Walmart winchester AA

[wayne goerres]

Send 40.00 and five shells to precision reloading and they will put them through a preasure barrel for you. Lower preasure dose equate to lower velocity It just dosn't always work on a fixed ratio(such as one FPS equals one PSI) And if you read the original statement you will see that nthese are not the same shell sherman bell tested.Winchester did not make these shells back then.

[Big Friend Ten (BFT)]

Originally Posted by wayne goerres

Lower preasure dose equate to lower velocity It just dosn't always work on a fixed ratio(such as one FPS equals one PSI)

Once again a logical assumption but only if all else is equal. There are no guarantees except that the ammunition will not exceed the SAAMI maximum (peak) mean working pressure.

How could this be so? Is the manufacturer using the same primers, powder, and wads? They may have even changed the design of the case! Changing any of the components (or amount of powder) can and will vary the pressures.

Perhaps what you are thinking of is total pressure during the time the load is moving through the barrel. If so then you are correct. Total pressure "under the curve" is what is doing the work of accelerating the ejecta. The ejecta includes all things moving don the barrel including weight of powder, wad, and shot. If however you were referring to the "peak" pressure which is what 99.99% of persons are referring when they refer to high pressure, then you would be wrong. Peak pressure is what will blow up a barrel if it is too high.

For example one could load a shotshell that would only develop 900 fps in a certain gun but have a peak pressure of 18000 psi. How could this be possible? If a small amount of very fast burning powder is ignited and burns developing a very high pressure but then the pressure curve drops almost immediately (because the powder is almost completely burnt) to less than 1000 psi the load will likely develop only a low velocity. No, a manufacturer won't sell something like this due the the risk of a secondary implosion. If different powder is used a lower velocity may be developed at a higher maximum "peak" pressure.

The bottom line is that unless you test or pay to have shotshells tested, all you will know is that they do not exceed the SAAMI maximum mean working pressure.

[Bill Murphy]

All we have to do to prove Mark's point is to read a loading manual. Loads of certain shot weight and velocity have pressure figures all over the map.