing had happened, he moved on up in 5,000psi steps. At no time did anything show up to indicate a problem until he finally got to 55,000 when at last it burst in fine style - peeled like a banana apparently. Quote Link to comment Share on other sites More sharing options...
motty Posted October 10, 2014 Report Share Posted October 10, 2014 I'm with you on this one Motty, things tend to get a little bit overkill on this forum at times, I personally dont know anyone who's had a gun Barrel blow to bits through using a fast cartridge or any homeloaded one, obviously, I've heard of Guns bursting through obstructions etc but I've never seen it done! Just recently, I loaded some proven recipe carts for "Shakin Stevens" and they kicked more than a 10G we were trying out at the same time!! and there was even another proven recipe from the same manufacturer for a further 2 gns of powder!!!!... we never at any time felt we were in danger, they just kicked like a mule!!! I suppose this is an interesting topic for many but I think most people just quote stuff from books they've read, after all, we all have to learn from somewhere but lets keep it real!!....this is not meant to be a put down towards anyone, just my thoughts thats all. atb...Dale. I've seen a burst barrel at close quarters. My mates o/u had it's bottom barrel go 'pop' when we were pigeon shooting. It must have been a stuck wad. It blew about a foot from my head. Under contract, Tom Roster tested some Remington Model 870 12 bore barrels to destruction. When he got to 25,000psi and nothing had happened, he moved on up in 5,000psi steps. At no time did anything show up to indicate a problem until he finally got to 55,000 when at last it burst in fine style - peeled like a banana apparently. Would you say, then, that perhaps some who are worried about using hp steel in their modern guns, should be less so? Quote Link to comment Share on other sites More sharing options...
wymberley Posted October 13, 2014 Report Share Posted October 13, 2014 Would you say, then, that perhaps some who are worried about using hp steel in their modern guns, should be less so? No, I make no comment either way - simply posted out of interest as I'd spotted the article while browsing. Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted October 13, 2014 Report Share Posted October 13, 2014 there is a big difference between bursting a chamber in a single event, and repeatedly weakening the chamber then having any event to damage the chamber completely. Quote Link to comment Share on other sites More sharing options...
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