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Posted: 6/3/2013 7:14:55 PM EDT
| I've followed the RCBS die instructions that call for a 1/4 turn lower so the press cams over. The tutorial here states to have the die touch and then back off a full turn and adjust as needed. I've also youtubed and found everything in between. I just watched the Sierra video where they use a mic guage for the shoulder and just curious if the measured method works the brass less or does it just set the shoulder better? I find the camover kind of strange, as touching should be enough. I'm loading for semi only. |
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If using RCBS dies, setup the die as RCBS suggests. This will ensure that the shoulder and all other dimensions would fit into the standard case gauge for whatever cartridge you are loading for. The camming over is ensuring all of the critical portions of the case are contacting the corresponding points in the die. I would strongly suggest doing this for an autoloader. Failure to size the case back enough can result in a round failing to go into battery.
I full length size all of my rounds; including those for my match rifle. All sizing is performed exactly per RCBS instructions. |
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Just to confirm, I would just trust the die and really no need to buy the case mic? This is what I've done, but the Sierra vid had me second guessing. You will eventually own some tools that you use on a regular basis early in the learning curve and then less as you go. They will get used often when a new set-up is being developed and then not so much. Case shoulder datum for a sporting chamber is one thing, and a match chamber is another. The Wylde chamber is slightly different than a typical Mil-Spec chamber. We give up a little in the Mil-Spec chamber to help with reliability in weather and dirt. Using the Mic Gage set will allow you to check your shoulder datum on fired cases. You can then use this length as a reference length to set the size die in a way that gives reliability while minimizing the cold working of your cases. You can always do this blind with a standard die set because they should give a default sizing to the minimum condition of the SAAMI specifications. It is always better to know because you measured and that requires owning some gages. You can start with what you have. I would suggest you get with a mentor and borrow some gages the first time. It will help you understand what they are for and if you will want to own them. |
The FL die & shell holder will set a safe, usable, working cartridge headspace. Not so with some shell plates on progressives. Cam over is not always needed. The die & shell holder just making contact may be plenty. Many handloaders have problems using tools, so i made this.  
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The Sierra video is the correct way of doing it, just FL sizing it so it fits every chamber is the easy way for RCBS to explain it and not get so many calls from people having trouble with their cases fitting their chambers.
I have case mic's, headspace gauges, and datum comparators for every cartridge I load and they are very useful tools, are they needed to make basic ammo, NO, but they sure do make avoiding and correcting issues fast and easy. I would say at the very least you should get a head space comparator like Hornady makes to use with your calipers, this will allow you to easily see how much your sizing your case and prevent chambering problems and over sizing your brass. I have seen several chambers that full length sizing created unsafe headspace and you won't know until it's a problem without some type of gauge to measure with. EWP |
| Also not a good idea to mix manufacturers of shell holders and dies if you are going to use the cam-over technique. Just for example, some Redding shell holders are a tad bit thinner than RCBS from base of cartrige to contact point. Still best to use some sort of accurate measuring device for precise headspacing. |
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As a career machinist and QA inspector I find it very difficult to believe that good consistency can be maintained without full contact on the shell holder. There are a number of things ranging from brass hardness to linkage play and compression that can effect how much a case is sized.
Yes this is my opinion. I haven't experimented with it personally. As far as a full length die "dangerously" over sizing a case by creating too much head space goes I have to say if that is happening the problem is with the chamber not with the die. You need to have your gun repaired if this is happening. I find the extremes I see on here kind of amusing at times. One crowd swearing by small base while the other is bumping back shoulders .002" All for what? One more cycle? |
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As a career machinist and QA inspector I find it very difficult to believe that good consistency can be maintained without full contact on the shell holder. There are a number of things ranging from brass hardness to linkage play and compression that can effect how much a case is sized. Yes this is my opinion. I haven't experimented with it personally. As far as a full length die "dangerously" over sizing a case by creating too much head space goes I have to say if that is happening the problem is with the chamber not with the die. You need to have your gun repaired if this is happening. I find the extremes I see on here kind of amusing at times. One crowd swearing by small base while the other is bumping back shoulders .002" All for what? One more cycle? It doesn't matter what causes the dangerous headspace, the point is without a gauge of some type to measure it you have no idea if it's safe or not. The point of handloading is to make custom ammo for your rifle, if the headspace is long then size it accordingly and it will be safe. EWP |
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As a career machinist and QA inspector I find it very difficult to believe that good consistency can be maintained without full contact on the shell holder. There are a number of things ranging from brass hardness to linkage play and compression that can effect how much a case is sized. Yes this is my opinion. I haven't experimented with it personally. As far as a full length die "dangerously" over sizing a case by creating too much head space goes I have to say if that is happening the problem is with the chamber not with the die. You need to have your gun repaired if this is happening. I find the extremes I see on here kind of amusing at times. One crowd swearing by small base while the other is bumping back shoulders .002" All for what? One more cycle? It doesn't matter what causes the dangerous headspace, the point is without a gauge of some type to measure it you have no idea if it's safe or not. The point of handloading is to make custom ammo for your rifle, if the headspace is long then size it accordingly and it will be safe. EWP Wouldn't the chamber have to be out of spec for this to occur? Using an RCBS FL die, correct shellplate and their instructions, how could you make the headspace unsafe? Maybe you could crush the case, but that would require completely overlooking the manufacturers suggested use. I view NS as being far more dangerous, as far as headspace goes. |
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Using an RCBS FL die, correct shellplate and their instructions, how could you make the headspace unsafe? This defective (IMO) shell plate caused case separation for me. The shoulder was pushed back a total of .014" Die .005" & plate .009" = .014" Each station gave a different shoulder bump if the FL die was adjusted on that station. It took a while to find the problem using a case gage & comparator.  Or a different way to measure. 
