I part exchanged my Southern Guns AR15 for a Howa. Took it to the zero range at Bisley to sight it in. Oh dear.
The factory ammo I had been using in the AR was keyholing at 25yds. FCA with plastic cases 69grn SMK. Worked fine in the AR up to 200yds.
So I tried some 53 grn factory that came with the gun.
Perfect. Same hole.
Only then did I find that as the AR has a barrel twist of 1 in 9 it will handle 69 grn.
I hadn't realised the Howa was 1 in 12 and wouldn't work with anything above 55 grn.
Ho hum... A lot of dismantling to do and full length resizing of my homeloads.....
Never occurred to me the Howa might have a different twist rate. I didn't make any difference when I was reloading for pistols.
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