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View Full Version : Exasperation, OAL and the Hornady LNL progressive.


wbunning
12-11-2016, 5:41 PM
So I've been using this Hornady LNL progressive press for a couple of years now. Overall, it's been "OK". Not superior, but OK. Loading only pistol calibers so far. Some folk have expressed issues with the priming system, but that system on mine has been rock solid in that respect.

My problem has been in variance the cartridge overall length. One day, after getting all the dies tuned in to where I thought I wanted them, I started micing each finished round. Jeebus! I was getting OAL variation of +/- 0.004. I tinkered and tinkered, labeled the shell plates and recorded OAL for each, replaced the shell plate hub that WAS worn, etc. I can't get my finger on why there is so much difference.

The variance is exacerbated by running only one case through the system at a time, as compared to having a full shell plate. Best idea I can come up with is that at the top of the stroke, the ram may have enough play in it to induce a little wobble at the seating die station. BTW, the station location of the seating die seems irrelevant.

For plinking ammo, it's not a huge deal, but I'd sure like to think the press was a little more precise.

Anyone else noticed this? Ideas?

Thanks, gang. Rant over.

Michael in California
12-11-2016, 5:49 PM
Do you think 0.004 matters? Measure some production rounds.

baih777
12-11-2016, 6:12 PM
Do you have the Hornaday bullet comparator.? The variance could be the bullets.

wbunning
12-11-2016, 6:27 PM
Do you think 0.004 matters? Measure some production rounds.

It doesn't matter much at 7-10 meters, but at 25 it seems to. It can ammount to nearly .01" in OAL from the shortest to longest, and the difference in pressure looks like it measurably effects muzxle velocity. When I load on the single stage and closely monitor powder charge and OAL, I get less ES and lower SD on the chrono.

Anyway.. I get your point, Michael. Thanks for the input :)

wbunning
12-11-2016, 6:28 PM
Do you have the Hornaday bullet comparator.? The variance could be the bullets.

No, I don't have one. I've been wondering whether variation in the surface of the meplat might be the culprit. Thanks for the idea.

OpenSightsOnly
12-11-2016, 6:36 PM
Buy match grade bullets.

wbunning
12-11-2016, 6:54 PM
Buy match grade bullets.

Yeah.. I'm starting to think that's the issue. Thanks. Sometimes it just doesn't pay to be a cheapskate ;-)

9mmepiphany
12-11-2016, 9:56 PM
It used to drive me crazy too, until I figured it was normal that there was a variance between seating with only a single case on the plate and having all the stations full.

It has nothing to do with the brand of progressive press you're loading on. I've read that a normal variance is .005" among all presses...the least is a Dillon 550. the most was the Dillon 650.

What I did was buy a Redding Competition Seating die. Each mark on the micrometer changes the seating depth by .001"

I set up a single case to be seated to the OAL I want and start loading...filling all the stations as the first case comes around to the Seating station. I check the seated bullet and just dial in the the adjustment I want.

I seat another bullet to verify the change in OAL and then just spend the next 10 mins loading a hundred rounds before stopping to reload the primer feed. I'm loading RMR and B&B bullets for 9mm and .38Spl and they have been very consistent

dwalker
12-11-2016, 10:32 PM
My buddy just ran a test where he did not change powder charge but did change OAL and there was no change in accuracy before there were issues feeding.

If you want more consistency use a SS press and very very good projectiles.

DougMurray
12-12-2016, 7:14 AM
I also saw a difference in length on my LnL when I was at the end of a run - ie, when there were no cases being resized in Station #1. It seemed that the bullets were seating longer (at Station #4) when that happens. I saw very little COAL variation in those in the middle of a loading session, though. If you find the same effect, just separate out the last 4 and use them for chrono testing or whatever. In my case, I couldn't see any difference in accuracy so I just forced myself to ignore it.

wbunning
12-12-2016, 8:58 AM
My buddy just ran a test where he did not change powder charge but did change OAL and there was no change in accuracy before there were issues feeding.

If you want more consistency use a SS press and very very good projectiles.

Most of my shooting amounts to plinking, so it's not all that important, I guess. It was bugging me more about why it should happen since all the cases sit on the ram plate, which seems stable at the top of tge stroke.

Anyway, when I'm working up new loads for the chrono, I do all the work on the S/S and seat each one exactly.

Thanks for your input.

wbunning
12-12-2016, 9:03 AM
I also saw a difference in length on my LnL when I was at the end of a run - ie, when there were no cases being resized in Station #1. It seemed that the bullets were seating longer (at Station #4) when that happens. I saw very little COAL variation in those in the middle of a loading session, though. If you find the same effect, just separate out the last 4 and use them for chrono testing or whatever. In my case, I couldn't see any difference in accuracy so I just forced myself to ignore it.

