Should I Clamp my 550 Toolhead?

[dka]

After years of using my 550B for pistol calibers, I've decided to give it a try making match-quality .223 for a custom Rem 700 I'm having built. I would like to make the Dillon press work for me, as opposed to investing in a quality single stage press, new powder measure, priming system, etc. Seems to me that a semi-progressive process will be required. Size on station one, then go off-line for case prep, then back on the press for priming (remove sizing die?), powder drop and seating. I've tricked out the Dillon powder measure using Tom Freeman's tips, to include adding the Unique-Tek micrometer. It drops Varget with +/- .1gr accuracy, so I think I'm okay there, but may begin by individually weighing loads. Now the seating question. I bought a Redding Type S Match Die set with the Competition Seating Die. Everyone raves about this Redding die, so I'm wondering if inherent movement in the Dillon tool head during cycling (though I'm using it essentially single stage) negates or diminishes the precision of the die. I'm pondering this and thinking....if I'm cycling the handle consistently and the tool head is therefore moving consistently on each stroke, is there any advantage in clamping the tool head to make it stationary? Unique-Tek offers a clamping set that requires tapping the tool head for hex bolts that replace the Dillon pins. Do I need to do this to get maximum effectiveness from the Redding Competition Seating Die? I'd really like your thoughts on this....and any other thoughts/experiences on loading match-quality rifle rounds on your Dillons. I'll go with a single stage press if it eventually comes to that, but I really want to give the 550B every opportunity to make this work.

All the best,

Deke

[glockrocker]

A friend of mine had the same concern as yours. He had a 550 and used jb weld to take the play out of the tool head. He lined the tool head slot on the press with a thin layer of jb weld. Then he put some kind of grease (slide glide?) around the edges of the tool head and inserted it into the press to mold the jb weld to the tool head. Then removed tool head and let jb weld dry. Repeated process until tool head was tight in the press. I remember watching the press operate and there was no movement whatsoever in the tool head. He was also able to change tool heads.

That being said, he later bought another 550 and has done nothing to eliminate the movement in the tool head on the new press. He said the press with the anchored tool head loaded no better/worse than using it as it came from the factory.

[John Dunn]

David Tubb writes in one of his books about loosening the dies so they can float and self-center, then pinning them through the lock ring into the die head. I think this would be a better approach.

[Carl Provan]

Second Idea is to use the locating pin holes in the toolhead. I am not sure of the screw size needed, but by inserting a heli-coil in the toolhead where the locating pins go and then use the matching screw to pull the tool head up against the top of the slot. This might do the trick and be specific to that toolhead. If filling the slot with JB weld or similar is the plan make sure you use the tightes fitting toolhead to start with. As then all other toolheads should still fit.

My 2 cents

[ChuckS]

I am pretty sure that Dillon has said to leave it float in the past. Do a search of this forum.

Later,

Chuck

[Keith_J]

Floating is always better. Precision Shooting Reloading Guide advocates using an o-ring between the lock ring and press/toolhead for this purpose. Of course this was "discovered" long after Richard Lee started using o-rings under the lock ring..

The "slop" in the toolhead is needed to allow for things like shellplate deflection.

[rishii]

another option if you want to use a dillon platform is to get an old 450

it's the earlier version of the 550, with a solid frame, you had to screw the dies into the press it self, no tool head to mess with. plus because there obsolete, there usually dirt cheap on ebay

http://search.ebay.com/search/search.dll?f...&category0=

[z40acp]

+1 on the 450 idea. It would certainly be the easiest and mutiple machines have their advantage. I have a 450, 500, 550 and 650. I don't know if it was just the luck of the draw but my old 450's powder measure is the most accurate. Downside is you have to push it to make it work. There were different 450 models, so make sure you get the one like the 550. I think it was a RL450.

[boz1911]

UniqueTek makes a kit to thread your die plate and bolt it in. Used it on my 550 to minimize COL variations and it(they) worked well. Loaded 10's of thousands of rounds with no problems.

[dka]

Thanks for the input, guys. Is there a concensus building for some amount of movement/flexion to allow dies to self-center....either inherent movement in the Dillon tool head or O-rings under dies in a fixed frame? I tried a search, as recommended, but couldn't find anything from Dillon indicating that tool head movement was an intended design feature. Maybe experimenting with some shim stock to secure the tool head is a good idea, as opposed to permanent alteration of the tool head for frame. Thanks again for your help. Any more thoughts on the merits of using a progressive press for match-quality rifle ammunition?

Regards,

Deke

[Bill H]

I have thought about all of this but really when the cases are fed into the dies doesn't the tool head end up in the same place all the time? BTW 2 weeks ago I shot a 7/16" 5 shot group at 200M with .308 ammo loaded on a "loose" 550. That was a great group but not an uncommon thing with 550 ammo.

[Keith_J]

Thanks for the input, guys. Is there a concensus building for some amount of movement/flexion to allow dies to self-center....either inherent movement in the Dillon tool head or O-rings under dies in a fixed frame? I tried a search, as recommended, but couldn't find anything from Dillon indicating that tool head movement was an intended design feature. Maybe experimenting with some shim stock to secure the tool head is a good idea, as opposed to permanent alteration of the tool head for frame. Thanks again for your help. Any more thoughts on the merits of using a progressive press for match-quality rifle ammunition?

Regards,

Deke

I think the outstanding accuracy capable in ammo loaded on a 550 is serendipitious with regards to the "slop" in the toolhead-frame fit. The slop was only "designed" to allow ease of replacement. After all, the frame is cast aluminum with the slot machined. Toolheads are die cast Zamak, a zinc alloy. Yeah, pot metal. If you were to shim/bed the fit, only one toolhead would be "perfect". And you would not see any improvement in accuracy.

People try to make reloading presses massive, holding bullets in precise alignment with the case, only to have greater runout than the benchrester who uses an arbor press. Newsflash, bullet runout isn't caused in seating, it happens in sizing because neck walls have a slight variation in thickness. Many benchrest shooters uniform the thickness with outside neck turning, usually for a perfect fit in a tight neck chamber. And in such chamber, no resizing is needed so they have runout minimized.

[dka]

Your comments are very persuasive...and consistent with what I've read about runout. I can see where this would be of more concern to a BR shooter than OAL veriation potentially caused during seating by a loose tool head. I don't foresee myself spinning cases and neck turning, so I'll heed your advice and keep the tool head it the way Dillon designed it. "Serendipitous" accuracy works for me. Thanks again for all your help.

Regards,

Deke

[dka]

Your comments are very persuasive...and consistent with what I've read about runout. I can see where this would be of more concern to a BR shooter than OAL variation potentially caused during seating by a loose tool head. I don't foresee myself spinning cases and neck turning, so I'll heed your advice and keep the tool head it the way Dillon designed it. "Serendipitous" accuracy works for me. Thanks again for all your help.

Regards,

Deke