Seating depth was all over the place

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Howa 9700

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Made an attempt to load about 30 rounds yesterday, with goal of making the entire run all the same. As identical as I could get them.....at least with equipment I have. Normal case sizing, primer install, etc, and trickled up powder to get all within 0.1 grain. Lee Powder measure was right half the time, but would throw charges as much as 0.2 grains light now and then. Amazingly, that being a big stick powder (IMR 4530) it only took a couple grains from the trickler to balance. May be more accurate than it seemed.

But that was not where the problem was. When seating bullets, I would bottom press out firmly, and sometimes a 2nd time, but when case length was measured, they varied by as much as 8 thousands, but most were 2 to 3 thousands more than what the dies were set for. Eventually had to resort to running them all thru again..... twice more, with a 90 degree turn the 2nd time. That finally got them all within 1 thousands of same length. And did that without touching the seating die.

Still using a Lee Breech loader press, which will bottom out, but does not cam over. Dies for that run were some of Pacific. Nothing special.

To get to a constantly reliable seating depth, does that take a press that cams over? Or do those require constant attention too?
 
Howa 9700 said:
Made an attempt to load about 30 rounds yesterday, with goal of making the entire run all the same. As identical as I could get them.....at least with equipment I have. Normal case sizing, primer install, etc, and trickled up powder to get all within 0.1 grain. Lee Powder measure was right half the time, but would throw charges as much as 0.2 grains light now and then. Amazingly, that being a big stick powder (IMR 4530) it only took a couple grains from the trickler to balance. May be more accurate than it seemed.

But that was not where the problem was. When seating bullets, I would bottom press out firmly, and sometimes a 2nd time, but when case length was measured, they varied by as much as 8 thousands, but most were 2 to 3 thousands more than what the dies were set for. Eventually had to resort to running them all thru again..... twice more, with a 90 degree turn the 2nd time. That finally got them all within 1 thousands of same length. And did that without touching the seating die.

Still using a Lee Breech loader press, which will bottom out, but does not cam over. Dies for that run were some of Pacific. Nothing special.

To get to a constantly reliable seating depth, does that take a press that cams over? Or do those require constant attention too?
Click to expand...
What cartridge, bullet, dies, and stuff like that.
 
6mm Rem, 100 grain hornady interlock and Pacific dies I bought 30 years ago, but just now starting to use.

I do expect a bit of variation in the bullets. Measured them by themselves with a comparator that measures off the ogive, and most within 1 to 2 thousands.......till one pops up that is 10 thousands off. When I find one of those, I set them off to the size.

My thinking is problem lies in the press. If I can get it right eventually, but have to run it down 2 or 3 times to get there, shouldn't have to be doing that. The Lee press bottoms out, but does not cam over.

Guess before going off the deep end, I have two other seating dies to try. One a Lee......the other a Bonanza that came with small base sizing die I never use. If they all do the same thing, it would point to the press.
 
If memory serves, instructions on most die sets say to adjust seating die body down to touch the ram, then back them up a turn or so, to get the crimper out of play. Then lock that down in place with locking collar. Then, adjust seating stem up and down. That is how this one is setup. But you still must bottom out the ram to get seating stem to same depth each time. Not sure if that sounds right with press that cams over, but that is what I think I meant.

Instructions with the Lee press has you set the seating die touching the shell holder, then a smidge more. That is the stop on the downstroke. Seating stem still goes up and down.

Edit: That is the instructions for Lee Press and Lee dies. Lee seating dies don't have a crimp feature as other dies do. Pacific dies setup same as normal. Bottom out the die on ram, then back them up a turn or so to get crimper up and out of the way. Then lock it in place. Then lower seating stem.

Now....Lee Press just bottoms out at bottom of the stroke. Ram and seating die not touching.
 
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If your ram touches the bottom of the seating die on each round it isn't the press. If the press has slop in the linkage it could be the press. With a feeler gauge check the top of the shell plate and the bottom of the die for a gap.
 
Lee dead length seat die is made to contact the shell holder. Comes as a 2 die set , with collet neck size die. https://leeprecision.com/reloading-dies/rifle-dies/lee-collet-dies/1

The contact between die bottom and shell holder acts as a stop.

Get a better press that doesn't "spring" Sorry.

The Redding Comp seat die can lightly make contact also. Both do not crimp.

Will the dead die fix the problem? My guess, no. A variation of .005" is ok by me.
 
From my personal experience what you are seeing are non-uniform shaped bullets. Measure the bullet length from base to tip. next you can pull the seating stem out of the die and check to see where the stem is making contact on the die. If contact is somewhere between the ogive and the tip if it is not in the same location every time it will cause variation. Just as length differential between ogive and tip.

Once was loading a box of plated 115gr 9mm that was doing the same thing so I stopped. Opened a new box and started again and it all just magically stopped. Nothing wrong with the press or the dies, just the bullets.
 
Had a problem similar to your's a few years back. Had trouble to find the problem but in the end it was the press. I had a hair line crack in one of the linkages that only manifested itself at full stroke.
 
