308 SB?

[Texas Solo]

I'll be loading .308 for the first time to feed a new F/TR rifle I'm building. I've heard two different theories on the use of small base sizing dies. Some say yes, because you may snag some brass that was shot out of a machine gun, and it needs SB resizing. Others say no, as it unduly stresses the brass. As I can't afford to purchase 1000 rounds of new brass (if I could find it), I'll be getting whatever I can for now.
I'd appreciate opinions from the experienced 308 folks here.

 

[CatShooter]

I'll be loading .308 for the first time to feed a new F/TR rifle I'm building. I've heard two different theories on the use of small base sizing dies. Some say yes, because you may snag some brass that was shot out of a machine gun, and it needs SB resizing. Others say no, as it unduly stresses the brass. As I can't afford to purchase 1000 rounds of new brass (if I could find it), I'll be getting whatever I can for now.
I'd appreciate opinions from the experienced 308 folks here.

I use small base dies for 223 and 308 - the difference is only a few more thou, it does not over stress the brass... and they make beautiful cases.

 

[BaconFat]

I have three FL .308 dies, a standard base and a small base Redding bushing and a Forster. For what ever the reason the standard base Redding will not size cartridges that will fit my Savage Mdl 12, couldn't close the bolt. Redding was willing to work with me on seeing what's wrong, but so far I've not messed with it. I bought a Redding SB with the intent of FL as my last step along with proper neck size. In the end I went back to using the Forster FL since I only FL size new to me brass and the Forster die always sized the brass so it will chamber in my rifle.

 

[bigedp51]

If I order once fired military brass or get large quantities of once fired range pickup brass I resize it once with a small base die. The small base dies only make the base .0005 smaller in diameter than a standard die at the base but they resize further down the case.

If you already have a standard full length resizing die then resize some cases and see how they fit the chamber. You can buy a small base later if you have problems down the road.

The only time I really needed the small base die was with once fired military brass fired in a M249 machine gun to bring it back to minimum dimensions. These type cases try and spring back to their fired dimensions after sizing. You can also use your standard die and try pausing and keep the case in the die longer for less spring back.

In 46 years of reloading I have never needed a small base die when using brand new brass fired in my rifles. Range pickup and once fired military brass is another story.

NOTE: Resizing dies have plus and minus tolerances so you could get a standard die that acts like a small base die. I have four .223 full length dies and each one is slightly different, buy the standard die and see if you need the small base die.

 

[navyrad8r]

+1 on what biged said,
any questionable (shady 8)) brass I get gets the SB die the first time, followed by a healthy trim and good close inspection. I am primarily shooting service rifles so reliable feeding is paramount in a match! May not be as critical in a bolt gun though. I would get your brass and size it then try and chamber it as suggested. then go SB if you must. Hope this helps...
cheers,
doc

 

[brian427cobra]

As long as the brass is/has only been fired in your weapon I doubt a Small Base will be needed

 

[bigedp51]

If your looking for the utmost accuracy you will not find it with mixed range pickup brass. In my AR15s I use mixed brass, in my bolt action .223 I use new prepped and weight sorted brass brass. (remove the extreme high and low weights)

If you read through the posts here you will see the people in the know saying to buy Lapua brass and just load and shoot with no special prep to the brass.

There is nothing uniform about range pickup brass, its OK if your shooting in minute of man silhouette targets but not if your shooting in minutes of an inch.

Meaning mixed brass equals prehistoric size bug hole groups.
(a Paleozoic era dragonfly had a 25 inch wingspan)

 

[KevinThomas]

Go for a Small Base die, if only to have it in your arsenal. You may not need it every time, but I can pretty well assure you, there are times when you WILL need one.

I ran into this exact problem this past weekend (at a match, naturally) with a batch of 308 cases that I DID F/L size. Even checked them on the gage to make sure H/S was right where I wanted it, and it was. The body diameter never crossed my mind, as I thought these cases were last fired in my Palma gun; the same one I was shooting at this match. First string, first sighter, I found myself fighting to get the round to chamber. It wouldn't. Once I got it extracted (no small feat, either) you could instantly see the scuff marks on the body, just ahead of the extractor groove. These cases WERE Full Length resized, but they it turned out to be some that had been fired in another of my 308 Match rifles, with a different 308 chamber than the Palma gun has. So there's other times they'll come in handy, and they're not just something to use if you're messing with mil-surplus MG fired brass. Sometimes even the good stuff can benefit from a little more squeeze.

