.308 small base die question

Melnibonean

Melnibonean

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So I went ahead and used my 2F-3F brass out of my M1A to load up around 100 or so rounds to test different powders and recipes for my new Savage 10TR. Problem is, the bolt wont' close on those rounds despite the usual full length re-size etc.... The gunsmith at my club thinks it's probably due to me not having used a small base die, as the chamber in the M1A allows the brass to expand outward a bit more than in a bolt.

So the question is, do I need to pull all those bullets and start over from the beginning, or can I simply remove the decapping pin out of 1 small base die (I bought 2 for this possibility) and run the loaded rounds through it?

Going forward, I bought a neck sizing die in addition to the SBD so that now no matter what brass I use, I won't repeat the same mistake again.
 
Pull the bullets and disassemble the loaded rounds, your dealing with insufficient resizing and brass spring back. When I buy once fired .223/5.56 cases I use a small base die and pause for 4 to 6 seconds at the top of the stroke. This lets the brass know who is the boss and to stay put after sizing and not "spring back".

Your cases were fired in a military chamber .002 larger in diameter and with longer headspace settings, and even after sizing the brass springs back trying to get back to its fired size. The effect is worse if the case was fired in a larger diameter machine gun chamber and some times I may have to size the case several times and pausing at the top of the stroke to return the case to minimum dimensions. I would recommend a Hornady cartridge case headspace gauge to measure your fired and resized cases for proper shoulder bump or setback.

I would "NEVER" try and size a loaded round for several reasons, the main one being the neck of the case if sized will compress the bullet and possibly become stuck in the die.
 
Thanks bigedp51. I guess I better get started on the bullet pulling....

Do I need to decap as well, or if I remove the pin from the die can I resize the case with the primer still seated in the case (but no powder obviously)
 
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bigedp51 said:
I would "NEVER" try and size a loaded round for several reasons, the main one being the neck of the case if sized will compress the bullet and possibly become stuck in the die.
Click to expand...

An empty stuck case is a bit of a chore to get out of a die. Can you imagine a loaded round stuck in a die? I have no idea how you would even begin to attempt to remove it.:confused:
 
yomomma said:
Pull your mandrel, you should be ok
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The die sizes the neck undersized to create neck tension when the bullet is forced in. The mandrel expands the neck on the down stroke to have a consistent ID on the neck of around .3065" usually. This is because the die manufacturer doesn't know how thick or thin the brass is at the neck so usually make the die to size it a little on the small size so it expands on the down stroke as it goes over the mandrel to make the ID consistent even though the OD might not be. Removing the mandrel means the die will most likely try to size the case down even further than .3065". So you'll have a .308" bullet inside a neck and a die trying to size it down to .306" or smaller. As bigedp51 said trying this with a loaded round will likely cause the loaded round to get stuck in the die. If it does work you'll be deforming the bullet something awful so I wouldn't expect it to actually hit what you're aiming at; it could tumble or just shoot terribly. That is assuming you can get the cartridge out of the die in some sort of fireable condition.

There may be special dies meant specifically for this purpose but a regular FL sizing die isn't. I've heard of people doing this with pistol cases but pistol dies work different and don't have a mandrel to apply a uniform ID to the neck (since there is no neck). With a die for a bottleneck rifle case it wont work.

Pull the bullets, resize the cases again using the waiting method bigedp51 mentioned, see if it works. Testing one or two pieces of sized brass in the intended firearm is a quick and easy way to check that they'll work. I do this with all my brass if I'm sizing it for a different rifle than the last one it was fired in. Saves headaches at the range.
 
yomomma said:
Ah no, wasn't trying to say to size a loaded round. He asked if he needed to de- cap as well after pulling bullet and dumping powder before sizing.
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Oops, sorry, thought you meant to resize the loaded rounds.

Taking out the mandrel will mean the necks don't get expanded to a uniform ID so there will be inconsistent neck tension. Inconsistent neck wall thicknesses will cause inconsistent neck tension anyway. If you aren't loading match ammo it isn't a big deal.
 
