Die Wobble when Threading into RockChucker 4

[Fotheringill]

When I thread a die (no matter which one) into my press, there is a slight wobble until the lock ring hits the top of the press. Then, it is in solidly without wobble. This happens with whichever die I am using. They are all cleaned on a regular basis.

Worry? Don't worry?

 

[MGYSGT]

Probably so it can accept any manufactures die threaded for that press

 

[JSH]

There are a lot of thoughts on dies in the press.

I am sure there will be some one along shortly that will explain threading better than I can for sure.

 

[philip brousseau]

I think it is a good idea to place a piece of metal with parallel sides on top of the shell holder when the die is in place and push against the bottom of the die hopefully squaring the die to the shell holder and then locking down the lock ring. just my thought.

 

[Fotheringill]

From what I am describing, it appears that the bottom of the lock ring is what holds the die in the "correct" 90 degree to the top of the press. Maybe the threads in the press were true to the top of the press and maybe they aren't. Maybe the top of the press is at 90 degrees to the threads and maybe it isn't. And maybe it is the flatness (for want of a better word) of the bottom of the lock ring when tightened down.

Please tell me to be quiet and not to worry or I will go off on another adventure.

Then, of course, there is the question of rubber O-Ring arrangements for some dies.

 

[Dusty Stevens]

Once you tighten it it wont wobble

 

[Fotheringill]

Dusty-

I know that but is it affecting anything adversely?

 

[Ned Ludd]

How long have you been using this press? Do your all of your loaded rounds have ridiculously high runout, or are they nice and straight? Your response will also be the answer to your question.

By analogy, a rifle barrel cut with fairly loose threads doesn't wobble in the action because the shoulder fit keeps it tight. That will not necessarily cause any issue with accuracy, but if it does, I'd expect the user would notice right away. Problems generally show up in the end product.

 

[watercam]

When in doubt, measure your case body, shoulder and neck run-out. If you are at .001"-.000" you do not have a problem.
If you are worried about it, place an O-ring between the lock ring and press and screw in until it contacts the rubber about a 1/4 turn. Re-establish your desired shoulder bump and go to town.
FWIW my Rock Chucker is 22 years old and has sized and seated something close to 24,000 Highpower rounds. Took it apart the other day to check for wear (even though I could not feel any) and found nothing to worry about. Occasional oil all around is all it's had and still pumping our straight ammo with or without the O-ring trick.

 

[Fotheringill]

How long have you been using this press? Do your all of your loaded rounds have ridiculously high runout, or are they nice and straight? Your response will also be the answer to your question.

By analogy, a rifle barrel cut with fairly loose threads doesn't wobble in the action because the shoulder fit keeps it tight. That will not necessarily cause any issue with accuracy, but if it does, I'd expect the user would notice right away. Problems generally show up in the end product.

I don't have high runout.

 

[Ned Ludd]

I don't have high runout.

Then I think your setup is working just fine. This may not be true of all die manufacturers, but the all the dies I own have fairly loose threads and tighten up square via the lock ring. I'm also using a Rockchucker press, so the threading of the press itself may be part of the equation. Nonetheless, I have never had any issues with runout. I do make sure the set screw on the lock ring is very tight so that it doesn't come loose with repeated use over time.

 

[D-4297]

Manufacturer's use a dimension when threading any piece , and there is a + / - factor called out on the blueprint . Thread gauges are used to check the threaded pitch diameter of the threaded part after threading operations are completed . These "standards" are standard machining practices across the machine trades industry industry so all 7/8" dies will fit all standard 7/8" presses . Kind of similar to the SAAMI standards , in general . Don't think you have anything to worry about . My Rockchucker was made in the 60's , and the dies are very loose when being screwed in , but they still turn out .001 - .0015 cases .

 

[Uncle Ed]

Many reloading manuals tell you "before" tightening the lock ring to size a case and at the top of the ram stroke tighten the lock ring. This will remove any slop in threads and center the die in the press threads.

Another method is to place a rubber o-ring under the lock ring and this will allow the die to move and self center as the case goes into the die.

I use Redding competition shell holders that make hard contact with the die and Lee lock rings that have rubber o-rings.

There is a very good article in the Speer #9 reloading manual on how to setup your dies in the press and improve concentricity.

Bottom line, if there wasn't any slop in the threads the die would not self center and be aligned. And there is also slop in the shell holder that allows the case to self center in the die.

 

[Rsadams]

Mine does it also , a little oil on the threads helps... Plus it stops the nails on a chalkboard sound when screwing in dies....

 

[NorCalMikie]

be quiet and not to worry

How's that? No worries mate.
OR, go out spend BIG $$$ on another press and end up with the same thing. Don't fix it if it ain't broke.

 

[Dub]

I understand why you ask the question but there is no cause for concern here. All normal.

 

[natdscott]

Threads do not align the die, any more than they do a rifle barrel or suppressor...

...it is the SHOULDER that has to be square.

 

[tmwinds]

I don't have high runout.

There's your answer.

 

[Dusty Stevens]

Dusty-

I know that but is it affecting anything adversely?

Not at all

 

[BronzeArcher]

When I thread a die (no matter which one) into my press, there is a slight wobble until the lock ring hits the top of the press. Then, it is in solidly without wobble. This happens with whichever die I am using. They are all cleaned on a regular basis.

Worry? Don't worry?

Seen the same on my RCII. I've loaded ammo on it for plenty of 200/200 scores and a couple of 200-20x's. Most days, the ammo I've loaded is much more accurate than I can possibly shoot it. I don't worry about the wobble. At some point it ain't the ammo, it's the shooter. My focus is on improving the shooter.