Precision handloading for AR's

When you AR's guys handload what neck tension do you use .004? I have two AR-10's (.243and.308) with Lijia barrels just sitting in my safe not getting any love so I want start giving them the love they deserve. Any tips on handloading for AR's much appreciated, never really gave attention to loading for the AR's always relied on my bolt guns for LRP.

From some AR Long range shooters use .004 neck tension and bump shoulder back .003

.004"-.006" neck tension, and no crimp.

.005" shoulder bump.

^^Might not be "the" way, but it's worked for me in .223 and .308 Win.

Agree that will work also.

I'll only FL size brass for an AR. If you do partial shoulder bumps and partial sizing, you can have some chambering issues, and AR bolts having difficulty chambering the round. AR's do not have the camming action, like a bolt gun does, so it needs to go in the chamber smooth as butter.

Sizing the case necks to a certain light weight neck tension is also a risk. You risk the bullet being seated deeper during feeding and risk the bullet being seated further out once the round comes to a stop in the chamber. I've seen too many guys get creative with their AR ammo loading and it lead to other issues. I want good neck tension and a case that will easily fit in the chamber. Tune the load with the powder charge, and load all the rounds consistent from one to the next, and it will be some good ammo.

Is it worth using Lapua brass

That's sounds like the right thing to do to prevent feeding issues. I wont worry about neck tension I'll use my regular FL die set and keep everything consistent. I have Lapua brass but probably will only use it in my bolt guns and go with Norma brass in the Ar's.

How hard does a case neck grip a bullet when the brass is work hardened? How hard does a case neck grip a bullet when the brass is annealed? When did tension become a linear measurement?

Good question River Rider, the hardness does change when heated. I believe neck tension has a lot to do with concentricity also. I always anneal after two firings and use the same neck bushing and never noticed a change in POI.

As usual I agree with RR on the variables but if you do like SPG said in the post above and use brass from the same rifle using what either Fireman or myself posted above you will see no problems.

Now with brass from other guns always FL size the brass.

I don't disagree with you, but there's no way to measure it.

I too anneal after two firings. Is the neck tension the same on the first loading after annealing as it is on the second? Probably not. But I see no changes in how it shoots.

So far, loose primer pockets are what tells me the brass is done. So far, I've not had the dreaded case head separation, or split necks.

There's 2 things we are talking about here for reloading for an AR. Neck tension and the body of the case. The neck tension, we have kind of gone over. But for the case body, if you do a partial shoulder bump, you are also not getting the sizing die all the way down to the case web, or on the side of the case towards the extractor groove area. This area often times is where brass will hang up in the chamber, or be over sized, causing the case to make contact with the chamber and fitting tight. This tight fitting will cause inconsistencies and hard chambering and/or hard extraction issues. If you have the right measuring tools and understand how to look for the signs of the brass making contact with the chamber, you can size this way. It's not how I would do it. It's too risky to take the chance of rounds hanging up and having chambering or extraction issues. There's one thing I learned a long time ago. I want each and every round to go into the chamber 100% with no issues. If you try advanced reloading techniques and get your tolerances too tight, it can cause you problems. Getting a round unstuck out of an AR can be an issue.

And I don't see an accuracy advantage in an AR between FL sizing and partial sizing of the case. Both can be just as accurate. AR's are rough on brass anyway, so cases will not last that long as a bolt gun. For an AR, I want to FL size the cases for 100% reliability, and work up a load that way.

I agree, I have always FL resized and trimmed the cases to the correct length and have no issues in any of my ARs. That being said, even though my ARs all shoot accurately, none are meant to be precision rifles.

I guess I've made the point effectively then.

I think someone once posted a link to some device that would give you a measurement of the force required to seat a bullet. I think it was made by Bald Eagle, but that may not be correct. I know of no other way to quantify the force requirement.

One reason I make the point is that I've heard the argument that you can pull a bullet (for whatever reason), and if the inside neck diameter is the same as what it was before seating the bullet the first time then you can just reseat the bullet without doing another thing and the neck tension will be the same. The thing is, I have tried this and I can most definitely feel the difference in force required to seat the bullet---which I interpret to mean that neck tension has changed. So: maybe the inside case neck measurements are not accurate enough to detect a dimensional change after pulling the initial bullet...or, what? Anytime I have wanted to pull a bullet to make a change of some kind, I have done whatever it takes to get perceptible neck tension back to where it *should be* (based on how it feels rather than a dimensional measurement).

I do agree with you JG, if the cases are annealed regularly and the I.D. of the necks actually are identical, then the neck's grip *should be* the same for each case. I j

It's too bad there's no way to examine the neck of a loaded round and evaluate the stress on the neck due to the bullet's presence. But just as I say that, I wouldn't be surprised if there IS a way, but no way to apply it to what we are doing in a cost effective device.

This exactly.

Have learned the same lessons.

I'm with you. I've pulled a bullet, and reseated after changing the charge, and it didn't "feel" the same. I've not done that in a long time. If I have to pull one, it's at least going to get sized again, before seating a bullet again. But oh wait! I just work hardened the brass a little more than it was by sizing it again.

But is the I.D. of each neck the same, if one did not turn necks on a lathe? Bet they are depending on how intolerant the measurement is. But when we get into thousandths or ten thousandths, I'm betting each case neck is an individual. Now we are getting very picky, though.

Yes indeed.

If you use a collet neck sizer, the neck I.D.s will be very close to perfectly uniform but I think neck thickness variation might still cause tension variation. Sometimes I'll turn case necks taking off only enough brass to knock off the high spots, or at least I did until I started buying only Lapua, Norma, and Nosler brass (and sometimes Hornady if necessary).

I suppose there are no limits as to how OCD you can get with this stuff, but if you don't draw a line somewhere you'll flip your lid!

I've found that anything over .002 gets you more resistance in seating bullets. Once the bullet has been pushed into the neck the seating tension is lighter. Pull the bullet and measure and you'll see that the bullet has resized the brass and you have .001-0015 neck tension. I use bushing or collet dies set to give .002 tension to minimize work hardening the brass.

Thanks for the assurance, just wanted to make sure I wasn't missing anything. My sons keep bothering me about the 2 AR-10's and they want to shoot them more than anything else.

That is a fact!

Not mentioned so far, small base resizing dies can help if feeding is an issue with reloads. A small base die provides resizing smaller in diameter lower on the case than a comparable full length resizing die.