Neck Size Process Question

[SG4247]

After full length sizing where I set the shoulder back .003"-.005" without the decap rod or expander in place. Next, I actually use the Redding bushing die or my Neil Jones custom bushing die to neck the brass neck down a little bit tight, like .260" at the ID.

Then, I use a seperate expander mandrel to get the neck ID at .261" or .262" depending on brass ductility.

This method provides very good runout on my equipment.

The neck ID is all that matters, get some .260,261,262 pin gauges to determine the finished neck ID, so the seating pressure is consistent.

[dega37]

SG4247, You do that just the first time right?

[Cornbread]

No, that is the sizing process. Pulling the expander ball through the neck with regular dies can induce runout. The above process is one that alot of benchrest, long range guys use. You need to have brass with consistent neck thickness,like Lapua, or turn the necks to take full advantage.

[dega37]

I don't understand that is about .020 of neck tension when it seems most people are only looking for .002. and if it expands to .291ish isn't that overworking the brass? Also by neck ID you mean you identify each piece of brass by the final sized result either .261 or .262?

[acourvil]

ID = inside diameter

[dega37]

Great info SG4247, and thanks for the assist acourvil. So SG, do you have a hand decapping tool? What is the mandrel you use, and did you have to buy custom mandrels, and where did you get your pin gauges, because starrett's set is about ~$250.

[454bore]

I take the button out of my S die to bump the shoulder with the de-capper in and next put the .288 button in to size the neck.
Then run the brass into a rcbs 243 die with a .2805 expander installed.
Do the same with my 6mmAR also using a .268 bushing and again use 243 size die with the .2405 expander.
The rcbs expander button is rounded and passes through the neck with little contact and works almost as good as a mandrel.
I like to turn the necks 1 thou on the 6mmAR since it has a tighter chamber.
When shooting for accurate load work up I shoot 1 shot at a time to take out any rough feed variations from the mag.

[SG4247]

I use a Lee decapping die in my press to remove primers first.

http://www.cabelas.com/product/Lee-Decapping-Die/1200579.uts?productVariantId=2959339&WT.tsrc=PPC&WT.mc_id=GoogleProductAds&WT.z_mc_id1=03227827&rid=20&gclid=CMLozfTAjtECFZC3wAodtOAEeg&gclsrc=aw.ds

Then tumble the brass for about an hour to remove carbon and clean the brass up so it doesn't wear on my dies.

The mandrel die was purchased from 21st Century Shooter and I bought their .261" Titanium coated mandrel for .264 bullets.

Pin gauges can be bought individually or as a large set - off of ebay. No need for Starrett, offshore pin gauges work just fine. I use .260", .261", and .262" gauges most often. The .261" pin gauge with a light slip fit works well for 6.5 Grendel.

[Rickc]

Merry Christmas

For those who work so hard to establish. 002 of neck tension how many anneal?

Seems to me you can't have consistent neck tension as the brass work hardens. For.me consistent neck tension is more.important.than that.perfect .002

And we are also dealing.with an AR not a precision. Benchrest bolt gun

[waynemac]

This is my first post on this forum.
Thought I'd just apply a little hard earned loading info... take it for what you paid for it...

For reloading for a repeater of any sorts, full length resize your brass. Use of a good bushing die in bolt action rifles will help with your ability to adjust your neck tension, however, my preference is to size the neck all the way to the shoulder for any auto loading rifle. Bushing dies don't normally do that, they size the top 2/3 of the neck and leave the portion just above the shoulder un- sized to help align the case / bullet in the chamber.

Bushing dies do there best when using neck turned brass. Most cases, including our be-loved Lapua have varying neck thicknesses. This variation manifests itself in cartridge / bullet runout and varying bullet pull. None of that contributes positively to accuracy. Those few thousandths represent a tenth here and there on our targets at 100 yards. Frankly, most of use can't shoot an AR well enough to see the difference. And I'll say here, using the expander needlessly over-works your brass when sizing with a bushing die.

For all the cartridges I load for the AR platform, I use quality standard full length dies. Redding has become my favorite, and I'm most familiar with them so my next comments will be with this brand in mind. With standard chambers, I strive for the SAMMI specked headspace. Especially if I have multiple rifles that I will be loading for. But for the one of, which my Grendel represents, I adjust my size die to give me .002 shoulder bump and I leave my de-capping stem slightly loose so the expander ball follows the case neck.
You can load some very good ammo with that system, and you can adapt it to your progressive press to load in volume if so desire.

Wayne

[Klem]

Merry Christmas

For those who work so hard to establish. 002 of neck tension how many anneal?

Seems to me you can't have consistent neck tension as the brass work hardens. For.me consistent neck tension is more.important.than that.perfect .002

And we are also dealing.with an AR not a precision. Benchrest bolt gun

Tried that a while back in F Class competition and saw no discernable difference in scores. I used the manual technique of a gas burner and rotating drill into a bucket of water. If it was doing anything the difference was being swamped by all other variables. Another shooter bought a fancy $500 rotating machine to perfectly control temperature and what part of the brass exactly received heat, while the lower half was protected. His scores didn't change either.

I agree with you absolutely, neck tension is more important than its given credit for.

[SG4247]

Using pin gauges to measure the sized neck ID, is just a great and cheap way start making accurate ammo.

If you dont know the exact ID of your necks, then you dont even have a place to start.

The next step in reloading could be neck turning, and later annealing.

It all just depends on your level of desired accuracy.

I document the number of times the brass is fired, and which rifle it came from.

As the fired count increases, so does the brass hardness.

One test I did confirmed for me that the neck tension value itself is not so critical, as is having the bullet seating force consistent for all the loads.

[Rickc]

Tried that a while back in F Class competition and saw no discernable difference in scores. I used the manual technique of a gas burner and rotating drill into a bucket of water. If it was doing anything the difference was being swamped by all other variables. Another shooter bought a fancy $500 rotating machine to perfectly control temperature and what part of the brass exactly received heat, while the lower half was protected. His scores didn't change either.

I agree with you absolutely, neck tension is more important than its given credit for.

Good info!

Now what have you found as far as the reloading process that did effect your scores?

[Rickc]

Using pin gauges to measure the sized neck ID, is just a great and cheap way start making accurate ammo.

If you dont know the exact ID of your necks, then you dont even have a place to start.

The next step in reloading could be neck turning, and later annealing.

It all just depends on your level of desired accuracy.

I document the number of times the brass is fired, and which rifle it came from.

As the fired count increases, so does the brass hardness.

One test I did confirmed for me that the neck tension value itself is not so critical, as is having the bullet seating force consistent for all the loads.

So if I understand you correctly you said it wasn't what the seating force was that was important but that it was consistent.

[SG4247]

Correct,

Sounds simple right? Just make all the bullets seat the same.

Now, you have to measure seating force, and figure out what variables make for seating consistency.

Doesnt matter if its a bolt or AR, they both need the same good quality, consistent ammo for great accuracy.

My video:

https://m.youtube.com/watch?v=6mA10IVnG1Y