Still need to FL resize if your single loading an AR?

[fella5]

When I started loading my AR-15, I purchased a FL sizing die that uses a neck bushing. I've been loading 80 gr Sierra Match Kings loading single shots and was wondering if I have to FL size or can I just use a neck sizer? The head space is about .001-.002 more after being fired once (Lapua). I have other once fired (Federal) brass that head space is .004 more than my once fired Lapua. So if my head space is .002-.003, I don't have to worry about bumping the shoulder? Still learning

Thanks

[Sport45]

IMHO, gas guns don't damage brass in the feed cycle. It's the ejection cycle that causes issues. I FL size whether I plan to single load or not since I don't have an easy way to make the ejection process manual as well.

[fella5]

Good to know....

I have a piston AR, so I have an option to turn it off and manually eject the case. But again... it might be a pain to eject if I don't FL size correct?

[dmazur]

I believe the main concern with FL sizing in gas guns is chambering reliably.

If the bolt can't lock up correctly, you could have failure to fire (bad) or a slamfire (worse).

I suppose ejection could be a problem, but with tapered cases I don't think it is a serious concern (unless you have a rough chamber).

[Fullthrottle]

As far as I have read semi-auto is recommended to be FL resized! Unlike bolt guns, neck sizing is best! Don't quote me on that....it is just what I have read!

[fella5]

Yeah that's what I have read and heard too. Well at least I know that I don't have to go out and buy a neck sizer die. Thanks for all the help guys!

[Unclenick]

Let me add that those who neck-size-only eventually run into a chambering limitation. The brass grows tighter with each firing cycle and gradually gets too snug even for even a bolt gun chamber. At that point they need either to FL resized or they need to have a body die (Redding or Forster) employed on them that leaves the neck alone, but works on the case body. Many use these dies to keep the shoulder bumped back 0.001" at every loading, as that seems to allow the case to do a little bit of self-centering that improves accuracy over a straight neck-size-only.

As you can imagine, if you let a case start getting tight from repeated neck sizing without body sizing in the AR, the threat of the out-of-battery slamfire would peak somewhere in the tightness range. I was just rereading part of Glen Zediker's book, Handloading for Competition, and he recommends setting shoulders back at least 0.002" for the AR in a FL sizing die. He feels that's the margin needed to prevent feed issues in that gun.

And do bear in mind that setting the shoulder back 0.002" in a FL sizing die is not the same as having a case that comes out of the chamber 0.002" short of making headspace. When you resize, the die first narrows the case, which lengthens the distance to the shoulder, then it sets the shoulder back. For the AR, you want that narrowing, which the as-fired case won't have.

An experiment: It depends on your gun and chamber and magazines and springs and even the brass, but have you ever noticed rounds you've had to eject without firing that don't feed reliably when you run them through the gun again? Next time you go to the range, take half a dozen extra practice rounds and your case head length gauge with you. Check the head-to-shoulder length of each of these cartridges and write it on the bullet with a Sharpie. Put the rounds into your magazine in a couple of different positions (i.e., first, last, middle), and when they feed, eject rather than fire them. Then check the shoulder setback on them again. It varies with the gun and the brass, but you often find the shoulder is farther back and the case is now fatter, as that's where the brass flowed. Fatter is the reason for the feed issue.

Hatcher noted long ago that a rifle bolt closed fast even by hand, as during rapid fire with a Springfield '03, could take five or six thousandths off the head-to-shoulder length of a .30-06. Just think what a self-loader bolt can do?

[fella5]

Very good info. Learning new stuff everyday which I guess is a food thing. I will try your test and see the difference in headspace. I think what made me think about just neck sizing was I was asked what rifle I would be shooting in this Long Range Rifle course (coming up next weekend). I told them an AR-15 and they told me I would need to load 80g SMK and load them individually. I bought a Bob Sled magazine for that purpose. Then they asked if the brass (new lapua) has been fire formed.... Hhhmm. That's when my mind went crazy. I knew that eventually you need to FL size brass because it would eventually be too tight, but I was assuming that I would be able to get away with firin new brass, neck size, fire again, then FL size. Since I already have a FL size die, I'm just better off being safe and FL size my brass. Now when the wife allows me to get a bolt action I will be able to fire firm brass.

Thanks again!

[Unclenick]

The 80 grain bullets are loaded singly in the AR because their long skinny ogives stick out too far to be able to seat them to SAAMI maximum COL (2.260"). They are normally seated wit 2.530"-2.550" COL (you can tweak this to your gun's preference). The extra quarter inch or so means they can't be expected to fit in or feed from magazines reliably.

Your take on the brass is correct. New cases are often run through a sizing die to remove dings from the necks, but it isn't essential if you have no dings. That brass is already the size they are commercially loaded at. I've shot tons of factory primed new Winchester brass in the past, when you could get it.

Once it has been fired in your gun, if your chamber is longish, the FL die will not return the cases 100% to original size anyway, and thus they will be partially formed to your chamber. If you want to hit the minimum 0.002" shoulder setback number more precisely and are using a conventional press with standard shell holders, then a Redding competition shell holder set may be of interest to you? It is five shell holders with the extractor groove lip thickened up to +0.010" over-thick in +0.002" steps. This prevents the FL die from going down quite as far over the case when you set it up the usual way, screwing it down against one of these holders. But it still lets you have the extra pre-loading squeeze of pressing the die against a shell holder, and that helps regulate the final shoulder setback.

