Dillon 550 vs. Forster Co-Ax

[Howa 9700]

So put a Dillon 550 into production mode, pushing out 9mm blammo. Had previously set it up and cranked out a few rounds, but moved to a different bullet, so started fiddling with seating stem, trying to fine tune it to the desired seating depth. A small adjustment seemed to result in either no change or big change........big being .005 to .010. Nothing like that happened on the Co-Ax. It is linear and dead nuts accurate.

I am aware that if you don't have brass in the sizing/depriming station 1, the shell plate on the 550 can rock a bit........I get a difference of about .005.......with or without brass in station 1. When loading, I try to lower the handle / raise the ram until it comes to a stop.

Is this OAL variation normal on a 550 or do I have a malfunction and need to look for the source?

 

[Howa 9700]

BTW, Lee Carbine 9mm dies. On both presses.

 

[LiveLife]

I am aware that if you don't have brass in the sizing/depriming station 1, the shell plate on the 550 can rock a bit

Unlike most other progressive presses (Including Dillon 650/750), 550 shellplate does not capture case rim rather push the rim around on top of carrier, which results in more consistent OAL variance less affected by shellplate tilt/deflection.

Lee [Carbide] 9mm dies

If you have the older powder through expander, variation in resized case lengths can produce differing amount of case mouth flare that can contribute to bullet tilt during seating that can contribute to OAL variance. To address this, I used to measure samples of different headstamp brass (Different headstamp brass will tolerance stack to OAL variance on progressive presses) and used shorter resized cases to set the case mouth flare so longer resized cases received slightly more flare and checked to make sure bullet didn't tilt during seating.

To address bullet tilt during seating (And during shellplate index when using inline bullet feeder die), Lee Precision has replaced the powder through expanders with stepped "M" style powder through expanders (PTX) now standard on most die sets - https://www.thehighroad.org/index.p...-through-expander.916523/page-4#post-12725787

They are $3.67 for 9mm - https://leeprecision.com/pm-exp-plug-9mm

Final production "stepped" PTX on the left, R&D sample PTX in the middle and regular "non-stepped" PTX on the right

 

[rfwobbly]

I am aware that if you don't have brass in the sizing/depriming station 1, the shell plate on the 550 can rock a bit........I get a difference of about .005.......with or without brass in station 1. When loading, I try to lower the handle / raise the ram until it comes to a stop.

Is this OAL variation normal on a 550 or do I have a malfunction and need to look for the source?

• As you have said, not filling the remainder of the case positions results in a lot of OAL variation. The root cause may be that the Dillion Tool Head has 0.01" of up/down free play, and the Tool Head must be lifted evenly and completely before consistent OALs are achieved. Using your procedure, I get it close, then go into production. Then, I only make final adjustments to OAL during production. This means for a new batch of ammo, I may need to pull the first 4 to 6 rounds and run them under stations #3 and #4 a second time. This is really easy on the 550 with its non-advancing shell plate.

• Your OALs will also vary on any progressive when you are not using case lube. This because the major force required is in Sizing the case at station #1, where as the Seating is taking place across the shell plate at station #3.

I feel certain that your issue can be found in some combination of these 2.

 

[Howa 9700]

As I think thru and recall the various steps, with and without a fully loaded shell plate, I think Wobbly might be right.

Also, I am using the Dillon powder measure, die and flaring funnel that came with the press and conversion kit. That is the only part of the Lee die set not used.

Since primer tube is loaded, was avoiding setting an empty case into station 1 sizing die, but if you don't press handle to seat the primer, you can do that all day long and it shouldn't matter. Have to remember that.

Single stage mind operating in progressive mode takes some getting used to. Like patting your head and rubbing your belly at the same time. Takes some practice.

 

[Howa 9700]

Was also having trouble seating primers. Press ran out of CCI and when I switched to some Ginex I noticed the primers had a "crushed" look to them. Something not right. After a lot of thought, switched to new brass and problem went away. So appears the issue was a combination of CBC range brass and Ginex primer. Won't be doing that again anytime soon.

 

[jmorris]

I am aware that if you don't have brass in the sizing/depriming station 1, the shell plate on the 550 can rock a bit.....

