It is true that Mr. Shawn has had some
decent success with 7-twist .223 rifles at 1,000. They work, but it is the additional tube length that makes the difference. We have had this discussion multiple times.

Being a Long Range Service Rifle shooter, I had no choice: it’s 20” long, or it’s not “Service”.

I can confirm that something on the order of 6.75 to 6.5” twist is REQUIRED for those bullets in a short tube. Being that Sierra originally intended the bullet for relatively short barrels, and their inherently conservative position as a manufacturer, I am behind their 6.5” recommendation.

The barrel I had was a Bartlein 8-6.5” progressive 5R. It worked, and even though it was a dedicated LR rifle (110 freebore at 0 rounds), it hammered quite well with “magazine” ammunition using the 77 SMK. Last I checked, the bearing surface of a 77 Sierra had nearly 1/4” between it and the lands, but I estimate the accuracy potential of the rifle as 1/2 minute at 300 yards. At 100…well, I could surely win a pile of $5 bills with it.

My point in that is that a guy shouldn’t be AFRAID of a fast-er twist .223 barrel, as it will shoot shorter bullets fine as well. If you want to try 90’s, do it.

In ideal conditions, even a 7.7” twist 20” can work at 1,000, but it requires you to push 80’s fast enough you are really risking case integrity. (though I did not try it with 2000MR, as it didn’t exist yet. That powder can go fassssst.)

But on my original point, the 8-10” difference between Shawn’s baby-Palma and my SR is EVERYTHING if you think a 7-twist is fine.

As to his success with the 7-twist Service gun: it is despite the barrel, not because of it, and I haven’t seen him shoot it much at 1,000, either. at Shawn..hehehe..

At the end of the day, even if you had a 26” “Spacegun” for the 90’s, it’s never going to be competitive at the long lines against even something as mild as a .308 bolt gun in the same length. It’s just not a thing, despite the occasional successful shooter like Bob Gill. Lots (lots) of extremely experienced shooters think the same thing, and it’s for good reason.

For the purposes of Mr. Zedicker’s rifle, he is correct, at least as far as 600 yards is concerned. There are lots of us that can shoot rapid fire and keep the bullets on a 12” plate, and more than none that could do it on half that size. It’s a pretty effective rifle at that distance, with the “new” bullets.

But for LONG range, I cannot in good conscience recommend a 90-grain AR…or ANY AR” that doesn’t end in -10.

-Nate

Editor: Shawn, it’s good to hear you got the 90s to work in a 1:7″ twist barrel. However, Sierra states on its webpage: “This bullet requires a barrel twist rate of 1×6.5″ or faster”. So Zediker’s comment is consistent with the official factory recommendation. Stability is a function of both velocity and barrel twist rate, so it could be that slower loads need the 1:6.5.

Link: https://www.sierrabullets.com/store/product.cfm/sn/9290/224-dia-90-gr-HPBT-MatchKing

Zediker has a conversational style, which I enjoy reading. He also covers a lot of information with not a lot of words. What do you find annoying about his writing?

Charlie

Has the most annoying writing style of any author I have ever come across. Very knowledgeable just a very awkward read.

Paul