Home Forums Reloading Varmint Rifles 5.56 loads in 223 chamber

Thanks for the info, and I spoke to a couple other folks that said I should be fine as long as I stick to lighter weight bullets (under 70 grains and all my 556 ammo is 64 grain) that aren't jammed into lands. The more I think about it the more I imagine the factories are running a little more lead in the 223 chamber just so there aren't major problems. I'll let you know how it turns out. Thanks again

I've never had an issue mixing and matching COMMERCIAL ammo between 5.56 and .223 chambers. As TAK pointed out this does not always apply to military ammo. In addition my full boat 5.56 loads are to warm for a .223 chamber in an AR, but work fine in the .223 bolt rifles I've tried them in.

Of course, just because I do it, doesn't mean you will want to, but those are my personal experiences.

Free bore is the only difference

I have chrono'd both and checked charge weights from FC .223 55 fmj vs LC 55 fmj

Maximum length for the AR15 fed from a magazine is about 2.250

I did run across an informational PowerPoint presentation that suggested M855A1 ammo is loaded to a higher pressure. I am not sure I recall correctly but I think I saw 58000 psi. Not sure I could find that webpage again. Sucks getting old...CRS, ya know!

Shot a good amount of it in standard .223 chambers. I've never had an issue beyond the government accuracy.

I've fired several variations of 556 in an H&R Handi Rifle with no ill effects. I would expect the same result from a 700 Remington.