[fritz1]

I have owned my Bushmaster Varmiter Special for about three years now and have been reloading for it. I use RCBS small base dies for a 223. Last year I bought a Ruger M77 MarkII 223 and have been using the same dies to load for it, with no problems. I just recently read that RCBS doesnt recomend loading for a bolt gun with the use of small base dies, does anyone know why this is? They seem to work just fine, I havnt had any problems. Should I buy a different set of dies for my Ruger?

 

[BKeith]

Not real sure what RCBS's reason is but two thoughts come to mind. First would be you are overworking the brass when it's not needed, which is going to shorten brass life. Second, it's going to reduce accuracy.

For any bolt action, I would look at neck sizing only first. There are some that does not work well in and require full length sizing, but I would not use a small base die even then.

 

[byrl]

The small base sizing die just sizes the case to slightly smaller dimensions (to minimum specs) to facilitate easier chambering in semiauto firearms. It probably won't hurt anything to use the small base sizing die with the bolt gun, but your brass will just get worked more than necessary and case life will be shortened. Unless you just happen to have a tight chamber in the bolt gun, the fit of the small base resized brass will be sort of sloppy. Using a regular sizing die or just a neck sizing die should increase accuracy and case life with the bolt gun. But you will then need to segregate your brass for the AR from the brass for the bolt as the two will not be interchangeable.

The AR (or other semiauto/pump/lever action) chambers are not smaller than bolt chambers. But sometimes regular die sized rounds bind up when being chambered due to the speed and feeding angles of the actions. When a round must absolutely positively chamber every time, then a small base sizer is the way to go. But it is not needed in most bolt guns in most situations.

 

[Lynn]

If you are loading for 2 guns and one requires a small base die I would stick with that in case you should mix the loads. I have five 223s that I use the same loads in, only one of the ARs requires a small base die so I use it for all of my loads. Accuracy is under one moa with the ARs, bolt gun and single shot, and under minute of barn in the mini 14 with the same load.

 

[bert621]

I wouldn't. I bought the small base die for a new Remington .223.
After I sized the brass I have on hand I backed the die off a turn and have been loading for the rifle since with no problems.

 

[varminter]

just get the LEE collet die for the Ruger. cost like thirty bucks and you wont be dissapointed. Brass will last longer too.

 

[nvshooter]

Small-base for me-- all the way...

I use the RCBS small-base dies for my ARs. A shell that won't slam into battery really pixels me off! I never have a problem with failure to chamber when sizing to one-quarter turn past shell holder contact. I do not consider any other ways...

 

[Deerjager]

I use the RCBS sb dies to load for three ARs, a Ruger 77 MkII and a Remington 700. All five rifles have no problem chambering the rounds. I have not had a problem with failure to feed in any of the five 223s.

 

[Sinbad12-2007]

I used to load for three different M100 Winchesters, all in .308. Two would feed and fire reloads made from standard base dies. The third I had to use the SB die on. Surprisingly, it was the most accurate of the three.

 

[MontyF]

I used to load for three different M100 Winchesters, all in .308. Two would feed and fire reloads made from standard base dies. The third I had to use the SB die on. Surprisingly, it was the most accurate of the three.

Had the same deal at one time with a Remington 742. Should have sold that rifle sooner instead of investing in a SB die set.

 

[c.robertson]

I have heard this discushion many dozens of times over the past 40+ years of reloading and it still perplexes me.
I have loaded for the following semi-auto rifles: 12/M-1 Garands, 3/M1-A's, 8/AR15's and more bolt guns than I can count. NEVER have I used 'small based dies' for any of them, REPEAT!! NEVER!! And I have NEVER had any problems with function in any way. (With one exception. Mislabeled ammo neck sized for bolt gun that jamed up an AR. I computer print labels and screwed up which box the label went on.)
I use RCBS standard reloading dies for all 25+ calibers.

Just don't understand what all the fuss is about.

