.223 Overall Length Issues


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J & J Speed Shop
April 9, 2010, 03:13 AM
I am trying to load some precision ammo for service rifle matches and I seem to be having a problem with the case overall length. For some reason I can't get a consistent overall length. I tried to sent the overall length to 2.255" and seems I get anywhere from 2.251 to 2.260 measuring with a good set of dial calipers.

My reloading:

PMC commercial brass
Full length sized
Trimmed with the Lee zip trim and chamfered inside & out
Varget 23.5 gr
Nosler 77 gr. BTHP
Lee Pacesetter die set
Lee challenger press


The only thing I can think of is my Lee Challenger press (aluminum O frame) is not up to doing precision rifle reloads. Am I being too anal? If the bullet seater die is set to a certain length how close should it be. I figure being set to 2.255" it should stay right around that number. Not drift .005" either way. Also could this being a compressed charge have anything to do with it?

THANKS

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918v
April 9, 2010, 03:23 AM
No, it's the bullets themselves. They vary that much, so the OAL varies that much. If you measure the OAL with a bullet comparator that indexes off the ogjive, the variance will be much less. Don't worry about it. This is normal.

J & J Speed Shop
April 9, 2010, 03:26 AM
"OAL with a bullet comparator that indexes off the ogjive"

Sorry could you explain or link me to a product?

918v
April 9, 2010, 03:32 AM
http://www.brownells.com/UserDocs/Miscellaneous/wb1208-Gauging14.jpg

http://www.brownells.com/.aspx/lid=12897/GunTechdetail/Gauging_Success___Minimum_Headspace_and_Maximum_COL

918v
April 9, 2010, 03:35 AM
A bullet comparator indexes off a more consistent area of the bullet nose (ogjive). Bullet tips are inconsistent due to variances in jacket length. It is not practical for a manufacturer to trim all the jackets to the same exact length prior to swaging, hence the inconsistent bullet length. But since the tip does not contact the rifling, that variance is not relevant.

JimKirk
April 9, 2010, 07:13 AM
http://www.thehighroad.org/showthread.php?t=516079

See post #7 and #8 for a simple method of measuring.

Jimmy K

http://www.sinclairintl.com/images/thumb/09-700_a-t.jpg

ole farmerbuck
April 9, 2010, 07:43 AM
I use Nosler 52gr BTHP's in my 22-250 loads and the OAL's are all over the place. As much as .014. I use Hornady 40gr v-max in my 223's and they might be off .001.

HJ857
April 9, 2010, 10:15 AM
Just to add to what 918v posted, which I think is dead on correct, the ogive is almost always consistent when measured with a bullet comparator even if the tips have significant variances.

There is a wild card though, and that's magazine length which may or may not be relevant depending on what rifle you're using. If so, you have to find a happy medium between ogive seating depth and the actual OAL.

For example, for my AR rounds I seat to an ogive depth of 1.930 which should give me an OAL of 2.260 (each bullet type will give you different numbers). However sometimes the bullet tip is so far off that even seating to that 1.930 depth yields an OAL that exceeds 2.260. In that case I'll seat the bullet a bit deeper so it doesn't exceed magazine length.

If I'm loading "match" rounds and I get a bullet that exceeds OAL with a correct ogive measurement, then rather than re-seating to a deeper ogive depth, I'm more likely to throw that bullet out so my rounds all have the same ogive depth, this is what gives me a consistent jump to the lands.

It can be a tough concept to wrap your head around, but once you start using a bullet comparator, you'll understand it almost immediately. The Hornady model that comes with multiple inserts for a number of calibers is a good deal.

http://www.midwayusa.com/viewproduct/?productnumber=231904

243winxb
April 9, 2010, 10:36 AM
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. http://www.thehighroad.org/showpost.php?p=6409882&postcount=9 Sorry could you explain or link me to a product? http://www.brownells.com/.aspx/lid=11470/guntechdetail/Gauging_Success___Minimum_Headspace_and_Maximum_COL

Taurus 617 CCW
April 9, 2010, 11:01 AM
I just set my dial calipers to my desired OAL and lock it down with the lock screw. Then I simply seat the bullets according to that and they all work fine in my gun. I am using them in an autoloading rifle so as long as they don't exceed the proper OAL they feed fine.

J & J Speed Shop
April 9, 2010, 01:29 PM
Thanks everyone now I understand. What would everyone recommend for the comparator? The Hornady one looks good. Any other ones I should consider? I am currently loading .223 rem and will be loading 30-06 springfield very soon

918v
April 9, 2010, 01:51 PM
They are all pretty much the same. I have the Sinclair hex-nut version and like it fine.

243winxb
April 9, 2010, 03:06 PM
Nosler 77 gr. BTHPMake sure the seater plug fits your bullets ogive correctly. The nose of the bullet should not contact the seating stem.

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