In my case, when I set up the seating die with just one case in thr press, then start feeding it, most of the subsequent cartridges seat longer. I went as far as numbering each station on the shell plate and measuring each bullet as they came off each station. That didn't reveal anything substantial.

It must be due to variances in bullet nose shape with the cheapie bullets I use, and what small play there is in the ram plate at the top of the stroke. With a full plate, thst play probably evens out.

smoothy8500
12-12-2016, 8:44 PM
It doesn't matter much at 7-10 meters, but at 25 it seems to.

Cheap plinking bullets? The accuracy effect at 25yds aint due to the OAL variations.

jimmythebrain
12-12-2016, 10:04 PM
What resizing die are you using?
Mixed brass?
Lubing your cases?

Some brass is harder to resize,
some primer pockets are larger than others and combined with some brands of primer are "harder" and have a greater diameter, a combination of these factors can make it harder to eject the spent primers requiring more force.
Harder brass or thicker brass may take more effort to flare/bell and then...crimp (undo the flare/bell in the case).
Variances in the bullet diameter can effect how much pressure it takes to seat them...
add all of this up occurring simultaneously at the top stroke a progressive press then the variables in resistance have an additive/subtractive sum effect. These multiples of variables go away in a single stage press and can be eliminated (compensated for) by just having a solid 'stop" built into the press that you travel to during the ram upstroke.

This hindrance/resistance effect and "play" in the LNL press explains why you get some wobble at the top stroke. As a result if you do not have a shell being resized-deprimed to cause countering pressure to your seating resistance the shell plate carrier will rock. The shell plate does not really matter since the base of each case (on the upstroke) rides on the shell plate carrier not the actual shell plate.
The shell plate carrier pivots on two allen head screws which attach to the outer ram tube. The inner hub (that turns) sits just a hair higher than the shell plate carrier and the shell plate attaches to this. A shim can be placed between the inner hollow ram and the bottom of the shell plate carrier to ensure even contact between the inner ram and the bottom/underside of the shell plate carrier to prevent rocking. This reduced but does not eliminate variances in the AOL.
I shimmed my LNL press to ensure the shell plate carrier rode on the inner ram and not the set screws but it caused so much resistance with shell plate advancing that I took the shim out. The slight variance for range ammo AOL is well worth smoother press operation.

If you use Hornady resizing dies these can cause more resistance at the top stroke.
9 MM is a tapered case so the mouth tension is not set by the cardbide/titanium nitride ring. You will see more AOL variance with tapered cases.

If you want to see if the problem is your seater die or just variances in the bullet profile... then put your seater die in a single stage press, no crimp and load a 10 rounds and check AOL's. A progressive press will do worse.

If you really want to have precise ammo- load the ammo in the LNL AP press, little to no crimp- then run them through a single stage seater/crimper die for final AOL that is less variable. Certainly less work than loading entirely in single stage.

wbunning
12-13-2016, 7:03 AM
Thanks for all the input, folks. FWIW, I have no issues in this regard using the s/s with any of my die sets. Apparently this is problem is more common with progressive presses than I knew about, being fairly new to the progressive ranks. I believe that, after hearing from all of you, that despite the inherent problem with slop in the shell plate carrier at the top of the stroke, I have been personally exacerbating the issue by running the first cartridge through solo when checking all the die stations, but it would seem that would only affect the first and last 4 cases. Easy enough to rectify that by pulling those 8 rounds and re-seat them later, and re-adjust the seating die when the first couple come through on a full plate.

Again, I am thankful to all of you for your helpful comments and tips! Stuff you can't learn from the books :-)

Merry Christmas to all.
-Walt

Dnele928
12-13-2016, 7:14 AM
Set your mic to two decimal places.

DougMurray
12-13-2016, 7:33 AM
Walt:

I think Jimmythebrain nailed the causes - at least, his thoughts are consistent with what I've experienced. Given that, although I've not tested it, I'd expect that only your last 4 cases would be subject to the most variation and the first 4 should be fine. I'm curious if you find that to be the case. If so, it would cut the ones you need to work on in half.

Carcassonne
12-13-2016, 8:07 AM
So I've been using this Hornady LNL progressive press for a couple of years now. Overall, it's been "OK". Not superior, but OK. Loading only pistol calibers so far. Some folk have expressed issues with the priming system, but that system on mine has been rock solid in that respect.

