Loading .223 test loads
PMC brass
Wolf 223 primers
55gr FMJ bullets
Shooting out of a 14.5" pinned carbine 1/7 twist with an aimpoint.

Hodgdons data says says 23 min to 25.3 max for H335. My lyman #49 says 24.3 min to 27 max. How do I take those 2 different set of data numbers to get a ladder for me? Ive read the 223 tutorial but im still a bit confused. Also, im using pmc bronze brass and the lyman manual uses Remington. Will this make a difference? My brass has been measured, trimmed, deburred , and primed, now just waiting for powder and bullet seating.

You can typically treat all the commercial brass the same. However military brass (LC, WCC, etc) has slightly thicker case wall, which means slightly less interior volume.  If you are loading near max, you should ideally have a different load for each military and commercial brass.  Personally I load .223 for plinking/training only which means I load on the low end and treat all brass the same.

As for the differences in load data between different manuals.  Make sure you pay attention to the COAL listed as well.  I have six different manuals, and I've noticed when there is a huge difference in powder charge then usually there is also a huge difference in COAL.  Less COAL means more pressure, which means less powder.

Youre right on coal also. Lyman has 2.260" and Hodgdons site has 2.200".

Bingo, that 6 hundreds of a difference in COAL can easily make up for a grain or two of powder charge.

As always, start low and work your way up.

Its just confusing for a noob like me trying to take those 2 different sets of data and find a number to start at

Military 5.56 brass has a higher internal capacity than .233. Please do not perpetuate that myth.

I have a bunch of 5.56 brass too, waiting for a super swage to come back in stock.

That's really good info there. I've wondered if there was a standard calculation you could figure on per c number of setback for rifle and pistol

Well setting the seating die was fun Pretty much wasted my first 10 cases. I think I finally got it set up right. Bullets are seating to right at 2.210".

I adjust a seating die like this

1.  set a case in the shell holder (since you trimmed them they should be the same length)
2.  start the die into the threads on the press
3.  lower the press arm/raise the shell holder/brass all the way up and hold it
4.  turn the die down till it touches the case and lock it in place with the lock ring

I don't crimp .223 (or .308 or 30.06) so I don't have to adjust the seating die further down than just touching the case mouth

5. raise the press arm/lower the shell holder/brass (if the brass has your powder load in it you're ready to proceed - if not, put your powder load into the case and put it back into the shell holder)
6. set a bullet in the case mouth
7.  loosen the bullet seater stem and turn the stem to raise the seater up in the die/away from the bullet/case
8.  slowly lower the press arm/raise the shell holder/brass up - if the bullet hits the seater then turn the stem to further raise the seater up so it does not contact the bullet
9.  Once the brass/bullet is all the way up, turn the seater stem downwards till it contacts the bullet.
10. lower the brass/bullet and look at it, if it needs to go deeper then turn the seater stem a turn and raise the brass/bullet again
11.  repeat step 10 till you get the over all length you want
12.  lock down the seater stem lock ring

Different bullets contact the seater differently and you may have to make an adjustment between brands for the same bullet weights.

I figure my overall length by
1.  It has to fit in the magazine
2.  it has to feed/chamber without the bullet hitting the lands of the rifling in the barrel

I do my reloads like this, then measure the over all length and write it down in the record book with the other info for that load (primer type, powder type/amount, bullet brand, style, weight, date, cases used, overall length.

I try to do my reloads in batches.  I clean the cases, I set up the die and resize the cases, I primer the cases and I reload the cases - I may prime 600 cases today and put powder/bullets in them tomorrow.  So I set the dies up and get a lot of shells out of them without haveing to remove/reinstall/measure everything as often as some folks might.  I do regulary, while reloading, check the die to make sure it hasn't started working loose.  I also measure 5 random powder loads out of every 50 cases.

Both of the above statements are false.

It has been shown on this and many other sites that 5.56 Military brass does NOT have less case capacity than 223 brass.  In fact it has been shown that most 5.56 brass has MORE case capacity than 223 brass.  As stated by ziarifleman above, Please do not perpetuate that MYTH.

It has also been shown time and time again that in a bottle necked rifle round the shorter the OAL the LESS the pressure and the longer the OAL the HIGHER the pressure.

NO, this is not good info, in fact it is dangerous info as it is all bass-ackwards and there is no way to calculate pressure in a bottle necked rifle round by OAL without pressure testing equipment.

I would treat the range as 23.0 grains min to 27.0 grains max



make 10 rounds each of 23.0, 23.5, 24.0, 24.5, 25.0



maybe 5 each 25.5, 26.0, 26.6, 27.5 since I anticipate I might have to pull the bullets.



Shoot 'em lower to higher, stop when you think they'll too hot, which means you may not get around to shooting the ones with the higher powder charges.  In that case pull the bullets, dump the powder
 

Thanks steve for clarifying this issue.

I believe what Anthony posted above in red is true for straight walled pistol cartridges.

Exactly. Put water in each, and you will see LC holds more.

not that we'll find it here, unless someone is a mathmatical genius, but i'm pretty darn sure there is a mathmatical equation that can give a value based on the known

space available in the case. Math can figure out everything, what do you think the basis of the pressure readings are?

For now I think what I'll do is my next test loadup of 223 i'll start lowest grain drop and chrono the difference with 1.220, 1.221, 1.223, 1.224, 1.225 and see if there is an

average difference per step up. Would be interesting to know that with powder x and seat x you will increase/decrease FPS by x number per .001 seat difference.

Of course the KEY to this testing will be to really work off of ogive seating depth OR...find 50 or so rounds that ogive and length are dead on the same.