RCBS X-Dies for the .223

Standard RCBS FL die loaded every thing in 223/5.56 for me. There is also the RCBS AR Series Small Base 2-Die Set with Taper Crimp 223 Remington

I'd like to share my experience with the X dies. I really really like them for ammo loaded to shoot in military style sporting rifles where gilded edge accuracy is not necessary or maybe not even attainable. For high quality precision rifles I would recommend that you segregate your brass and use standard dies, and just trim your brass as necessary.

The reason why is that IME, the X die will force the neck down into the shoulder and give you the "dreaded donut" there at the neck shoulder junction, which will adversely affect your accuracy if your bullet should happen to protrude down past that location. If this is not an issue for you, then by all means.... carry on!

OP for the AR 15, do you presently reload? What die do you use? Do you use a SB die? If not, then all you will gain form using the SB X die is potentially diminished accuracy as the die works the brass at the web area to be even smaller than your chamber.

Regards,
Stubb

All I load for is semi-autos, mostly AR15s. The only dies I use anymore are the X dies, SB. I go ahead and get the small base dies because I want my ammo to function flawlessly in EVERY GUN OF THAT CALIBER I HAPPEN TO PICK UP.

I have half a dozen or so different AR15s and one of them will give problems chambering if I do not use the SB dies. Every one of them will do sub MOA @ 100 yds with the right load--all loaded with the X die SB. That's plenty good enough accuracy for me. If I had a bolt gun or something I would probably go back to the regular dies for it only.

The X-dies require you to trim the cases a bit shorter than normal ONE time, then they don't require any more trimming as long as the die is adjusted properly when sizing.

I don't have any problems whatsoever with my X-dies, and I know for a fact that any 223 ammo I grab will work in any AR I grab. YMMV

Regular. I use the same x-die for reloads in my Bushmaster and Savage 12FV.

I have no idea where this "donut" thing came from. If your initial trim was correct, there is no way this should happen. If you are getting a donut, sounds like you are trying to resize a piece of brass that is too long for the x-die.

Since you are buying a new die, I recommend getting the small base dies.

While probably not necessay, particularly if you only reload cases fired in your rifle, the varibility of 223Rem/5.56 NATO chambers could cause you grief with chambering resized cases not fired in your rifle.

Why take a chance. You won't lose anything by buying the small base dies.

cfullgraf said:

...You won't lose anything by buying the small base dies.

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You will lose case life by overworking your brass as a Small Base (SB) die is wont to do. A SB die does squeeze a lot of brass at the web area, which has to go somewhere, typically up the neck towards the case mouth. Each fire / resize cycle will force more brass up the case walls towards the neck with a SB die than would be the case with a standard die. This in conjunction with the typical headspace tolerances will "stack" in a sense, and may lead to premature case head failure.

Handloading for semiautos presents a unique set of concerns, among them is slamfire, which is the primary reason for a SB die. Just know that the price one pays with a SB die is decreased brass life. -- Of course with a SLR, one stands a pretty good chance of losing the brass in the weeds before it wears out anyways...

Steve in PA said:

I have no idea where this "donut" thing came from.

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The "donut" thing is a ring on the inside of the case at the base of the neck which forms a constriction that will deform the base of bullets which are seated over top of it. It comes from any of two or three causes. In the case of the X die, the donut comes from the neck being jammed back into the shoulder by operation of the mandrel located in the assembly that threads into the top of the die, just as designed.

Even were one to trim his brass "short" initially per the instructions, eventually the necks will grow to the point that the mandrel at the top of the die presses the neck down into the shoulder, as it is designed to do, and donuts will form. This constriction will cause accuracy to suffer.

In theory, small base sizing should shorten case life as mentioned by stubbicatt but in 7 or 8 years of using a small base die in 223 Rem, my case life has not changed from before. Also, at each resizing, I measure each case length and trim only those that are over length. I have not seen an increase in the number of cases that I have to trim during a resizing session.

I have two ARs that I would gave to segregate cases per rifle if I did not use a small base die.

