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jeepcreep927 10-01-2009 07:08 PM

Micrometer Dies?
I am trying to decide if RCBS "Competition" dies (no bushing) are worth the extra money. I am doing a build on a Stevens 200 receiver (same as a Savage 10, minus accutrigger). I know the action is perfectly fine so I don't want to debate that. It is going to wear a Douglas XX stainless barrel in .222 Remington, set to minimum headspace, standard SAAMI chamber, no turn neck.

Is it worth it to get the micrometer Competition dies from RCBS? This is going to be a non-competitive paper puncher and 200 yard maximum varmint rifle. I would like to squeeze as much accuracy as I can obviously, but if the dies are not worth it than I will skip them. I have never use dies like this before and have excellent results with plain Jane 40 year old Lyman dies in my .308 LTR, which will do 3's and occasionally 2's forever with 110 grain VMax.

I'd appreciate input from any accuracy freaks and handloaders. Thanks.

RL357Mag 10-02-2009 01:49 AM

Your question really depends on the accuracy you will be getting with the rifle you are building. If the rifle routinely shoots groups in the 1.75" to 2" moa range, it's doubtful that a bench rest seating die will give any noticeable improvement. If the rifle turns out to be a tack driving varminter, then benchrest or competition grade dies are a worthwhile investment. The micrometer die, also known as a "straight-line seating die" utilizes a sliding chamber (spring loaded sleeve) that fully supports the cartridge case as the bullet is seated. The purpose of this is to align the bullet with the case mouth perfectly before seating begins. This assures the utmost concentricity, an important variable in the accuracy equation. The micrometer seating stem is a plus. Of course if you are looking for benchrest accuracy, you might also want to consider a concentricity guage and neck uniforming tool.

1hole 10-02-2009 01:51 AM

Well, without saying something offensive about RCBS expensive so called "Competion Die" short sleeve seaters I'll just say get either Forster BR or Redding Comp dies with the full length sleeves RL357 mentions. The long sleeves actually do a better job than conventional dies. And neither of those brands is any better than the other, IMHO. Redding copied Forster's excallant seater die but, so far, not their great sizing die/expander design.

Micrometer seater heads don't do a thing for the ammo. They are only a user convience. I have seaters with and without the mic heads and don't really care which I use. I set both with external gages so that I can be sure of what the end result is anyway.

cpttango30 10-02-2009 02:11 AM

Where you are going to see a difference with a micrometer dies is if you use an OAL gauge like the Hornady (Stoney Point) set up. Then you can get precise measurements of seating depth and they transfer over easier than with the lock nut threaded seater plug. Other than making minute adjustments the micrometer dies in my eyes is a waste of time and money if you are not going to get the OAL gauge.

I think you would have better luck going with the Hornady New dimension die set with the floating seater. These are my choice for dies right now.

jeepcreep927 10-02-2009 09:17 PM

To make sure I am getting this:
I think I realize the micrometer only makes it easier to adjust COAL. RCBS "Competition Dies" say there is a window that allows the bullet to be fully supported, as it's inserted through a window in the die body. That was my main attraction to them as it made sense to me to keep the bullet concentric. If that feature in itself is not worth it than I will skip them.

I don't have any illusion that this rifle will be bench rest accurate, I just wondered if these dies would be beneficial, since they don't require neck turning of the case or a specific diameter die bushing.

Thanks to everyone for your input.

1hole 10-03-2009 02:35 AM

" RCBS "Competition Dies" say there is a window that allows the bullet to be fully supported, as it's inserted through a window in the die body. That was my main attraction to them as it made sense to me to keep the bullet concentric."

That side window is a user aid. I suppose it helps some folks but it's nothing new, it's just a copy of what at least two die makers produced in the 60s (Herters/Vickerman). It wasn't very popular then, dropped off the market for many years until RCBS decided to make it again and lable it a "comp" die. I've never heard anyone claiming it did a thing for accuracy, then or now.

Actually, it's major asset, a small one IMHO anyway, is the short sliding sleeve could possibly align a bullet better before seating entry IF it fit snugly. That was also tried in the 60s by at least two makers and it also died by the early 70s (Herters/Lyman).

Fact is, short sleeves (ie, RCBS and Hornady) can ONLY partially control the neck at best and not the lower body at all. The short sleeve's ability to align anything is wholly dependant on both its inner and outer diamerters while the base of the case rides where ever the ram/shellholder take it. And, from what I know of them, both of those critical dimensions are "sloppy'" enough for gravity to assure they don't hang up in use. That's okay I guess but it's not great.

The Forster/Redding design has a full body sleeve. It fully contains and aligns the case with the bullet before any seating pressire is initiated. Sure, some dimensional slop exists. But the sleeve is firmly spring loaded, gravity plays no part, and the slop is over the full length so total alignment is quite good. It's as close to a Wilson type hand die as can be put in a threaded press. (That's why Redding copied it, and they did good. But neither RCBS nor Hornady has done that.) I have never heard of any serious BR shooter using the cute little window dies.

Let me say I do think the RCBS Comp dies, both styles, are good dies overall. But not a whole lot better than conventional dies (which are, after all, quite good). So, for what they cost, why not get the better designs? Especially since at least the Forster's are quite a bit less expensive!

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