Too much variance in OAL?

[Newby]

Hello everyone,

My first reloader...Dillon 550B

My situation is that when I set it up (everything tight) I was getting consistent OAL of 1.15 -1.155 with a 124 gr Montana gold 9mm, BUT, when I tested it using all 4 stations as a progressive, the OAL went to 1.158-1.160, then when I did it single every time it loaded to 1.45 to 1.47

How much variance is normal? Is there something I am doing horribly wrong? I'm not loading any powder yet as I'm just trying to get it dialed in.

How consistent should it be?

I'm a bit worried at this point I will not be able to load consistent ammo...

I just ordered the Unique-Tec toolhead clamp just to see if that could help things from shifting. I thought it worth a try.

Edited July 1, 2010 by Newby

[G-ManBart]

First off, no you're not doing anything terribly wrong, or even slightly wrong The range variation you're seeing is actually pretty small.

There are a number of things going on here. For a couple of reasons, progressive presses with rotating shell plates will always show a couple of thousandths difference in OAL between all of the stations full and just having one case in at a time. I haven't put much (hardly any) time to figure it out, but what I think is that if the resizing station is empty, the shell plate can raise slightly higher. That makes a small change in seating depth and it also seems to flare the case mouth slightly more. Some folks take the first couple and last couple of rounds loaded and set them aside for practice. I don't bother with that, as none of my guns are that OAL picky, but I will avoid using those rounds for chrono testing just to be a little more precise. The other thing is that there is some slight variation in bullets, so that can make a slight difference as well. Lastly, brass will make a slight difference. If it's mixed brass you're getting slightly different lengths and thicknesses and even if it's sorted for headstamp you'll find slight differences once it's been shot one time.

In short, your numbers seem fine to me, try setting the OAL so that you hit the target number with all the stations full and you should be fine. R,

[Sarge]

Normal for your 550. When you run at full power with the press adjust everything with the shell plate full.

[GrumpyOne]

First off, no you're not doing anything terribly wrong, or even slightly wrong The range variation you're seeing is actually pretty small.

There are a number of things going on here. For a couple of reasons, progressive presses with rotating shell plates will always show a couple of thousandths difference in OAL between all of the stations full and just having one case in at a time. I haven't put much (hardly any) time to figure it out, but what I think is that if the resizing station is empty, the shell plate can raise slightly higher. That makes a small change in seating depth and it also seems to flare the case mouth slightly more. Some folks take the first couple and last couple of rounds loaded and set them aside for practice. I don't bother with that, as none of my guns are that OAL picky, but I will avoid using those rounds for chrono testing just to be a little more precise. The other thing is that there is some slight variation in bullets, so that can make a slight difference as well. Lastly, brass will make a slight difference. If it's mixed brass you're getting slightly different lengths and thicknesses and even if it's sorted for headstamp you'll find slight differences once it's been shot one time.

In short, your numbers seem fine to me, try setting the OAL so that you hit the target number with all the stations full and you should be fine. R,

Fully agree. I load on a 550 as well and have noticed the same thing. Follow Sarge's advice and only do measurments when all the stations are full.

Bart, what I think happens is that the caseses themselves (when they're in the shell plate) keeps the shell plate from having any slack in it, since all 4 stations will contact the case in some way on the up stroke (down stroke of the arm), and with nothing in the other stations, there is some slack between the shell plate and the top of the ram, causing the shell plate to move slightly up and down.

[Newby]

Thank you for the responses.

What variences are you guys seeing while loading with all stations filled?

Also, just bought a bunch of "1 x fired brass" and many of these (just the cases) do not fit in the case guage because they have expanded a bit too much (before reloading them) Are these ok to use, or are they likely shot out of a glock or something that had an unsupported chamber and are therefore not fit to use??

Thanks again,

jeff

[GrumpyOne]

The variances should be minimal with all stations filled. As far as the brass is concerned, all brass expands when fired, so fired brass generally won't fit in a case guage. And as for some of them fitting and others not, it all depends on the chamber of the gun they were fired in, whether it was tight or not. I've said this a thousand times, now I have to say it again. THERE IS NO PROBLEM WITH GLOCKED BRASS! IT IS TOTALLY RELOADABLE! Secondly, even a Glock chamber is not completely unsupported, just not fully supported. Size them, load them, fire them....many times over (if you aren't loading major, that is!).

On a side note, what reloading manual are you using?

[Newby]

The variances should be minimal with all stations filled. As far as the brass is concerned, all brass expands when fired, so fired brass generally won't fit in a case guage. And as for some of them fitting and others not, it all depends on the chamber of the gun they were fired in, whether it was tight or not. I've said this a thousand times, now I have to say it again. THERE IS NO PROBLEM WITH GLOCKED BRASS! IT IS TOTALLY RELOADABLE! Secondly, even a Glock chamber is not completely unsupported, just not fully supported. Size them, load them, fire them....many times over (if you aren't loading major, that is!).

