Talk me out of buying a small base sizing die

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SWThomas

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So I'm getting my feet wet loading 308 for my AR-10. I posted a thread a week or so ago and a member mentioned using a small based sizing die. I'm currently using Dillon dies and have loaded 50 rounds with them. All rounds fired perfectly in my AR-10. But the comment about the die got me worried that I may be doing something wrong. What would be the benefit of switching to a small based sizing die, and what problems could arise if I don't?

Do any of you guys use regular dies to size 308 for an AR-10, and if so, have you experienced any problems?
 
Dillon claims their resizing dies are made to minimum dimensions. Some folks even call them "small base".

For cases fired in your rifle, regular sizing dies should work just fine.

But, if you buy once fired cases, they may have been fired in a machine gun and your die may not resize them enough to chamber. Just be aware and do some checking after buy some once fired cases.

Hope this helps.
 
I used to think the small based die thing was a bunch of baloney. I had loaded for a couple of semiautos in 308 Winchester with no problems using a regular die. Then came an M1 Garand that, until I switched to a small base die, had multiple closed bolt slam fires. The day came that I switched 308 Winchester dies (new but regular dies) and the semiauto that had functioned fine with the older dies had multiple episodes of failure to feed and failure to cycle until I bumped the shoulders back a little.

In conclusion, I think many get by with regular dies in reloading for semiautos but exceptions occur. If your gun functions well with brass sized with your die/shell holder combination I would continue doing what you're doing.
 
Talk me out of buying a small base sizing die
Click to expand...
O.K..

Don't buy a small base sizing die.

I have been reloading .223 for AR-15's, mini-14's, and Remington and CZ-527 bolt-actions since 1970.

With a standard RCBS sizing die.

You DO NOT need a Sm. base die unless your standard FL die will not resize cases so they will chamber again.

And it sounds like your Dillon die is doing just that perfectly fine!

rc
 
Right now I'm chasing the accuracy goal with my GAP-10 but I will be having a precision bolt gun built soon. Here goes...

- Turning case necks

- Using bench rest primers VS standard primers

- Using competition seating dies over standard dies

- Crimping and not crimping

- Loading to be just off the lands or kissing the lands

- Uniforming primer pockets

- Deburring flash holes

- Bumping shoulders VS resizing to factory specs
Click to expand...

Okay, here goes.

- Turning case necks: Don't waste your time - buy Lapua brass.

- Using bench rest primers VS standard primers: Buy the Russian primers (Tula/Wolf) - very low ES/SD numbers and much cheaper.

- Using competition seating dies over standard dies: I use a competition seating die - makes for much easier adjustments for bullet seating depth.

- Crimping and not crimping: NEVER CRIMP BULLETS THAT DON'T HAVE A CANNELURE - and you will be using match bullets that don't have a cannelure.

- Loading to be just off the lands or kissing the lands: Either be more than .010" into the lands or more than .010" off the lands. Match bullets come off of different machines and the ogive location will vary by up to .010".

- Uniforming primer pockets: I do it - doesn't take much time.

- Deburring flash holes: I do it - doesn't take much time.

- Bumping shoulders VS resizing to factory specs: I use a combination of a body die which bumps the shoulder back and resizes the case body, and a bushing neck sizer die.

Hope that helps.

Don
 
sm base dies

It's been close to 30 years since I started reloading 30-06 for my Rem pump 760 but I seem to remember reading that sm base dies should be used for this rifle.

I never had anything but small base dies so don't know if anything else would work.
 
rcmodel said:
O.K..

Don't buy a small base sizing die.

I have been reloading .223 for AR-15's, mini-14's, and Remington and CZ-527 bolt-actions since 1970.

With a standard RCBS sizing die.

You DO NOT need a Sm. base die unless your standard FL die will not resize cases so they will chamber again.

And it sounds like your Dillon die is doing just that perfectly fine!

rc
Click to expand...

That's because ALL Dillon sizers for bottleneck cartridges are small-based dies. Go ahead, ask them.

To the O.P.: It's true that regular (non-small-based) dies sometimes work fine in the rifle you have and if that's true in yours, no need for an RCBS small-based die (or Dillon sizer), unless ...... 1. You plan to build up a stash of handloads for the future, to work in any AR rifle you could possibly own, find, or steal in the years to come ..... or 2. You want handloads as predictable and dependable as factory. Keep in mind that most factory loads are sized smaller at the base than even small-based dies.

