Inconsistant OAL with .223

[disneyd]

I am loading some plinking ammo using some cheap tracer bullets that I bought a while back. They are pulled milspec tracers.

For some reason I am getting inconsistent OALs when seating the bullets. I am shooting for a 2.255 OAL. For some reason I am getting weird variations in the length. After getting it set at 2.255 I load a few rounds (Hornady LNL) and spot check the OAL every 5 rounds or so. I am getting some that are going over 2.260.

What is weird is that I can put the round back through the die and it will often, but not always, bring it down closer to the original setting (2.255). On some running it back through doesn't change it.

I have checked and cleaned the die and don't see any problems. I'm also making sure I am fully bottoming the press every time.

I'm using Lee dies.

Anyone run into this before? I've never had a problem with these dies using other bullets.

Before anyone asks, yes these rounds are all going into a dirt berm in case some of them light... but so far the light-up rate with this powder is about 2 percent.

 

[Tim the student]

I am among the most inexperienced reloaders here, but the first thing that popped into my mind is that your bullets are not consistently sized.

http://www.larrywillis.com/bullet-shape.html This guy here says that he measured .012 difference from the ogive to the base on Sierra Match's. Assuming that his info is accurate, its not hard to believe that yours might be even more inconsistent considering that they are pulled military tracers. Have you done any measurements on your bullets? That might explain half of your problem.

I'm sure that many others here will be able to shed more light on your problem than I can.

 

[rcmodel]

+1

That sounds about right.

Different ogive shape on some of them results on different OAL.

However, it doesn't explain why a second trip through the die would correct it.

Any chance you short-stroked the press a few times without realizing you did it?

There is also the possibility that some of your brass is different.
Some loaded more times then others, or a different manufacture.
That results in different neck hardness, and different seating pressure needed to seat the bullet.

rc

 

[JimKirk]

Tim
Black hair is measured to be around 1/450"
Light hair is measured to be around 1/1000"
So you could say that some Sierra bullets are a "hair" short or long
Therefore disneyd your OAL is 5 light hairs long
Now if that is mouse hairs ..who knows!

Sorry I couldn't help it!
Jimmy K.

 

[Tim the student]

Made me about spit on myself!

 

[matrem]

That results in different neck hardness, and different seating pressure needed to seat the bullet.

Are you referring to static deviation,or just the tendency to "short stroke" the press?

 

[rcmodel]

Both.

A harder case neck makes it harder to seat the bullet.

One could lead to the other I suppose.

rc

 

[JimKirk]

Really what I think:
"If" the bullets are the same company or the same lot, which would be questionable ..then the method of "pulling" may have played a part.
"if not" then the bullets themselves could be of various ogives which would be just like changing brand of bullets. If a Sierra "Match" varies by .012 what would a military bullet(made by who?) vary?
Also what RC said about hard brass, it may cause spring in your press by .005.
Are the bullets tumbled clean or do they have some type sealent on them?

Sorry about the being a hair off

Jimmy K

By the way How do they pull military bullets?
I whack'm in the hammer thing or with the forster puller which puts 4 small marks on a bullet, but no real damage.

 

[matrem]

it may cause spring in your press by .005.

Sounds like it's time to replace or repair the press!

 

[JimKirk]

Well thats all his OAL is varying by. The thickness of a dollar bill!

JK

 

[MCMXI]

disneyd, what powder and how many grains are you using? These are plinking loads you say but is the load compressed slightly, a lot or not at all. If the bullet is being pushed down into the powder, that can affect OAL the first time through the press.

I gotta say ... I really DON'T like reloading .223 ... it's easily my least favorite of ALL the calibers that I reload.

 

[243winxb]

Seating depth variations

There are a number of possible causes for overall length variation. One is the way it is measured. If you measure overall length from the tip of the bullet to the base of the case, remember to subtract the variation due to bullet length tolerance. The bullets will vary in length due to manufacturing tolerances (bullets with exposed lead noses are the worst in this regard) and this will add to the overall cartridge length variation. Remember that the bullet seater plug does not (or shouldn't) contact the tip of the bullet when seating, but contacts farther down the ogive. For a more accurate seating depth measurement, take the seater plug out of the bullet seating die, place it on top of the cartridge and measure from the base of the case to the top of the seater plug.

Another possible cause for bullet seating depth variation is seating and crimping at the same time when trying to apply a firm crimp to untrimmed cases. Variation in case length also causes variation in the amount of crimp applied. Long cases get a heavier crimp than short ones. When seating and crimping at the same time, the crimp is formed as the bullet is seated into the case. The crimp will form sooner on a long case, and therefore the bullet will not be seated as deeply. The solution is to seat and crimp in a separate step (the Lee Factory Crimp die is good for this) and/or trim cases to a uniform length.

The amount of force required to cycle a progressive press varies with the number of cases in the shell plate. When the shell plate is full, it is harder to lower the lever than when there are one or two cases present. This can lead to variation in cartridge overall length because there are different loads placed on the working parts of the press. When the shell plate is full, seating depth will be slightly long, because the load is higher and all of the clearances are taken up. With the shell plate nearly empty, the load is not great enough to squeeze out these clearances, and the seating depth is short.

 

[disneyd]

Thanks for all the input guys. Let me see if I can address everything everyone brought up.

I think it is probably a combination of two things you guys brought up:

Differences in the bullets: They are pulled milspec tracers that were sealed. So I'm sure the pulling force needed to be high because of the tar-like glue. I don't see any marks on the bullets so I'm not sure how they were pulled. However, I'd be surprised if they were pulled via inertia since I'm assuming the original rounds were crimped.

Differences in required seating force: I haven't tried to clean the bullets so some have a little of the tar/glue on them that gets shave off when the bullets are seated causing some to require more pressure that others.

It isn't a compressed load at all.

I'm going to load some more this evening. I'll pull the seater stem and use it to check the ogive differences on the bullets.

 

[JimKirk]

243 gave in long words what I was saying about press spring or tolerances being taken up.

Jimmy K

 

[smokey262]

If you have at least 0.015" to the lands just shoot it. These are not match grade rounds and 0.005" is nothing to worry about, especially if you are reading to the tip and not the ogive