Hornady L-N-L OAL issue

[Cranium]

In this video, I am demonstrating the issue I am having in setting the overall length (OAL) with my loads.

I start with my OAL being 1.0796" and show it is repeatable to 0.0001" while using just a single station. As soon as I have all the stations working, and specifically a casing in the powder drop/expander station pushing on the shell plate from the opposite direction, my OAL increases by 0.01".

I have called Hornady and explained the issue and shown the video and they are a bit baffled. They acknowledge that there is some flexing or tolerance issue that causes the change in the OAL but this issue typically causes a decrease in OAL rather than, as in my case, an increase in OAL.

Does anyone else experience this? Any fixes? The workaround that I am using is that, as in this case, my desired OAL is 1.09" so I set it for 1.08". I'll have a few rounds that come up shorter during reloading but the majority will be where I want them. But I'd much rather avoid variances altogether.

http://www.youtube.com/watch?v=F8uj6zN7iJM

http://imageshack.us/m/715/9118/oalissue.jpg

http://imageshack.us/m/42/5996/oalissue1.jpg (http://www.youtube.com/watch?v=F8uj6zN7iJM)

[parrott1969]

I have variances with both of my presses, Dillon and hornady. I just find a happy median that I can live with. If you do not mind me asking, is that a 9mm? what charge are you using?

[Doby45]

I have found the best bet is to set you OAL with all stations full.

[468]

Can a .01 difference in AOL cause any problems?

[Cranium]

It is a 9mm 120 gr lead cast bullet that has a 12.1 BHN.

I'm loading using Power Pistol and using 5.4gr.

I chrono'd 49 rounds and threw out the top and bottom 4 to account for the changes in OAL I'm receiving.
In the 41 rounds:

Average Velocity = 1118 FPS
Extreme Spread = 34 FPS
Average Power Factor = 134
Average Ft/lbs = 333

[Cranium]

I've called Hornady and they have looked at the video. The technician also feels the 0.01" is a bit excessive but right now they are baffled as to why the OAL increases with a casing on the powder drop rather than decreasing. Pressure applied to the shell plate on the powder drop side would appear to cause the seating side to rock up; thereby decreasing OAL instead of increasing it.

They had an engineer look at the video and I'm going to try a few things they suggested:
Move the seating die to station 5 and see if there is any change in this issue Remove the PTX expander from the powder drop and see if there is any change in this issue Mount a dial indicator (happen to have one) on the press to measure any difference in how high the shell plate and base plate are raising. This may have to be done at multiple locations if it is determined there is flexing somewhere to isolate it.


Hornady did state that they have a shim that may resolve the issue if it is what they think it is. The have been phenomenal about addressing this issue so far and getting back to me with updates on their progress. Top notch customer service!

[Whistler]

As Doby45 stated, you must have all the stations full when setting your first OAL.
That is, put an empty case in all slots of the shell plate, adjust the OAL and then set all the dies back in their stations.

Did you measure the 0.0001" differences with that caliper? I have not seen any caliper that is that exact, even the best have tolerances of +/- 0.0001". You'd have to use a micrometer for that.

Even with match grade ammunition, that low variances have little if no effect (unless you're a bench rest rifle shooter, but then you'd be using a single stage press in any case). It might as well be that the bullets have variances greater than what you believe the press to have.

I would say that your 0.01" variance is definitely from not adjusting your dies properly. What brand of dies are you using? I always recommend Redding if you want consistent ammo (and don't we always want that?).

[Cranium]

I have found the best bet is to set you OAL with all stations full.

This is fine except for when I have a case that doesn't feed or a primer that doesn't seat correctly or anything else that results in sending an empty shell holder around the stations. This would result in a round that would be too short. But this is pretty much what I've done as a workaround so far. I set the OAL to be 0.01" shorter than I want with just a single case knowing it will be where I want with all stations full. For the most part, I'm running minor loads so a little more pressure and speed won't hurt anything. But my 147gr Speer GDHPs are averaging 1030 FPS and a 151 PF so they are a lot closer to becoming an issue.

[Cranium]

Did you measure the 0.0001" differences with that caliper? I have not seen any caliper that is that exact, even the best have tolerances of +/- 0.0001". You'd have to use a micrometer for that.


Yep...it was measured with that caliper and does have a resolution of 0.0001". :)
I took a screen shot at 1 minute and 47 seconds in the video. You can see the numerical reading of 1.079" on the display. There is also a vertical line bar on the far right. Each tick there is 0.0001". So in this case, it shows 1.0796". These weren't el-cheapo micrometers and I've had them for about 15 years.
http://imageshack.us/m/577/8910/starrett.jpg

Looking on Starrett's site, their calipers only read with a resolution up to 0.0005" now. So I guess that kind of accuracy was determined to be too expensive or not needed in calipers. These also have a connector to hook them into a computer to record measurements.

