COAL question.

[praythenspray]

I picked up some of the Hornady 62 grain FMJ to try out. According to this, https://press.hornady.com/assets/sit...-60-62gr-1.pdf . It says the COAL is 2.229" for the 62 grain FMJ.

From searching around on this site, It seems like the consensus leans towards loading to a COAL of 2.250". And when I loaded some bulk 62 grain PRIVI Partizan in the past that is the coal I used. That was also the stated coal in the latest Sierra reload book I use.

So I assume that the Hornady COAL is due to the cannelure. Then again, after web surfing I read on some various sites that they have worked up loads with a COAL of 2.220".

I guess I am curious about what would be the minimum length for a loaded round for the AR? I mean besides over pressure of the case, what would be the only other detriment, potential accuracy?

[HKGuns]

RDCV: If the rounds have a cannelure, and you want to try to use it, seat to the length that allows that, but you don't have to......

For 5.56 loads, i go with the longest published OAL as long as it will fit into the magazine without issues. Shorter will increase pressure and jump to the rifling, longer is usually always better and safer as long as you check to ensure you're not jamming them into the rifling, which will also cause a pressure spike. I typically always load 5.56 to magazine length as that is the limiting factor for most of the heavier stuff. You also need to ensure you have enough bullet in the case, so just pay attention to what you are doing on both ends of the scale.

Curious what others will tell you.

[308sako]

If there is a cannelure on the bullet that would be a decent place to start if you are crimping. If not, the anything under 2.260" COAL should function without difficulty.

[markm]

Use the cannalure. Lots of factory ammo is much shorter than 2.25.