Lee Seating Die Inconsistency?

[peeplwtchr]

Hi All-

New to reloading. I bought a 4 die Lee 9mm set. When I first started using the dies, the Seating die was dead on accurate. After maybe 500 rounds, I am getting OAL variances. Today I was getting .002 or .003 variances.

I was shooting for a 1.100 OAL, using Berry's bullets and Titegroup 3.9, 4.0, 4.1 gr.. I cleaned the inside of the seating die last week. I checked my caliper against another. I use minimum flair, just enough to get the bullet stable.

1. Does the variance matter in terms of performance?

2. What are some possible causes?

3. Is there a better Seating die, and why?

Thanks!

 

[Project355]

It may be the way the seating stem is interacting with the ogive of the bullet. I use the term ogive in a more generic sense, since some bullets are straight taper and such...

Anyway, if there is a slight variance in just where and how the bullet itself interacts with the seating stem, you'll get some variance in seating depth.

Think of it this way. You're ram is still moving to the same spot, with the same shell holder. The die is firmly in your press, and the seating stem isn't moving, so the only thing left is how the stem pushes on the bullet. Its most likely dissimilar curves, or angle against curve.

If your overall length is varying only .003, I'd not worry too much over that.

(edited in...)

Lee has a rather coarse adjustment for the way it limits the seater travel. I don't have Lee 9mm dies, but do have Lee 45acp dies. The "stem" actually floats in die, and is stopped by the aluminum seating adjustment, which has an O-ring for friction against moving. What I said up above can easily be your problem, but ... the Lee setup is not quite as trustworthy as some others. You can get gunk/crud between the floating "seaing stem" and its adjustment stop screw, and that can also cause issues.

But... only .002 or .003? I'd seriously move on to SHOOTING those rather than being concerned about 'em

 

[peeplwtchr]

Okay thanks. I think I discovered the issue. I cleaned the inside of the Seating die last week, with Qtips and alcohol, 3 times, I just used a bore mop, and discovered brass flakes where the lip that meets the mouth of brass is. I had no idea I'd need to clean a Seating die. Ran 4 bullets, and was only off by .001 on one dummy round.

And as far as the coarse adjustment, I agree. I'd like something with reference points, as I am trying many powders, and will have many OALs to reset for.

 

[LiveLife]

New to reloading ... 4 die Lee 9mm set ... getting .002 or .003 variances.

2. What are some possible causes?

When using mixed range brass with bulk bullets, OAL swing of .003"+ is not uncommon. Tilting bullet while being seated will also add to the OAL variance. Many reloaders, even seasoned reloaders would be happy with .002"-.003" OAL variance using mixed range brass and bulk bullets.

You are doing good!

If you are using progressive press, shell plate tilt/deflection will also add to the OAL variance and separately resizing the bullet will decrease the OAL variance but with .002"-.003" OAL variance, I would not bother.

1. Does the variance matter in terms of performance?

It's not the "finished OAL" rather "chambered OAL" that will determine the accuracy of your rounds. If you are experiencing bullet setback, it will likely overshadow finished OAL variance.

If you are not experiencing any bullet setback, then .002"-.003" OAL variance may not affect accuracy much but when accuracy testing to see if it does, you also need to factor shooting variance that could overshadow.

3. Is there a better Seating die, and why?

I use Dillon, Hornady, Lee and RCBS dies and prefer Lee dies for 9mm.

Why?

Lee 9mm resizing carbide ring is tapered with nice radiused die mouth to produce smooth tapered resized case. And Lee dies tend to be on the "undersize" side and they tend to reside OD to smaller diameter and resize further down towards the case base for greater neck tension.

For my USPSA match loads, I used Dillon 550 and Lee Pro 1000 and my finished rounds' dimensions were consistent and my match pistols could not tell the difference and been happily reloading over 600,000 rounds mostly using Lee dies.

I do like Dillon's feature of being able to take apart the die from top without removing the die from tool head.

 

[peeplwtchr]

Uuuuuuuuuh, 600k rounds? WHAT THE ****?

I am using only Geco brass right now, I sort by Headstamp, as it is one of the best factory rounds in all my guns. I shot thousands, so am now reaping the benefits of free brass. Glad I cared enough to save it over the last year and a half, on the 1 in a million chance that I would ever waste my time reloading. All I can say now is WTH did I just get myself into?

I was suspecting tilt as well, great info, thanks!