[fella5]

Thanks again... I have a Honady LNL AP press since I was loading .223 for plinking, etc. So now since I'm actually trying to load ammo more accurately I use the press sort of like a single stage. After preping and priming the cases, I weigh the powder and charge the round. I then just place the round in the shell holder before the bullet seating stage on my press and seat the bullet. I know that a single stage is better for this than a progressive press. So the die I'm using is the RCBS Gold Match FL die set. You think I should get the Redding Competition Bushing 3 die set using the Hornady shell plate holder that is on my LNL press now even though I cant use the Redding shell holders? I read that the Redding is the way to go, but don't know how well the die I have matches up to the Redding Competition.

[dmazur]

IMO, there's very little difference between a progressive used one station at a time and a single-stage (for most uses).

However, I found that on a Dillon 550B, a loose shell plate can support the case instead of the top of the ram, giving inconsistent resizing as well as "tipped" primers.

Also, there are claims of better results if the toolhead (Dillon again) is attached to the frame consistently, rather than with loose pins. UniqueTek has a product that addresses this.

With the Hornady LNL AP, there shouldn't be toolhead issues as it uses 5 LNL bushing positions. So, as long as the shell plate allows the brass to be supported from beneath the positioning notch rather than by the shell plate itself, you should get consistent results.

[fella5]

I'm going to check some measurement when I load up more ammo. I really didn't check how much neck run out I had with the new Lapua brass, but my bullet run out was inconsistent. Bullet run out was between .001-.007 and that is why I'm questioning either its the LNL AP press or maybe the RCBS Gold Medal die.... But maybe it's my FL die that I left in the press that is set 1/4 turn after contact with the shell plate which might be the cause, but who knows. I will just try different stuff to see if I can get better results.

[Unclenick]

I got numbers like that years ago when I tried to reload Lake City .30-06 brass on a Lyman turret press I had. I was using Redding dies. What fixed it was getting the Redding Competition Seater die. It uses a full length sliding sleeve to keep the case straight. I understand the Forster version of this die also works well, but that the half-sleeve Hornady version is not as good. That part is hearsay, though, as I only have personal experience with the Redding.

You press will work fine, but you may find it difficult to get consistent setback without taking some additional step, like throwing a shim washer over the case to sit on top of the shell holder. You'll have to try it and see?

[fella5]

Well it seemed to me that when I ran some new Lapua brass into my FL die, and seated the bullet, I had around 0.010-0.025 run out. My previous measurements, I didn't run the brass through the FL die. I also tried turning the round 3-4 times while seating the bullet and that did help some what.

[steve4102]

Bullet run out was between .001-.007

This is not bad, I strive for .000-.004 in my Hunting/Plinking rifles. I never check runout on New unfired brass, I wait till after it's been fired and sized.

I had around 0.010-0.025 run out.

This however is not so good, even for new unfired brass. IMO most runout is caused by the sizing process not the seating process. The best seating die in the world can fix what the sizing die has screwed up. I would shoot em and start over.
I never could get my RCBS dies to produce nice straight ammo, but then again I have only tried the standard RCBS dies. For nice straight concentric ammo I like to neck size with the Lee Collet die followed by the Redding Body die seated with the Forster BR seater, this combo is hard to beat. If I can't get this combo I head straight for the Forster BR FL two die set, works excellent for nice straight ammo.

[wncchester]

"...was wondering if I have to FL size or can I just use a neck sizer?"

We can have opinons but we can't know. You have the rifle and tools, why not just load a couple and try it?

[mehavey]

"...was wondering if I have to FL size or can I just use a neck sizer?"

In a word: YES
In lots of words: even single-loading, you are operating an autoloader that must close the bolt without any assistance/feel/nudge/foreknowledge/hint-of-a-worry on your part. It must close. Even single-shot and relying on the bolt assist if a case sticks is a bad habbit as the assist does not have the camming leverage that a bolt handle gives you.

The only way to insure closure is to size the case at least 0.002" under as-fired condition. Failing your having a case headspace gauge to measure this 0.002", you must full-length resize

.

BTW: The AR design has one of the safest out-of-battery designs around. If the bolt hasn't fully rotated, the firing pin won't protrude from the bolt face. Pull the bolt carrier out and push the firing pin from the rear while rotating the bolt itself to see what I mean.

[Unclenick]

Fella5,

Those runout numbers are huge. It almost has to be the case that sizing pulled the necks off-axis. You need to look at sizing without it, then measuring neck runout. If it's already way off, it may be due to the new cases not being snug against the sides of the die? If not, then the expander may have pulled them off. Lubing the inside neck and gently running it over the expander as a separate operation may help.

[fella5]

Well I should of checked this first but I didn't.... the reason for my 0.020-0.60 bullet run out is because my RCBS Comeptition Gold Medal seater stem is not made for long bullet tips. So I will need to send RCBS the stem along with 5 bullets and $20. The bullet tip was being pressed down by the stem and not being seated by the bullet ogive and thus my huge run out.

Does Redding or Forster competition seater work with the 80gr Sierra Match Kings or do I need a custom stem from them also?