 

[MontyF]

I have heard this discushion many dozens of times over the past 40+ years of reloading and it still perplexes me.
I have loaded for the following semi-auto rifles: 12/M-1 Garands, 3/M1-A's, 8/AR15's and more bolt guns than I can count. NEVER have I used 'small based dies' for any of them, REPEAT!! NEVER!! And I have NEVER had any problems with function in any way. (With one exception. Mislabeled ammo neck sized for bolt gun that jamed up an AR. I computer print labels and screwed up which box the label went on.)
I use RCBS standard reloading dies for all 25+ calibers.

Just don't understand what all the fuss is about.

I can't speak for everyone here on the need for SB dies, but in my case that 742 would chamber factory rounds without an issue. My dies at the time were Pacific Dura-Chrome, which would work good in the pump rifle and bolt guns in the same 30-06 chambering. The SB dies cured the failure to chamber problems on the semi-auto.

 

[ROGER4314]

I have used SB and FL dies almost exclusively because I shot matches a couple times a month for 7 years. My #1 purpose was to obtain 100% reliability and that did the trick. If I need to S Can some brass that got tired, it was just fine but every round had to chamber properly and function without fail. Never did have a match failure due to ammo. Did have stock to action bolts come loose on a 1903A3 and had to withdraw from a match.

Flash

 

[SHY_BEAR]

I was just wondering about this last week myself. I have an OLD Sierra manual from 1978, and it states that there are 2 basic approaches to accurate handloads. One is the "Neck Size only" camp and the other is to "Use Small Base Dies, in order to ensure that each round is concentric and lays in the chamber the exact same way from round to round...." I also own a new, latest edition of the Sierra manual and havent found this in it... I own many sets of RCBS dies, some are neck dies, some regular full length and some small base. I am as confused as can be about all this myself. It would be different if RCBS worded it differently than in capital leters and such strong words "...DOES NOT RECOMEND USING SB DIES IN BOLT ACTIONS...." Like something bad will happen if You do! I mean, are the loads dangerous in bolt guns or not? Are they just awfully inaccurate, which would go dead AGAINST the Sierrra manual (1978 one) or what? I got SB dies for 06' because I have a 742 and a GArand, but also own FL dies and neck size too, as I own a couple bolt guns if I wanted to go for all the accuracy I can squeeze out. Now Im all confused as to whats the best route to take over all.

 

[fguffey]

Again, it seems talking about about it is more rewarding than doing it, does anyone measure before and after, to me it is a conflict to use a small base die on a case that will be fired in a chamber that has been cut with clearance to accommodate ease of extraction, and one of those chambers is cut .00025 larger in diameter that the chambers that came before it, the 03, 03A3, M1917 and the M1 Garand were designed to chamber the same round. Speers in their reloading manual under definition of terms says the small base die is nothing more than a very precession full length sizer die, I took a picture of my micrometers and gages, the picture weighed 400 lbs, again, I have BAR dies and small base dies, when determining the difference between 'REGULAR' dies and BAR dies most when measuring can not determine the difference, it is possible I have some very good REGULAR die.

The base of the case is not sized because of the deck height of the shell holder, the deck height of my shell holders is .125, then their is the radius at the die opening, the case is round, the case has a tapper so I wonder if anyone measures and if so what tool do they measure the round tapered surface with.

To me datum is not a line, I never pass up an opportunity to pick up datums if they are cheap.

F. Guffey

 

[fguffey]

Shy-Bear, there is a conflict in the accuracy statement, they can not have it both ways as in leave the case body like it is and neck size because the case fits the chamber then recommend using a small base die to reduce the dimensions of the case to assure ease of cambering. To me it is an either or but not both.

I believe the reloader that purchased 500 cases, culled, matched and fired all of them then culled again and then reloaded them again, fired for accuracy and rejected the cases that were not accurate then started again until he settled on 40 cases of the 500, then he went back and determined the difference between the accurate cases and the cases that did not produce accurate results, the accuracy or the ability of the rifle was never suspect.

