Rock Chucker Variability - Is This Normal or Not?

[SEM]

I have worn out 1 older rock chucker early 70s badly worn out, Still look for OLD light or unused rock chuckers for me the best press I have used and ABUSED, One of my current is getting a bit loose, I live for wild catting, Todays presses are not so good I no longer fall for trying them, best advice RCBS gave me clean and relube every now and then, I like Tetras poly lube for the pivot points and (old stuff here) Penns muscle lube for the ram

Forgot some one on this site I think mentioned a while back, when moving a shoulder run the press to the top twice Double Tap, I do that it does help with spring back

 

[Rsadams]

Setup your dies correctly and why would you keep pushing down on the press handle once the bullet is seated? I would imagine that with anything you can force more movement than it should be... If there's a problem with the press contact RCBS and they will make it good...I have had my share of problems with RCBS but they have sent the parts to correct the problems free of charge everytime... I bought a kit years ago when I first started and pretty much everything was bad but they made it all good... Keep in mind any decent handloads should be alot better than factory ammo... Exept maybe Federal Gold Medal Match , I don't know how they make that stuff shoot so good...lol

 

[CarlGeorge]

Setup your dies correctly and why would you keep pushing down on the press handle once the bullet is seated? I would imagine that with anything you can force more movement than it should be... If there's a problem with the press contact RCBS and they will make it good...I have had my share of problems with RCBS but they have sent the parts to correct the problems free of charge everytime... I bought a kit years ago when I first started and pretty much everything was bad but they made it all good... Keep in mind any decent handloads should be alot better than factory ammo... Exept maybe Federal Gold Medal Match , I don't know how they make that stuff shoot so good...lol

I have stopped applying additional force. Or more correctly, I'm paying more attention to the finish of the downstroke and doing it consistently. It was when I wasn't paying that close of attention is when I was seeing the issues.

I'm definitely going to completely disassemble, clean and lube the press. I think that's a wise immediate next step.

Thanks all!

 

[johara1]

A rockchucker doesn't have a very big ram but if kept clean it should last a life time. Most take the primers out on them and never clean the press or lube it. So you can buy new again and repeat the cycle or take care of it and use the old one for decaping..... jim

 

[Rsadams]

I have stopped applying additional force. Or more correctly, I'm paying more attention to the finish of the downstroke and doing it consistently. It was when I wasn't paying that close of attention is when I was seeing the issues.

I'm definitely going to completely disassemble, clean and lube the press. I think that's a wise immediate next step.

Thanks all!

Not enough people pay attention to cleaning their equipment that's for sure... If you find a problem definitely contact RCBS I feel confident they will get you back in business... Once something stops application of more force is not a good idea because it will lead to slop or possibly broken parts... I may catch some for this but there's plenty of great shooters even championship shooters that just don't seem to care about the powder being down to the kernal or a small amount of seating depth etc.... Would it be nice for every round to be exactly perfect , sure , but you have to be able to shoot them that perfect... I certainly can't and don't pretend to be able to... I went to Dillon awhile back and for my pistol and AR loads it's wonderful but I still load my large rifles on my single stage stuff weighing each charge etc...

Now with everyone on house arrest it's a perfect time to service our stuff and do all the crap we have been putting off... For me that meens retention of fence lines , cleaning and organizing my small shop and maybe even all the stuff in my spare and reloading room... We all have a junk drawer I now have an entire junk room for some reason...lol

 

[Uncle Ed]

When seating bullets on your old Rockchucker use the method below.

When the duct tape rips and the string breaks the bullet is fully seated.

 

[carlsbad]

independent of all the other answers about your gear and setup, .001-.003" variability can be easily attributable to variations in springback on the brass. Annealing should help but not eliminate it. Top quality consistent brass is better. --Jerry

 

[CarlGeorge]

Well - I spent much of the afternoon disassembling, cleaning, lubing, and reassembling the press. I will say it is REALLY REALLY smooth now!

I will also say I didn't see any obvious problems. The Ram Pin / Ram connection was very tight. There was a bit of play between the Ram Pin and Toggle Block. I've got an email into RCBS asking if that's normal. (RCBS is closed due to the virus issues. But it sounds like they're doing what they can online.)

