3 reloads on 7mmRM

Discussion in 'Reloading' started by CRNA, May 15, 2011.

  1. CRNA

    CRNA Well-Known Member

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    Just curious what everyone's opinion is. I have been made really paranoid by some people on this forum that are totally against belted magnums. I am new at hand loading and just wanted some experienced eyes to see my brass and give me their .02. I have loaded these 3 times. Getting a little more stiff to close the bolt when I slide these pieces of brass into the chamber. I just don't want to get into some problem with case head separation. I have looked at this brass for a while, and one minute I think it looks fine and then my paranoia kicks in and I wonder if I know what I'm looking for.

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  2. Wingnut

    Wingnut Well-Known Member

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    This has happened to me when I started loading at the top end of my 7 Rem Mag. The problem is that full length resizing dies do not form the area right below the belt. Over time this swells from pressure and then it becomes hard to chamber and unload your firearm. The solution I found is to use Innovative Technologies magnum case resizing collet. It uses a seperate die and collet placed over the cartridge to size the entire case up to the belt. It worked wonders and even made it possible to get more reloadings out of each piece of brass without case seperation. Good Luck!
     

  3. jimbires

    jimbires Well-Known Member

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    I've never had the problem wingnut is talking about , I've heard of it but never had it . are you full length resizing ? are you measuring how far you are pushing the shoulder back ? I don't think you'll see any problems on the outside of the case , I never have . what you want to do is make something like a dentist pick out of a piece of wire . go inside of the case and pull the pick up and down the case sides just above the belt . if the case is stretching , due to pushing the shoulder back too far , you will be able to feel the pick go into a groove right above the belt is the trouble spot . I push my shoulders back .001 - .003 just like a non belted case . I have 7 rem mag cases that are loaded 7 times with no problems . usually my necks split , or the primer pockets are loose when I junk them . Jim
     
  4. CRNA

    CRNA Well-Known Member

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    Jim,
    I have full length sized the cases for two firings. The last sizing was done with a neck sizer. My plan is to just bump the cases when they get too tight to comfortably chamber a fired case. I am thinking of getting a gauge to help me in this. I think it would be pretty difficult to just go by feel and not bump the shoulder back to far. I have heard of the dentist pick/paper clip trick. I will certainly give it a try. Thanks for the reply.
     
  5. jimbires

    jimbires Well-Known Member

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    I use a RCBS precision mic to measure my case . I also use the redding competition shell holder set . I can measure my fired case and then use the shellholder +010 , +008 , +006 , +004 , +002 , and watch my headspace change . when I get right around .002 headspace I stop . then the next time I resize brass I know what shellholder to use and I adjust the die down to touch the shell holder . this way I get the same results every time . I can't go by feel on this either , I prefer to measure . I'm guessing the neck sizing only could be your tighter bolt feel . that and your mind worrying about case separation . LOL you'll need to spend a little money but you will be able to know what is going on . if you just resize to push the shoulder back a little the belt on the case means nothing . the belt is nothing to fret about . Jim
     
  6. backwoods83

    backwoods83 Well-Known Member

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    You should just neck size after the first full length size, you should get 3-4 reloads then you can bump the back a bit. Sometimes people overlook simple stuff, have you trimmed your brass yet, its probably stretched way past max col if you haven't.
     
  7. CRNA

    CRNA Well-Known Member

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    Where are you measuring on the case? I assume you are measuring the shoulder? If you are measuring the shoulder, then what tool are you using to measure the shoulder and the "bump" you are getting with the shell holder?
     
  8. CRNA

    CRNA Well-Known Member

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    Well, there really wasn't a problem with the bolt being stiff. I expected that with only neck sizing. I was just getting paranoid about case head separation. The brass is measured and trimmed if needed after every sizing.
     
  9. jimbires

    jimbires Well-Known Member

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    I'm measuring from the shoulder to the base ( case head ) . the RCBS precision mic is made to do this , it is cartridge specific so you need to buy one for every cartridge you want to measure . here is link with a picture of one . it is one base with two tops . one top is used to measure brass length to the shoulder ( head space ) . the other top is used to measure your ammos COAL to the ogive of the bullet . it also has a dummy round that you use to find your COAL to the rifling . I don't use it I prefer to use the bullet I'm loading to check this . all you do is put the case in it and screw it together and take your measurement , very simple . the mic comes with instructions . Jim



    RCBS Precision Mic 308 Winchester - MidwayUSA
     
  10. CRNA

    CRNA Well-Known Member

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    Jim,
    I will look at the tool in the link. Thank you for your help. I appreciate it!!
     
  11. Shootin4fun

    Shootin4fun Well-Known Member

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    I am about to start reloading 7mm RM for the first time. I have reloaded several lesser calibers up to a 270 Win, but have never worried about head spacing or "bumping shoulders". Now I need some experienced advice on this stuff as I move into the belted magnum realm, and maybe it will even change my methodology on lower powered cartridges. I reload for all the usual reasons...accuracy, cost of shooting, and projectile selection.

    I've always full case resized. I always just set the sizing die the way the RCBS manual says to do; something like adjust it down to touch the shell holder when in the fully extended position, and then back off 1/8 turn from there, if I remember correctly. (Don't have access to my reloading stuff right now.)

    Now with the Mag, I'm sure things will be more critical. Is this method of adjusting the sizing die adequate?

    Should I start out by just neck resizing or continue full case resizing?

    Bullet seating dies with the micrometer built in seem like a good investment - less trial and error, especially if you are going to use several different bullets.

    Resizing dies with the micrometer built in seem like a way to insure consistency if you are concerned about bumping the shoulder. Is this something we need to worry a lot about?

    Planning minds want to know!
     
  12. backwoods83

    backwoods83 Well-Known Member

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    For hunting purposes the full length is ok, anything beyond that I reccomend neck sizing and then using a innovative technologies body die for the belted mags when setting the shoulder back. A micrometer seater is not a must, rcbs and redding dies and many others seat .033-.035" deaper for every 360 degree clockwise turn and vise versa.
     
  13. Joe King

    Joe King Well-Known Member

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    Treat it the same as your 270.
    Long ago before I got my Redding dies and still used RCBS FL dies I partial resized till I got some cases that chambered stiff, I then turned my FL die down incrementally till the case chambered easy but I could still feel it when the bolt closed. That was before the match barrel and uber tight custom chamber, the only thing I ever had to do with my cases after initial prep was anneal the necks every so many firings. I still have those cases 10yrs later:)
     
  14. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Can you feel a thin spot with a bent paper clip just a bit off the bottom of the case?? If you are really paranoid section one of your cases with a dremel. That will tell you exactly when you need to pull your brass from service. I'll do that occasionally and if I get a catch I'll section one for sure.
    I'll usually get .060" or more trimming before a 7mag is out to pasture. I've got brass loaded at 8 firings(all fl set up to my gun) ) and they are still going strong.