Designing the 2-diameter paper patch bullet.

[Distant Thunder]

Mike,

I have absolutely zero experience with 16-wist .45 caliber other than what I've seen other shooters do with theirs. I have always stayed with the 18-twist because it is what I know and it has worked well for me.

When I was trying to decide what length to go with in my 18-twist .40-65 I ran the numbers using several different formulas and came up with a range of results. Because that is my silhouette rifle and would likely only be shot out to 600 yards I chose a length a bit higher in the range to get a maximum weight for the rams, but not push it to the high end and run into stability problems. I settled on 1.250" OAL and it has worked very well out to 600 yards just as I had hoped.

You could do the same thing for a 16-twist .45. Run the numbers using the different formulas and if you're going to shoot out to 1000 yards just stay toward the lower end of the numbers you find.

I don't think that weight is all that big of a deal, within reason, that is to say as I would gladly give up some weight in favor of stability. We all want to shoot a 545 grain bullet and I know that, but if that heavy bullet is only marginally stable it is going to struggle when the winds get nasty. I would much rather shoot a 520 grain bullet that is well stabilized so it doesn't go all wobbly when it gets hit on the nose by a quartering headwind or bumped in the butt by a tailwind.

A very important thing to note is that the optimal length, as I call it, is somewhat dependent on the nose profile. A bullet that is more blunt with a shorter ogive can be a little longer than one that is more sharply pointed with a long ogive. My .45 caliber bullet has an ogive that is almost one half the OAL. While it is an elliptical form I like cap the nose with a radius that is approximately 1/3 caliber. Arnie's bullet is similar but the radius is closer to 1/4 caliber. He and I both believe this makes the bullet preform better at transonic velocities and it helps increase the weight without making the bullet longer.

I believe I've said it before but let me repeat that I am not a ballistic expert. My opinions are base on my experiences from 20+ years of shooting long range matches. For most of that time I have machined my own bullet molds and tested everything I've read and heard that seemed reasonable. The bullet I use now and for the past few years is the result of what I have learned. While it has worked very well in two of my rifles it has not worked as well in other rifles apparently. I have made a few other molds of the same design for other people and their results were not as good or they never really worked with the bullets enough to know for sure. I don't really know which is the case.

I'm sure others would like to know what length you find would be optimal for your 16-twist so please let us know what you come up with.