Easy peezy. I f-ed up sizing .308 for a bolt gun but had my die set for my M14. Not surprisingly all 100 cases would not chamber in the bolt. Luckily I caught it before charging and seating. Here's what you do:
Pull your bullets and dump your charges
Pull your decapper/expander out of your die and set it for full contact with shellholder
Lube your cases and size them
Reinstall your expander and run the cases up into the die until you feel the expander clear the neck then withdraw the case
Check trim lengths if you need to, trim if necessary and load
And of course test fit cases before final loading. Also, when fl sizing all the way, have a look where the die and shellholder meet at the top of the stroke when sizing a case. Even though they may make firm contact when setting the die up, once you get a case in there it may provide enough resistance to prevent that last little bit of shoulder bump.
 
Are you still going to be shooting the M1A? It sounds like you should separate your brass and only use M1a reloads in the M1a. I think that using small base dies so you can use the same ammo in both will lead to overworking the brass and eventual case head separation.

I'd get 2 different headstamps of brass to tell them apart and then tailor the ammo you are loading to the gun.
Full length (not SB) size the semi-auto ammo, and only neck size the ammo for the Savage.
 
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I have six .223/5.56 dies and we live a a plus and minus manufacturing world and no two dies are exactly the same. My RCBS AR series .223/5.56 small base die only makes the base of the case .0005 smaller in diameter than my standard RCBS .223 die. BUT the small base die also sizes further down the case than the standard die. I also have a Lee .223 full length die that sizes the base of the case .001 smaller than my RCBS small base die does. So nothing is written in stone when it comes to die sizes.

Below the top two dies are the ones I use the most with my two AR15 and Savage bolt action .223. The Lee die and Redding body dies are not used and are put away because I full length resize all my cases and neck size very few rifles except milsurp with larger diameter chambers.

223dies002_zps4596712d.jpg


dies003_zpsf9af9a52.jpg


All my AR15 ammunition is sized with my small base die for two reasons, 1. it doesn't size the case that much smaller than my standard die, 2. for reliability in chambering and extraction.

Just remember military chambers are approximately .002 larger in diameter and your standard full length die is already a small base die. (but it may not be if it is on the plus side of manufacturing tolerances)

So simple answer to your small base die question, measure the base of your fired cases and then full length resize and measure the base again. And how much smaller is your resized case than its fired diameter and how much wiggle room does it give you. On top of this military brass is either thicker or harder in the base area than commercial cases and cases like Remington and Federal are softer and will expand more in the base so your die size also depends on the cases you are using. My practice blasting AR15 carbine ammo uses mixed brass so all these cases are sized with small base dies.
 
supernova said:
Easy peezy. I f-ed up sizing .308 for a bolt gun but had my die set for my M14. Not surprisingly all 100 cases would not chamber in the bolt. Luckily I caught it before charging and seating. Here's what you do:
Pull your bullets and dump your charges
Pull your decapper/expander out of your die and set it for full contact with shellholder
Lube your cases and size them
Reinstall your expander and run the cases up into the die until you feel the expander clear the neck then withdraw the case
Check trim lengths if you need to, trim if necessary and load
And of course test fit cases before final loading. Also, when fl sizing all the way, have a look where the die and shellholder meet at the top of the stroke when sizing a case. Even though they may make firm contact when setting the die up, once you get a case in there it may provide enough resistance to prevent that last little bit of shoulder bump.
Click to expand...

This sounds less painful than having to scrap the entire lot and start over. Thanks for the tip!

Quiet said:
Are you still going to be shooting the M1A? It sounds like you should separate your brass and only use M1a reloads in the M1a. I think that using small base dies so you can use the same ammo in both will lead to overworking the brass and eventual case head separation.

I'd get 2 different headstamps of brass to tell them apart and then tailor the ammo you are loading to the gun.
Full length (not SB) size the semi-auto ammo, and only neck size the ammo for the Savage.
Click to expand...

ipscgraz said:
^^^

I have brass dedicated to some of the rifles I shoot. If nothing else I have a reason to stockpile more brass, and as Quiet mentioned, probably adds to longevity.
Click to expand...

Yes, I'm keeping the M1A, but you're right about overworking the brass. From now on will keep separate brass for the Savage and another tool head for the Dillon set up with the Neck sizer die on it just for it's use.

That means I'll probably be putting the other SBD on the EE one of these days.


Thank you to everyone for the advice. Much appreciated.
 
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