Inconsistent OAL with LNL ?

[gregj]

I picked up a used Hornady LNL last year, and just recently started loading 45ACP 200gr lead SWC (Missouri Bullets) on it, and cant seem to get consistent OALs. My target is 1.25 and they range from 1.2495 to 1.2610, from a small sample taken. I didnt seem to have this problem with RN or plated SWC, which I've loaded several thousand on the LNL.

I'm seating and crimping in two seperate steps, using the Hornady seat/crimp die to seat only, and a Redding Taper Crimp die in the last station to crimp. Everything is clean, I'm using the wadcutter seating stem, and I dont believe I'm short-stroking the press.

I did find a similar post , but nothing there that seemed to address my concern.

As in the linked post, I can take a long OAL round and re-size/crimp and it comes out much closer to my target OAL. I understand the possibility of a loaded shell plate may cause more resistance, but when I go fairly slowly and methodically, I would think it wouldnt make a difference. I have noticed some lateral slop in the linkages when the ram is all the way up, causing the ram, subplate, and shell plate to rotate some, possibly 1/8". Not sure if this movement would be enought to cause the OAL differences?

 

[Blue68f100]

Check for lead and wax in the seating die.

If your shell plate is not indexing problem will cause alignment issues. Your jumping on the upstroke indicates the indexing is off and need adjusting. Make sure the shell plate is tight. Mine seams to loosen up if I do not really tighten down on it. This could have some impact it just depends on the dies. I would expect shaved lead if the bullet is cocked and not aligning properly.

 

[gregj]

I've checked the plug to make sure there are no deposits on the end, but will check for shavings in the die. Maybe I need to back it out more, since I'm only seating with it.

The shell plate is indexing correctly, and remains snug/tight. Not sure I said I was jumping on the upstroke, so not sure what you mean there. ?? Thanks

 

[Steve Koski]

Vaguely related: Dillon 550's seat about .004" shorter when only one cartridge is in the press.

My only guess is that you're using a seating plug that does not fit the bullet profile, perhaps a round nosed seating plug. If you then use a flat nosed bullet, you're likely to get inconsistent seating depths.

Koski

 

[Canuck-IL]

Check the bullets - how inconsistent are they in OAL?

It's not a critical measurement assuming they chamber ok ... try measuring for a consistent cartridge base to SWC shoulder - bullet noses vary a lot, even Sierra SMKs make one crazy if you pay attention to OAL - on those, it's the ogive that matters, assuming they fit in a mag.
/Bryan

 

[gregj]

Check the bullets - how inconsistent are they in OAL?

There are some variances in the bullet length. However, I'm using the flat stem for wad cutters to seat them, so the bullet is being seated by the flat point not the ogive, so the length of the bullet would be irrelevant to the COAL. Right? Now if I was measuring from the case base to the bullet shoulder, or calculating the seating depth, I think the bullet length would then be a factor.

 

[dudlee]

Plus or Minus .006 inch is about what I'm getting on my LNL too. I'm using a Lee seating die and a separate crimp die in station 5 ...same for roundnose or flatpoints.. Happens with 9mm and 45acp.

 

[243winxb]

Some Dillon shell plates will be different at each station, dont let the dies touch the shell plate. A Hornady LNL might work different??

 

[gregj]

No dies are touching the shell plate.

But it does look like the shell plate indents are not quite lined up quite right, causing the case to tilt a little as it goes into the die. Not much, but definately noticeable. I'll call Hornady monday and see what they say.

 

[dudlee]

I did an experiment with a round in all 5 stations and was getting .010-.020 longer length than by seating a bullet with the other 4 stations empty. I could consistantly get +/- .002 on OAL with 4 stations empty.. No dies are touching the shell plate..This was with 9mm Lead round nose..

 

[EddieNFL]

I did an experiment with a round in all 5 stations and was getting .010-.020 longer length than by seating a bullet with the other 4 stations empty. I could consistantly get +/- .002 on OAL with 4 stations empty.. No dies are touching the shell plate..This was with 9mm Lead round nose..

Press flex.

 

[ConcernedCitizen]

Vaguely related: Dillon 550's seat about .004" shorter when only one cartridge is in the press.

My only guess is that you're using a seating plug that does not fit the bullet profile, perhaps a round nosed seating plug. If you then use a flat nosed bullet, you're likely to get inconsistent seating depths.

Koski

I've noticed the same thing as Steve Koski. The sizing die is what makes the most difference. My LnL will seat 0.003-0.004" shorter if I'm not running through all the stages, or if I'm running already sized brass and skipping the sizing die.

 

[gregj]

Would spraying a little case lub on prior to sizing be enough to reduce the "press flex"? One would think as big of a ram on the LNL that there wouldnt be much if any flex.

I may try tonight and see.

