Caming press

squeeeeze

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May 21, 2011
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Arizona
Was watching a long range only video where he was setting up his dies and was caming over both the seating die and the sizing die. I have never done this before. What are others doing? I am trying to find a way to get my reloads more consistent. I typically have very little variations then randomly I will have a COAL that is outside the norm but my process feels the same so I am unsure what is causing it. THinking if I use the caming method that may take this away. Thoughts?
For your COAL are you measuring from the tip to base or ogive to base? Tip to base COAL can vary a lot more.

I’ll cam over when I need to. I base it on when the shoulder can’t be set back any more and won’t chamber, or hard chambering. I’ll cam over until the shoulder is where I need it. As I seat my bullets I’ll seat partial as well then turn like 3 more times approx 120* and continue to seat partially each turn then seat fully. This seems to help with my runout. I also have a couple sets of Redding competition shell holders I’ll use as well.

I’ll have to try @ButterBean ’s technique of holding the brass there for 10 seconds to prevent less spring back. Hadn’t heard that before but makes sense.
 

P7M13

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I never have the seater die touching the shell holder on conventional die sets. As mentioned above, the crimp feature will touch the case mouth doing so.
This.
I have Hornady and RCBS dies, that if the seater die touches the shell holder on full stroke, you're crushing the shoulder on your case.
To find out the limit of my seater die (and FL too), I will remove the expander mandrel/ball, size a case, and then see where the case will feed to without resistance. Works very well in finding the shoulder.
 

243winxb

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Sep 9, 2016
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Lee Collet (neck) die
Just bought one in 243 Win to play with. Loaded 10 rounds using Lee instructions for a RCBS press that cams over.
Placed 28 pounds of weight on the lever to size, because Lee FAQ said 25 lbs minimum would put 600 lbs on the ram. Neck tension not good. Measured mandrel at .240"
Takes a lot more force/effort then my bushing die.

If I feel like "working out" I will get out the Lee Collet Neck Sizing Die.
 

Patriot007

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South Ga.
It really works with the collet dies.......time it takes to get the next case ready (5-10 seconds) is perfect.
Youtubers kill me when they size a case or expand a case neck in there videos. You would think they were running a marathon. Always seat a bullet slowly, and expanding/Collecting case necks should be done slowly and held for 4 to 10 seconds depending on the brass. Consistent annealing after every firing is a must. Think of it as relaxing your brass. I don't need any uptight brass hanging out in my reloading room. If I want that, I'll invite the wife in. LOL.:)
 

ButterBean

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Just bought one in 243 Win to play with. Loaded 10 rounds using Lee instructions for a RCBS press that cams over.
Placed 28 pounds of weight on the lever to size, because Lee FAQ said 25 lbs minimum would put 600 lbs on the ram. Neck tension not good. Measured mandrel at .240"
Takes a lot more force/effort then my bushing die.

If I feel like "working out" I will get out the Lee Collet Neck Sizing Die.
That's why I cam over, It takes all the work out of it and it makes it consistent
 

Savage 12BVSS

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Dec 20, 2019
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Just bought one in 243 Win to play with. Loaded 10 rounds using Lee instructions for a RCBS press that cams over.
I don't set mine up according to lee's instructions, I use the J. Valentine method that comes up in most searches on lee collet neck die adjustment from Benchrest Central. Less collet lines in the neck and less pressure to size, find it and read it, this guy put some time into figuring it out. Its a case of lee making a very accurate and concentric neck sizer, but not explaining how to adjust it properly at all. I was ready to give up on the first one I bought till I stumbled into the different adjustment method, now I have a collet neck die for every cartridge I load for. Too much pressure and you will remove the alum. cap without screwing it off as mentioned in other posts. If you can't find it PM me and I'll send it to ya :)
 

7stw

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I think there may be a mis- conception, as to the amount of cam over that Brother Bean is referring to. It's not the full, rollover. As the amount that works, WITHOUT DAMAGE,is at the very bottom of the stroke. You have to keep adjusting the die body, until you get a amount that dosent crush the collet, but give a uniform amount of pressure. Additionally, if you do need more effect, you can polish, the mandrel, effectively reducing the inside diameter, therefore applying a little more neck tension, all else being equal.
I'm in the boat of using slight cam over only during resizing. The only time, that during seating, would be IF you are roll crimping during the seating process. That may be what the OP was referring to. There are knowledgeable people that have wrote many threads on this topic, and the collet, and FCD as well. Tempers flare, but experience wins everytime.
Happy and Healthy Holidays to all.
 

Savage 12BVSS

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7stw is right, some of us have a press designed to cam fully over with all dies, some do not and have to be more careful. The RCBS Summit I now use is a cam over press. That along with the shell holder movement and side/fore and aft movement changed my world and got me loading straighter more concentric cartridges.

I know there are some that don't believe concentric ammo is necessary or any more accurate..........I find I'm never swayed by debate when compared to real actual hands on results and experience with something. When I talk about collet/mandrel neck dies, press movement to help align cartridge to die, camming over with dies, removing spindles and expander ball's and rotating the cartridge several times when seating its because they have all worked together for me..........if it just plain works I make it a part of my reloading process.

At the same time I have changed from neck sizing only and incorporated a full length sizing step, also really changing the way I flash hole deburr if at all as well. I never intend any offence just one persons way of doing it. It's what makes this site great! :)
 
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Mike from Texas

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Sep 7, 2013
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North Texas
As mentioned not all presses cam over. My Forster CoAx doesn’t or at least I’ve never had it set up to do that. But it does have hard stops at the bottom of the stroke and produces very consistent ammo.
 

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