That said, reliability (and safety) of your handloads depends on other factors too. Brass quality (always a factor with used brass), headspacing that allows bolts (in all guns you may shoot) to close and lock reliably every time, yet not over-stretch cases, and of course being able to load a safe, dependable, powder charge, repeatably.

And don't believe the myth that squeezing the base circumference by another .001" is harder on brass as pushing a shoulder back .004" or more.
 
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If your firearm is not having any problems chambering the cartridges with the current dies your using, then I don't believe there is a need for a SB die. From what I understand, SB dies are only needed when you are encountering chambering issues due to the bottom portion of the brass needing to be sized down slightly smaller.

I currently load without them, and I haven't had any issues. But again, every firearm is different, some benefit from them, some don't.

GS
 
I suggest you buy a small base die if your chamber is tight. If it's not, then don't.

But either way, I suggest you put any new pickups of unknown origin into a case gauge, BEFORE you size them. A case gauge measures the shoulder, not the case body. If the case is too big to fit at all, it's not going to size right, so chuck it. It should be pretty close, even if it's unsized.
 
I think this falls under the heading of: If it ain't broke, don't fix it!

Like said above, your Dillon dies seem to be working just fine so buying small base dies isn't necessary.
 
Use small base if you are having problems. I have been loading 20+ years for auto loading rifles, many calibers w/Dillon dies- no problems. Don't anticipate issues where none exist.
 
I don't use small base dies. If my rifles won't run on ammunition resized to factory dimentions that fit my case gauge, then I fix the rifle.

I don't need a gun that won't run on factory ammo and needs special undersized rounds to work.
 
Everything I own works fine with regular dies, except the Model of 1917 I bought last summer. It must have been chambered with a worn reamer or something because the chamber is tight. Its killin' me to buy that die for a gun I'll probably not shoot that often. A buddy is sizing some brass with his SB die and I'll probably try neck sizing for future reloads before I take the plunge.

Laphroaig
 
I'm getting bulk milsurp once fired 5.56 cases sized to minimum on a case gauge with no problems in a Redding standard F/L die. If I have one that is really hard to resize I make sure to pull it out of the plate and check it in the case gauge.
 
jmorris said:
I don't use small base dies. If my rifles won't run on ammunition resized to factory dimentions that fit my case gauge, then I fix the rifle.

I don't need a gun that won't run on factory ammo and needs special undersized rounds to work.
Click to expand...

Who does? But we're not talking about sizing less than factory dimensions. Stock sizers currently made by RCBS or Dillon or anyone else, regular or small-based, certainly don't.

Factory ammo is smaller in circumference near the base than that resized with either regular dies or small-base dies.

Put another way.....to make ammunition resized to factory dimensions near the base of the cartridge, you really would have to have special dies built that size smaller than either small-based or regular dies do.

Regular dies may make you ammo that fits your case gauge, but they are still bigger around near the base than factory.

For example: I just grabbed 2 cartridges and 1 fired case of Remington Core-Lokt .308 (1 new factory cartridge, 1 case fired out of my Remington R25, and one cartridge resized with an RCBS small-base sizer). I measured the circumference of each case .300" from the case head. Results below:

New factory cartridge measured .464"
Fired factory case measured .469",
The small-base resized cartridge measured .466"

So....if you want to resize back to factory you need dies that size .002 smaller than small-based dies!

The difference between small-based sized and regular sized is typically only .001"....rarely .002", but that .001" is enough to increase the number guns that reliably shoot reloads to very near the 100% goal. Regular dies don't.

The only rifles that need "fixing" are those with out of spec chambers. Chambers cut closer to the minimum specs, but yet are still within spec, are done to increase accuracy. The Remington R25 I have (DPMS made) is extremely accurate for a factory rifle....but it won't shoot Wolf Ammo reliably, let alone reloads sized with regular sizers. I'm not about to "fix" a rifle that shoots sub MOA using good factory ammo, or small-base sized reloads.
 
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ok,, like others have said , it sounds like you don't need them , some more food for thought ..IF you did need them , in order for a small base die to do it's job you have to run your case all they way in them , witch bumps your shoulder back to minimum, working your base more than it may need to be , shorting brass life, and giving you more head space than you my want, I'm a firm believer in working my brass as little as possible , it will last longer and shoot tighter groups,
 
savanahsdad said:
IF you did need them , in order for a small base die to do it's job you have to run your case all they way in them , witch bumps your shoulder back to minimum, working your base more than it may need to be , shorting brass life, and giving you more head space than you my want,
Click to expand...