 

[LiveLife]

600k rounds? WHAT THE ****?

And $175,000 (Yes, 3 zeros not counting rifle cartridges) and 14 presses later .

 

[bersaguy]

Agreed, Lee is good equipment, but has its limitations. .003 is about as consistent as it gets, unless I am very meticulous about cleaning and set up. Also, I've found some variation with Berry's Bullets as well...in addition to them being quite soft. If I seat them more than once, it seems they deform a bit and can measure a bit off. Also, if my crimp is too heavy, they can grow .001-.002. I think I've hit the limit of consistentcy with Lee and Berry's. Not to say I'm not turning out good rounds, they all shoot just fine, but if I want to get absolutely dead on, match grade results, I think I would need to upgrade my equipment and components. Not something I want to do at this point.

 

[LiveLife]

Agreed, Lee is good equipment, but has its limitations. .003 is about as consistent as it gets

Not so fast as we already myth busted that.

Using (ELEY match grade) RMR bullets with very consistent nose profile/ogive where bullet seating stem contacts further down from tip, Lee equipment is capable of .001" OALvariance - https://www.thehighroad.org/index.php?threads/9mm-oal-not-consistent.873260/page-2#post-11604629

Shooting Sports USA reviewed ELEY .38 Super Comp match ammunition with RMR 124 gr FMJ RN bullet ... measurements showed very consistent .001" OAL variance ... And produced 25 yard average group size of 1" - https://www.thehighroad.org/index.php?threads/rmr-bullets.864542/#post-11413616​

Here is summary of OAL variance of reloading regular vs using pre-resized brass. The results illustrate the benefit of using pre-resized brass to reduce OAL variance on progressive press (Pro 1000 used), even with mixed range brass - https://www.thehighroad.org/index.p...progressive-press.833604/page-2#post-10779806

BLAZER - 9mm RMR 115 gr FMJ:

• Regular: 1.115" - 1.118" = .003" OAL variance
• Pre-resized: 1.115" - 1.116' = .001' OAL variance

R-P - 9mm RMR 115 gr FMJ:

• Regular; 1.115' - 1.118" = .003" OAL variance
• Pre-resized: 1.115" - 1.116' = .001" OAL variance

WIN - 9mm RMR 115 gr FMJ:

• Regular: 1.114" - 1.117" = .003" OAL variance
• Pre-resized: 1.114" - 1.115" = .001" OAL variance

BLAZER - 9mm RMR 124 gr FP:

• Regular: 1.070" - 1.072" = .002" OAL variance
• Pre-resized: 1.069" - 1.070 = .001 OAL variance

 

[peeplwtchr]

And $175,000 (Yes, 3 zeros not counting rifle cartridges) and 14 presses later .

Dude, you're like a heroin addict of reloading.

 

[LiveLife]

Dude, you're like a heroin addict of reloading.

Reloading is not just a hobby but a passion for some of us.

And there are many THR members who will put me to shame.

Remember that life is short and we are all going to die? I am sure going to try to reload 1 million rounds before I kick the bucket.

 

[peeplwtchr]

Reloading is not just a hobby but a passion for some of us.

Yeah, a year ago when I saw someone at the range using a cart to haul thier gear, I told myself literally "I will never let myself get to that point". Guess what; I needed one 3 months later.

This is going the same direction.

 

[cfullgraf]

Today I was getting .002 or .003 variances.

Do you realize how small 0.001" is?

0.002" to 0.003" variance is well within the measurement error of most reloaders and the measuring equipment they use.

As others have said, your reloads will perform just fine.

 

[12Bravo20]

I personally would not worry about .002"-.003" OAL variance as long as the rounds pass the plunk test along with feed and shoot well out of my pistols.

The average piece of paper measures 0.004" so you are talking about less that the thickness of paper difference.

 

[Trey Veston]

I've only been reloading a few years and when I started (.45 Colt) I noticed that there were variations between OAL and powder charges round to round. It drove me absolutely nuts. When I set a mechanical device to a precise number, it should stay at that number, dang nabbit! I bought the Lee single-stage press kit and solved the powder charge variations by acquiring a 70's vintage RCBS powder measure.

But, the OAL variations continued even as I expanded to 10mm, 40 S&W, .450 Bushmaster, and 9mm. I've relaxed a bit over the years and now check about every tenth round and adjust as necessary. I still use that original single-stage press and have a mixture of RCBS, Lee, and Hornady dies and the Hornady dies seem to be more consistent.