Unlike most other progressive presses (Including Dillon 650/750), 550 shellplate does not capture case rim rather push the rim around on top of carrier, which results in more consistent OAL variance less affected by shellplate tilt/deflection.

If you are trying to locate the source forget about the shell plate on the 550, unlike all the others, the case is not "in" the shell plate. The base of the case doesn't touch it, the shell plate is only there for locating and extraction from the die. If you lined the case up by hand it would be seated to the same depth it would be if the shell plate were there, so any tilt wont make any difference.

550 shell plate on left.



If you are going to use your progressive as a single stage or not have all stations full, shim the tool head "up" or helicoil the tool head and use screws to hold it up vs the pins that let it float.

 

[Howa 9700]

So source of variation on the 550 is in the tool head? That makes sense and reaffirms the practice of not trying to fine tune seating depth without a shell in station 1 to balance it out. And maybe 2 and 4 as well, as that is the condition it will eventually operate under.

BTW, the Co-Ax has as much floating slop in the die as the 550 does, but with only one die in use at a time, that goes away.

 

[jmorris]

So source of variation on the 550 is in the tool head?

Variation comes from a lot of things.

Using a 4 station press and doing work at each station vs using it with only 1 occupied will certainly do it.

If you stroke your co-ax with and without a case in there, there will be a variation in how much the die moves in the slot.

Your 550 is no different, it will just effect the remaining 3 too.

I setup progressives one at a time, then final adjust once everything is full.

 

[LiveLife]

So source of variation on the 550 is in the tool head? That makes sense and reaffirms the practice of not trying to fine tune seating depth without a shell in station 1 to balance it out. And maybe 2 and 4 as well

4 station press and doing work at each station vs using it with only 1 occupied will certainly do it ... it will just effect the remaining 3 too.

I setup progressives one at a time, then final adjust once everything is full.

Yes, with any progressive press, set up of dies are initially done with one case run through but final adjustment of dies is needed in "progressive mode" with shellplate full of cases as to account for variation in shellplate tilt/deflection from differing resizing effort/force.

There are several reloading variables that contribute to OAL variance and to minimize the variance, you must address all of them (To me, from variables that effect OAL most to least):

• Bullet nose profile/ogive - Due to wear of bullet forming dies and other factors, bullets from multiple machines used by the same manufacturer can have differing bullet nose profile we call "ogive". Since Lee bullet seating stem/plug does not push at the tip rather further down the bullet (There's a hole at the bottom of the stem/plug), variation in bullet nose can significantly affect finished OAL. Plated bullets with soft lead core can deform during bullet seating/taper crimp process to produce greater OAL variance than jacketed bullets. To maintain utmost bullet nose profile/ogive consistency, @longdayjake of RMR will replace bullet forming dies sooner to maintain higher level of consistency and likely why ELEY chose to use RMR in-house manufactured jacketed bullets for their centerfire match ammunition (And why I use RMR bullets for all of my reference/myth busting measurements as they are more consistent than other bullets). To reduce this variable, use more consistent jacketed bullets.
• Case wall thickness - Depending on headstamp and lot, case wall thickness can vary, especially where bullet base gets seated down to and in turn require differing resizing effort/force to affect shellplate tilt/deflection which can vary bullet seating along with case mouth flare/crimp amounts. To reduce this variable, cases can be sorted by headstamp and further by resized case length to produce more consistent case mouth flare and taper crimp amount.
• Condition of brass/Work hardening/Expansion Amount - Depending on headstamp and lot, even for same headstamp but different lot, brass alloy quality can vary based on sourcing of brass delivered to the manufacturer. As brass cases are repeatedly shot and reloaded, work hardening will make the brass less malleable affecting resizing effort/force. Factory chamber dimensions, modified/polished chambers and/or overly expanded 9mm Major brass (Especially at case base, meant to be shot once and not reloaded again) can all affect resizing effort/force. To reduce these variables, even with using same headstamp brass, you can separately resize the brass to eliminate varying resizing effort/force on other dies.
• Bullet tilt during seating - Bullet tilt during seating can add to OAL variance and many reloaders have used stepped "M" style expander to hold bullets straight before being seated. Lee Precision is replacing all of their powder through expanders (PTX) with stepped PTXs and since you are using Lee dies, you can purchase new PTX separately. To reduce this variable, use stepped powder through expander.
• Toolhead float/play - According to Dillon, there is .004"-.005" play of 550 toolhead and recommended to tighten die lock rings with all stations full and ram lever in down position to center the dies and toolhead. To eliminate toolhead float/play further, there are zero play toolheads available. Using progressive presses like Hornady/Lee Precision with breech lock bushing is another option to eliminate toolhead float/play.