Take your measurement of the ogive part of the bullet for comparison. This way you eliminate the malformity of the nose. You can use your seating stem if you remove it from your seating die. Bullets vary as said, but normally if you measure from a point that is referenced (ogive) you will get a much more consistent measurement. Then expect around 0.003" variation with a good grade bullet. More on the cheap stuff.
 
Already did that. I'm using a Sinclair bullet comparator to measure from the ogive.

If it turns out the press is source of variation, may need to consider an upgrade. Been able to load some halfway decent stuff that goes BANG, but trying to improve on that.
 
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Howa 9700 said:
6mm Rem, 100 grain hornady interlock and Pacific dies I bought 30 years ago, but just now starting to use.

I do expect a bit of variation in the bullets. Measured them by themselves with a comparator that measures off the ogive, and most within 1 to 2 thousands.......till one pops up that is 10 thousands off. When I find one of those, I set them off to the size.

* * *

Guess before going off the deep end, I have two other seating dies to try. One a Lee......the other a Bonanza that came with small base sizing die I never use. If they all do the same thing, it would point to the press.
Click to expand...

Did you have any luck trying different seating dies? I would expect the Lee seater stem (maybe those others too, but I have no experience with them) to get along just fine with Interlock bullets. Before blaming the press, I would try a different type of bullet (ELD-M?) and see if you are still getting the same level of variation in your finished cartridges.

Particularly in hunting and plinking ammo, I expect a few thousandths variation in the final cartridge overall length (COAL) of my loaded ammunition due to variation in the bullets---more with BTHP bullets and less with polymer tipped bullets. I would have to go back and look at my notes to see if I've recorded my observed variation with Interlocks as I don't recall offhand. I do typically see noticeably less variation in cartridge base to ogive (CBTO) length measured with a bullet comparator than I do COAL measured without because bullet noses often vary. You mentioned that you had a bullet comparator, but it's unclear to me whether you measured the CBTO of the cartridges or just used the comparator on the bullets themselves. If you haven't measured CBTO, do that and see if the variance is still as great as the variance you're seeing in COAL. If the variance decreases substantially, then I think you can conclude you are seating them "consistently" notwithstanding the variation in COAL.

My only other advice is to: (i) record what you are observing/measuring in your reloading notes, and then (ii) go shoot them and see if you're seeing any difference on target (and then record that back to your reloading notes). This year I used some old, factory second Edge TLRs that behaved similarly to what you describe: most of bullets measured within 2 thousandths but every now and again I'd have one vary by 10 thousandths, and that difference led to the same kind of variance in CBTO. It was infuriating. But, I marked the outliers and then shot them next to the others. They all shot to same POI and were plenty accurate for my hunting purposes out to 350 yards. I couldn't tell which were which from my on-target performance.

I understand the obsession with consistency/accuracy (it's part of the reason I reload---I like to be as consistent as I can be, even when I don't need to be), but you're not going to eliminate all of the variance in loaded cartridges without using match grade components and dies. And if you're going to go that route, then I suppose you can blame the press too and get a heavier/stiffer one of those while you're at it.

Edit to add: I missed your post where you said you were measuring to the ogive, so ignore that part.
 
Process I'm using is to first measure 2 or 3 finished rounds.......actual overall length to see where those are, then do the same with bullet comparator to ogive. That lets me "calibrate" the rounds so I know how much the comparator is adding. Then measure all subsequent rounds off that. Goal is to eliminate any variation in length from the tips. Ogive should be the most consistent measurement.

Have also measured a large lot of bullets. As suggested, the Interlocks are normally withing 2 thousands, but then a few will run 3 or 4 over the baseline, and now and then will find a bullet 10 thousands over. Those get set aside. Have been tempted to sort an entire box into an egg carton so as to pull identical bullets when doing load workup. Eliminate that variable. Doing this with Interlocks as that was what I had. As of today, also have SST and ELD-X bullets. Also have some Noslter Partitions and those were pretty consistent. All this is with hunting bullets for hunting rounds. Hopefully accurate hunting rounds.

Have found a seating depth variation of up to 5 to 10 thousands on almost every seating die I have, and that includes one with Micrometer adjustment on it. But.....when I run these thru a 2nd time........with a 3rd bottom out after a 90 degree turn, they all fall within 2 to 3 thousands of each other. But it is taking me three full downstrokes, firmly bottoming out at the bottom, to get them there.

BTW for those wondering about all this obsession, have seen numerous references to where loads can be "tuned" by altering seating depth. Groups opening and closing by altering nothing but seating depth. Interval to test is 3 thousands. If that theory is valid, and if my test loads have that much or more variation, it could be possible that a flyer in a group was from seating depth, not the powder load. So goal is to just make them all the same to eliminate the variable. Easier said that done......at least for me.
 
Howa 9700 said:
BTW for those wondering about all this obsession, have seen numerous references to where loads can be "tuned" by altering seating depth. Groups opening and closing by altering nothing but seating depth. Interval to test is 3 thousands. If that theory is valid, and if my test loads have that much or more variation, it could be possible that a flyer in a group was from seating depth, not the powder load. So goal is to just make them all the same to eliminate the variable. Easier said that done......at least for me.
Click to expand...