As others have stated, .003" is within spec and nothing to be concerned about.

 

[Hooda Thunkit]

If you are concerned about .003 variance in your loaded rounds, go get a box of factory 9mm (if you can find one). Grab your measuring apparatus and measure a dozen of those rounds. I think that will ease your concerns.

 

[Walkalong]

If your overall length is varying only .003, I'd not worry too much over that.

Yep, even a .005 spread isn't bad, .003 is good, and with a great fitting seater stem and a good batch of cases (Not 15 headstamps with thin and thick brass) nearly .001 is achievable, but unusually, and not needed.

 

[Project355]

OAL should not be brass depenent, as seating depth is regulated by the face of the cartridge head against the shell holder in relation to the seating stem. But I guess sone cases may flex

 

[Bill M.]

"Is there a better Seating die, and why?"

Yes, there is a much better seating die. The Redding Competition seating die is a much better seating die than the Lee. The why is because it has a moving sleeve that holes the bullet in alignment with the case while seating. And because the die is made to good tolerances. And because the shape of the bullet plunger matches a lot of bullets.

I replaced my 9mm Lee seating die with the Redding and have been very happy with the loads from the new die. Actually I like the die so well that between Ebay and Midway I now have the competition seating die for all 3 handgun cartridges I load. A large expense but to me the results have been well worth the cost.

 

[mokin]

If you are concerned about .003 variance in your loaded rounds, go get a box of factory 9mm (if you can find one). Grab your measuring apparatus and measure a dozen of those rounds. I think that will ease your concerns.

I did that one night. I felt a little silly regarding my level of quality control when I finished.

 

[Walkalong]

OAL should not be brass depenent, as seating depth is regulated by the face of the cartridge head against the shell holder in relation to the seating stem. But I guess sone cases may flex

I used to think the same thing, but some
cases are just more resistant to sizing and expanding, and when we are trying for the lowest possible spread consistent brass does better.

When I retired my horrid mix of all kinds of range brass and sorted out 3K plus all the same headstamp it did better all around. Not a huge difference, but it improved things.

 

[murf]

neck tension is a much more important issue. a round banging into the feed ramp and loosing ten thousandths off the length has a much greater affect on your results than a three thousandth variance in seating depth.

luck,

murf

 

[sequins]

Brass characteristics vary. A bullet might seat more deeply on thinner brass, or less springy brass. By about .001-.002" in my experience. Using pulled LC cases i bought pre-primed from RMR vs. Lapua factory new, with no expansion and .002" undersized mouths (the surplus isn't perfectly even, so maybe 0.001" - 0.004") my surplus brass varies .001" - 0.002" in COAL my lapua does not vary.

 

[Project355]

I used to think the same thing, but some
cases are just more resistant to sizing and expanding, and when we are trying for the lowest possible spread consistent brass does better.

When I retired my horrid mix of all kinds of range brass and sorted out 3K plus all the same headstamp it did better all around. Not a huge difference, but it improved things.

Basic mechanics dictates some flex someplace. I hear what you're saying though, and it could be variable seating force was/is causing a bit of (for lack of better term) micro wedging between ogive and seating stem. The stem being forced a bit more downward on the ogive due to greater effort to resist seating on behalf of the case.

 

[rfwobbly]

Do you realize how small 0.001" is?

0.002" to 0.003" variance is well within the measurement error of most reloaders and the measuring equipment they use.

Allow me to put this in perspective... the average human hair is 0.003 to 0.004" in diameter.

 

[peeplwtchr]

"Is there a better Seating die, and why?"

Yes, there is a much better seating die. The Redding Competition seating die is a much better seating die than the Lee. The why is because it has a moving sleeve that holes the bullet in alignment with the case while seating. And because the die is made to good tolerances. And because the shape of the bullet plunger matches a lot of bullets.

I replaced my 9mm Lee seating die with the Redding and have been very happy with the loads from the new die. Actually I like the die so well that between Ebay and Midway I now have the competition seating die for all 3 handgun cartridges I load. A large expense but to me the results have been well worth the cost.

Researching this die. Pricey, but the concept seems worth it. Very unique and sensible design compared to others, probably will end up in my stash at some point. New project for the backlog: Ladder testing Lee Seating die vs. Redding. Rabbit hole of reloading.