Some questions about neck tension

[BHuij]

Hey everyone--

Back again with another weird question. I've been shooting more cast .223 through my AR. It's accurate enough to be enjoyable plinking, and I really wanted to test out a new powder and a new red dot sight I got for my birthday. Still planning on getting a separate upper or just replacing the barrel for now to make the AR into a .300 BLK, just have a lot of stuff higher up on the priority list as my wife and I are trying to put a down payment together for our first home.

So during all of my more "serious" testing with .223 in my AR, I was mostly sizing to .225" after powder coating. Never had any trouble seating the bullets since I was using a Lee universal expanding die to slightly bell the case necks before charging/seating.

With my most recent batch of .223 bullets that I have culled, gas checked, PC'd, and heat-treated to BHN 28, I forgot to size. They are micing out to .228" in diameter, and now that they're super hard, I'm hesitant to try sizing them down. They still seem to seat just fine and they're certainly no less accurate than the .225s, but I kind of wondered if I was swaging them down upon seating anyway. This is especially true since I am using the stock Lee expander ball in my sizing die, which they say sizes to an actual inner diameter of .223". I haven't confirmed that myself, since I don't have the tools to get a critical ID measurement.

As luck would have it, I accidentally seated a bullet before charging the case the other day, so I ended up having to pull the bullet with my kinetic puller. As a side note, pulling light 55gr bullets that are seated with at least .005" of neck tension takes an insane amount of hammering with that thing... haha. But it came out and I decided to mic it and see if it was mashed. Nope. Still exactly .228". So it appears having a BHN of 28 is hard enough to resist being swaged even with excessive neck tension.

So my question is, should I be worried about this, or would it be reasonable to expect an increase in accuracy if I was using less neck tension? I can have Lee make me a custom expander ball for my sizing die for like $8 or something, that would give me an actual inner diameter of, say, .225" or .226".

My understanding is that less neck tension = less pressure = potentially a less consistent burn. Since I'm currently using a reduced load of Ramshot TAC, which is a ball powder, "consistent burn" is already kind of a tall order. I'm not sure lowering my neck tension would actually help anything. Whereas in my research, the only reason I could find to be worried about excessive neck tension with cast bullets was to make sure it wasn't so tight it was swaging the bullets down. Other than that, it seems consistency from round to round is more important than more or less actual tension, although most people say somewhere in the neighborhood of 0.002" is ideal.

So, try with less neck tension, or is that unlikely to actually help anything? I know the only way to find out is to try it, but I'm not sure whether it's worth trying yet.

 

[fiver]

228 might not chamber.
227 is about all I can get in the ball seat area in almost all of my 22 cal rifles.

there is another way to set your neck tension, LEE makes those little neck tensioner dies that also poke out the primers.
they don't use an expander ball.

 

[Spindrift]

I can not give you a definate answer, but if it chambers, and accuracy is not worse, then you should’nt have anything to worry about. The extra neck tension can probably come in handy in a semi auto, too.
As a side note, I use these expander plugs from NOE to control neck tension. The fit right in your Lee universal flaring die, and provide both neck expansion and flaring. Not too expensive, either. And the dimensions are right on the money, as usual with NOE products.
http://noebulletmolds.com/NV/produc...cts_id=1584&osCsid=iigcl5pa2csul0o9f0s61m5dn3

 

[Bass Ackward]

My understanding is that less neck tension = less pressure = potentially a less consistent burn. Since I'm currently using a reduced load of Ramshot TAC, which is a ball powder, "consistent burn" is already kind of a tall order. I'm not sure lowering my neck tension would actually help anything.

I doubt it would either being .004 over bore. Still, some of that diameter is “soft” diameter. Only Professor Gun & his assistant Mr Target knows for sure.

 

[Jeff H]

.............there is another way to set your neck tension, LEE makes those little neck tensioner dies that also poke out the primers.
they don't use an expander ball.

And, within a narrow but very useful range, they are adjustable. I've found this especially useful in the 222 and 223 with cast.

For bolt-actions, I've been able to tweak the die to just hold on to the bullet enough to stay where it belongs while going form magazine to chamber without resizing the bullet with the neck. The same amount of friction has worked well for me in the 223 in single shots. I've not messed with the semi-auto/cast/22 caliber combination.

 

[462]

"there is another way to set your neck tension, LEE makes those little neck tensioner dies that also poke out the primers.
they don't use an expander ball."

Yep, open the box, throw the directions away, there you go.