On a side note, what reloading manual are you using?

I have the lyman #49 and will be getting a few others asap. Any suggestions?

[Sarge]

The variances should be minimal with all stations filled. As far as the brass is concerned, all brass expands when fired, so fired brass generally won't fit in a case guage. And as for some of them fitting and others not, it all depends on the chamber of the gun they were fired in, whether it was tight or not. I've said this a thousand times, now I have to say it again. THERE IS NO PROBLEM WITH GLOCKED BRASS! IT IS TOTALLY RELOADABLE! Secondly, even a Glock chamber is not completely unsupported, just not fully supported. Size them, load them, fire them....many times over (if you aren't loading major, that is!).

On a side note, what reloading manual are you using?

I was going to go on a rant but this pretty much sums it up!

[GrumpyOne]

The variances should be minimal with all stations filled. As far as the brass is concerned, all brass expands when fired, so fired brass generally won't fit in a case guage. And as for some of them fitting and others not, it all depends on the chamber of the gun they were fired in, whether it was tight or not. I've said this a thousand times, now I have to say it again. THERE IS NO PROBLEM WITH GLOCKED BRASS! IT IS TOTALLY RELOADABLE! Secondly, even a Glock chamber is not completely unsupported, just not fully supported. Size them, load them, fire them....many times over (if you aren't loading major, that is!).

On a side note, what reloading manual are you using?

I was going to go on a rant but this pretty much sums it up!

Grumpy Sarge

[crockett]

I have just purchased my 650 setup for 45acp. I set COL for 1.26 and most of the time get a variance of 1.260 plus or minus a couple of thousands however some of the time I get a COL of 1.265 or 1.255. Last set of 100rnds I had 20rnds that fell outside the +- .002. and had to reseat one at a time. I took the seating die apart and cleaned everything however did not notice any improvement. Any suggestions?

[Newby]

I ran my press again with all stations loaded and have only 2 thou varience, OAL from 1.151-1.149 My goal is 1.15, I think this is now very acceptable. I did order the clamp kit and will report if it helps or not to tighten the tolerances even more.

[Sarge]

I have just purchased my 650 setup for 45acp. I set COL for 1.26 and most of the time get a variance of 1.260 plus or minus a couple of thousands however some of the time I get a COL of 1.265 or 1.255. Last set of 100rnds I had 20rnds that fell outside the +- .002. and had to reseat one at a time. I took the seating die apart and cleaned everything however did not notice any improvement. Any suggestions?

Welcome to the forums! Are all your cases the same headstamp? I load 9mm on a 550 and my tolerances tightened up alot when I went to all same headstamp. I rarely see a drift of more than.002.

What bullets are you using. Loading 45 are you using lead? some bullets have slight variations in their shape and will seat to different depths. Lead bullets can get deformed a little.

[crockett]

Thanks for the response. I cant believe how helpful and open this forum is...

I am using mixed brass and expected this to cause some variance. I had the same type of variance with LRN and Rainer FMJRN. I will try to check everythin with a fully loaded shell plate.

Just an FYI I took a year off from reloading and decided to get back into the hobby. In the past I was using a Lee 4 hole turret and am still using the Lee dies on the Dillion. Should I convert everything to Dillon dies? I do not remember this kind of variance on the old Lee, but it ran a lot slower and was more effort (4 pulls per round).

[Sarge]

From what I can gather here LEE dies are good dies. Dillons are what I use because I ordered everything together. I think the Dillons are good dies as well but they are designed with speed in mind hence they have some bevel to them where the cases go into the die. The only negative thing is that the bevel can result in some of the very bottom of the case not getting sized. I bought an EGW Undersized Die which is a lee die and there is very little bevel inside the mouth. It sizes lower on the case but if you try to go real fast with the handle you will catch an occasional case mouth on the edge of the die. Just go a little slower and it is perfect.

[HiPowering Along]

Hello everyone,

My first reloader...Dillon 550B

My situation is that when I set it up (everything tight) I was getting consistent OAL of 1.15 -1.155 with a 124 gr Montana gold 9mm, BUT, when I tested it using all 4 stations as a progressive, the OAL went to 1.158-1.160, then when I did it single every time it loaded to 1.45 to 1.47

How much variance is normal? Is there something I am doing horribly wrong? I'm not loading any powder yet as I'm just trying to get it dialed in.

How consistent should it be?

I'm a bit worried at this point I will not be able to load consistent ammo...

I just ordered the Unique-Tec toolhead clamp just to see if that could help things from shifting. I thought it worth a try.