F. Guffey

 

[TMan]

I have heard this discushion many dozens of times over the past 40+ years of reloading and it still perplexes me.
I have loaded for the following semi-auto rifles: 12/M-1 Garands, 3/M1-A's, 8/AR15's and more bolt guns than I can count. NEVER have I used 'small based dies' for any of them, REPEAT!! NEVER!! And I have NEVER had any problems with function in any way. (With one exception. Mislabeled ammo neck sized for bolt gun that jamed up an AR. I computer print labels and screwed up which box the label went on.)
I use RCBS standard reloading dies for all 25+ calibers.

Just don't understand what all the fuss is about.

Well, I'm at the 45 year point, and own several rifles in several calibers.

My CZ527 has a very tight chamber, and requires a SB die for any once fired brass not shot in that rifle.

My current 7mm Mag, a CDL also has a chamber on the small side, and brass fired in any other 7RM needs to be squeezed hard.

Brass fired in my M7600 Whelen is fine in my CDL whelen, but not the other way around, and all of my hunting loads go through a small base die to prevent problems on a hunt.

.30-06 brass, fired in a Garand, rarely feeds well in a pump or bolt rifle without some extra squeeze.

Like most things, it depends, but in my experience, loading a single cartridge for more than one firearm, usually requires a SBD at some point(s) for consistant and relaible function. I've never noted any dramatic effects on accuracy.

 

[unclenick]

That's my experience, too. It's all about elasticity and spring-back of the brass coming out of the sizing die. If a case starts out too big for the next chamber you will use it in, then running it through a small base die will normally guarantee the fit, as long as the rim isn't bent nor the head badly burred by an extractor. It should drop into a case gauge when you're done. If the case has been fired in the chamber you will use it in, then it is atypical for it to need a small base die.

The one exception that comes to mind is when the standard FL die is not at minimum tolerance. They are like a chamber that way, with a range of specifications. Lee, for example, has their standard FL dies a little on the generous side to minimize overworking the brass. If you have a very tight chamber and a very generous standard FL die, then trouble may ensue. Custom gun makers often cut a sizing die with the same reamer used to cut your chamber, but just short enough to allow the shoulder to be set back a thousandth or so by the die.

Incidentally, if you just have a few cases that don't resize adequately, I find that running them back up into the same sizing die and letting them rest there for a count of five, then withdrawing them, rotating them 180°, then running them back in for another count of five can sometimes set a shoulder back as much as an additional 0.002". That's the number I measured on LC .30-06 cases from my original Garand barrel. Its military chamber was about 0.007" over minimum as received.

As to the accuracy issue, I suppose the small base die narrowing cases until they lie lower in the chamber can improve accuracy in some instances. Since bullet tilt in the neck has an upper limit to its adverse effect (owing to the bullet being able to straighten itself beyond a limit of a few thousandths TIR), the slight upward angle of a case lying lower in the chamber may bias out the upper half of the tilt by pushing it beyond that limit. But if you have the gear to keep the bullets seated straight, then the neck-sizing-only approach makes the most sense, especially if you orient your cases on loading the chamber so that the high side of any runout they have is always at the same place on the clock. A.A. Abbatiello found years ago that this practice cut bullet tilt error in half on the target.

 

[ranger335v]

"I never pass up an opportunity to pick up datums if they are cheap."

I have a couple - three hundered datums and a few dozen correct head spaces in mixed calibers I'll never use again. PM me with an address and I will send then to you free but they are not sorted, you'll have to do that yourself.

 

[Country]

Small base dies are only used 'IF you need them" Some factory chambers cut with worn reamers can be tight and match chambers are arranged to be tight . Enter the small base die. However you use standard dies first on a standard factory chamber and only go to small base if you can't size the case down enough to rechamber easily.