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One of Us |
Nope. This:
And this:
I wouldn't touch a rifle that hasn't been test fired. There are two types of people in the world: those that get things done and those who make excuses. There are no others. | |||
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One of Us |
This is from American National Standard Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Rifle Ammunition for the Use of Commercial Manufacturers (2015): "The following specifications define the proof loads based on tests fired in standard test barrels with the ammunition at a temperature of 60°-80°F (15.6°-26.7°C). Tests shall be in accordance with the procedures and equipment shown in Sections II and III of this Standard. Pressure values are given on the following pages in terms of minimum and maximum averages and extreme variations for 10-round tests in standard test barrels. The Standard Deviations for Definitive Proof Cartridges are derived from the Standard Deviations for service loads. A multiplication factor of 1.25 is used to obtain Definitive Proof Load Standard Deviations from Service Load Standard Deviations. The Standard Deviations for Definitive Proof Cartridges are derived from the Standard Deviations for service loads. A multiplication factor of 1.25 is used to obtain Definitive Proof Load Standard Deviations from Service Load Standard Deviations. The minimum and maximum average Definitive Proof Pressures are computed as follows: The Minimum Average Definitive Proof Pressure is calculated by multiplying the Maximum Probable Lot Mean (MPLM) service pressure by a factor of 1.3 (i.e., 130%) and rounding UP to the nearest multiple of 500 psi. The Maximum Average Definitive Proof Pressure is calculated by multiplying the Maximum Probable Lot Mean (MPLM) service pressure by a factor of 1.4 (i.e., 140%) and rounding DOWN to the nearest multiple of 500 psi. The Proof Maximum Extreme Variation (EV) is calculated by multiplying the Proof Standard Deviation (which in the case of Centerfire Rifle is equal to the Service Standard Deviation multiplied by 1.25) by the constant 5.16(14)) and rounding UP to the next 100 psi. The Minimum Proof Individual (MPI) pressure is positioned three standard deviations (proof) below the Minimum Average Definitive Proof Pressure, with the calculated value being rounded DOWN to the next multiple of 100 psi. Example (using transducer data): Cartridge: 22 Hornet MPLM Pressure = 50,200 psi SERVICE = 1,960 psi 1. Definitive Proof Load Standard Deviation (PROOF) = Service Load Standard Deviation (SERVICE) x 1.25 i.e.: 1,960 psi x 1.25 = 2,450 psi 2. Min. Avg. Proof Pressure = Maximum Probable Lot Mean Pressure x 1.30 i.e.: 50,200 psi x 1.30 = 65,260 psi rounded up to nearest 500 psi = 65,500 psi 3. Max. Avg Proof Pressure = Maximum Probable Lot Mean Pressure x 1.40 i.e.; 50,200 psi x 1.40 = 70,280 psi rounded down to nearest 500 psi = 70,000 psi 4. Max. Proof E.V. = Proof Standard Deviation ( (PROOF)) x 5.16 i.e.: 2,450 psi x 5.16 = 12,642 psi rounded up to next 100 psi = 12,700 psi. 5. Minimum Proof Individual = Min. Avg. Proof Pressure – (3 x (PROOF)) i.e., 65,500 psi – (3 x 2,450 psi) = 58,150 psi rounded down to next 100 psi = 58,100 ps" I always defer such matters to the Gunsmith!