I did some testing by seating some .223 bullets. The variance seems to be improved. I'm posting this report to document for posterity that a deep clean appears to have helped. No - I'm not going to crank on the handle after it's bottomed out. I'm just trying to understand in detail how the press is behaving and how I will get the best results out of it.

Thanks everyone for their input and advice.

CG

 

[Bugs]

Good thread, thanks all for posting. . . I've been loading since dirt was new and would occasionally get some variances in shoulder bump that I couldn't account for. Finally (after god know's how many years) tore the old rockchucker apart, cleaned and re-greased with T25. What a difference. . .

 

[johara1]

Remember when you size and get variation first.... it will size more consistently if the brass is annealed and second dwell time has a lot to do with sizing the same, it ain't a race. ..... jim

 

[338 dude]

Perhaps you should try setting your dies for some cam over and use the redding competition shell holders to get the appropriate shoulder bump.

Works well for me.

 

[6MMsteve]

Remember when you size and get variation first.... it will size more consistently if the brass is annealed and second dwell time has a lot to do with sizing the same, it ain't a race. ..... jim

yep I use a couple seconds dwell time..I simply turn my head and look out the window then ram down...I may have to take my neck apart and grease the muscles and deburr the brain stem

 

[johara1]

how I slowed down is to put the lube on while the one is in the press, it seems to be enough time for it to size the same... jim

 

[JMayo]

I use a pma tool to micro adjust die. Shoulder bump, neck sizing with fl sizing die.
My older brass has to have the die down 1thou compared to my newer brass even after annealing.
Also my measuring ability can find differences of half -one thou ...

I love hearing all this EXACT measuring talk.

 

[johara1]

I use a pma tool to micro adjust die. Shoulder bump, neck sizing with fl sizing die.
My older brass has to have the die down 1thou compared to my newer brass even after annealing.
Also my measuring ability can find differences of half -one thou ...

I love hearing all this EXACT measuring talk.

Anneal it and all stays the same.... jim

 

[Field_2_Fork]

For bullet seating everything (now - .284) is going great. Using the Redding Competition Seating Die, along with the handle methods I describe, I get the seating depth I want basically 100% of the time. I'm using Berger 180gr Hybrid Target bullets.

For sizing I'm using full travel of the press handle. But imagine that point where the case is fully in the die and the press handle is all the way down. If I put additional force on the press handle after it's in the full-down position, I believe I'm getting an additional up to .003 or so of additional ram travel.

It's this additional "flex" or "ram travel" or whatever I'm trying to figure out is within the realm of normal for a press like a Rock Chucker.

I'll restate something from the original post: For now I understand this behavior and I'm able to work with this behavior and create the ammo I want. I know how to use the press to improve consistency and reduce substantially the variability. I'm curious if this variability is normal or abnormal......leading to an understanding if this press is heading south in some way.

Thanks.

I've only been reloading for a few years, but for what it's worth I've noticed exactly what you are experiencing with my RC press. It is an older press that I got from a friend. It certainly has enough flex in it to seat the bullet deeper than intended, this really doesn't require much extra pressure at all. Like you, I'm quite light on the handle now, with more consistent results.

Cheers.

 

[CarlGeorge]

I'm gonna close this out reporting on how RCBS handled this situation. Add yet another story to the long list of great customer service stories.

I emailed RCBS and told them of the variance. (Note this was done before the thorough cleaning, which ended up improving the press's performance.) I didn't ask for service or parts, but rather asked whether the variance I was seeing was normal.

Their response said the pins could be off and "We'll send you some." Since the phone line said the factory was closed, I figured I might follow up when they opened and ask for the parts. When I submitted my question I didn't recall sending my mailing address, so I figured I had to re-contact them to give them those details.

Today a package arrived with numerous pins and some e-clips. Maybe they had my address on file - or it was on the form I submitted. I don't know. But, like always and along with many others, I continue to be blown away by RCBS Customer Service.

CG

 

[edwardware]

I'm not setting up to do the cam-over?

Found your problem. Camover ensures that pushing harder is actually retracting the ram, because it's already cammed over the top. It's much more consistent that way.

 

[KY_Windage]

That "variability" you describe gives you easy precision. Use it to produce wonderfully consistent rounds, through the vagaries of the confounded brass. I certainly do.

 

[Shooter13]

how I slowed down is to put the lube on while the one is in the press, it seems to be enough time for it to size the same... jim

Exactly what I do!