Jim Watson
Member
Right, same as the conventional single shellholder standardized long ago by Pacific.
The red area is where a rifle or pistol die will make contact. The distance from the platform to the red area should be close to .125" View attachment 1105627
The shell plate can be placed on any flat surface to measure each station.
This
Part 13781 Shellplate Platform on 550. View attachment 1105632 The platform is bolted to the Main Shaft/ ram.
Brass is most important for accuracy.
For 45acp, i buy 500 new Starline and keep them is the same rotation. All fired & reloaded the same.
If using range brass, accuracy may not be as good.
I did test 5 different brands for bullet pull/neck tension. To move the bullets, it can run fron 45 lbs to over 100 lbs. This much difference cant be good for accuracy. (Not tested)
I’m more interested in if there’s really measurable precision or accuracy increases in pistol rounds. I am a proponent of consistency, including COL or CBTO, but there are a lot of variables in reloaded rounds and for short range competition loads I’m not sure it’s worth chasing a thou or two.
that would have flipped the results in my favor if a single shot had been in the next advantageous position.
To be clear, I am going to ask how you are measuring your powder down to the thousandths of a grain and how sure you are of your check method. If +/- .001” is significant +/- .001gr is too. There are threads on this forum about measuring down to the thousands of grams, BTW so the subject is of consequence.Ok, I want to "bore out" the seating insert on my 9mm Redding Competition die.
The objective is to prevent any contact of the inside of the seater insert with either the bullet meplat or ogive, except at just ONE point: The very bottom "rim" of the seater insert.
The inner diameter of the insert at the rim is just the right size to catch the bullet a short distance above the theoretical intersection of bullet shank and ogive. So, if I can bore out the rest of ID of the insert, and prevent any other point of insert-to-bullet contact, i'll have my "prefect hollow cylinder" which will always engage that precise height above the base of the cartridge case. Hence, a consistent BTO. (If nothing else, like a non-flat or tiltable shell plate as discussed earlier, interferes!).
I realize that the "right" way to do this is to take the insert to a machinist and ask him to do it using a lathe or other machinery that only a machinist has on hand. But I am wondering if I could possibly do it myself. I do realize that perfect concentricity of the drill bit (or other suitable cutter device?) with the insert's centreline is critical, especially on the Redding die which encapsulates the cartridge case and bullet both before letting the bullet enter the insert. If the boring is off center at all, the pre-centered bullet will crash into one side of the insert instead of entering it smoothly. So, I doubt I can "do this at home".
I have the following applicable tools in my home workshop to use in this effort:
- A high quality 17" 1.5 hp floor standing drill press with infinitely variable drive speed and even digital rpm display
- A modest collection of drill bits in the "usual" sizes, but not any "unusual" sizes. It turns out that a drill bit with diameter of "about" 9/32" would be the right size to use. A 1/4" drill bit would be too small. A 5/16" drill bit would be too large (It would make the "hollow tube" wall too thin, and would require incredible accuracy in centering of the drill bit in the insert opening). Home Depot offers such a 9/32" drill bit, only via online ordering, and I had ordered one on Monday, and my wife just told me that it has arrived at our house. So, I have THAT part of the required solution, for either me or a machinist to use.
Is there ANY PRACTICAL way I can do this at home? (I'm thinking you'll say "no", but thought I'd ask)
And yes, it IS worth trying, as this approach is exactly how I successfully solved the exact same problem with my 6.5 Creedmoor Redding Compeition seating die. But I had a local gunsmith right nearby who could do it literally the next day for me on his lathe. I don't have such a resource in my new home city.
Jim G
We usually picked up a couple of points as the bigger bullets (i.e. 45acp vs 9mm) hit the perforation to a higher zone, Joe once gained six points.
To be clear, I am going to ask how you are measuring your powder down to the thousandths of a grain and how sure you are of your check method. If +/- .001” is significant +/- .001gr is too. There are threads on this forum about measuring down to the thousands of grams, BTW so the subject is of consequence.
Ok, I want to "bore out" the seating insert on my 9mm Redding Competition die.
The RCBS die set comes with 2 seating stems. Not a perfect fit to the bullets, but close enough. My COL variation was less then factory rounds.
The expander is an M type. This helps with bullet alignment. Perfect for lead bullets. My G3C is not accurate enough to notice, or its my poor eye sight these days?
View attachment 1105728
Hand me a Dr. Pepper and pass the popcorn, please. I'm going to sit back and watch how many ideas are rejected because they're hard, or expensive, require learning some new skill, or take a lot of effort.The OPs whole argument breaks down when it meets a revolver. It is an interesting read tho. I'm 78, short on components, and believe after Nov. things will get better within 2 more years, but I'm not interested in bug hole accuracy with handguns. In fact, for the purpose for which Sam Colt first invented them, a 3" group is better'n all in the same hole.
I'm going to drink Pepsi and eat popcorn and watch this thread tho....
The OPs whole argument breaks down when it meets a revolver. It is an interesting read tho. I'm 78, short on components, and believe after Nov. things will get better within 2 more years, but I'm not interested in bug hole accuracy with handguns. In fact, for the purpose for which Sam Colt first invented them, a 3" group is better'n all in the same hole.
I'm going to drink Pepsi and eat popcorn and watch this thread tho....
And, yes, the Dillon "round nose" one was a BIG improvment
The great annoyance of the Dillon seating die is that it is adjusted by turning the whole die body in and out on coarse sloppy threads. OK if you get it adjusted for one bullet, one OAL, and stay with it, but if you want to make up different loads, it is a pain in the neck.
I have the Hornady Microjust (cheaper than Redding) in 9mm and .45 for 1050, an old Lyman in the 550 head for .45 Small.
By "on and on", I'm sure you meant to include ambient temperature, barrel fouling, powder position at instant of firing, primer seating depth, primer-to-primer-pocket fit and flash hole diameter.A little off topic here, but if you make a setup cartridge at the COL(s) you want, it’s very easy to get the Dillon seater positioned within a few thou. It might not be as easy as a micrometer but it’s fast. I switch between Blue RN and RMR FPs all the time. And that includes flipping the seater stem . Takes less time than changing heads.
I’m still interested in the CBTO discussion, but not sure where that falls in the overall debate of accuracy related to bullet consistency, propellant, neck tension, case length, concentricity, charge weight, and on and on.
I’m still interested in the CBTO discussion, but not sure where that falls in the overall debate of accuracy related to bullet consistency, propellant, neck tension, case length, concentricity, charge weight, and on and on.