How many calibers are there in the AR10?

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14 years 5 months ago #4629 by lotoofla
Replied by lotoofla on topic Re:How many calibers are there in the AR10?
One of the geeky things that I have done is to see how the relation of powder speed relates to bore size. I started with the 25-06 and compared it with the 270win matching bullet weights, and optimum powders for max velocity, then 270 vs 280, then 280 vs 30-06, 30-06 vs 8mm-06, 8mm-06 vs 340-06 and on and on. When you look at the smaller bore size, it always required a slower powder, when you get to the big bores .358-.375 the powders are faster than IMR 3031 (375 whelan). So when it comes to port size for calibers smaller than 30cal start at .040" (1.0mm) and then make up a batch 90% loads using the top 5 powders for velocity. Shoot each one singlely and with each one that does'nt lock back the bolt, enlarge the port size, till they all lock back.
Tom

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14 years 5 months ago #4630 by a Guest
Replied by a Guest on topic Re:How many calibers are there in the AR10?
Thats the hunt and peck method why don't figure the PSI to hole dia over the dwell length to buffer spring compression rate and do it right. I don't think you were a master armor because I give out the formula for this in class train and sign most of them off on this system. Sounds like a parts changer.MSH

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14 years 5 months ago #4631 by lotoofla
Replied by lotoofla on topic Re:How many calibers are there in the AR10?
One of the things I learned years ago is that you can never put metal back after its cut off. PSI is only a third of the equation. The full equation is: PSI+volume+duration.
If you have 19,000PSI but only 1cc, with a say 4 nano second duration it may not work. But say you have 18,000PSI and 3cc's and 10 nanoseconds then it will work, but I'm using hypotheticle numbers here but the 'triad' is mechanicaly sound. The proof of this is in the M-14 gas system.
Tom

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