Need help with my (new to me) 223

  • Thread starter Deleted member 115654
  • Start date

Deleted member 115654

Bought his at auction because I am a great fan of Schultz & Larsen. It is a custom in 223.

Screen Shot 2020-11-21 at 9.04.36 PM.jpeg

I went through and cleaned it up including cleaning the bore to bare metal and the Dyna Tek coating system.

Then off to the range. Only ammo handy was 5.56 green tips 62 gr and Fiocchi 55 gr fmjbt.

Set up target @ 25 yards, bore sighted and sent the green tips down range. 3 made a 5" group hitting the target sideways (keyholing). Then I tried 3 of the 55s, they went in one hole. Adjusted the scope and went to 100 yards.

5 of the 55s made a nice round 1.5" groups. (The same ammo has never been any better in my match grade AR)

Seems to me this barrel has a slow twist and I should try bullets in the 40-50 gr range with a short bearing surface.

Suggestions welcome.


Well-Known Member
Jun 30, 2013
If the 55s worked and the 62s didn’t, then yeah I would say it’s a slow twist barrel. You can check your twist rate with a cleaning rod. There’s some good videos on YouTube how to do this. I would stick with 50gr and lighter in this rifle though.


Well-Known Member
Mar 7, 2016
I'd check the twist rate, that'll save you a lot of frustration. I have a 1-14" twist 22-250 that won't shoot the 50 gr vmax's (keyholed). 40 gr vmax's shot so so. It did shoot the 50 and 55 gr BT's well. 55gr flat based Hornady SP shot okay as well. So far the best group I've had are the 55 gr Berger Match Flat based bullets, that surprised me. So it all depends, but I think try flat based bullets with longer bearing surfaces lighter than 55 grs. Maybe the 53 gr SMK flat based bullets.


Well-Known Member
Sep 9, 2016
The Sierra 53 grain #1400 bullet is of the conventional flat base design, should do ok in a slow twist.

Had a 243 high round count barrel that didnt group till 10 fouling shots were fired.

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