Shell Holder and Concentricity Shenanigans

[kingaling]

First off, I'll start with letting you all know that yes, I'm guilty of being in possession of a couple "safe queens" as I haven't been shooting nearly as often as I would like. I'm changing that (I got time). I got some recoil management things to address as well as just practicing the fundamentals. Issues that are magnified as fuck on a 300 Win Mag when compared to my .223. Anyways.... check this out.

I still want to load the most repeatedly precise/concentric ammunition possible given the equipment and money I'm willing to spend.
Recently (within the last few months) I have done a lot of reading and listening to reviews of equipment etc and found a couple things I have been doing wrong or could do better. So watch this rabbit hole...

• I was only neck sizing over the last couple years. Figured it's good enough for what I do / how often I shoot. I'm changing that. FL all the way.
• One reason I started FL sizing is because even though I trickle my powder to exact weights, I routinely get fliers. A chrono showed crazy variations in velocity.
• Craziness turned out to be caused by two (three since i failed to read) things:
  • I had sensitivity of chrono set too high. Read the directions again and fixed that. Reading is NOT overrated. Spread the word.
  • Since I was only neck sizing I wasn't bothering with trimming very often. That was a mistake. I found some of my brass exceeded recommended cartridge lengths. This is now fixed.
  • After getting my precise measuring skills on, I started paying attention to headspace and realized that my 300WM fire-forms the headspace to 2.274" but my die (FL RCBS non bushing) sets it to 2.276" after a resize. It does that no matter how far down into the press I screw the die. The die is literally "incapable" of bumping the shoulder back below that depth. As a result, the rifle has to crush the headspace back down to chamber size every time it fires.
• Read some stuff. Joined this forum right about that time (great info here btw. holy shit).
• Bought a set of Redding Type S bushing dies and while I waited for those to arrive I did some research on the issue of the die not being able to bump a shoulder. Turns out there is quite a lot of people online saying they have used sandpaper to reduce the deck height of the shell holder so the brass can be run further into the die body. Got the visual... makes sense. The shell holder hits the bottom of the die later instead of sooner.
• Did that and it worked. I can now bump my should back to 2.272" (-.002" bump). Then a few days later I purchased a concentricity gauge just because I was curious. All my brass is at least .002" TIR right out of the die (standard FL RCBS non bushing). By the time I seat the bullet, TIR could be as much as .005". WTF.
  • Looking at that Area419 Zero press... My little Hornady LnL Classic has some slop in the ram when fully extended. But anyway...
• Decided to check if sanding the shell holder could have caused concentricity issues. Bought a depth gauge from Mitutoyo and measured three points on the deck; left, right and rear. Measured those points on an unaltered shell holder and they were all the same; .1243". There is no vernier scale on the device so I eyeballed that .0003". Sue me.
  • After sanding (as carefully as I possibly could I swear it), I had 3 different measurements on those same points; .1070, .1076 & .1152 (again with the 10000th of an inch eyeballing in the absence of a vernier scale)
• 
  
  Looked at Redding's competition shell holders because I saw they come in a set of varying deck heights and maybe I can forego sanding my shit and causing uneven shell holder surfaces. Unfortunately their shell holders don't work that way. They increment the height instead of decrement it. They will not sell a shell holder where the deck height is less than the standard height of .125". I contacted them and asked. There is a liability issue apparently. I have heard people say they have ripped off the top of a shell holder from making it too thin. Maybe that's the liability reason.

I suspect the best course of action regarding not being able to press enough of the case into a die to achieve a proper shoulder bump is to use a lathe to trim the bottom of the die then. I say a lathe because manually sanding "anything" is likely to cause uneven surfaces and then said equipment should probably just be considered fucked where concentricity is a concern.

I don't have a lathe. Guess I'll have to pay someone to fix my dies next time this happens.
I haven't called around yet so if anyone knows who will machine .002" or .004" off the bottom of a die in the Phoenix AZ area let me know :>
I haven't used my Redding dies yet but just in case I have this problem again...

Anyways, thanks to the entire Sniper's Hide forum members for all the great info so far. Learned a lot here even before joining.

 

[E-Tool]

But how are your groups? Accuracy, and precision; You can worry addressing about variables all day but if it doesn’t make that flier go away why do it?

 

[kingaling]

But how are your groups? Accuracy, and precision; You can worry addressing about variables all day but if it doesn’t make that flier go away why do it?

Agreed.
So AFTER i addressed the trim and headspace issues, my 300 WM shoots .75" groups or less at 100 yards. Also my SD according to my chrono is 9.2 last time I went out. I been shooting 5 strings of 5 rounds each. I still get the occasional flier though but I'm gonna chalk that up to me and my fundamentals. Once the barrel heats up though that group starts to spread and drop in elevation. I'm thinking maybe its because is a stock Remington 700 and I haven't floated the barrel and bedded the action. I have already decided that from now on, my attempts at precision will be on my RPR chambered for 300 WM.

 

[TheOfficeT-Rex]

How did you sand the holder?

i had to sand 4k(or 6k? I dont remember) off the bottom of a sizing die before. I used a granite slab and wet sandpaper. I’m sure it’s not perfect, but I also prefer not to squish my shell plate with my dies (Dillon 550) so I left 2k of clearance.

