Heavy Loads

by Sarge , Central Misery, Friday, November 07, 2014, 21:59 (3609 days ago) @ Sarge

An old friend blessed me with a near full box of 3oo grain, .452" Hornady Mag XTPs. It is old production and has a single cannelure. Linebaugh's writings indicate you can go as high as 23.0 grains if H110 under this bullet. I loaded a short batch with 22.0 grains of WW 296 powder in new Starline brass, with CCI Large Pistol Primers and finished with a firm crimp.

I tried to run six of them across the old Betamaster; but the sun was sinking, it was windy as hell and I got an Error reading on the first shot. The five that did register averaged 1093 tps with an Extreme Spread of 41.44 fps and a Standard Deviation of 18.11 fps. These are not bad numbers from a short 45 Colt. Recoil was not painful but you can tell when they go off. There were no flat primers or other pressure signs. Three of the empties dropped from the cylinder under their own weight and the other three jumped right out with a light bump of the ejector rod.

Would the 300 XTP expand at this velocity? Only ine way to find out... four gallons of water backed by a Brownells catalog, backed by a saw block.

The impact ripped all four jugs & launched the caps; I found the bullet buried in the catalog about to its base.

The bullet had expanded better than I hoped and it didn't appear to have lost much weight. Granted, some of that expansion probably occured after it hit the catalog; but it shows the advantages of retained momentum & bullet weight apply to heavy JHP's as well.

The only thing that remained was to see if the load shot to the sights. I knew it would print high; the question was how much. I stapled up a paper picnic bowl & held six o'clock on it from 25 yards and fired a couple of rounds standing, unsupported. I repeated the process from 65 yards seated in my hunting chair, with the gun rested over one knee. The results were, once again, were better than I expected.

I'll probably bump this up to about 1150 fps and see how she rolls.