Newby - you'll be more than pleased with the Unique-Tek clamp kit. I had a worse problem with my 650 in variances in OAL with my 9mm setup. Ordered the kit, simple to tap the toolhead and a few turns of a hex key wrench later the OAL variance is less than .002 per round. The kit is well, well worth the money.

HP'ing Along

[benos]

Another thing to do to reduce OAL variance - make the final tightening of all the die lock rings with a full Shellplate and the handle all the way down. This elimates all the tolerance variables from the Toolhead and even the Dies's threads.

be

[Newby]

Another thing to do to reduce OAL variance - make the final tightening of all the die lock rings with a full Shellplate and the handle all the way down. This elimates all the tolerance variables from the Toolhead and even the Dies's threads.

be

I have done this and am now holding a tolerance of less than 2 thou. I've ordered the cnc toolhead with clamp from Unique and will be comparing that as well.

By the way, Brian, after reading your "Beyond Fundamentals" I went from the about 20/30 to 10th/30 shooting steel plate in just two weeks. I have so much more to learn, but am really enjoying my progress.

[benos]

Another thing to do to reduce OAL variance - make the final tightening of all the die lock rings with a full Shellplate and the handle all the way down. This elimates all the tolerance variables from the Toolhead and even the Dies's threads.

be

I have done this and am now holding a tolerance of less than 2 thou.

There ya go! Over the years I've loaded some real tack driving pistol and rifle ammo on a box stock 550 with no mods, other than adjusting everything properly.

By the way, Brian, after reading your "Beyond Fundamentals" I went from the about 20/30 to 10th/30 shooting steel plate in just two weeks. I have so much more to learn, but am really enjoying my progress.

Thanks! The fun thing about learning and enjoying your progress is that as long as you keep your mind open it never ends.

be

[SA Friday]

A variance of +/- 0.002 is virtually nothing. Hell, a variance of +/- 0.002 (I might even say 0.005, but it would probably set off the truely anal reloaders of the world, those long distance rifle shooters...) is still not enough to cause a distinguishable difference even in precise long distance rifle rounds.

You can quite literally get enough flex in the reloading machinisms or the pressure exerted at the bottom of your reloading stroke, or even in the tolerances of the calipers to get a variable of +/- 0.005 depending on how they are made.

+/- 0.005 is what I strive for in OAL. Anything smaller just doesn't matter.

[Newby]

I am plenty happy with a variance of less than 2 thou. I am curious if the unitek toolhead with clamp will improve things further and will post my findings.

This is a very helpful forum

[GrumpyOne]

A variance of +/- 0.002 is virtually nothing. Hell, a variance of +/- 0.002 (I might even say 0.005, but it would probably set off the truely anal reloaders of the world, those long distance rifle shooters...) is still not enough to cause a distinguishable difference even in precise long distance rifle rounds.

You can quite literally get enough flex in the reloading machinisms or the pressure exerted at the bottom of your reloading stroke, or even in the tolerances of the calipers to get a variable of +/- 0.005 depending on how they are made.

+/- 0.005 is what I strive for in OAL. Anything smaller just doesn't matter.

Well said! IMO, striving for less than .002 is a waste of time and effort.

[Boxerglocker]

Reviving this thread to ask...

Can someone please tell me what thread size the Allen head thumbscrews are that the Unique Tool head lock down kit come with? I have several small size heli-coil kits and need not buy thiers if I have the one I need... only have one toolhead to do for my dedicated to 9mm XL650.

Thanks

[Pat Miles]

Reviving this thread to ask...

Can someone please tell me what thread size the Allen head thumbscrews are that the Unique Tool head lock down kit come with? I have several small size heli-coil kits and need not buy thiers if I have the one I need... only have one toolhead to do for my dedicated to 9mm XL650.

Thanks

Allen head screws are 5/40.

Pat

[Boxerglocker]

Reviving this thread to ask...

Can someone please tell me what thread size the Allen head thumbscrews are that the Unique Tool head lock down kit come with? I have several small size heli-coil kits and need not buy thiers if I have the one I need... only have one toolhead to do for my dedicated to 9mm XL650.

Thanks

Allen head screws are 5/40.

Pat

Thanks, 5-40 NC of course woul have to be a oddball I don't have. I would hate to buy the kit just to do one toolhead. My 650 ia a dedicated 9mm machince and have no need for the extras.

Edited October 9, 2010 by Boxerglocker

[rodell]

They are actually permacoils, not helicoils, if that matters to you. If you are tapping the toolhead, it matters as the permacoils and helicoils have different requirements.

If all you need is the bolt, you can get it at McMaster-Carr.

If you need only the coils, I can spare a couple - I bought more than I needed (long story).

I also have the Whidden Gunworks machined toolhead already tapped - very nice.

Edited October 9, 2010 by rodell