Recently I've been shooting a new Bobby Tyler 45 Auto Rim that was built from the ground up on a Ruger OM 357 frame. The gun is shooting great with 3 different bullets & powders but I'm not surprised.
What did surprise me, & I keep forgetting to mention it is, the difference in brass. Many times, six gun prophet John Taffin has cautioned against mixing different brands of brass, especially in the smaller calibers or capacities. A 45 Auto Rim is basically the same capacity as a 45 Auto, not really a lot of powder. In a 9mm it can really become a problem, trust me.
I started out from day one using new Starline brass, which is known to be of high quality & lasts for a long time, some of mine has now been fired 4 times & is still going strong. Also on the shelf was some factory PMC 45 Auto Rim so I shot some of it and then weighed both cases, Starline & PMC, what a surprise!
The Starline tipped the scales at 88 grs, while the PMC weighed in at 99 grs, yikes! You can see that if a person worked up to what you consider the mythical maximum load using the Starline brass & then dropped the same charge into the PMC brass you could very easily get a pressure spike, especially with a fast burning powder.
That's why you don't use someone else's loads, ever without working up from 2-3 grs below. Changing anything always changes everything!
Dick
