Max loads using a 125 sierra

[320pf]

I have been shooting 125 g Speer TNT with 19 g W296. This load is listed as a Max in the Sierra manual (of course with the Sierra 125 g bullet). I have chronographed this load many times in different weather/temp conditions and it always chronos at 2270 ±20 with a C.O.A.L. 2.082. (similar tomy H110 loads)

I loaded up 20 rounds using Speer 125 TNT with 20 g W296. The C.O.A.L. was 2.091. When I chronographed 5 shots of this load I got 2530 ±20 fps. At first I thought that my chronograph was not working. So I tested it with some 22LR from my Ruger 10-22 and they chrono'ed at 1100, like they always do. Then I chrono'ed 125 g Speer TNT with 19 g W29 and got 2250 close to what I always get with this load. So I concluded that the chrono was working fine.

I then shot two more five round chrono tests groups and got 2550 ±30 and 2540 ±20. The overall appearance of the primers is only slightly flatter than the 19 g load. Both loads also show about 1 in 5 primers with a slight cratering.

I did not have a chance to mic the heads to see how much the case heads are expanding... that is my next test. I would like to figure out if I can run this load on a regular basis.

These loads were all shot from my 16-inch 1:7.5 twist Noveske barrel. The gas port is in the the standard pistol position (not the Olympic arms pistol position). This is the first time that I have given my Noveske barrel a real workout. Most of my load development has been with my 16-inch 1:8 twist Olympic arms barrel.

The outside temp was 48 to 55 °F.

320pf