 

[PO2Hammer]

I get very little (-.005”) OAL variation with my 550 from the first to last round.
When I ran CBC brass I got OAL increases up to .010”, that stuff is hard.
Same results as I had with my T-7.

 

[LiveLife]

I get very little (-.005”) OAL variation with my 550 from the first to last round.

When I ran CBC brass I got OAL increases up to .010”, that stuff is hard.

And thick.

These are 12/3/6/9 o'clock measurements .200" below flush where base of 115 gr FMJ/RN bullets typically get seated down to - https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10713822

CBC: .015"/.014".014"/.015"
CBC: .015"/.015"/.014"/.015"
CBC: .014"/.015"/.014"/.013"

BLAZER: .011"/.012"/.011"/.010"
BLAZER: .010"/.010"/.012"/.011"
BLAZER: .012"/.011"/.011"/.012"

.FC.: .013"/.012"/.012"/.011"
.FC.: .011"/.011"/.012"/.010"
.FC.: .011"/.012"/.012"/.011"

Starline: .012"/.012"/.013"/.012"
Starline: .012"/.013".012"/.011"
Starline: .012"/.012"/.013"/.013"

R-P: .013"/.011"/.012"/.014"
R-P: .012"/.012"/.014"/.012"
R-P: .012"/.012"/.013"/.012"

WIN: .014"/.013"/.0125"/.013"
WIN: .013"/.013"/.0125"/.012"
WIN: .015"/.014"/.013"/.014"

 

[rfwobbly]

As I think thru and recall the various steps, with and without a fully loaded shell plate, I think Wobbly might be right.

Just remembered this....
When my 550 was only being used for loading 32ACP, the cartridges were so small and the Sizing forces so low that I was getting inconsistent OALs. The solution was to shim the Tool Head to the raised position. A strip of cardboard about an inch long was snaked in on both sides (ending up near the locating pin positions) while the Tool Head was being inserted into the press body. This kept the Tool Head permanently raised, and then loading 1, 2 or 3 at a time made no difference.

Of course, my 550 was dedicated to 32ACP production, which may not be an option for you.

 

[SingleActionAndrew]

Here's a kit if anyone is having a hard time getting started...

Toolhead Clamp Kit - SKU: T1230

The UniqueTek Toolhead Clamp Kit ™ enables the toolhead of Dillon 550, 650 & 750 presses , or the die plate of RCBS Pro 2000®/ Piggyback™ -3 & -4 presses , to be CLAMPED into the press frame. This corrects the loose fit between the toolhead and press frame, thus reducing OAL (overall length)...

uniquetek.com

 

[nettlle]

I have shimmed the tongue and groove fit with Scotch tape on my 550 tool heads to eliminate play. These Scotch tape shims stick to the tool heads and the difference in COAL improved enough to make doing it worth while. There are more professional methods but using the Scotch tape shimming method may identify one of your sources of inaccuracy.

 

[Howa 9700]

I went back thru the setup to set my COAL and this time had brass in all 4 stations, as would be the case when in progressive mode. Ran several pieces thru and all were within .001 above or below of where I was shooting for. I can live with that.

The other thing is I got to test out the Inline Fabrication LED light. That is night and day better! Comforting to be able to see the powder charge has dropped. Will eventually learn to trust the "feel" of setting the primer to know one was inserted.

 

[nettlle]

It does make a difference with all the stations loaded. I have the Inline Fabrication Skylight also. Makes a big difference.

 

[LiveLife]

I went back thru the setup to set my COAL and this time had brass in all 4 stations, as would be the case when in progressive mode. Ran several pieces thru and all were within .001 above or below of where I was shooting for. I can live with that.

Awesome!

I love happy endings.

 

[9mmepiphany]

I love happy endings.

Me Too