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Old September 1, 2000, 11:44 PM   #9
bfoster
Senior Member
 
Join Date: October 13, 1998
Location: N. of Fords Switch, OK, USA
Posts: 297
Hutch & Southla1... I' m located in Cardington, Ohio. In answer to your questions I'll respond with an outline of how we develop commercial loads. Feel free to accept or reject them as you will; they are partly guided by the conservatism of an engineer working in a litigation plagued field.

When we receive a sample of a bulk powder (non-canister grade), brass, primers & bullets, we start with a very low charge and work up with a long series of shots using a modification of Creighton Audette's load development method: we are looking at bullet placement, pressure and velocity of single shots loaded in small, progressively increasing increments.

If you are not familiar with the Audette method, it is described in Volume III, Highpower Rifle Shooting, NRA Championships Training Clinics Manual Series. A few years ago Randolph Constantine published a worthwhile development of this in Precision Shooting. I don't have the reference at hand (I have loaned it out), but I am sure that it was republished in one of the Precision Shooting Annuals. While the core of the article delt with barrel vibrations, nodes, load tuning et cetera, the author added a chronograph to the test- (the description of the physics involved may be debatable, but the results achieved speak well for the method used). I have simply added (Oehler) pressure sensing instrumentation, and ginned up a simple bit of software to help sort through the data generated.

Once "promising" loads are identified, we revert to a more standard type of load development- we fire strings of at least 20 because we are looking for a combination which will give a high sigma.

The pressure gun itself is simply a modern adaption of the old Universal Bond type.

As testing is carried out for commercial purposes, and as commercial components do vary on a lot to lot basis far more than do the products available to reloaders, I do not publish results.

When I have, on occasion, given specific data on some of the forums (including this one) It has (almost) always been backed up by my own tests. Likewise, some of the data Saeed has published on the 244 H&H (at http://www.accuratereloading.com) may, in part, derive from data which I provided to him. This was generated as a result of ongoing experiments with "exotic" barrel designs.

Given the current legal climate we accept work only from commercial enterprises. That said, within the rather narrow range to which we have applied ourselves, I do have some data on consumer grade components. While the expense of running tests for individuals is probably prohibitive, (as would be tests conducted by H.P.White Laboratory etc.) If I have data which might be of use for ordinary handloads I am more than willing to share it.

The e-mail link in my profile is still good. Frrl free to contact me.

Bob

[This message has been edited by bfoster (edited September 02, 2000).]
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