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one of us |
Yes. Why shouldn't that be expected and done. Like when the rifle is screwed together and bedded into its stock but but still far from finished. Or as the Brits say, "shooting it in the white." That seems like a logical time/place in the construction process to shake a rifle out with some range time. If I were a gunmaker it seems like a good investment of time to affirm all is well or discover any issues or problems that need corrective action before the investment of final finishing. What if that barrel maker that never lets a bad one out of the shop finally does, or that unbreakable spring breaks give way, or the something didn't get screwed down like it was thought to be, or there is a true material defect waiting to happen, etc... After final finishing and assembly seems like another good time to shoot the gun too. Look, In my day job I have to bring a no stone unturned approach to everything I get involved in and I appreciate that approach when I recognize it in other professionals as well. It's not free but certainly prevents unforeseen problems after a project is in the books. | |||
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One of Us |
I always test fire every project after cutting a chamber. But.... It's not the gunmaker that's making the investment. My clients are happy to pay for the time & materials it takes to do it right the first time. I'm happy to have them as clients. | |||
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Moderator |
uhm, i think either i totally failed to say what i meant, or you didn't read it right.. either way, it's kinda my fault. as you state, from Douglas, they only test fire - that's were i said testing for function (the gun doesn't blow up under standard loads) I also state the CIP/EU (not US) has different requirements - we might be talking past each other. on saami/cip/ansi SAAMI is VOLUNTARY and membership is not required, and it's regs are only applicable to members - it's an industry, not Govt' or NGO CIP is REQUIRED under places it holds authority - ansi is even more voluntary than SAAMI - one could be a saami member and entirely ignore ansi, if they please. opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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One of Us |
Thanks all. I passed on it based on this advice. | |||
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One of Us |
I'm curious..Why didn't he just fire the damn thing? | |||
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One of Us |
I am curious as to whether or not the OP purchased it! And if it worked when he fired it. | |||
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One of Us |
Come out of quarantine and read 2 posts up | |||
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One of Us |
Ha! Alcohol does have side effects! | |||
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One of Us |
Me too.... | |||
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One of Us |
FWIW I have owned a couple of Schultz and Larsen rifles in 7x61 S&H and did read somewhere where this rear locking action had been tested to 120,000 PSI with no adverse effects. It was not clear whether this testing was proofing or just an advertising ploy to prove how good the S&L rifle really was. They were an exceptional rifle accuracy and velocity wise, the original factory 160 gr SPBT gave close to the advertised 3,100 fps in my M60 model with the 26" barrel and I handloaded the Sierra 160gr SPBT to an honest 3,000 fps. The perception of "hot rod" may have come from the very flattened primers of the Norma factory ammo and early incipient case head separation if handloading. This may have been to do with generous headspacing of the belted cartridge and shoulder setback if carelessly FL resizing when handloading. I only partially resized to give a snug headspace on the shoulder, got good case life and never experienced any hard extraction with factory or handloaded ammo when loading to the high velocity levels. Fired Norma factory ammo 7x61S&H case | |||
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One of Us |
I've only had one rebarrel by dpcd, small sample size, but from the way that one shoots I know where I'll send any future work, without hesitation. "If you’re innocent why are you taking the Fifth Amendment?”- Donald Trump | |||
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One of Us |
I passed on this rifle but did end up ordering two new ones from builders that test fire and prove the accuracy of their work. I am not asking for much, just verification that they shoot as well as they look. At the end of it all, an inaccurate gun, no matter the cost, is worthless. | |||
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One of Us |
Yessir. We've all heard "only accurate rifles are interesting". Zeke | |||
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one of us |
I test fire every gun that leaves my casa, new or used, and I guarantee its accuracy whatever that may be..but bottom line is its just easier to refund the client and keep everyone happy, fix the returned gun or whatever and resell it, but Im not in the business, so the monitary aspect isn't a particular problem..Thats the nice thing about it being a hobby.. Keep in mind that AR has no guarantee policy so you accept that and your on your own..but Ive never had to refund a AR sold gun that I recall. Mostly I can fix most any gun that doesn't meet my standards, so that's a plus. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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one of us |
Depends on who you talk to reference "test loads"....We only deal with max loading as individuals, or we fill a case with Bullseye put the gun in in a tire, tie a string on the trigger and get go to the other side of the shop and pull the string.. What Have I learned from this? A jap Arasaka is indestructible, a Mauser puff up like blow fish, a pre 64 Win fractures like a handgrande..but it takes a lot of powder to blow most of them up...Not all that scientific but its fun!! Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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One of Us |
Well, all is well that ends well. Was able to get the builder to do the testing. Tested perfectly and have a commitment that if anything is not perfect, send it back. Honorable man and a pleasure to do business with. | |||
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