I’m going to make a suggestion here that is based on my own personal experience, so ymmv. Don’t fret that much about seating depth for hunting bullets like the Interlocks. Find something that’s safe and gives acceptable accuracy and move on. When I think of .003” increments, I think of competition shooters who have crazy good equipment to control all known variables and practice black magic to manipulate barrel harmonics. Barnes suggests working in .025” seating depth intervals when using their copper bullets. I do that for all hunting bullets, if I mess with it at all.

Others may reload much more precisely than I do and may have had better luck chasing things like this. But with hunting ammo in particular, I usually jump them .050” to lands and don’t worry about seating depth too much unless I just can’t get the bullet to shoot after playing with other variables. It’s not that tuning seating depth doesn’t work—too many people who shoot better than me know that it does. But in my mind it’s just waisted effort unless you’re chasing 1/2 moa accuracy or better. For hunting loads, I focus on getting “good enough” accuracy at or around a target velocity, under max load, and stop load development. Bonus points if I can achieve a relatively low velocity ES and SD, but honestly for my hunting purposes it doesn’t matter. Here’s an article challenging “conventional wisdom” on seating depth you might find interesting. https://precisionrifleblog.com/2020/04/28/bullet-jump-research-and-load-development-tips/

It takes a lot of shots to prove that any particular load is statistically better than another. Another article on that subject: https://precisionrifleblog.com/2020/11/29/statistics-for-shooters/. I know I spent a whole lot of time analyzing 3-shot or 5-shot groups and drawing rash, unmerited conclusions from them, only to have my “best load” shoot rather average the next time out. I still chase stuff like this with my target rifle because I love tinkering with reloading. But my experience with hunting rifles and hunting bullets is it’s not worth the effort most of the time. Once your hunting rifle and load can consistently group 5 shots around an inch at 100 yards at a velocity you like, stop tinkering and practice with that load.
 
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I was doing some other work in my reloading room today, and so I went back looking for data on interlocks I’ve loaded in the past. I didn’t find where I’d recorded actual variance in cbto or coal in a useful way, but I still have 7 rounds of 30-06 loaded with 165 interlocks on hand. So I measured them. They were loaded on an RCBS single stage press using Redding dies (including competition seater). Bullets seated to top of cannelure. COAL varies by 0.006” over those 7 rounds while CBTO varies by only 0.002”. I would have just set the seating stem and left it—I don’t chase a particular overall length by changing the die setting from round to round while loading.

Just thought it might be useful for OP to have some actual numbers with same bullet type to compare to. It’s not a lot of data, and I’m not the forum’s best reloader (by a long shot), but it’s some actual data.
 
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Are your cases trimmed to the same length? I have the Lee breech lock press, was my first press. I had the same kind of problem in the beginning but I bought my trim tools and trimmed all of my cases and it fixed the problem.
 
Howa 9700 said:
Process I'm using is to first measure 2 or 3 finished rounds.......actual overall length to see where those are, then do the same with bullet comparator to ogive. That lets me "calibrate" the rounds so I know how much the comparator is adding. Then measure all subsequent rounds off that. Goal is to eliminate any variation in length from the tips. Ogive should be the most consistent measurement.

Have also measured a large lot of bullets. As suggested, the Interlocks are normally withing 2 thousands, but then a few will run 3 or 4 over the baseline, and now and then will find a bullet 10 thousands over. Those get set aside. Have been tempted to sort an entire box into an egg carton so as to pull identical bullets when doing load workup. Eliminate that variable. Doing this with Interlocks as that was what I had. As of today, also have SST and ELD-X bullets. Also have some Noslter Partitions and those were pretty consistent. All this is with hunting bullets for hunting rounds. Hopefully accurate hunting rounds.

Have found a seating depth variation of up to 5 to 10 thousands on almost every seating die I have, and that includes one with Micrometer adjustment on it. But.....when I run these thru a 2nd time........with a 3rd bottom out after a 90 degree turn, they all fall within 2 to 3 thousands of each other. But it is taking me three full downstrokes, firmly bottoming out at the bottom, to get them there.

BTW for those wondering about all this obsession, have seen numerous references to where loads can be "tuned" by altering seating depth. Groups opening and closing by altering nothing but seating depth. Interval to test is 3 thousands. If that theory is valid, and if my test loads have that much or more variation, it could be possible that a flyer in a group was from seating depth, not the powder load. So goal is to just make them all the same to eliminate the variable. Easier said that done......at least for me.
Click to expand...
The .003 adjustments are to find a window, just like in ocw when finding a charge window. Then load to the long side of the window as the throat will never get any shorter. Stay with the same length until on target results say you need an adjustment.
 
make some dummy rounds with flat nose bullets and a flat seating stem to see how much variation you get and compare
 
I noticed the same problem with ammo loaded on my rcbs ammo crafter press. I tried loading on my Hollywood senior press and got much better Loa uniformity (1-2 thousands variation). It comes down to how much play there is in the linkages.
 
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