Redding Competition Seater Question

[FALex]

So I was going through and loading a few rounds and decided to check seating depths on each round. Normally, I will seat the first 5 or so, make sure the depth is where I want it, and go with it. Anyhow, I noticed that I was having some swings with my depths. I was measuring to ogive using the Hornady LNL measuring tool and Lapua Scenars. For the most part, some of the swings were about +/-.001-2 but I had a few where they were -.005 to .006. I did note that the rounds with these more significant swings required more pressure on the ram than the other rounds.

I'm assuming there's a correlation there, but that leads to a secondary issue wherein some cases have a tighter neck tension than others (I prepped all of the cases the same way, turning the necks, running them through a FL bushing die with a 289 bushing). It is important to note that I was necking up .243 brass to .260. Is it possible that some of the cases had some "spring back" as a result of originally being .243?

Is it normal to have the minor deviations of .001-.002? Anyone had any experiences where they had prepped brass all the same, but ended up having some cases with more constricted necks?

Thanks all.

 

[mdmp5]

The seating stem seats off the superior portion of the ogive. Variance in bullets are the reasoning behind the seating depth variance you are experiencing

 

[Milo 2.5]

The seating stem seats off the superior portion of the ogive. Variance in bullets are the reasoning behind the seating depth variance you are experiencing

His varying seating pressure has just as much to do with it.

 

[FALex]

Thanks for the responses guys. Just so I am clear: 1) The neck tension will directly effect the ability to seat bullets at a desired length and 2) there is a variance in the location of the ogives of bullets, ergo, the ogive placement is not 100% consistent, bullet to bullet.

This about sum it all up?

 

[Cattlelackranch]

Are you crunching powder with compressed loads?

 

[Fursniper]

All a bushing die does is size the outside of the case neck. An expander mandrel sizes the INSIDE of the case neck which IMO is the more importent of the two giving you a more consistent bullet release. Yeah, if you're using the expander ball in the sizing die, yes, that works the internal case neck too but again, (imho) will also give you more neck runout. Yes, it's also an additional step (expander mandrel), so you pays your money and picks your poison lol.

As to bullets, yes, plated bullets are different in size, length AND width (sometimes the reason for more felt seating pressure). Unfortunately, if you want bullets all the same size you have to go to solids which also unfortunately means you must sell one of your children to afford them...... (unnecessary anyway unless you're shooting ulr distances & demand the best...)

 

[Sig Marine]

You said you were necking up so I assume this is the first sizing and seating for your .260 using .243 brass. You also didn't mention if this was new brass or if it had been fired a number of times. Also, if new brass or brass cleaned in stainless steel media or unltrasonic, did you you lube the inside of the necks before seating he bullets? This all said, variations in neck diameter and the variations felt in bullet seating pressure are related and partly responsible for the variations in seating depth. Once you've fire-formed the brass to your .260 chamber, sizing should be more uniform but variations can still exist. If you want to take this to the next level, annealing will help with sizing, felt pressure when seating bullets and, as a result, more consistent seating depths. Inside neck lubrication will also reduce the amount of variation. Also, as mentioned above, some bullet manufactures are more consistent in their ogives which will result in more consistent seating.

I use Lapua brass and Berger 140 Hybrids, don't turn my necks, use a Redding FL sizing die w/bushing, Redding Comp/Micro seater, anneal after every firing, lube the inside of my necks with dry graphite and my seating depths are within .001 with 80% being the exact depth and all feel the same when seating the bullet.

Given some of the advice you gotten, I appreciate a follow-up report giving us feedback on what worked or didn't work for you in helping to eliminate the large seating depth variations...Semper Fi

 

[Milo 2.5]

One other thing that helps a lot is buying the vld seater stem, it grabs the bullet farther down the ogive. You need to sift through the advice given, we all come to a result in a different fashion. Also remember seat depth is way more critical in a new chamber, once you've found your seat depth, rarely can you go closer to the lands and retain accuracy for the first 500 rds or so.
Sending link to long stem, pull your die apart and measure, the short one is 1.005" long for reference.
http://www.midwayusa.com/product/80...onfirmation-_-OrderConfirmation-_-ProductLink

 

[FALex]

Thanks for the info guys. Yes, this was brand new brass that had been necked up to .260, that's why I was curious if there was some spring back. I had no idea people lubed the inside of their necks to seat bullets, that doesn't mess with the powder at all?

So my process is to FL size the brass and turn the necks (already lubed, the .243 to .260 cases are extremely tight on the neck turning mandrel). Once I complete those two steps, I toss the brass into my US cleaner for a few minutes to get the lube off. I dry them, neck size with the .289 bushing, trim chamfer, then load.

Milo 2.5 are 139 Scenars "VLD" type bullets, or does using that seater not necessarily require a VLD bullet?

 

[Milo 2.5]

Thanks for the info guys. Yes, this was brand new brass that had been necked up to .260, that's why I was curious if there was some spring back. I had no idea people lubed the inside of their necks to seat bullets, that doesn't mess with the powder at all?

So my process is to FL size the brass and turn the necks (already lubed, the .243 to .260 cases are extremely tight on the neck turning mandrel). Once I complete those two steps, I toss the brass into my US cleaner for a few minutes to get the lube off. I dry them, neck size with the .289 bushing, trim chamfer, then load.

Milo 2.5 are 139 Scenars "VLD" type bullets, or does using that seater not necessarily require a VLD bullet?

I think it'd work better on the scenar than a berger, it's fatter ogive bullet.

 

[Praeger]

Is it possible that some of the cases had some "spring back" as a result of originally being .243?

Yes. Even with brass from the same lot, some pieces could have slightly different hardness. You can easily check with a micrometer. After you have processed your brass, pick one and measure the neck diameter. Make sure the OD of the neck has been chamfered so you don't measure any burr at the case mouth. Use the lightest pressure on the micrometer thimble, it is easy to compress the casing neck and get a false reading. Lock the micrometer thimble and check another piece. You can quickly sort out any outliers. Use a micrometer stand, it'll speed up the process.

Is it normal to have the minor deviations of .001-.002? Anyone had any experiences where they had prepped brass all the same, but ended up having some cases with more constricted necks?

Yes. For my match ammo, I'm happy if everything falls into a .003" variance. Tighter neck tension will add .001 or .002 to a CBTO length. Some bullet ogive diameter variance can also be expected.

 

[Sig Marine]

...I had no idea people lubed the inside of their necks to seat bullets, that doesn't mess with the powder at all?... I toss the brass into my US cleaner for a few minutes to get the lube off. I dry them, neck size with the .289 bushing, trim chamfer, then load.

Stainless Steel pins and Ultrasonics do a very good job cleaning brass, including the inside of the necks. By removing all of the carbon residue inside the neck, you have created a metal to metal contact surface when seating the bullets which can make for uneven tension when seating. Dry graphite lube inside the necks will not have any effect on your powder, will solve the metal-to-metal friction problem and should give you more consistent seating.

 

[domdoc]

The Redding Competition micrometer seating die had a problem years ago with not being able to seat against a tight neck, or to compress a powder column. I bought other seaters, and I don't know if Redding changed anything with that die. Any box 2-die rifle set will seat just fine. I have Forster micrometer, Forster Benchrest, and Lee Dead Length seating dies. When I check total cartridge runout, they are all the same (under 0.002"). So I usually use the Lee, which is the easiest to use. Unlike most box 2-die sets' seating dies, the Lee does not crimp, so you can run it down to the top of the press ram, which automatically "squares" the die. Others that crimp require a spacer of some sort, to keep the crimping section from touching the bullet. Don't crimp.