I got excited about the long throat .405 winchester idea on a Encore and deceided to see just what could be done friday morning. I made a .4116 throater that exactly matched the groove depth of my 24 inch Thompson center barrel with a lead angle of 1 degree. I set up the barrel in my jet lathe and using some long precision brass rods that I made to match the bore, I got the bore dead nuts centered between the spider and the four jaw. I used a case with a woodleigh 400 gr SN seated about .250 beyond the factory cannelure as a throater guage and ran the throater in using a JGS floating reamer holder. It took about 2 minutes to produce the long throat. I then put some new cannelures on the bullets and off to the range. Based on quickload I produced loads with IMR 3031, Varget , H414. and ww748.
Basically it was very easy to hit 2150fps with all the powders described. I actually saw 2215fps with one H414 load! Thus, the long throat .405 win ( in an ENCORE and I'm certain a Ruger #1) will in fact duplicate the 450/400 Jeffery. I did not use a strain guage, but all loads were in the 57 to 60 Kpsi range as estimated by quickload. Encore actions can easily handle the level of bolt thrust produced by a case head of the dimensions of the .405 winchester at this pressure level. This was confirmed by Mike Bellm, Virgin Vallet Custom Guns and even a TC tech I talked to. As anticipated,the Encore handled these loads without the slightest hint of sticky extraction or deformed primers. The action opened easily and the brass and primer pockets appeared just fine. The best accuracy came with H414 and IMR3031. Five shot groups at 50 yrds offhand were <2 inches. Recoil was no where near as bad as expected. I mounted a leupold M8 2.5X scope on the gun and with it's eye relief there was absolutely no problems. The gun is quite light and handy and excellent for offhand shooting. I had a muzzel brake on the barrel and my wife named it Mini-cannon! It's definately loud! With a 270 win and a 12 gA -3 inch barrel as companions to the .405 long throat win. barrel you could basically have a briefcase sized take down rifle with which you could hunt any game in the world. Note: I will provide the detailed load information only by e-mail( most of you will understand why). Project Finished!-Rob