Micrometer seating die: Is that what I am looking for perfect..

[tkdguy]

centering and alignment for more accurate performance out of a 300 WM? Or am I looking for another die altogether? Thanks.

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[bsa1917hunter]

You can achieve extremely concentric ammo, with just your run of the mill RCBS die set. Just adjust it properly and you'll be good to go. This may not be what you are wanting to hear, but its the truth.

 

[JuglansRegia]

The RCBS micrometer seating die has a sliding piston that you drop the bullet onto through a window, then it uses a longer shell holder that allows the cartridge to get up into the die to seat the bullet all nice and lined up, there is no crimping feature though.

 

[Goosebrown]

Micrometer dies are really useful when you're developing loads. Once you're dialed in though set the screws in your die and make a couple dummy rounds so you can reset the die to them as needed.

I wouldn't spend the money on them myself.

 

[tkdguy]

The RCBS micrometer seating die has a sliding piston that you drop the bullet onto through a window, then it uses a longer shell holder that allows the cartridge to get up into the die to seat the bullet all nice and lined up, there is no crimping feature though.

so I'd need a total of three dies to make this work?

 

[Goosebrown]

there is no crimping feature though.

Don't crimp.

 

[v0lcom13sn0w]

i use standard rcbs dies. if u wanna go all fancy look at LE wilson micrometer chamber type dies and an arbor press

 

[v0lcom13sn0w]

Don't crimp.

x2

 

[awshoot]

Micrometer dies are really useful when you're developing loads. Once you're dialed in though set the screws in your die and make a couple dummy rounds so you can reset the die to them as needed.

I wouldn't spend the money on them myself.

I've been thinking about this recently -- some years ago I bought fairly pricey set of Redding dies with a micrometer die. It makes developing a load easier (but not easier than a set shell holders with different thicknesses). Anyway, I finally settled on a load and seating depth and now, every time I pull out that die, I'm extra careful to not accidentally turn it and change the setting (though I do always measure even when I'm sure it hasn't been moved). I don't see any spot to use a set screw. Anyway, I have an RCBS set for the same cartridge -- it is more fiddly to deal with the screw and nut but once it's set, it takes a lot to unset it. Going forward (if I get a new caliber at least) I think I'll focus on the dies that you can really lock down rather than micrometer type, and use those shellholder sets that come in different thicknesses like these: Competition Shellholder Sets - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

 

[bsa1917hunter]

x2

You guys may not, but thats a little secret that (some in the know) helps to reduce TIR. I always set my seater to slightly crimp the bullet. And honestly, i havent ran across too many guys that load ammo as consistently accurate as the ones that come out of my press. Id lay money on that statement.

 

[DizzyJ]

There is a difference in bullet seating dies, and I've measured the difference.

Really depends on what you expect of your ammo and how anal you choose to be.


The competition style bullet seating dies have a closer tolerance between the seating stem and sleeve/body. This makes it easier for you to achieve better alignment and thus less runout between the case and bullet.

This is my personal favorite seating die. https://www.brownells.com/reloading...s/ultra-micrometer-seater-dies-prod59246.aspx

The micrometer top won't necessarily give you better alignment over the standard competition seater, but it is nice to be able to dial in exactly to your seating depth. It's well worth it (IMO).

Just be careful not to have too much compression of the powder. A little bit of "crunch" on a longer stick type powder is ok, but not a hard compress of the powder, especially ball powders.

 

[DLS]

A couple of thoughts here.

Back when I was an active high power shooter, I had a number of loadings. For short range matches and the 200 yd. line stages I used Sierra's 60gr. HP. For the 300 yard line I used Sierra 77's or Hornady's 75's depending on what was cheaper. For 600 yards I used Sierra's 80 gr. bullets. Having a micrometer seater allowed me to easily dial in the proper seating depth depending on what load I was building. It also makes it easy to let the length creep out a bit as the throat wears. I'd hate to have to use a standard die for this, even if I had dummy loads prepared (which I did prior to getting the micrometer die).

For the blaster ammo used in my kids AR's I use a standard die and lock it down with the nut. Since the seating length rarely changes on these loads it works just fine.

What rifle are you shooting? If it's a standard grade hunting gun a standard die should work just fine. There are other things in play that will open up your groups far more than changing seating depth a few thousands here or there.

If you are looking for a load, then will stick with that load, once again a standard die will be fine.

Just some thoughts on the subject. I hope this helps.

