Reloading belted mags.

Discussion in 'Reloading' started by cjp45, Feb 23, 2006.

  1. cjp45

    cjp45 Active Member

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    What is the difference between reloading for a belted mag. and standard cartridge? The ease or difficulty of reloading belted mags. will dictate if I buy 300 Win. mag. or not.
     
  2. Varmint Hunter

    Varmint Hunter Well-Known Member

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    I neck size all of my belted mags. Unless you are really pushing the pressure limits you will get several reloads without difficulty. If you run pressures high then you will need to run them through a full-length die periodically.

    No different than the way I reload my non-belted cartridges.
     

  3. kbb468

    kbb468 Well-Known Member

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    I would like to see what everyone's opinion is about this also. This to will affect my choice between a 300 wsm or a 7mm mag.
     
  4. gonehuntingagain

    gonehuntingagain Well-Known Member

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    I don't do anything different with my 300WM than with any other cartridge.
     
  5. Bart B

    Bart B Well-Known Member

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    The big difference in reloading bottlneck H&H belted cases and bottleneck rimless cases is that darned H&H belt. Top shooters have known for over 60 years that unless one sizes the case body all the way back to it, accuracy will suffer.

    Check out the following web site for one solution:
    http://www.larrywillis.com

    After WWII when folks used the .300 H&H Magnum and later the 30 and 28 caliber cartridges bases on large cases with the H&H belt for 1000-yard matches, they learned that best accuracy happened when new cases were used. It wasn't until someone (top riflesmith Elmer Shook, I think) cut about 1/4th inch off the bottom of a .30-.338 full-length sizing die then cut its top off just below the shoulder, smoothed off the sharp edges and used this die to size the case body all the way to the belt. Conventional full=-length sizing dies left about 1/32nd of the case body just in front of the belt unsized. This special "body sizing die" seemed to work best after a conventional full-length sizing die was used. And the case shoulder has to be set back to almost its new position so the case headspaces on the belt like it's designed to.

    Top military 1000-yard shooters gave up on full-length sizing and just used new cases all the time. They must have given away thousands of .300 Win. Mag or .30-.338 Win. Mag. cases to all the civilians at the big matches.

    Both military and civilian top shooters tried neck sizing but the results were never consistantly great. Once in a while someone did great with neck sized cases, but the folks who used new cases or full-length sized cases second sized with the special body die (or double sized) shot the best scores much more consistantly.

    My own tests confirmed this. I've worn out four .30-.338 barrels shooting 1000-yard matches. Each one's been tested at least twice for accuracy using neck-only sized cases as well as single full-length sized, double full-length sized and just brand new cases. I fired 15-shot test groups at 1000 yards as follows:

    Neck-only sized cases, 12 to 22 inches.
    Single-full-length sized cases, 8 to 15 inches.
    Double-full-length sized cases, 5 to 7 inches.
    New cases, 5 to 7 inches.

    I recommend you stay away from belted cases unless you're willing to double size them with proper full-length dies.
     
  6. kraky2

    kraky2 Well-Known Member

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    Bart--I find your results really interesting. I don't doubt them but it just doesn't seem to make sense. Do you have any idea why "not filling the chamber" with tight fitting brass would cause this. I have to admit over at Snypers Hyde the guys that shoot benchrest seem to be looking for the collet die real hard.....they are kind of on hold looking for a manufacturer that can make the quality die at a lower overhead. (Applaud them for not letting it get cheaper).
     
  7. davewilson

    davewilson Well-Known Member

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    it's because after 1 or 2 firings some will fit almost loose in the chamber and some will be almost a crush fit.most 1k competitors full length size their brass because they are more accurate than neck sizing.

    that's how i understand it,but Bart has a whole bunch more experience then i, what say ye Bart?
     
  8. Hired Gun

    Hired Gun Well-Known Member

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    I ignore the belt along with the rest of the brass body. I haven't full length sized a case in near 20 years now. When I used full length dies I adjusted them to only hit 1/2 to 2/3 of the neck any way. Now I only use Lee Collet dies on everything. My 257Wby's, 7mmRM's, and 300Wby's all shoot best with fire formed brass. Cuts my groups in half neck sizing. After a few really hot ones sure they get snug to close but they usually won't hold a primer by then anyway. At reasonable pressures just keeping my lugs and recesses clean and well lubed and the bolts close nicely.
     