 

[fiver]

throw the size die away too.. LOL.
I got a story about the LEE 223 size die I got some years back.
it would hang on to every piece of brass I ever put in it.
I tried throwing it out the back door twice, it made it's way back to the reloading room both times, once in a bale of hay picked up at random off the neighbors hay storage lot.
I finally ended up throwing it off a bridge.

 

[BHuij]

I would have guessed that .228 bullets wouldn't chamber as well. And I suspect they probably wouldn't chamber in my TC Compass.

But I've had nary a jam with the AR and so far I've sent 40 of them downrange at upwards of 2500 FPS. It was accurate enough to easily hit silhouettes offhand at 100 yards. I'm loading a bunch more and will be shooting some 10-round groups on paper off the sandbags next time so I can see how well it's actually doing in terms of MOA.

Thanks all, glad to know there's not any reason to be worried about the neck tension as long as I'm not swaging the bullet. Who knows, maybe going from .225" to .228" accidentally is what helped me get the accuracy I've been after all this time

 

[fiver]

no reason for it to not be the reason.

 

[freebullet]

The low end psa barrel is a constantly changing creature, every 300 rds or so it gets bigger in there. The 2 in 556 I had wouldn't chamber 225 when new.

Congrats on the first house. Hope that works out well & quickly for you.

 

[BHuij]

The low end psa barrel is a constantly changing creature, every 300 rds or so it gets bigger in there. The 2 in 556 I had wouldn't chamber 225 when new.

First I've heard of this. Any idea what the mechanism is that's changing internal dimensions? Is it just pressure? I've never had any trouble chambering anything, but I've put probably 600 cast bullets down the barrel and another 100 or so jacketed is all.

 

[freebullet]

Pretty simple on the ones I had. Throat erosion, No throat when new, to much throat soon thereafter. Super soft steel on the really cheap ones, wears quick. Flame cutting

 

[Intheshop]

Watch your runout...... and another is seating depth,with high "tension" numbers. Not saying it "is" an issue,just watch.Observation here,as tension numbers go up.... there's more stress on the seating operation. It's harder to keep the cartridge straight the more force it takes to seat. Recognizing some folks requirements on runout are completely different from others.

Small OAL depth differences.... and I'm talking really small... can show up on paper. But it's going to take a very accurate rig and driver. As the throat erodes,these small dimensional changes can come and go,in and out of "tune". Will show up with skinny barrels before "varmint" or target barrels.

Good luck with your project.

 

[BHuij]

And I'm assuming you're talking about Bear Creek Arsenal barrels? I bought it from PSA, but it is BCA brand. And it is basically "bottom shelf" cheap. I wanted my first AR finished quickly, and never intended it to be a match rifle

 

[freebullet]

And I'm assuming you're talking about Bear Creek Arsenal barrels

Me? I was speaking of the psa freedom line. Don't know who make's them. The ones I tried were 06-12. The ar9 is 16 I think, much better quality, did need throated to accept factory or any cast. Kind of a get what you get deal.

Sounds like yours does reasonable. Ian's psa 308 did some nice work from go, I'm inclined to believe I'm a dud magnet with psa, seems they are getting better.

 

[Ian]

The PSA 308 is simply excellent in fit and finish, I'd have to say the barrel is probably the only thing lacking good finish but only on the outside...and I care not a bit about that. The bolt carrier, barrel extension, and upper are missing any and all machine marks, smooth, polished, and finished real nice. Tore the upper down tonight in anticipation of changing the gas block and got a good look into the muzzle with the brake off, looks real good inside. This whole upper including a very well-made ff handguard, bcg and charging handle was only $399.99 shipped to my door, so you know they don't have much in the SS barrel. Its got a nice throat for cast too with no burrs and the chamber is polished with no reamer marks. Needless to say my expectations were blown away, especially after I shot it.

 

[BHuij]

Well glad to hear you got a good one. I'm inclined to believe at this juncture that my poorly-installed flash hider was a big part of the problem. I have replaced it with a thread hider. I have shot in once since then, with 19.5 grains of Ramshot TAC (~2600 FPS area). But I wasn't shooting paper, I was just trying to introduce my brother to the world of shooting, and test out my new red dot sight. I will say this, once I got that RDS zeroed, the AR was having zero trouble hitting steel at 100 yards offhand. On Saturday I will actually put some of these on paper and see how they're grouping.

I know there are things I can do to improve accuracy at this point, but for plinking ammo, "easy to hit steel at 100 yards" is good enough, and especially for relatively fast velocities in the cast bullet world. I think even if I find that the load is only 4 MOA or something, I can still be happy with it for what it is.

 

[fiver]

and compared to what you have been getting [even with jacketed] your not doin bad at all with cast bullets at 25-2600 fps.