USMC PMI

No big deal, we are all learning here. Now anyone that reads the post will know the slight differance between a 1:14 and a 1:12 twist in a .223 rifle! I had no idea that NEF or H&R (owned by the same parent company now) made their .223 rifle with a 1:12 twist. It seems that the typical standard for a non-speciality .223 was a 1:9 twist that will fire the mid range typical bullet weights and lengths well (around 55 gr to 69gr).

charlie brown

One other note as far as bullet weight is concerned with the 1:12" twist. I have tried 3 different bullets with my rifle using W748 at various charge weights. The bullets have been the 45 gr Speer SPT, the 50 gr Sierra Blitzking and the 55 gr Cabela's Critter Ridder, which is a SPT type bullet also. I have observed (with my rifle anyway), that I can use the same powder charge (starting at min.) for both the 50 gr and the 55 grain bullets and the longer bullet of the 50 gr Blitzking will generate higher pressure than the 55 grain will!!

When I was working up loads, I increased in .5 grain incriments, and I now have about 35 loads of the 50 grain Blitzkings with 27 grains of 748. This was one grain over the minimum charge, and locked 2 cases out of the 15 others in the chamber. The rest are now retired, as I cannot get the bullets out. I am shooting the 45 grain bullets right now with 27.5 grains of 748 and I am getting approx. 1" groups at 100yds at about 2" high. At 200 yds, I am about 1" low, however the last time I went shooting, it was windy so I was unable to get a solid group at that distance. I had 3 bullets spread out about 6" along a horizontal line. I still have some 55 grain bullets left, but I think I will stick with the 45 grain bullets for now until, for some reason I feel it is necessary to change, as that bullet should work fine for coyotes and jack rabbits, (I have already used it on jacks, and have pics, but have not shot a coyote as of yet).