 

[gregj]

Now that I have a better idea of what to look for, I did some googling and found flex is thought to be the cause for this problem. A lot of posts state the shell plate is flexing. But doesnt the shell plate just keep the cases upright? The only pressure should be on the ram, linkages, and the base plate, which is most likely where the majority of the flex is coming from. Am I off on this??


Also, thought I would add, that I hadnt noticed/seen this varying OAL problem until I started seating and crimping seperately. Guess this puts the seating die now closer to the opposite side of the plate, where the flex would be more apparent.

 

[243winxb]

You didn't have a problem with RN or plated SWC. The problem might be in your seating die. Try this, turn the seating plug down as far as it will go in the die, lock it. Then screw the die in or out of the press to get the correct COL. If the bullet is hitting the crimper in the seating die to early or wrong, this might correct it. Taper crimp in a seperate operation.

 

[243winxb]

Now that I have a better idea of what to look for, I did some googling and found flex is thought to be the cause for this problem. A lot of posts state the shell plate is flexing. But doesnt the shell plate just keep the cases upright? The only pressure should be on the ram, linkages, and the base plate, which is most likely where the majority of the flex is coming from. Am I off on this??

I feel your correct in your thinking.

 

[gregj]

You didn't have a problem with RN or plated SWC. The problem might be in your seating die. Try this, turn the seating plug down as far as it will go in the die, lock it. Then screw the die in or out of the press to get the correct COL. If the bullet is hitting the crimper in the seating die to early or wrong, this might correct it. Taper crimp in a seperate operation.

243winxb: I had run a case up into the seat/crimp die, then backed it out about a half turn or so from where it makes initial contact with the flared case. Shouldnt this accomplish the same thing? I will try as you suggested tonight and see if it makes a diff.

I had some variance with RN and plated, but I was using seat/crimp die in the last station, and to do both functions, and the variance was acceptable. I really think having the die do both functions in station 5, puts the die almost at the neutral point of any flexing so the impact on COAL would be less than if seat and crimp are done separately.

If lubing the cases doesnt minimize the variances, I may resize seperately for my match ammo. I hate the idea of doing this, as it kind of defeats the purpose of having a progressive press.

 

[Blue68f100]

With all stations going I will get a difference of about 0.010". But I change my die to be set for all stations running. This way I only get the std bullet variation of about 0.003-0.005" drift. The highest load is on the sizing station, #1 where your bullet seating is in station 4 or 5. In #4 the high load on #1 causes the base to deflect pushing up on the opposite stations. If your getting more the 0.010" something else is going on. Your sizing dies is maybe too tight, and need a little lube from time to time. Or it's hitting the shell plate and flexing the base. Remember to set the die with the ram at the highest not camed over. I switched over to Hornady dies for this reason. The Ti coating makes the die create less friction and run smoother. They also have a larger radius which helps with alignment. The first time I ran into this was with a 357mag. My RCBS carbide sizer would take twice as much load over the Hornady. I have now replaced all my pistol dies with Hornadys.......

Normally a 0.010" dev will not have any impact on bullet performance. It takes over 0.025" to notice a difference on the rounds I have tested. But if your OAL is at the magic line that a increase in 0.010" send it over the edge try changing the OAL and see if you can find that sweet spot. Normally the sweet spot on pistol ammo has a window of about 0.030" and even greater on some depending on the barrel.

 

[cfullgraf]

If lubing the cases doesnt minimize the variances, I may resize seperately for my match ammo. I hate the idea of doing this, as it kind of defeats the purpose of having a progressive press.

I run my progressives by resizing and expanding cases in one session, then at a later time reload them. I prefer to clean my cases between resizing and reloading and the press mounted priming systems and I do not get along.

While you will lose some productivity, it is not as much as you might think. I do the resizing step shortly after shooting and store the brass for later loading when I sufficient pieces to make a loading run worth while. You can fly through the resizing process as it does not take as much care as when dropping powder and bullets.

I find, i can prime cases by hand as fast as filling primer tubes and seating the primers on the press. Plus, I never feed an improperly primed case to the press as I get to inspect each case and seated primer.

But, I can see that ammunition needs could grow to the point that my two step process could become cumbersome.

Since I am not resizing at the same time as seating the bullet, my seating depths are as consistent as on a single stage press.

 

[ConcernedCitizen]

I'm with Blue68f100 on this one...

I set my press to seat properly when running all five stations. This means that my last 3 bullets will seat a hair deeper, as will any cartridges I run through individually, but I can live with that. I'm more concerned with having the majority of the cartridges come out within tolerance under normal operating conditions. This is just my preference, at least for pistol ammo.

For rifle ammo, I intend to size and trim first, and then run a decapping die in the first stage to remove any tumbling media from the primer pockets. In this scenario, I shouldn't have to worry about the variance, as there should be no friction on the first stage.

I'm still pretty new to the press, so I still have a lot of experimenting to do.