I realize this is real late in this game, but for what it may be worth to late comers, I have shot hundreds of 70 gr. speer semi spitzers out of old .223 rifles...mostly Ruger M77s but also a Remington M7 and I believe a Remington 788, but not sure about that one (about 50 years ago). I think they all had 12 inch twist but don't honestly remember. What I remember very well is that, in spite of their weight, they shot fantastic in every gun I used them in, and had a shoe box full of 3 shot groups you could cover with a nickel or dime, albeit some of those were with a varmint rifle. Either way, they were often the most accurate bullet, or very close, as any other bullet I shot in .223. Just FYI, for accuracy in those days, I usually shot 53 (?) gr. Horandy match flat base HPs because they also shot great in every .223 I owned. And, I hunted deer with 53 (?) gr. Barnes X, which were also incredibly accurate in my guns (FYI deer: Two broad side pass throughs, one from directly behind went through 17" of spine, then several inches of neck and stopped under the hide on front of neck. All DRT, believe all hit CNS.) Unfortunately, never killed a deer with the speer, but ran a lot of tests that indicated they would be very effective on deer. Test was usually milk jug with a piece of 3/8 inch OSB board inside, and otherwise filled with magizines, and water. Let it all soak overnight. I duct taped two of those together, one with the osb in front and the other in the rear. Also tested w/o the OSB. Tested out to 200 yards and remember that I would have used them without question on game. Somewhere, I have notes comparing wound channel diameter and depth in those tests, but only remember I considered them to be more than adequate to 200 yards, which would have been my limit of use where I hunted.
