Alex,
How do you adapt a RCBS Precision mic for AI cartridges? If not, how would you proceed with AI cartridges?
Thanks,
Fred
2 guns same caliber
- Thread starter RetiredArmy
- Start date
Alex,
How do you adapt a RCBS Precision mic for AI cartridges? If not, how would you proceed with AI cartridges?
Thanks,
Fred
I'd be tempted to beg/borrow an action wrench, barrel nut wrench & barrel vise from someone if you don't already have that stuff.
Take a piece of fired brass from the RPR, put it in the Savage and re-adjust the headspace to match as close as possible. You may not
need to adjust your dies at all after that 15 minute procedure.
-Rick
RetiredArmy
Gold $$ Contributor
Rick, I own a savage action wrench. Will try the shims first as the savage shoots pretty dang good. You know, if it ain't broke!!!
Thanks
Bill
Thanks
Bill
Perhaps I should have mentioned the Redding Comp S/H's. But for my needs they come up short for the following reasons: 1/ They only increase in deck height-which will not be of any use if your chamber is on the short side ( requiring grinding the standard S/H top face to less than the .125" standard) of which I have quite a few chambers cut this way. 2/ They are expensive-you must buy the whole set- If you have chamberings with varying rim diameters it can really add up. 3/ In my discipline ( Short Range BR) I believe controlling shoulder bump to the nearest 0.001" WILL show up on target. Die shims allow me to tweak each case to the exact desired number.4/ The manufacturers seem to have trouble controlling the deck heights to a reasonable tolerance, so I have learned to dedicate a S/H to one specific die in order to get the shoulder bump I desire. The shims are the only variable and used to control those few cases that resist sizing. ( I have absolutely NO problem getting consistency when changing out die shims- they always bottom out without variation).
I never used die shims , but I have previously adjust my die up away from the shellholder to get my desired shoulder bump . the problem I had was my shoulder bump varied a fair amount . I blame this on differing brass hardness , hard brass would size less than soft brass . annealing more often seemed to help the problem , but not fix it . I decided to try the competition shellholders . using these the die contacts the shellholder giving me more consistent shoulder bump . now I anneal every time and use the correct shellholder , my shoulder bump varies little to none .
I don't, I always say the case has resistance to sizing; some cases have more resistance to sizing than the press can overcome. For years and years I have said I increase the presses' ability to overcome case sizing resistance by shimming the case off of the deck of the shell holder. At the same time when sizing cases for short chambers I use the shim between the deck of the shell holder and case head. My favorite shell holder is the RCBS because it fits the case like a hand-me-down shirt.
F. Guffey
That is were I was heading also.
Two things here . 1) Not sure why anyone excepts out of spec chambers . If making hard contact with a standard shell holder does not size your case down enough your chamber is out of spec . Send it back so you can use the right equipment rather then making , grinding , lifting and or tweaking what should be working in the first place . I'm not even sure why one would want a short chamber , it just makes the cartridge less effective . Not one AI chamber reduces the amount of powder allowed yet some think reducing case volume is better for the cartridge . If anything you'd think reaming your chambers to field gauge sizes would be better then making them smaller .
2) If you choose to have these out of spec chambers either long or short . That's fine , but it seems you are outliers and need custom or specialty items in order to reload your firearms . So why confuse the average reloader by saying these types of things are best or better when they only apply to what can only be described as wild cats ? In these type of situations of course you are going to need to do some pretty creative things and more power to ya .
I am the only reloader that measures the length of all chambers from the shoulder to the bolt face. Again, I have one chamber that is .016" longer from the shoulder of the chamber to the bolt face than a minimum length case. I am now convinced I am the only reloader that understands my long chamber is .011" longer than a go-gage length chamber. To take it one step further my chamber my long chamber is .002" longer than a field reject length chamber.
All I am required to do when sizing cases for my long chamber is off set the length of the chamber with the length of the case from the shoulder of the case to the case head. My rifle with the long chamber is not the exception, back in the old days a smith got blamed for all of the long chambers. My rifle with the long chamber has his name on it.
F. Guffey
There are other factors involved which require one to reduce the s/h deck height/ or cut the bottom of the die. Those being tolerances with the s/h and die may stack up against you, then add in unusually hard or work-hardened brass and differences in press construction......and you'll have problems even if the chamber is with-in spec. I have encountered this with many factory rifles.
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There was a time when I did as F , Guffey recommends and use a feller gauge under the case in between the case and shell holder to size down those hard to size cases .