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I suppose a gage could help you find the problem but a case head separation or pending sign of after the 2nd or 3rd reload and or the very loose fit in you chamber would be a good indicator too. I guess it depends on the skill and knowledge of the hand loader.
I'm still on fence about the consistency attainable by backing off the size die to reduce shoulder set back. |
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As a career machinist and QA inspector I find it very difficult to believe that good consistency can be maintained without full contact on the shell holder. There are a number of things ranging from brass hardness to linkage play and compression that can effect how much a case is sized. Yes this is my opinion. I haven't experimented with it personally. As far as a full length die "dangerously" over sizing a case by creating too much head space goes I have to say if that is happening the problem is with the chamber not with the die. You need to have your gun repaired if this is happening. I find the extremes I see on here kind of amusing at times. One crowd swearing by small base while the other is bumping back shoulders .002" All for what? One more cycle? It doesn't matter what causes the dangerous headspace, the point is without a gauge of some type to measure it you have no idea if it's safe or not. The point of handloading is to make custom ammo for your rifle, if the headspace is long then size it accordingly and it will be safe. EWP Wouldn't the chamber have to be out of spec for this to occur? Using an RCBS FL die, correct shellplate and their instructions, how could you make the headspace unsafe? Maybe you could crush the case, but that would require completely overlooking the manufacturers suggested use. I view NS as being far more dangerous, as far as headspace goes. It is not an 'unsafe' problem but a brass life problem. If you force the shoulder back to every time so it will fit ANY correct chamber you will have case head separations from repeated stretching . By only moving the shoulder back enough to ensure reliable chambering in the same gun brass life is extended. In many cases it improves accuracy also. The loaded round has less space to rattle around in the larger chamber. Bullets closer to concentric with the bore tend to perform better (and then you can sort your brass by neck wall thickness variation...). |
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No issures using RCBS dies & shell holder. The Dillon shell plate was my problem. My other Dillon plates are not as bad as the 223 one, but still need something to measure shoulder bump. No noticeable resistance was noted using Dillon RL 450 loader. Shell plate not replaced.
So, aside from faulty equipment, there should be no issue. I can see the value of a case gauge when something isn't working properly. Was it noticeable that there was more resistance on that one particular station? Did RCBS replace the shell plate? |
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I suppose a gage could help you find the problem but a case head separation or pending sign of after the 2nd or 3rd reload and or the very loose fit in you chamber would be a good indicator too. I guess it depends on the skill and knowledge of the hand loader. quote] When running an M16A1 ,the first sign was a case separation. A closer look at the brass showed a thin line in the body on other rounds.The carbine was checked with a chamber headspace gauge & passed. But Colts seem to have a long chamber compared to others, as it requires a "Colt" gauge . I'm still on fence about the consistency attainable by backing off the size die to reduce shoulder set back.[/
The FL die & shell holder must make contact for a more exact shoulder bump. How much you "cam over" can even make a difference. The Redding competition shell holder set seems to be the fix.. http://www.midwayusa.com/product/525874/redding-competition-shellholder-set-1-308-winchester-30-06-springfield-45-acp  |
| Case gauge. Get one. Set your die so EVERY sized case goes into the gauge all the way. Depending on your press, your shellholders/shellplates, and your dies, you may wind up with anything from "nowhere near touching the holder" to "mashes the holder really hard." But the gauge will tell you when you are properly set. |
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