If you did need small base dies to get the case to chamber, case life becomes irrelevant. If you cannot chamber the case because it is not sized enough, what good is it?

My experience with 223 Remington, which I exclusively resize in small base dies, is my case life is still the same. Maybe I shorten the life of the base of the case, but I scrap the case before that happens for other reasons.

Case gauges for bottle neck rifle cases such as those offered by Dillon and Wilson do not measure the diameter of the body. They are cut generously in that dimension. Check the manufacturers' information. Therefore, they are not an indicator that one needs small base dies. They are not chamber gauges.

The vast majority of folks do not need small base dies for their semi-auto rifles. But, of those folks, many take the stand that "I do not need a small base resizing die with my rifle, never have, so nobody needs them" and will not recognize that a small percentage of guns under certain circumstances benefit from small base sizing of cases.
 
Put another way.....to make ammunition resized to factory dimensions near the base of the cartridge, you really would have to have special dies built that size smaller than either small-based or regular dies do.
Click to expand...

Roll or push through sizers are what you need if you are trying to resize the rim or very bottom of the case. No size die can fix what it can't touch.
 
jmorris said:
Roll or push through sizers are what you need if you are trying to resize the rim or very bottom of the case. No size die can fix what it can't touch.
Click to expand...
if you needed to resize the rim I would think the primers would be falling out at that point ,

lets make this simple .. if you need them , get them , if you don't , then don't, however if you get a round stuck in your AR ....... well lets just say that's when the fun starts !! trust me ..... you can also do as I did and have a 3rd die in your set that only sizes the web down to what it needs to be
 
if you needed to resize the rim I would think the primers would be falling out at that point
Click to expand...

Machine guns with loose chambers can let a case expand that would normally be trash but can be fixed with a machine that can fix the base. There are many ways for the rim to get dinged up that can be ironed out with the machines I am talking about.
 
savanahsdad said:
ok,, like others have said , it sounds like you don't need them , some more food for thought ..IF you did need them , in order for a small base die to do it's job you have to run your case all they way in them , witch bumps your shoulder back to minimum, working your base more than it may need to be , shorting brass life, and giving you more head space than you my want, I'm a firm believer in working my brass as little as possible , it will last longer and shoot tighter groups,
Click to expand...

No, it's the other way around. To make a regular die work you often have to push the die in all the way in, plus a quarter turn. Backing them out to bump the shoulder less leaves the case even bigger around, and increases the chance for hard bolt closure. (that's one of the reasons besides squibs and dbl loads, where "reloads" got a bad name.)

On the other hand if you have a small-base die, you start out smaller, so if you need to bump the shoulder less you can and still have the base area small enough to close nearly all bolts safely into battery. I'm pretty sure Dillon figured that out a long time ago, and thus cut all their sizers smaller to work in all rifles not just bolt actions....with a minimum of case working.

If RCBS can be faulted in this area, its because they chose to make small-based dies, (including the newest latest whiz bang AR die sets including taper crimpers (also a good idea)), separately, as a marketing decision to sell more dies. And why not? You can size minimally if you have a rifle that allows it. So then you can have separate dies for bolt action hunters , and AR's.....or you can buy one, a small-based die and get by pretty fair with either.

I still maintain, that the best reason to use small-based dies is if you want to load a storage room full of ammo, and want to end up with ammo that will shoot in any gun of that caliber, NOT just the gun you had when you reloaded it.....that got stolen or traded!;) (the only other way to be sure, is to save your pennies and fill it with factory).

Think about it....the two most serious reasons a smart buyer chooses NOT to buy reloads at a gun show (or an estate sale): 1. No first hand knowledge of the type and amount of propellant in each case. and 2. No first hand knowledge that it will load in your rifle....even if the seller assures you the regular sizers were set to "cam over!"

jmorris said:
Roll or push through sizers are what you need if you are trying to resize the rim or very bottom of the case. No size die can fix what it can't touch.
Click to expand...

Of course, but neither small-based sizers nor regular sizers size that low. The "base" they are referring to is the base of the die where sizing actually starts, not the case, not the shell holder, but the bottom of the sizer .

The damaged machine gun brass you are referring to is best bought cheap enough to recycle.......or not at all.....of course unless you are jmorris with the tools and skill to machine it back.:)
 
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