  9. Buffalobob

    Buffalobob Writers Guild

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    Reloading belted cases is not really any different than other cases. I usually fire every case once just to get it to chamber size and then load it up with my hunting laod.

    I don't shoot benchrest so my principle concern is hunting accuracy. Belted cases have over the years been "magnum" cases and some variaton of H&H cases. In other words,if you were a long range hunter you were most likely using a belted case because you needed the velocity in order to deliver a killing impact at long range.

    Probably the most famous of the long range benchrest clubs is at Willaimsport Pennsylvania. These people have been shooting 1000 yd matchs on some ole ridgeline with nasty winds for about half a century. You can look at the cartridges that are used and you will find many many 300Wby based wildcats.

    Read the results and you can make up your own mind about belt or no belt.


    Williamsport

    In fact, if you read Howard Wolf's advertisement of smithing 50% of the winning guns, he says he specializes in the 30-378 Wby -- not only belted but double radiused too. Maybe he is an idiot and don't know anything about guns. /ubbthreads/images/graemlins/confused.gif
     
  10. Taos

    Taos Well-Known Member

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    I have been neck sizing for thw .264 for 25 years without seeing any accuracy difference, I will have to full length size some and see what happens.
     
  11. Bart B

    Bart B Well-Known Member

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    Taos, in the late 1960's, my first long range target rifle on a Win. 70 action was a .264 Win. Mag. Sierra Bullets' Test Range Manager explained why I should full-length size cases for it instead of neck sizing 'em. So I did some tests. I knew the barrel was going to wear out quickly, so I limited my tests to two 15-shot 1000-yard groups. Neck sized cases shot about 13 inches with Norma 139-gr. match bullets. Same bullets in double-full-length sized cases went into 7 inches. Won some 1000-yard matches with that barrel but it died at 648 rounds and started shooting wash-tub size groups.

    Martin Hull (then Sierra's bullet tester extraordinaire) gave me a couple of boxes of their then-new .264 caliber 140-gr. match bullets. He said if I could shoot them well enough to win a couple of matches, Sierra would give me 2000 more of them to use in my next three .264 Win. Mag. barrels. I shot four 10-shot test groups at 1000 yards with them but none were under 20 inches, so I told Martin Hull I couldn't get them to shoot. He said neither could Sierra. Apparently they couldn't get jacket material good enough to make those long jackets' wall thickness uniform enough. They had the same problem in 1970 with their first .284-inch 168-gr. HPMK bullets. It wasn't until the 1980's before anybody could make copper sheets good enough for very accurate, very long match bullets.

    Sierra's guy told me he used full-length sizing dies for all of Sierra's test ammo; both stuff to test their bullets for accuracy in very thick and stiff test barrels as well as all kinds of rifles to develop handload data. When he gave me a tour of their California site, their loading room was very well stocked with only full-length sizing dies. Sierra still full-length sizes all their cases for testing and I don't think anybody shoots their bullets as accurate at 200 yards than they do. Martin Hull passed a few years ago but I still remember his phrase explaining how a bottleneck case has to fit the chamber for best accuracy; "It's gotta fit the chamber like a turd in a punch bowl!"
     
  12. davewilson

    davewilson Well-Known Member

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    Bart, some turds might be a press fit!
     
  13. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    Bart, some turds might be a press fit!

    [/ QUOTE ]
    I agree. When one considers a GO gage for H&H belted cases is .220, the NO-GO gage is .223 and the FIELD gage is .226, that's only three thousandths spread for normal use and six for emergencies.

    Which means that step in an H&H fired case that's been traditionally full-length sized and is much longer than .006-inch will probably interfere different ways with different cases with proper headspacing. If another sizing die gets rid of it and sizes the H&H case body down to its original diameter all the way back to the belt, there won't be any interference in proper headspacing.
     
  14. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Check out the 1,000yd group fired by this belted case.
    300 Win Mag