Loc: San Antonio, TX
I finally got around to doing some load work for my 12 inch TCA Contender barrel in 32-20 WCF. Most everyone knows that the groove diameter of the T/C barrels in this chambering are actually .308, but almost all of the reloading manuals as well as online resources state that the use of bullets as large as .312 are okay to use as long as you begin below max and monitor pressure signs as you progress upwards in charge weight. There is an excellent article on this site concerning the 32-20 WCF in a Contender, and I must admit I probably read it 3 or more times before gathering supplies and beginning my load work. While I did have a quantity of some Hornady 100 grain XTP's for use in my Marlin 1894CL in 32-20 WCF, I decided to pursue the path taken in the article by using .308 diameter bullets with much better ballistic shape. While searching the MidwayUSA.com website for projectiles, I decided on some Hornady 110 grain V-Max, and a relatively new bullet, at least to me, a Speer 123 grain Gold Dot that lists as being .310 in diameter. The V-Max, being a varmint bullet I reasoned, should expand at the low velocities I could get with the 32-20. The Gold Dot is designed for the 7.62X39 which is a relatively low velocity round, producing about 2300 fps from rifles. I knew I couldn't quite get those speeds, but maybe close was good enough.|
Initial loads used the Hornady 110 grain V-Max seated out to engage the rifling in an attempt to fire form the brass to the chamber. I loaded 14.0 to 16.0 grains of W296 in 1/2 grain increments in Starline brass and ignited with CCI 400 primers. Groups were 5 rounds each and fired at 50 yards. The best groups were 14.5 grains with a .509 CTC measurement and velocity of 1766 fps, and 15.0 grains with a .721 CTC measurement and velocity of 1818 fps. I then performed my standard expansion test at 50 yards by shooting through 3 each one gallon jugs filled with water backed up by a box of rags to catch the bullet. I used the most accurate load of 14.5 grains W296 and touched the trigger. The jugs jumped up at the shot, but even 50 yards away I could tell it just didn't look right. I walked down range, and the closer I got the better I could see that the first jug had split from the impact, but the second and third jugs were still half full of water. The bullet had completely penetrated all three jugs, and when I retrieved it from the rags I found that the bullet hadn't expanded at all, only losing the plastic tip. Well scratch that idea, or at least this particular bullet. I was considering giving up on this "rifle bullet" experiment, but I did have some of the Gold Dots still to try. I now had quite a few fire formed cases and was trying to determine the best way to size them without moving the shoulder. Well, it's not much of a shoulder, more like a slope. I wanted a way to keep the case centered in the chamber to achieve the best accuracy with the least amount of fuss. After contemplating using a spacer under the lock ring of the F.L. sizer die, I decided to try using my LEE collet size die for the 300 Blackout. It worked! It would squeeze about the top .200 inch of the 32-20 case to hold the .308 or .310 bullets. The shoulder and case body were untouched. I chamfered the insides of the cases to help with bullet seating, and didn't expand the mouth at all. I didn't have any crushed cases during bullet seating, but I did carefully hold the bullet as it entered the die, and gently seated the bullet. I reran the same load work of 14.0 to 16.0 grains of W296 and the CCI 400 primers, with the only change being the Speer Gold Dots were off the rifling by about .020
Not certain if you can tell, but the best load was 16.0 grains of W296 with a velocity of 1904 fps and group size of .730 inch CTC. This was looking promising, but now the dreaded expansion test. I had read a review on a website about this bullet needing 2200 fps at impact to expand, but the individual hadn't actually tested them, so I had to find out for myself.
The bullet completely penetrated/exited all three jugs at a distance of 50 yards. It has a retained weight of 121 grains, and expanded to a diameter of .600 inch. I performed the test with a 14.0 grain charge that was going 1777 fps at the muzzle, not the accuracy load of 16.0 grains going 1904 fps at the muzzle. I am not certain what this load is capable of game wise, but I might be very tempted to use it on a turkey, maybe even a small hog. It might even work on our small Hill Country Whitetail doe, providing they are about 50 yards away or less.