Seating depth/COL for 55gr 223

[SanDiego619]

I got some bullets from bobsbullets.com that are obviously not in my reloading manuals. I looked up reloading data for CFE223 and 55gr rounds. There are two rounds listed, with two different COLs, and the powder charges are different enough for me to make this post and ask.

55gr BAR TSX FB:
24.7 grains
2.18" COL

55gr SPR SP
26.0 grains
2.2" COL

I am surprised to see that much of a difference in charge, is it because the first bullet is longer, so it seats deeper into the case, increasing pressure?

For bullets that aren't listed in any manual like mine, is the procedure to start with a low charge like 24gr and use a chronometer to see how it is? Or is there a way to look up COL by bullet weight and length?

[SanDiego619]

I found a good video of a guy loading CFE223 with Bobs' Bullets. Very informative. It sounds like with unknown bullets I just have to do methodical testing of different loads and COLs.

Guy testing bobs bullets

https://www.youtube.com/watch?v=pRCH6kD5Xxg

[Sheldon]

The Barnes have no lead in them and as a result will be a longer bullet for the same weight versus a bullet that does have lead in it. Longer bullet means less case capacity, so smaller charge for same pressures.

[Tripplet918]

Hodgdon recommends the BAR TSX CFE 223 load to be min 24.7 to max 27.1 grains.

For the SPR 26 to 27.8 grains.

Are those load recommendations, or max powder charge from the bullet maker? They may have been chosen for accuracy.

Having loaded 223 and 556 a while, the min and max ranges are generally wide. The most accurate load velocities can be all over the place depending on projectile. Depending on your objective in reloading, you can use a known safe load and call it a day. Or, you could so any of the load development processes to find the most accurate load for a given rifle.

The difference could be as good as sub-MOA results, if the rifle is capable of it, to 3-4 inch groups at 100 yards, or it may not even matter at all if the recommend group already suits your rifle.

It is good to test loads at a minimum and check for pressure signs, accuracy and on an AR, ejection patterns.

[SanDiego619]

Hodgdon recommends the BAR TSX CFE 223 load to be min 24.7 to max 27.1 grains.

For the SPR 26 to 27.8 grains.

Are those load recommendations, or max powder charge from the bullet maker? They may have been chosen for accuracy.

Having loaded 223 and 556 a while, the min and max ranges are generally wide. The most accurate load velocities can be all over the place depending on projectile. Depending on your objective in reloading, you can use a known safe load and call it a day. Or, you could so any of the load development processes to find the most accurate load for a given rifle.

The difference could be as good as sub-MOA results, if the rifle is capable of it, to 3-4 inch groups at 100 yards, or it may not even matter at all if the recommend group already suits your rifle.

It is good to test loads at a minimum and check for pressure signs, accuracy and on an AR, ejection patterns.

Those were the minimum charges, but I didn't realize one was pure copper and the other was jacketed. That makes sense why one was seated deeper and needed a smaller charge.

I'll start with the minimum and shoot 5 rounds of each, working my way up while checking the cases for overpressurization, and paying attention to the ejection pattern, and also, my groupings.

I don't have a chronometer but I'll look at groups and other things and see which load gives me the best groups.

Thanks for the advice!

[TomReloaded]

You can't fit enough cfe223 into a case to cause a problem with 55gr bullets. Starting at minimum is a pretty big waste of powder, it won't be the load you're looking for.

You don't need to match data to brands. You match material, and profile.

So if your bullet is a jacketed lead flat base, you can use any jacketed flat base data of the same weight. You can't use copper data, or boattail data.

The max load of 27.8gr is 51.3kpsi for 55gr bullets. It's tons of powder and a pretty full case, and you still have some headroom.

[JackEllis]

I had an interesting experience with Hornady .308 GMX bullets that's made me cautious. The Hornady book has a pretty wide range of allowable charges for that bullet and several others of the same weight. About halfway between minimum and maximum I started seeing cratered primers and stopped.

If you're inclined, load one round at minimum recommended charge for the type of bullet you want to test and then load one each at 1/2 grain increments until you get to the maximum. Shoot 'em off until you see pressure signs, if any.

[bhilliker@comcast.net]

Jack---would you do 2 at each grain increment for consistency or do believe one is enough???

[Tripplet918]

Jack---would you do 2 at each grain increment for consistency or do believe one is enough???

The Scatterlee method uses only one road per load focusing on velocity trends per charge, while monitoring the cases for pressure signs.

Its effective, but not as definitive as some of the more involved processes. I wouldnt use it for mixed brass reloading.

I personally use 5 per load with the traditional charge weight load development process. Thats because youre using groupings and POI in making determinations. Thats to weed out human error.