Case length causing COAL to change?

[HillbillyfromAL]

Hey I've searched around but can't seem to find any answers on this. Here's the problem I've got Hornadys Rifle 2 die set .308win. I've measured the cases after I trim them. On a case at 2.005 it sets the bullet at 2.870 which is what I want, however on a case that measures 2.003 it set the bullet at 2.880 which is too long. I'm using once fired brass, and 175gr SMK's. I would like to know if this is just because the Hornady dies are shit, or if I really need to make the cases absolutely perfect. I'd appreciate any help on this it's really pissing me off.

 

[ChadTRG42]

Re: Case length causing COAL to change?

No, the COAL variation won't be because of .002" difference in the length of the case. Are all the cases the same headstamp, same brand, and have the same amount of reloads on them? Different mfg's of brass have different neck thicknesses, and can cause a tighter or looser neck tension effecting the seating depth.
Plus, the tips of the SMK will vary some, causing the different seating depths when measured from the tip. Try measuring from the ogive of the bullet, and see if you get the variation. Also, I like the Hornady dies, so I don't think the dies would be causing the problems.

 

[HillbillyfromAL]

Re: Case length causing COAL to change?

Thanks for the quick response. I'll have to try to measure the thickness of the cases at the neck, but they are they same. I seperated them to take out some of the varieties. Some are Winchester Supreme,and some are Federal gold Match, but it did work out the same when I cut each type of case to those measurements. Oh and the .002 on the case length was acommon variant that I made sure to use with both types of cases. I'll try to measure the thicknesses and see if there is any difference. Thanks again

 

[HillbillyfromAL]

Re: Case length causing COAL to change?








Ok I think I've figured out the problem, Thanks to ChadTRG42. The Ogive was the problem. The seating stem that I have doesn't touch the tip of the bullet just the ogive and that was different enough to make a hundredth of an inch difference in COAL. I'll give Hornady a call and see if they have one that is flat like the one that came with my .45acp die set. If not I'll have to figure something out with this one. Thanks.

 

[Outsydlooknin75]

Re: Case length causing COAL to change?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HillbillyfromAL</div><div class="ubbcode-body">






Ok I think I've figured out the problem, Thanks to ChadTRG42. The Ogive was the problem. The seating stem that I have doesn't touch the tip of the bullet just the ogive and that was different enough to make a hundredth of an inch difference in COAL. I'll give Hornady a call and see if they have one that is flat like the one that came with my .45acp die set. If not I'll have to figure something out with this one. Thanks.








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You dont want to seat to the same length when measured to the tip. You want to seat to the same length to the ogive and dont worry about the length to the tip.

The tip is going to vary, find a length seated to the ogive that still fits in your mag and run with it.

 

[Fuzzball]

Re: Case length causing COAL to change?

If you're measuring off the bullet tip you really don't have a problem, it's just (mostly) meaningless bullet variation. You sure don't want a seater plug that presses on the point, that would smash those sharp tips.

 

[cinosbus]

Re: Case length causing COAL to change?

+1 for NOT getting a flat seater. You WANT the seater to push on the ogive. OAL really doesn't matter to the rifle as long as it fits in the mag. The jump from the ogive to the rifling DOES matter - so that's why the seater pushes from there.

 

[HillbillyfromAL]

Re: Case length causing COAL to change?

Thanks for the input guys. I won't be getting a flat seating stem. I remeasured the bullets this time using some map markers to see everything better. The Ogive where the stem contacted to the tip was the difference. I just wonder if this is normal for the SMK's or if some of these are bad. Thanks again.

 

[McCrazy]

Re: Case length causing COAL to change?

SMKs are notorious for having inconsistent tips compared to other bullets, though tips aren't the best way to measure on any bullet.