OAL increases when loading progressively

[Blackstone45]

So when setting up the dies on my progressive press, I adjust the depth of each die in turn. I settled upon a OAL of 1.095" for my 9mm. But once I started running the press, the OAL would increase, and vary between 1.099-1.103". Ultimately, it's only about .004" variation, and i believe well within what is acceptable. But why is the OAL longer? Is it because when loading progressively, with cases in every station, the seating station is subject to varying resistances? If I run these rounds just through the seating die again with nothing else happening on the press, it gets them down to the original 1.095" with .002" variation at the most.

Edited June 6, 2021 by Blackstone45

[ddc]

Pretty much what you suspect. The additional resistance of a full shell plate, mostly from the sizing die, is resulting in a hair more distance between shell plate and tool head.

Also be aware you will see differences based upon head stamps.

For example if you set up your tool head with a bunch of Blazer brass and then change over to S&B or CBC don't be surprised if you OAL grows a bit.

[Sigarmsp226]

Blackstone - There are several variables that can contribute to the slight OAL change and variance. I am sure others can provide additional factors that could contribute to this but the first two that come to my mind (I have experienced this exact same thing) would be related to ——- 1> Mixed head-stamp brass or 2> Because on a progressive run with 5 to 7 operations occurring at the same time because the “shell plate” has to “float” to allow the ability to rotate I would think that adjusting your shell plate ever so slightly might reduce the OAL variance you are experiencing.... It worked for me on my Dillon 650....Mark

[Sigarmsp226]

DDC - I guess I was typing my response when you submitted yours - Great minds - 

[MikeyScuba]

I’m happy with anything under 50 thou. That is +/-.0050

 

Hmm now that I think about it it’s actually +/-.0025, the deviation (or spread) is .0050 

For my revolver rounds i aim for 1.19 but get them deviating between 1.1875-1.1925.  Not bad for coated lead.

[38super]

Give the charging handle an extra bump during seating, also helps clear powder bridging when using Varget.

[AHI]

adjust seating OAL by averages . you will never get every one the exact same.

 

factory loaded ammo varies also . More than you thank. To get your length you 

will have to load shorter so the long ones aren't to long. A LOT OF YOUR OAL

VERATION  IS  IN THE BULLET. Make Shure you have the correct seating punch.

 

[ddc]

1 hour ago, AHI said:

...factory loaded ammo varies also . More than you thank...

 

That is so true.

[Blackstone45]

Re-adjusted my seating die with cases in every station, and getting pretty low variation in OAL now (only around .002")

[ddc]

4 hours ago, Blackstone45 said:

Re-adjusted my seating die with cases in every station, and getting pretty low variation in OAL now (only around .002")

 

That is excellent, about as good as it gets.

[hlsccsfa]

On 6/6/2021 at 10:08 AM, ddc said:

Pretty much what you suspect. The additional resistance of a full shell plate, mostly from the sizing die, is resulting in a hair more distance between shell plate and tool head.

Also be aware you will see differences based upon head stamps.

For example if you set up your tool head with a bunch of Blazer brass and then change over to S&B or CBC don't be surprised if you OAL grows a bit.

 

I have exact same experience with these brass, I sort out S&B, CBC, WIN, etc... and use them as one time brass, load and shoot them in local club matches. My practice ammo and ammo for major match are only loaded with Blazer or Federal brass.

[CHA-LEE]

The biggest variable on a Dillon press that will effect OAL when the shell plate is full vs not, is the actual tool head. I used to see OAL variance in my ammo depending on how many stations were full in the shell plate. Nothing dramatically different, but different. That all stopped when I installed the Unique Tek Dillon Tool Head Clamp kit. This kit basically locks the tool head into the frame of the press so it can't shift around while loading. After installing this kit all of my OAL variance issues went away. I listed a link below to this kit. I have no direct affiliation with Unique Tek. I simply use products that are great and this is one of them.

 

https://www.uniquetek.com/product/T1230

[Ludde]

On 9/2/2021 at 11:29 PM, CHA-LEE said:

The biggest variable on a Dillon press that will effect OAL when the shell plate is full vs not, is the actual tool head. I used to see OAL variance in my ammo depending on how many stations were full in the shell plate. Nothing dramatically different, but different. That all stopped when I installed the Unique Tek Dillon Tool Head Clamp kit. This kit basically locks the tool head into the frame of the press so it can't shift around while loading. After installing this kit all of my OAL variance issues went away. I listed a link below to this kit. I have no direct affiliation with Unique Tek. I simply use products that are great and this is one of them.

 

https://www.uniquetek.com/product/T1230

 

Did you combine this with floating die rings or did you use a oem dillon toolhead with conventional die locking nuts?

[Sigarmsp226]

Cha-Lee - Thank you for posting the details about the Uniquetek kit. I just watched a short video on you tube showing how simple the kit is to use. I also walked out to my reloading room and realized that my 650 OEM heads do have some “slop” in them. Because I load 9mm, 300 B/O, 223/5.56, 308, 30-06, 38 Spl., 40Cal, and 45 ACP I am thinking I will pick up the large kit for just over $50.00 and get my tool heads threaded with inserts.
 

