First time bullet seating question

[hardlyworking]

I've got some 1x fired cases all prepped up and ready to load with a Lee Classic Turret and Lee 223 dies.

Priming I'll do on the press, carefully
Powder will be weighed by hand and funneled into the cases

Seating the bullets though, and die adjustment question for you guys:

If I want a good place to start (for an AR, not a bolt gun) can I just put a factory loaded round in the sizer, run the ram up, and then tighten the adjustable seating element until it touches the factory bullet, and call it good?

I know that seating longer up-to and even touching lands is often good, but, I need to keep things mag-length for now and just need a place to start.

Thanks for the advice!

[M27]

Your load book should give you the proper length with the bullet powder combo but will probably be somewhere around 2.250"

you can ball park with the factory round, but a different ogive will give variances in seating depth.

start with the seating die set longer than needed then needed seat, measure with calipers, shorten, and repeat in small increments until at the proper length.

[reckoner]

What kind of bullets are you using? Do they have a cannelure?

For my AR, I seat my bullets so that the mouth of a case that's 1.750" (middle of the SAAMI spec) ends up right in the middle of the cannelure. That gives an OAL of about 2.220" with the bullets I use.

[LynnJr]

Start as long as your magazine can handle without losing any gun functionality then seat deeper in 0.005 increments until you find a sweet spot.

[noylj]

Why not just load to mag length and check if the round chambers? Each bullet will have a different shape and a different COL.
Take one case, seat the bullet until the case (minus powder and primer) fits the magazine and see if it feeds and chambers. If it does, that is your COL.
COL in a manual is NOT a recommendation, but simply what they used and is usually shorter than what a handloader would use. It may be good enough, but it won't be ideal.
I load the longest COL I can, and that means almost always long enough to still fit the magazine. If using a round nose or flat meplat, you may need to go shorter than mag length, as those bullets hit the lede/rifling at a shorter COL.

[JMP]

Lynn is correct again. ARs are most constrained by magazine length. What he suggested is the only rational way to go.

[J-cat]

Don't use a factory round for setting your OAL. Use your brain, a dial caliper, and the recommended OAL from the bullet manufacturer. OAL depends on the bullet. Some need mag length. Others have to be loaded longer than mag length, like 75gr Amaxes. Still others have to be loaded substantially shorter, like Nosler 64gr bonded solid base. If you're loading a military looking FMJ with a crimp groove, use an OAL that places the case mouth in the middle of the crimp groove. Then crimp into it.

[hardlyworking]

Thank you all!

This is exactly what I was looking for. I primed up 30 cases last night with CCI #41, I've got the load data for the powder I have (best I could come up with without paying another hazmat was Accurate: LT-32) and plan to load up some this weekend.

My XM193s measure at 2.250, the load data looks like 2.260 but that's with a 40gr V-Max, I expect these 40gr Nosler's HPs to be a bit shorter without that polymer tip.

[Grunt81]

Several good responses by very knowledgeable members.

In my experience with reloading for an AR platform, your limiting factor will always be your magazine. You would need to have an OAL of 2.450ish in a true 5.56 chamber, in order to make the ogive of common 55 and 69 grain bullets touch the grooves (rifling). It'll be shorter for a Wylde or Compass Lake chamber, and even shorter for a true .223Rem chamber.

Several service rifle competitors load rounds in this ballpark OAL, with the heaviest .224 bullets made, but they need to load one into the chamber every time they pull the trigger in slow fire and almost always have a 1:7 twist rate with a minum of a 20" barrel.

I'd never use a factory round to try to copy. Factory ammo is designed to function in every firearm, and will never be as accurate as a tailored load for that firearm. Norma or Lapua factory ammo can get close, though - not because they magically guess what's right for YOUR rifle, but because they set the standard in factory ammo consistency.

55 grain fmj bullets with a cannelure, will always seat shorter than SAAMI max, since you crimp into the cannelure. A lot of competitors don't believe in crimping, since it's "blasphemy" to deform a bullet. But they use expensive competition dies which set ideal neck tension instead of crimping. I crimp all my semiautomatic rifle rounds to ensure no set back or inertia-induced"lengthening" when the bolt slams home during chambering.

For heavier bullets, figure out what is the max OAL you can fit into all your magazines. Military magazines have thin metal walls, and may allow you to seat as long as 2.290". Polymer Magpul P-Mags have thicker walls. The longest I can fit in there and have reliable cycling is 2.269". That is my OAL for 69 and 75 grain match bullets. Make sure you can load at least 3-5 rounds in that magazine before deciding on a max OAL for that magazine. You can keep it simple and let your smallest magazine dictate your max OAL. This max OAL is definitive for every bullet and bullet weight you ever load and intend to shoot from your magazines.

[Grunt81]

Don't use a factory round for setting your OAL. Use your brain, a dial caliper, and the recommended OAL from the bullet manufacturer. OAL depends on the bullet. Some need mag length. Others have to be loaded longer than mag length, like 75gr Amaxes. Still others have to be loaded substantially shorter, like Nosler 64gr bonded solid base. If you're loading a military looking FMJ with a crimp groove, use an OAL that places the case mouth in the middle of the crimp groove. Then crimp into it.

Great advice. I'll add, for someone who wants to shoot 75 grain Hornady bullets and wants them to fit in the magazine, the 75 grain HPBT fits the bill.

[hardlyworking]

Thanks Grunt!

Right now, I'm still learning, but I do plan to look into 69 and 77 gr TMK, 75 gr HPBT and 77 OTMs eventually.

I do have a 20" rifle gas barrel 1:8 wylde so once I get my feet wet I'll start over with the heavier rounds and a different powder.

[Grunt81]

Is it a Rock River? I have a Windham Weaponry VEX, 20" stainless steel, with 1:8 twist and Compass Lake chamber. This rifle shoots the 69 grain HPBT Nosler Custom Competition very well, 0.5 MOA 5-shot group at 200 yards.

[hardlyworking]

Home build, barrel is an ARP.

[hardlyworking]

Loaded up 15 rounds last night, using calipers and checking OAL while dialing down the seater die.

5 sets of three, starting at the 1/2 way point in powder charge, and going up 0.5 grain increments, stopping 0.5 grains under book max.

My top powder charge was right at the base of the neck, top of the shoulder

The 40gr flat base bullets are SHORT, and I definitely do not have 1 caliber of seating depth in the neck. More like 1/3 of a caliber (.08 out of .223). This makes me a little worried, because it just doesn't seem like enough grip. I did not crimp these, but do have a factory crimp die I could use.

They are seated to 2.252, I was able to fill a 10-rd Pmag and then strip them back out.

Testing a group of three all of them dropped into the chamber muzzle down, and then fell out muzzle up. Same three in the Pmag, were stripped by the BCG and chambered, and hand cycled back out dropping the bolt from bolt-catch or pull and release. Testing these three saw no setback, or pull out, all were still right on 2.252.

I had read that one caliber of bullet shank should be in the neck, but this definitely is not what I have with these when loaded to near max mag length.

Good to go?
Would you crimp with so little neck contact?
Would you seat them deeper?

[Grunt81]

The necks of .223 brass are close to a quarter inch long. If your powder level is sitting flush with the shoulder, then you should be able to get near the .224 seating depth without compressing the powder. I'm assuming you're using an extruded (stick) powder?