But that was also when to size my cases to my chambers the die and shell holder did not make contact . Close but not quite
EXAMPLE but not the actual setting
What the over all issue was is what Guffey often describes as the case winning and not the press when my die and shell holders were not making hard contact . This looseness/variance in my die setting allowed press deflection or better yet ram linkage flex/deflection resulting in inconsistent sized cases from head to datum point especially those slightly more work hardened cases that did not want to size down that extra .001 to .002 I wanted . That's when I'd use the feeler gauge idea to dare I say bump the shoulders that much more .
One day it was finally explained to me in a way I understood how the competition shell holders work . I finally grasp the idea of how when used correctly they remove all the press flex/deflection allowing your press to win every time regardless of how stubborn the case is . I bought a set and have not looked back . I don't doubt they are not perfectly ground from set to set or even s/h to s/h . They're pretty close for me but I've not actually measured them directly . I judge how well they work based on the incremental differences they size my cases . They seem pretty consistent in that regard but I'll admit not perfect .
But that was also when to size my cases to my chambers the die and shell holder did not make contact . Close but not quite
EXAMPLE but not the actual setting
What the over all issue was is what Guffey often describes as the case winning and not the press when my die and shell holders were not making hard contact . This looseness/variance in my die setting allowed press deflection or better yet ram linkage flex/deflection resulting in inconsistent sized cases from head to datum point especially those slightly more work hardened cases that did not want to size down that extra .001 to .002 I wanted . That's when I'd use the feeler gauge idea to dare I say bump the shoulders that much more .
One day it was finally explained to me in a way I understood how the competition shell holders work . I finally grasp the idea of how when used correctly they remove all the press flex/deflection allowing your press to win every time regardless of how stubborn the case is . I bought a set and have not looked back . I don't doubt they are not perfectly ground from set to set or even s/h to s/h . They're pretty close for me but I've not actually measured them directly . I judge how well they work based on the incremental differences they size my cases . They seem pretty consistent in that regard but I'll admit not perfect .
Bottomed out is still bottomed out (s/h touching die base). You can stand on the press handle and it still won't bump the shoulder anymore.There was a time when I did as F , Guffey recommends and use a feller gauge under the case in between the case and shell holder to size down those hard to size cases .
But that was also when to size my cases to my chambers the die and shell holder did not make contact . Close but not quite
EXAMPLE but not the actual setting
What the over all issue was is what Guffey often describes as the case winning and not the press when my die and shell holders were not making hard contact . This looseness/variance in my die setting allowed press deflection or better yet ram linkage flex/deflection resulting in inconsistent sized cases from head to datum point especially those slightly more work hardened cases that did not want to size down that extra .001 to .002 I wanted . That's when I'd use the feeler gauge idea to dare I say bump the shoulders that much more .
One day it was finally explained to me in a way I understood how the competition shell holders work . I finally grasp the idea of how when used correctly they remove all the press flex/deflection allowing your press to win every time regardless of how stubborn the case is . I bought a set and have not looked back . I don't doubt they are not perfectly ground from set to set or even s/h to s/h . They're pretty close for me but I've not actually measured them directly . I judge how well they work based on the incremental differences they size my cases . They seem pretty consistent in that regard but I'll admit not perfect .
Adding to the deck height (which is what the +2, thru +8 comp. s/h's do) result in less sizing. I've been through this ad- infinitum.
Correct but I was speaking to my own experience were my chamber size required there be no bottoming out . If I did the case would have been sized .008 to .010 shorter then I intended . Not having the die and shell holder bottoming out resulted in the linkage in my press being a problem because it flexed to much .
Here are two photos . both have the die adjusted exactly the same . To just touch the shell holder with the ram fully up when not sizing a case . The second is what happens when the sizing process causes stress on the press and linkage . Notice the gap that appears
That gap is .011 and shows how much flex/deflection my Hornady L-n-L classic press has when sizing a case . When sizing cases like this I could have a ES variance of .004 head to datum from case to case . When the comp shell holders are used I've reduced that ES variance to .001 with most actually only being .0005 different from one another .
So how do you get consistently sized cases to .001 or under when your die and shell holder don't make contact while FL sizing ? I have to assume those shims other posters have talked about ??? IMO if your die and shell holder don't make hard contact ( bottom out ) inconsistent case sizing will follow .
By using FL dies that minimally size -i.e. dies that are custom matched to the chamber. For PPC and BR cases for competition I modify my presses to not cam-over. When I get the odd case or two in a batch that resists sizing as evidenced by the datum to base measurement AND verified by chambering with the stripped bolt method to my desired bolt drop feel (yes, I check every case), I add 0.001" worth of shims between the press and die. If it still is a tad tight, I add 0.001" more. Been doing it this way for years because it gives consistent results and I don't like fighting presses and bolts.
Thanks for the clarification. I kinda figured it was something to that effect .
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