New Loads And Psi


Dear Bruce,

I understand that you create some of your own loads (I may be wrong) but you will not distribute the data. I understand. Liability is everything. I’m considering making some of my own. However, what I’d like to know is how to test the Pressure. Is there an outfit that can check this and is it expensive?

By the way, I love your motto. Most of us are so willing with our opinions but can’t accept that our heads must be “in the clouds.” Just for fun you should listen to the “duck hunters” at the sweatlines in CA. They are a hoot!

Of your articles I can’t say that I agree with you, but at least you give a rationale for your opinions. Some of the magazine articles seem to create reality to fit the situation.

Thanks again for the leads on Bismuth reloading and your refreshing views.

Marc
Sacramento

Dear Marc,

It pains me to admit that I did indeed “create” some of my own shotshell loads. I was absolutely convinced that I was on the right track until I had a chance to talk to the ballisticians at Federal and Lyman. It was sort of like a shade tree mechanic meeting NASA. Of course, they have to deal with the “corporate factor” of legalities and public sales, where the home brewer only has himself to blame when things erupt or frames stretch.

Over the years the one thing that I have learned is that there are enough published loads out there to cover any need that I may have. The more I shoot, the more I tend to standardize. This makes finding recipes and components easy. It also permits me to practice with the same shells I use in matches or in the field. For example, I load just about everything that I shoot to about 1200 fps. (I buy my steel loads). While the performance of a load of #9s at 1200 and a field load of #5s at 1200 is obviously different, I have gotten used to it. I find that nothing is to be gained by higher speeds that can’t be accomplished by proper pellet size selection. There are exceptions, but not many.

Now as to pressure testing- life has gotten a lot easier in the past ten years since the standard has shifted from LUP (lead units of pressure) to PSI on a piezo-electric pressure sensor. In the old days a special pressure barrel was used that had a hole drilled in the chamber area. A lead plug of an exact size was inserted and the gun fired. The lead plug was compressed by the shell pressure and the amount of compression was carefully measured on a tarage table where it was equated to a pressure curve. This was not back yard stuff.

Today piezo-electric sensors are placed on the chamber area of a standard gun and the resulting stretch in the metal can be easily read. No need for a special test barrel. That’s the good news. The bad news is I don’t know where you get one or get access to one. And I don’t think that it is backyard equipment yet as chronographs have become.

Ballistic Products is well known for carrying leading edge reloading supplies and, as you know, is a great source for bismuth components.

I appreciate your kind comments about the site. As to not agreeing with me all the time, heck, I don’t agree with myself all the time either. If I was always consistent or correct, I would never be learning anything new. The world of shotgunning has undergone some tremendous changes in the past thirty five years and I am just hanging on by my fingernails. But what a ride!

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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One Response to New Loads And Psi

  1. Bill E. says:

    Tom Armbrust has been doing accurate pressure testing for many, many years even going back to the older lead crusher system described by Sir Technoid that is no longer used. If you want to have your own recipes tested you can contact him at 815-451-6649. The address is Ballistics Research, 1108 W. May Ave, McHenry, IL 60051. I think he charges about $25 for 3-4 shells and you should not test less than that number due to variances per shell. His prices drop as if you test larger quantities. (Don’t forget you can only ship ammo through UPS.) IMO, he is quite inexpensive because the data you get back includes pressures for each shell, individual velocities plus highs and lows, standard deviations, etc. In other words, he provides a Jr. Technoid all kinds of data to cogitate over. I used him in the past when I was developing some loads for some Damascus barreled guns I owned. This was before RST was founded and there weren’t any low pressure loads readily available on the commercial market. I also used him when I developed some loads for those same Damascus guns using black powder. Having said that and outside of some other unique needs not met by any factory recipes, I agree completely with Bruce that the factory data is the best to follow.

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