[1hole]

"Can a .01 difference in AOL cause any problems? "

No.

[Cranium]

I would say that your 0.01" variance is definitely from not adjusting your dies properly. What brand of dies are you using? I always recommend Redding if you want consistent ammo (and don't we always want that?).

I would have to disagree with you on that. In the video, I seat 3 bullets with no other cases in the other stations. The measurements of these (as seen on the video) are:

1.0796"
1.0797"
1.0795"
I don't think any die, regardless of brand can be expected to do any better than a repeatable tolerance of 0.0002". :)
btw....these are Hornady New Dimension dies so it does speak well to their quality.

[Cranium]

"Can a .01 difference in AOL cause any problems? "

No.

If you know for certain that .01 won't cause any problems, how about .02 or .03? What criteria are you using for this determination and where is the line drawn for having issues? Is this for major and minor loads alike?

[Colorado4wheel]

Always set OAL with all the stations full. Just adjust the die out till you have the OAL you want. Then check the OAL as your loading. Not as you have been doing it.

[bbqncigars]

Were the cases of uniform length prior to running them through the press? Another variable to consider, I know.

[Colorado4wheel]

It doesn't matter if you have small differences in case OAL for Pistol.

[Colorado4wheel]

I watched the entire video. That is totally normal. You should have measured all the rounds (but the first two) that you loaded with a full shell plate. They would have been very close to 1.089". That's just the way a progressive works.

[Cranium]

Thanks for all the feedback on this. I realize that it isn't a huge deal at a maximum of 0.01" when loading 9mm in almost every situation. I guess my concern is when I start loading 223 or other rifle rounds and want them to be as accurate as possible.

I'd like to eliminate as much slop in the process as possible and it is just a little sloppy to me that the seating can be done within 0.0002" but in a progressive may vary by 50x that amount if there isn't a good balance of rounds across the shell plate.

[GMT210]

I consistently see the 0.010 AOl length increase with my LNL as well. It has been so consistent between 45acp, 9mm, and 357 that I actually set my seating die 0.010 deeper with only a single station and it comes in perfect when I am loaded up with all stations.

GMT210

[buck1]

The measurement .001 . We would all like our ammo to be exact spot on but in a progressive its not exactly perfict.
For your exacting standards (nothing wrong with that) I recomend a single stage press if you cant live it.
Or just mark the first few rounds as fouling shots, Dont forget about thermal groth of the gun as it begins to warm.
Just my .02.......Buck

[Colorado4wheel]

Thanks for all the feedback on this. I realize that it isn't a huge deal at a maximum of 0.01" when loading 9mm in almost every situation. I guess my concern is when I start loading 223 or other rifle rounds and want them to be as accurate as possible.

I'd like to eliminate as much slop in the process as possible and it is just a little sloppy to me that the seating can be done within 0.0002" but in a progressive may vary by 50x that amount if there isn't a good balance of rounds across the shell plate.

First thing to realize is that you have Excellent repeatability. You proved it in your video.

Second thing to realize is that if you use the press as intended it will have excellent repeatability. Running as a SS it's down to .001" as a progressive it's down to .001" you simply can't ask for better.

Finally you need to understand won't change that the press behaves differently as a SS then it does as a progressive.

So if your worried about OAL changes when you start and stop your loading cycle you simple put a case in the stations ahead (and at the end behind) your final round.

Example.

To start your series of loading you simple put a empty and upside down primed case in the station that is about to throw powder. I use the same case over and over again. That's why the primer is upside down. Cycle the handle. Check the powder drop in that case and DUMP the powder back in hopper. Put the case back in the seating station (because it indexed). Continue loading (You already have a sized case in station 2 because the press indexed). As you load that case well support the process through the crimp station (even it has no flare).

To end the process you simply don't push to prime on the last couple cases. The entire shell plate doesn't need to be full. Important stations are sizing and crimp. It's easy to just size a case and remove before powder drops.

[noylj]

Sorry, but if this is a concern, you will just have to go to a single stage press. All progressives have some small amount of shellplate play.
COL is not as critical as some think and the main concern is too short COL (less than the minimum referenced in the loading manuals). Have you seen any effect on target?
If you are breaking your loading rhythm that frequently, you need to look at your procedure. Then, you can take the long outliers and run them through the seating die again.
Next, measure the length of your lead bullets and then measure the resulting cartridge COL. Bullets vary enough that the COL will always very some.
Next, I found that I had to keep the shellplate bolt tight.
Finally, the timing can be just slightly off and cause the shellplate to tilt slightly due to the primer seating not being correctly timed/indexed. Even a small kink in the retain spring can reportedly have an effect.