Small base vs regular rifle dies

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FoghornLeghorn

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I have three .308 cal rifles. Springfield Armory M1A. Sig Sauer 716. And an old model Browning lever rifle.

I've never reloaded 308 and just noticed that my dies are not small base.

Do all semi autos require small base? What about the lever rifle?
 
You shouldn't need small base dies, but it's easy enough to find out. Size them with your sizing die and see if they chamber.

Don
 
I full length size .308 brass in the Lyman die set I got in the early 70s when I began reloading. Works in my M1A and in the BLR I have, as well as my other .308s.

If your rifle chokes on full length sized brass from a standard die, THEN go to a small base die. If not, why bother??
 
It depends on the chamber size.

Try a regular full length sizing die set fully into the press ram. This usually works and you'll get more case life, 5 or 6 cycles perhaps.

If that's not letting the rifle fire and eject fired cases easily, then use the small base die. Accept only 2 or 3 reloads per case to be safe.
 
As a corollary question to this, if you have a rifle that "could" require SB dies (lever, semi-auto) and you have not yet purchased the die set would you advocate just buying the SB dies anyway? Any harm (other than perhaps decreased brass life) in just going to a SB die right from the start?
 
If that's not letting the rifle fire and eject fired cases easily,..
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Might just be the difference in our manner of speaking, but I would change "fire and eject" to "chamber and fire".

In my experience, extraction and ejection after firing are not influenced by the size of the case when chambered. After firing other factors have dominance.

Other than possibly squeezing, stretching and re-squeezing the case more than needed (thus shortening case life some) I don't see a mechanical reason not to start with SB dies.

Growing up and getting into reloading in an era when everything was "bought off the shelf", there was no internet, and one's choices were what ever the shop had on hand, and SB dies were seldom stocked (but would happily be ordered for you) starting with SB dies was something few of us did, and when things worked without them, we usually didn't go back and get them. :D

SB dies were not generally considered something you needed for semis, levers (and pumps?) but were looked on as a likely solution if you had a problem with ammo sized in regular dies.
 
and you have not yet purchased the die set
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Yes, I have the die set. I've had it for years, but have not loaded for it. Dunno where, when or why I bought it.

I'll follow the above advice, viz. load some rounds and if the rifles like it, won't worry about buying SB dies.
 
FoghornLeghorn said:
I have three .308 cal rifles. Springfield Armory M1A. Sig Sauer 716. And an old model Browning lever rifle.

I've never reloaded 308 and just noticed that my dies are not small base.

Do all semi autos require small base? What about the lever rifle?
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In theory, you should never need a small base die. If you use new brass, you wont need one. If you use surplus military brass, you will definitely need one.
 
reynolds357 said:
In theory, you should never need a small base die. If you use new brass, you wont need one. If you use surplus military brass, you will definitely need one.
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Why? I've used standard full length sizing dies with once fired arsenal cases shot with semiautomatic service rifles. Functioned fine in commercial and service rifle barrel chambers.

Accuracy was not as good as when new but such is life with service rifle's out of square bolt faces.
 
Why? I've used standard full length sizing dies with once fired arsenal cases shot with semiautomatic service rifles. Functioned fine in commercial and service rifle barrel chambers.
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I'm sure they did. However, few people get those. What most people get when they buy surplus 7.62 NATO brass is stuff that was fired from machineguns.

And the combination of oversize machinegun chambers and brass spring back means sometimes, sizing the GI brass in standard FL dies just isn't enough to return the brass to dimensions that will easily work in tighter semi auto/commercial rifle chambers.

THEN a SB die set is the next step.
 
To me it would seem like using the SB dies might increase the chance of a case head separation even in just one reload, possibly. This may be a pretty remote possibility, but in an increased possibility none the less. I have a set for my .223 that I got in a trade deal on some other equipment. After trying them I measured several cases and when comparing them to my regular dies found no difference. This is in brass shot from two different rifles, one in 5.56x45 the other a .223 Wylde chamber. It was also mixed brass so didn’t seem to matter what brass it was. I no longer use either of these dies, which were RCBS by the way. Now I full length body size with a body die and neck size separately with Lee collet die.
 
44 AMP said:
And the combination of oversize machinegun chambers and brass spring back means sometimes, sizing the GI brass in standard FL dies just isn't enough to return the brass to dimensions that will easily work in tighter semi auto/commercial rifle chambers.
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Exactly what specs dimensions does an M60 machine gun 7.62 NATO chamber have that are larger than a commercial 308 Winchester chamber? SAAMI versus MIL SPEC.
 
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To me it would seem like using the SB dies might increase the chance of a case head separation even in just one reload, possibly.
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Not really. The only thing a SB die does is resize a little further down the case. What causes the incipient case head separation condition is an excessive amount of headspace caused by bumping the shoulder back too far. You control this by how far down you screw your resizing die into your press.

Don
 
I know that, but if there was a drawback to even keeping you from using it from the get go that’s what I was basing my statement on. Also why I said it might be a remote possibility, not a likely probability. Most likely not a good reason not to use a SB die from the start, but just something to consider.
 
USSR said:
Not really. The only thing a SB die does is resize a little further down the case. What causes the incipient case head separation condition is an excessive amount of headspace caused by bumping the shoulder back too far. You control this by how far down you screw your resizing die into your press.

Don
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RCBS says their Small Base Sizer Die sizes the case from the shoulder to the head of the case a couple of thousandths smaller in diameter than a Full Length Sizer Die. In certain calibers it also sets the shoulder of the case back a thousandth or two more than the Full Length Sizer Die. They also say the small base sizer resizes cases below SAAMI minimums.

Both case body diameters and length (case headspace?) will be less if the die's set to stop the shell holder at the top of its stroke. Head clearance (case head to bolt face dimension when fired) will also be greater
 
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