Thread: 228 Speer projectiles in 223.

Hmmm. It depends. Quite a bit of "depends" is in the throat design. I followed GPMs thinking for years until I got involved with 8x57s, which if you read Yank gun-writers rubbish are death traps with the differences between the S,J and I bores ranging from 0.318 to 0.323.

However a bit of study shows that the Euros were well aware of potential issues and nearly all military rifles were re-throated to allow the use of 323 ammo in older weapons. Reamer design was also changed for 8mm type cartridges.

Since I learned of this I've used quite a few oversized projectiles for obscure Chamberings, being careful to work up loads in the usual way. They usually shoot pretty good, I have a 8x57 with an octagonal barrel, full intregal rib and very light that has a 0.319-0.320 bore. It shoots 170 gn Hornadys 323's into very small groups.