 

[gmerkt]

You guys may not, but thats a little secret that (some in the know) helps to reduce TIR. I always set my seater to slightly crimp the bullet.

Thanks for the insight. I had to look that one up, TIR, Total Indicated Runout, I think you are referring to (not Termite Inspection Report). I hadn't thought about enhancement of TIR as a result of a gentle crimp.

I'm not a match shooter so I'm not too compulsive about certain procedures. I don't rule out a crimp on rifle ammo. I shoot quite a bit of rifle ammo through auto loaders, often use bullets with cannelure so I crimp into that for reliability factor. But sometimes I use match bullets with no cannelure, those I often just kiss the outer edge of the case mouth with a gentle taper crimp to eliminate any sharp edge. Never to the point of bullet deformation by imparting a ring to the bullet jacket. When I load match bullets, I use fairly fresh brass so as to have adequate bullet pull. When I do crimp, I always do it as a separate step.

 

[P7M13]

Have both RCBS and Forster micrometer seater dies. I trust both. I don't worry about the setting, because I will measure and dial in the dies every time I start a new loading cycle. The 10 minutes it takes is well worth it.
In my unscientific methodology, I have noticed a couple of things affect alignment and concentricity.

• On some bullets with a very sharp point, the standard seating die cup is not shaped properly for the point, so you are basically pushing from the point only. Easy way to check this is to take the seater out and visually inspect how the bullet seats in the cup.
• On some bullets, I note visually that the point is different (PSP bullets come to mind). Variances in ogive and point shape will affect seating.
• If your neck tension is not uniform, you will need different forces to seat the bullet. If you consider Flat Base bullets, sometimes they really don't want to enter the case neck square.
• Burrs inside necks can affect seating alignment.

I'm not OCD enough to re-point my bullets. I've done neck turning and noted no discernible improvement in accuracy.
What I attempt to do is cover the law of averages by doing the following:

​

Before Seating​

1. Anneal cases / trim to length / deburr neck inside and outside.
   
   Seating Step:
2. Set the bullet in the neck as squarely as possible.
3. Run the ram up slowly until you feel the bullet being pushed into the neck. Watch the ram travel to gauge the amount of seating that has been done.
4. Back the ram off, rotate the bullet 90°-120° in the ram.
5. Run the ram back up, moving approximately 1/4 to 1/3 the seating depth again.
6. Back the ram down, rotate again. Because I'm doing this left handed, I'm usually rotating counter clockwise.
7. Repeat step 6 until the bullet has been completely seated.

After a while, the steps above become muscle memory and don't slow the process at all.

I then set the case on a machine shop granite stone and roll it away from me. I focus on the ogive just below the point and watch for wobble there.
The ones that have been rejected are due to case neck or base defect. Pull the bullet, dump the powder, toss the case.
When your watching the bullet roll on a granite block, variations are pretty visible. I have a runout gage and have measured, my eyes can see runout of +/- 4 mils.

 

[Certaindeaf]

I think you want a sizing die cut with the same reamer used on your chamber.

 

[tkdguy]

I think I found what I need or something like this: Redding Premium Series Deluxe 3 Die Set.

 

[DizzyJ]

I think I found what I need or something like this: Redding Premium Series Deluxe 3 Die Set.

Seems like that set gets fairly consistently high reviews.

 

[Goosebrown]

i use standard rcbs dies. if u wanna go all fancy look at LE wilson micrometer chamber type dies and an arbor press

That's what I do. Everyone I know does except a few with bonanza/forester.

 

[Goosebrown]

I've been thinking about this recently -- some years ago I bought fairly pricey set of Redding dies with a micrometer die. It makes developing a load easier (but not easier than a set shell holders with different thicknesses). Anyway, I finally settled on a load and seating depth and now, every time I pull out that die, I'm extra careful to not accidentally turn it and change the setting (though I do always measure even when I'm sure it hasn't been moved). I don't see any spot to use a set screw. Anyway, I have an RCBS set for the same cartridge -- it is more fiddly to deal with the screw and nut but once it's set, it takes a lot to unset it. Going forward (if I get a new caliber at least) I think I'll focus on the dies that you can really lock down rather than micrometer type, and use those shellholder sets that come in different thicknesses like these: Competition Shellholder Sets - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

Oh good call. Excellent investment. Redding BTW. Blows doors on like product from RCBS although they're both great

 

[Goosebrown]

I think I found what I need or something like this: Redding Premium Series Deluxe 3 Die Set.

Excellent choice if You're not going LE Wilson which is a different level