My problem has been in variance the cartridge overall length. One day, after getting all the dies tuned in to where I thought I wanted them, I started micing each finished round. Jeebus! I was getting OAL variation of +/- 0.004. I tinkered and tinkered, labeled the shell plates and recorded OAL for each, replaced the shell plate hub that WAS worn, etc. I can't get my finger on why there is so much difference.

The variance is exacerbated by running only one case through the system at a time, as compared to having a full shell plate. Best idea I can come up with is that at the top of the stroke, the ram may have enough play in it to induce a little wobble at the seating die station. BTW, the station location of the seating die seems irrelevant.

For plinking ammo, it's not a huge deal, but I'd sure like to think the press was a little more precise.

Anyone else noticed this? Ideas?

Thanks, gang. Rant over.


Common problem with LNL.

How I fixed the problem. Seat the bullet 0.010"-0.015" higher, and don't crimp. Then remove all the dies except the bullet seater and crimp die. Re-seat the bullet to the correct height, and crimp.

Another problem is you are most likely seating the bullet on the ogive, but are measuring the cartridge length on the tip.

If you want supper target ammo, use a single stage press and measure each powder charge.

.

wbunning
12-13-2016, 11:32 AM
Thanks, Jimmythebrain, for all your input as well. That was a LOT of work you put into that reply. You have some good ideas. Here are my answers to your questions/solutions so others as well as myself can compare their own experiences to mine:

What resizing die are you using?
Hornady for the most part.

Mixed brass?
happens with both mixed as well as new/same headstamp.

Lubing your cases?
Yes.

some primer pockets are larger than others and combined with some brands of primer are "harder" and have a greater diameter, a combination of these factors can make it harder to eject the spent primers requiring more force.
I deprime before wet-tumbling, so my cases go in primerless.


A shim can be placed between the inner hollow ram and the bottom of the shell plate carrier to ensure even contact between the inner ram and the bottom/underside of the shell plate carrier to prevent rocking. This reduced but does not eliminate variances in the AOL.
I shimmed my LNL press to ensure the shell plate carrier rode on the inner ram and not the set screws but it caused so much resistance with shell plate advancing that I took the shim out. The slight variance for range ammo AOL is well worth smoother press operation.

I took the LNL all apart not long ago to replace another part, and wondered about shimming the shell plate hub. I'll forget that thanks to your experience.


If you want to see if the problem is your seater die or just variances in the bullet profile... then put your seater die in a single stage press, no crimp and load a 10 rounds and check AOL's. A progressive press will do worse.
No problems with the S/S. When I want to do more precise loads I do it all on the S/S.

If you really want to have precise ammo- load the ammo in the LNL AP press, little to no crimp- then run them through a single stage seater/crimper die for final AOL that is less variable. Certainly less work than loading entirely in single stage.
For a while after I discovered this problem with the progressive, I resorted to running the brass through the LNL to size/prime/expand/flare only. Then manually powder drop/seat/crimp on the s/s. That solves most of the issue, just takes more time. I may go back to that process and just not worry about the minor variance in the seating depth for blaster ammo.

wbunning
12-13-2016, 11:33 AM
Walt:

I think Jimmythebrain nailed the causes - at least, his thoughts are consistent with what I've experienced. Given that, although I've not tested it, I'd expect that only your last 4 cases would be subject to the most variation and the first 4 should be fine. I'm curious if you find that to be the case. If so, it would cut the ones you need to work on in half.
Hmm.. yeah. Next run I'll save the first and last 4 and measure them. I think you are right.. should just be the last 4.

wbunning
12-13-2016, 11:42 AM
Another problem is you are most likely seating the bullet on the ogive, but are measuring the cartridge length on the tip.
Yep.. definitely was a problem at first. A 'witness' ring was evident on some ogives when I first started using plated bullets. I have that pretty well solved by filing down the cup rims on the round nose seating stems to where they aren't deep enough to cause that. Hint: when you find crappy dies at garage/estate sales, or fleabay.. buy them for the seating stems :-)

If you want supper target ammo, use a single stage press and measure each powder charge.

Definitely. Like many others here I suspect, I cut my reloading teeth on a single stage decades ago, and was accustomed to having more precisely seated bullets. Only recently did I decide that I 'needed' a progressive press. In the amounts that I load, typically only 300-500 rounds per week, I most likely DON'T really need it. In the past, and I may go back to this practice, run a ton of brass through the LNL first to size/prime/expand/flare. I can process a lot of brass quickly that way, Then I have a bunch of 'ready' brass handy and then manually powder drop or measure, seat/crimp on the single stage. Faster than doing each step on the s/s, but not as fast as doing it all on one pass on the progressive, and it produces more precisely loaded cartridges.