I've been at this a while, and Murphy STILL has a way of finding me on the firing line from time to time.

 

[Texas Solo]

+1 on what biged said,
any questionable (shady 8)) brass I get gets the SB die the first time, followed by a healthy trim and good close inspection. I am primarily shooting service rifles so reliable feeding is paramount in a match! May not be as critical in a bolt gun though. I would get your brass and size it then try and chamber it as suggested. then go SB if you must. Hope this helps...
cheers,
doc

Doc....PM sent.

 

[Hondo64d]

Go for a Small Base die, if only to have it in your arsenal. You may not need it every time, but I can pretty well assure you, there are times when you WILL need one.

I ran into this exact problem this past weekend (at a match, naturally) with a batch of 308 cases that I DID F/L size. Even checked them on the gage to make sure H/S was right where I wanted it, and it was. The body diameter never crossed my mind, as I thought these cases were last fired in my Palma gun; the same one I was shooting at this match. First string, first sighter, I found myself fighting to get the round to chamber. It wouldn't. Once I got it extracted (no small feat, either) you could instantly see the scuff marks on the body, just ahead of the extractor groove. These cases WERE Full Length resized, but they it turned out to be some that had been fired in another of my 308 Match rifles, with a different 308 chamber than the Palma gun has. So there's other times they'll come in handy, and they're not just something to use if you're messing with mil-surplus MG fired brass. Sometimes even the good stuff can benefit from a little more squeeze.

I've been at this a while, and Murphy STILL has a way of finding me on the firing line from time to time.

I had almost the exact same thing happen to me with my recent .308 barrel. Would not chamber cases that had been fired in my previous .308 barrel even though the headspace was the same. A Redding small based body die seems to have corrected that issue, and once those cases have been fired in the new chamber, I haven't needed to go back to the small based die.

John

 

[bigedp51]

I had almost the exact same thing happen to me with my recent .308 barrel. Would not chamber cases that had been fired in my previous .308 barrel even though the headspace was the same. A Redding small based body die seems to have corrected that issue, and once those cases have been fired in the new chamber, I haven't needed to go back to the small based die.

John

A 5.56 NATO fired in a M249 machine gun is really stretched out of shape, the chamber is over .003 larger in diameter and the GO and NO-GO gauges are over .003 longer than SAAMI gauges. If you buy once fired Lake City cases that were fired in a M249 sometimes you have to pause on the ram downstroke with a small base die to let the brass know you mean business and stay put. Maybe that's why they call it "fire forming"

Cases like this will even "grow" longer after sizing and they sit for a while, giving "spring-back" new meaning.

Below, M14 cartridge and chamber drawing and Clymer chamber reamers with varying chamber diameters.

 

[Shynloco]

Go for a Small Base die, if only to have it in your arsenal. You may not need it every time, but I can pretty well assure you, there are times when you WILL need one.

I ran into this exact problem this past weekend (at a match, naturally) with a batch of 308 cases that I DID F/L size. Even checked them on the gage to make sure H/S was right where I wanted it, and it was. The body diameter never crossed my mind, as I thought these cases were last fired in my Palma gun; the same one I was shooting at this match. First string, first sighter, I found myself fighting to get the round to chamber. It wouldn't. Once I got it extracted (no small feat, either) you could instantly see the scuff marks on the body, just ahead of the extractor groove. These cases WERE Full Length resized, but they it turned out to be some that had been fired in another of my 308 Match rifles, with a different 308 chamber than the Palma gun has. So there's other times they'll come in handy, and they're not just something to use if you're messing with mil-surplus MG fired brass. Sometimes even the good stuff can benefit from a little more squeeze.

I've been at this a while, and Murphy STILL has a way of finding me on the firing line from time to time.

I had almost the exact same thing happen to me with my recent .308 barrel. Would not chamber cases that had been fired in my previous .308 barrel even though the headspace was the same. A Redding small based body die seems to have corrected that issue, and once those cases have been fired in the new chamber, I haven't needed to go back to the small based die.

John

+1 and AMEN. Was given some previously fired Lake City Match brass by a friend who competes in F/TR (Model 70) for years. He told me then that I might need a Small Based Die for these previously fired casings to fit into my chamber. True to his words, the bases of the LCM casings were SLIGHTLY too large for my new dedicated chambered .308 Benchrest rifle. Resized them in my new Redding SMD and they now shoot every bit as accurately in my rifle as the Lapua brass that I mostly use exclusively. Buying that Small Base Die was worth every penny.

Alex