In my opinion and experince, there are lots of upside to using a small base die for resizing 223 Remington cases and virtually no downside. BUT, if you already own a standard resizing die and you are not experiencing any issues, I would not replace it just to get a small base sizer.

Apologizes but I have no experiece with the X-dies regardless of the flavor.

It seems, most of the folks that use them, like them.

I have my opinions about them but with no actual experince with thd x-dies, my opinions would be useless and therefore not offered.

If I were buying it would be the small base die:
.001 or .002 thousandths extra squeeze at the base area does not work the brass enough extra to make any difference.....I get the same brass longevity either way. I also get ammo that feeds smooth in any gas gun, not just the one I loaded it for. For me that's peace of mind if I want to load a few thousand to put away for a storm. I don't know what rifle I'll end up with then.

Dillon must agree.....ALL their bottleneck sizing dies are small base. Don't believe it? Ask them. Also noteworthy is that even small base sized brass is NOT sized back to factory....still bigger around....just smaller enough to be more reliable. Accuracy? Better than most factory.

One more point....brass longevity with AR15 use, is based more on ejector damage, shoulder stretch and bumping back, which can move the brass .006" or more.

I'm going to use these dies for loading ammo for a 5.56 chambered AR-15.

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From Sierra.

Despite the oft-repeated advice that autoloaders, pumpguns and lever-actions require small base dies, the Service Rifles may be the exception that proves the rule. While it’s true that all of these action types lack the powerful camming forces of a bolt-action, the more generous chamber dimensions common to most Service Rifles are normally compatible with standard dies. Please understand that this is a general statement, and that there are exceptions to this. The point is, you don’t need to automatically go to a small base die set. Most of the standard reloading dies produced by reputable firms, such as RCBS, will resize fired brass properly to work in these rifles.

I load for several semi-autos including a few AR-15's, none of my rifles require the use of SB dies, standard FL dies work fine for me.

ArchAngelCD said:

But the question here is, should I buy a standard X-Die or small base X-Die?

You guys are focusing on the small base part but not discussing my original question.

I would appreciate to the point discussion for once. I rarely ask a question and I never do seem to get an answer.

Thank you...

*EDIT*
I do load for the .223 already but mostly for a bolt action rifle although I have made several hundred rounds for the AR too. I currently own 2 sets of .223 dies, a Lee set and a 2 piece RCBS set. Bolt action rifle brass is kept separate from the AR brass.

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Sigh. Some people!

Get whatever you want. In fact, get one of each if it makes you happy. You might do well to get both and see which one works best for you and sell the one that you do not like as much. I would not buy a SB die unless I needed it and would recommend that you not get it unless you need it. I did my best to tell you why you didn't need it. Oh well....

I think you will like the X die if you aren't concerned about gilded edge accuracy. Buy it and try it. If you don't like it, sell it to someone else. In fact, I have one in 308 and another in 243, and I'll sell them both to you for 1/2 retail if you want them, and can use them.

Here's a direct answer for your AR loading--get the SB X dies and be done with it. That way if you get more semiautos in the future you'll have no doubt about whether or not you can load ammo that will chamber 100%

Here is what the RCBS SM die did to my once fired Grendel brass. I sent the die back to RCBS with a handful of once fired cases. They were going to open up the die, but found replacing it with a Standard FL die was a better solution.

The case head diameter of the Grendel is the same as that of the parent case the .220 Russian, the 7.62×39mm, and PPC cases. This is larger than the 5.56×45mm NATO. If the "sm" die you used was a mismarked .223 that would account for that. Didn't know RCBS made a small-based Grendel sizer....learn something new every day. Your FL regular sizer was obviously the right one....the Small based sizer if the right one would've sized it only .001"smaller than your other die ....what I see is a lot more than that.

mtrmn said:

Here's a direct answer for your AR loading--get the SB X dies and be done with it. That way if you get more semiautos in the future you'll have no doubt about whether or not you can load ammo that will chamber 100%

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What I said.....in many fewer words! ....to the point.

Didn't know RCBS made a small-based Grendel sizer....learn something new every day.

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Here ya go.

http://www.midwayusa.com/find?sortby=1&itemsperpage=24&newcategorydimensionid=12661