Granted I may not need this for my pistol calibers but f I am going to do do my dedicated rifle caliber tool heads that are already set up why not do them all.

 

If anyone knows a reason that I should not consider using this kit please share your concerns before I pull the trigger on this purchase….Thanks Mark

[CHA-LEE]

4 hours ago, Ludde said:

 

Did you combine this with floating die rings or did you use a oem dillon toolhead with conventional die locking nuts?

 

I used the OEM Dillon Tool Head with the conventional die locking nuts. There is enough wiggle room in the shell plate for the brass to shift around if needed.

[CHA-LEE]

58 minutes ago, Sigarmsp226 said:

Cha-Lee - Thank you for posting the details about the Uniquetek kit. I just watched a short video on you tube showing how simple the kit is to use. I also walked out to my reloading room and realized that my 650 OEM heads do have some “slop” in them. Because I load 9mm, 300 B/O, 223/5.56, 308, 30-06, 38 Spl., 40Cal, and 45 ACP I am thinking I will pick up the large kit for just over $50.00 and get my tool heads threaded with inserts.
 

Granted I may not need this for my pistol calibers but f I am going to do do my dedicated rifle caliber tool heads that are already set up why not do them all.

 

If anyone knows a reason that I should not consider using this kit please share your concerns before I pull the trigger on this purchase….Thanks Mark

 

The way that kit is setup you don't "Have To" thread all of your tool heads. Its not an all or nothing thing. Just thread the tool heads for the calibers you are seeing OAL variance in and use the standard Dillon tool head retainer pins for the rest of the calibers. I also want to point out that if you are worried about investing $50 in a press upgrade then you are playing the wrong game.

[Sigarmsp226]

21 minutes ago, CHA-LEE said:

 

The way that kit is setup you don't "Have To" thread all of your tool heads. Its not an all or nothing thing. Just thread the tool heads for the calibers you are seeing OAL variance in and use the standard Dillon tool head retainer pins for the rest of the calibers. I also want to point out that if you are worried about investing $50 in a press upgrade then you are playing the wrong game.

To provide a little more clarity  - I never said I was “worried or afraid” to invest $50.00 into one of these kits. Having reloaded for over 35 years and currently having three Dillon presses - one being a RL1100 and two being XL650’s, and also having two single stage presses I think I understand “The Game” I am playing in…

 

But why invest any money into something that others here may have experienced issues with after having used the product for a period of time. 

[Blackstone45]

I've invested in an Armanov floating toolhead and some floating lock rings. I plan to use that toolhead for my 50m PPC precision loads.

[LMS]

On 9/2/2021 at 4:29 PM, CHA-LEE said:

... After installing this kit all of my OAL variance issues went away...

 

Are you saying you have zero variation now, or it's within some acceptable tolerance?   If the latter, what would that be?  

 

I have one too and I love it, but I still get variations of +/- 0.004 and I use a Redding Competition seating die.   I keep wondering if that's what I should expect or if I need to keep chasing something closer.

[CHA-LEE]

31 minutes ago, LMS said:

 

Are you saying you have zero variation now, or it's within some acceptable tolerance?   If the latter, what would that be?  

 

I have one too and I love it, but I still get variations of +/- 0.004 and I use a Redding Competition seating die.   I keep wondering if that's what I should expect or if I need to keep chasing something closer.

 

In a progressive press there will ALWAYS be a minimal amount of OAL variance because the shell plate itself needs to be loose enough to rotate. The type of bullet you use also comes into play when measuring OAL because the tip of the bullets can vary from one round to the next. This is especially true for coated or hollow point bullets. Lastly, there will also be a slight variance in the angle the bullet is pushed into the case. If the bullet is seated when it is slightly tilted the OAL will not be the same as a bullet that is seated straight.

 

I use coated 40cal 180gr Gallant Bullets with mixed head stamp brass. My target OAL is 1.165. I just measured the OAL of 10 different rounds picked randomly from my last reloading session and the Max/Min OAL was 1.1650 - 1.1675. So the limited sample that I measured only had an OAL variance of 0.0025. This is also with what I would consider fairly inconsistent thickness or layering of the coating which is typical of just about any coated bullet.

[Chills1994]

On 6/6/2021 at 9:34 AM, MikeyScuba said:

I’m happy with anything under 50 thou. That is +/-.0050

 

Hmm now that I think about it it’s actually +/-.0025, the deviation (or spread) is .0050 

For my revolver rounds i aim for 1.19 but get them deviating between 1.1875-1.1925.  Not bad for coated lead.

tenths….

 

hundreths…

 

thousandths…

 

soooo… fifty thousandths

= 0.050 “

 

or you could call it 5 hundreths

 

as you have it typed in 0.0050 , that’s just 5 thousandths .

 

or you could call it 50 ten thousandths

 

 

Edited September 14, 2021 by Chills1994