Gary Reeder
that is a good question. Any necked down cartridge
Tuesday, May 14, 2019, 15:19

will produce slightly higher pressures and the more it is necked down the more pressure. That was one of the main problems with the WSM and WSSM cartridges, especially the WSSM. You have a cut down 416 Rigby cartridge necked down to 22 or 25 and that builds up a tremendous amount of pressure.

I have used the water hose description quite a bit when talking about pressures. You take a water hose with water running thru it full blast. You squeeze it down to about half that size, you build up the frontal and rear pressures considerably.

The same thing goes with a 44 Magnum necked down to 22 caliber. I have knows several cartridge developers to try this and have damaged frames and cylinders due to the maxed out pressure. That is why I try to stay with stepping it down no more than 2 steps. Like the 44 Mag necked down to 41, one step.The 410 GNR surprised me that it worked and worked great as it was stepping the 454 case down 2 steps, to 44 and then to 41, but it worked. The pressures are about the same as a 454 so it is only in a 5 shot cylinder.

But the 445 down to 41, is no problem. At least I have never seen any problems with it. As far as the rifle primers or pistol primers if the gun has an action job where the hammer spring has been lightened I prefer to stay with pistol primers. Rifle primers are a slight bit harder and you can easily get some light strikes.

As far as powder residue is concerned, usually using a slightly heavier bullet will stop that. The heavier bullet will be in the barrel a micro second longer and will help burn the powder. Also using ball powders a magnum primer is always the best way to go. Every loading manual I have ever seen always reminds people to use magnum primers with ball powders like 296, H-110, etc.

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