 

[kingaling]

How did you sand the holder?

i had to sand 4k(or 6k? I dont remember) off the bottom of a sizing die before. I used a granite slab and wet sandpaper. I’m sure it’s not perfect, but I also prefer not to squish my shell plate with my dies (Dillon 550) so I left 2k of clearance.

So seems like the common method (according to the internetz) is to get some wet or dry fine grit, lay it on a nice flat counter top and go to work in a figure 8 motion (sandpaper stationary on the countertop and the shell holder in your hand making figure 8's over the paper). Even through a little bit of lube (remington gun oil is what i used) on the paper. It took a while. I actually reduced the grit after a while because I got tired of how long it was taking.

 

[TheOfficeT-Rex]

Fine grit sandpaper’s will take a lot of passes by hand to remove material, it’s mostly scratch removal once you get past 400 or so. Although, “fine” grit means different levels depending on who you talk to. You probably don’t need a 5k grit mirror finish on a Shell holder.

Also, when I say wet sanding, I meant with a hose, although any gun oil should help reduce the abrasive wear.

 

[kingaling]

Fine grit sandpaper’s will take a lot of passes by hand to remove material, it’s mostly scratch removal once you get past 400 or so. Although, “fine” grit means different levels depending on who you talk to. You probably don’t need a 5k grit mirror finish on a Shell holder.

Also, when I say wet sanding, I meant with a hose, although any gun oil should help reduce the abrasive wear.

Haha yeah I stepped down on the grit more than once during the process. I think I was on like 600 by the time I started seeing measurable results.

 

[TheOfficeT-Rex]

I think I was on like 600 by the time I started seeing measurable results.

Holy smokes. I’d start at 320 or 400 and go slowly to start, depending on how much I wanted to remove.

 

[Mad_Charlie]

Mineral spirits is a great cutting fluid when wet sanding steel.

 

[AllenOne1]

Holy smokes. I’d start at 320 or 400 and go slowly to start, depending on how much I wanted to remove.

180 grit for me. You're just removing material from the bottom of the die or top of a shell holder, they don't have to touch and they don't have to be perfectly flat.

 

[kingaling]

180 grit for me. You're just removing material from the bottom of the die or top of a shell holder, they don't have to touch and they don't have to be perfectly flat.

The reason I was concerned about it being perfectly flat was because if there is camover, the shell holder will not engage the bottom of the die perfectly flush. I was concerned that could cause the brass to not be pushed into the die perfectly causing a lopsided/concentricity issue. Like... the actual surface the case is sitting on is still level but when the "top" of shell holder starts to get pressed against the bottom of the die, it will do so unevenly causing more stress on 1 side than the other.

But yeah regarding the grit... I started out with a super fine grit before I realized that approach sucked. That's what I get for being a noob. lulz

 

[AllenOne1]

The reason I was concerned about it being perfectly flat was because if there is camover, the shell holder will not engage the bottom of the die perfectly flush. I was concerned that could cause the brass to not be pushed into the die perfectly causing a lopsided/concentricity issue. Like... the actual surface the case is sitting on is still level but when the "top" of shell holder starts to get pressed against the bottom of the die, it will do so unevenly causing more stress on 1 side than the other.

But yeah regarding the grit... I started out with a super fine grit before I realized that approach sucked. That's what I get for being a noob. lulz

If you wanted a perfect match between the die and shell holder you might be able to place a piece of sandpaper between the die and shell holder and pull it out while applying light pressure with the ram. Repeat for a couple of hours for a perfect match. Now you would need to index the die and shell holder going forward to keep them matched. Not 100% sure this would even work.

Or you could just make sure you have a couple thousands clearance as the press goes into cam over.

 

[Rocketmandb]

Or you could just make sure you have a couple thousands clearance as the press goes into cam over.

Yep...

 

[Deleted member 10043]

Just clean the case holder with brake cleaner once in a while and moveon.org

 

[kingaling]

Figured I would update this post with my results after a few mods to my equipment.
So I have been using a Hornady LnL Classic press. I was thinking about getting one of those 419 presses but then I was like... lets not spend that money just yet. In my press I noticed some play in the ram:

Comparing that with what I read about the 419 and how great it is in general to have no play in the ram, I went to Cabelas and found exact same press as my current one. Opened it up, ran the ram all the way up and there was absolutely NO play at all. Sold!

This press combined with my new Redding dies AND following the advice of you guys here that suggested to trim more off the shell holder so it doesn't touch the bottom of the die, resulted in .001" TIR or less runout on my resized brass.
I haven't been to the range yet but I'm sure all will be fine. It couldn't possibly be worse.

Most important things learned from this rabbit hole in my opinion:
1. Even though the instruction sheets that come with RCBS and Redding (probably most dies) instruct you to screw die in until it touches the shell holder, it's not a requirement. In my case it actually caused problems because I had to sand my shell holder.
2. There should be as little play in the ram as mechanically possible in your press. I don't know if it was always like that, or if it was something I did. But I'll be making sure I keep my new ram body clean and lubed from now on to reduce wear.

And on that note, I'm done. Thanks for the info guys!