deershooter Posted February 22, 2012 Report Share Posted February 22, 2012 (edited) Just been on the net reserching high pressure sensers and gauges, could you make a pressure test gun by using a 1000 Bar digital pressure gauge ?I have all the machining equipment to manufacture the gun its self but what I dont know is would one of these senser gauges work I know that the old test guns used to use copper slugs which crushed under pressure .However this must be antiquated now with all the modern tec we now have this would be good when load developing . let me know your thourghts Deershooter Edited February 22, 2012 by deershooter Quote Link to comment Share on other sites More sharing options...
sitsinhedges Posted February 22, 2012 Report Share Posted February 22, 2012 Chap on here was talking about a strain gauge some time ago. Seems to fit outside the barrel and measure pressure by the movement in the tube when it's fired. That could be another avenue to go down http://en.wikipedia.org/wiki/Strain_gauge Other than that just buy Floating Chamber's lead crusher gun he has for sale Quote Link to comment Share on other sites More sharing options...
HW682 Posted February 22, 2012 Report Share Posted February 22, 2012 Your biggest problem might be getting one with a fast enough speed of response. The raw sensor might be ok, but any form of conditioning or processing to give you a read out etc would be too slow in most instruments I would think. Do you have any particular model in mind? Quote Link to comment Share on other sites More sharing options...
Floating Chamber Posted February 22, 2012 Report Share Posted February 22, 2012 To be really accurate, you need a PCB Model M-117B piezo-electric transducer. Quote Link to comment Share on other sites More sharing options...
HW682 Posted February 22, 2012 Report Share Posted February 22, 2012 To be really accurate, you need a PCB Model M-117B piezo-electric transducer. Good call sir. Some interesting sensors in their catalogue and several dedicated to this job. That's the sort of thing I was thinking of when I said a raw sensor. The term guage (to me at least) suggests something with an integral indicator and any general purpose device is likely to be too slow. http://www.pcb.com/Linked_Documents/Pressure/PFScat.pdf Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted February 23, 2012 Report Share Posted February 23, 2012 not to mention calibration shells, just manufacturing a proof barrel is a nightmare, if you are manufacturing a barrel, you have to make it, have it proofed and put on ticket. or the police will kick up a stink. technically you are manufacturing a lethal gun. it can be done, i`ve heard of guys making puntguns and having it proofed. but i think the police went nuts. but the guy said what he was doing, i`m lead to believe he had an escort to the proof house. after the transducer is added, test shells need to be fired to calibrate the sensor. ie, 3000psi and 7000psi and 14000psi, a graph is then produced. then any subsequent firings should align with the graph, if they dont, they are too hot or too cold. then you need the fps at 2.5m to fully calculate what a shell is doing. getting the proof shell recipe is a major obsticle. the proof house has its own recipes. pressure is pressure, speed is speed. 2 completely different criteria, none should be taken for granted. Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted February 23, 2012 Report Share Posted February 23, 2012 i did plan on getting a single baikal and welding a transducer to it. but that idea was scrapped. something to do with the 12gauge chamber dimentions, if they are slightly out, then the data is very suspect. that is one way of doing it. Quote Link to comment Share on other sites More sharing options...
Floating Chamber Posted February 23, 2012 Report Share Posted February 23, 2012 i did plan on getting a single baikal and welding a transducer to it. but that idea was scrapped. something to do with the 12gauge chamber dimentions, if they are slightly out, then the data is very suspect. that is one way of doing it. There's nowt wrong with a lead crusher for amateurs. The system was used for many years. (My Helston will be up for sale soon with a new cradle.) Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted February 23, 2012 Report Share Posted February 23, 2012 There's nowt wrong with a lead crusher for amateurs. The system was used for many years. (My Helston will be up for sale soon with a new cradle.) i have absolutely no idea how they work, or to interpret the data from such a device. the loads that i`m trying to develop would be very healthy in pressure, i dont want any screwups no matter how small. Quote Link to comment Share on other sites More sharing options...
Floating Chamber Posted February 23, 2012 Report Share Posted February 23, 2012 (edited) At one inch from the breech face there is a hole venting through to a 'yoke' on top of the barrel. In this hole is a close-fitting piston of 0.225" dia. A test cartridge is placed in a sleeve which has a hole, one inch from the end. This is so that a drill can pierce the plastic/paper case. The shell is removed and chambered with this hole vertical and aligning with the hole in the chamber. A pure lead 'crusher' cylinder, (exactly half-inch tall) is placed on the piston and under the 'anvil' on the yoke and secured by the clamp screw. The breech is closed and the gun cocked. BANG! Gases are forced through the shell case and act upon the piston in the yoke which moves upwards and crushes the cylinder. The crushed length (called the 'remaining length') is measured and the crushed length looked up in a table: Examples: Crushed length, 0.452" 3.25 tons per square inch. Crushed length 0.422" 4.00 tons per square inch, Crushed length 0.377" 5.00 tons per square inch. Edit: There are 120-odd values in the table* up to 5 tons. * This table can also be found in W. W. Greener's book, p325 OK? FC Edited February 23, 2012 by Floating Chamber Quote Link to comment Share on other sites More sharing options...
deershooter Posted February 23, 2012 Author Report Share Posted February 23, 2012 There is no requirement in law to have a gun proofed unless you want to sell it you can make what you want as long as it is added to your certificate Deershooter Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted February 24, 2012 Report Share Posted February 24, 2012 There is no requirement in law to have a gun proofed unless you want to sell it you can make what you want as long as it is added to your certificate Deershooter i think it was to confirm it complied to the 24" or longer barrel. Quote Link to comment Share on other sites More sharing options...
derbyduck Posted February 24, 2012 Report Share Posted February 24, 2012 i think it was to confirm it complied to the 24" or longer barrel. why would anyone want to make a puntgun under 24inch ? Quote Link to comment Share on other sites More sharing options...
Floating Chamber Posted February 25, 2012 Report Share Posted February 25, 2012 why would anyone want to make a puntgun under 24inch ? To keep up their jacket for a bank raid? Quote Link to comment Share on other sites More sharing options...
Guest cookoff013 Posted February 26, 2012 Report Share Posted February 26, 2012 why would anyone want to make a puntgun under 24inch ? you`d be suprised at whats been made in the past. if i recolect, someone made a blank shotshell warning device that had a normal cartridge, shot a burglar that repeatedly broke into a property. he got prosecuted for manufacturing a firearm that didnt confirm to the 24" rule. Quote Link to comment Share on other sites More sharing options...
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