Titan ReloadingInline FabricationReloading EverythingWideners
Lee PrecisionRotoMetals2MidSouth Shooters SupplyRepackbox
PBcastco Load Data
Page 3 of 3 FirstFirst 123
Results 41 to 50 of 50

Thread: Fun with the 8mm

  1. #41
    Boolit Master
    Join Date
    Aug 2007
    Posts
    791
    I'm with Mauser 98K. The following method is what I use to prep the pockets on dimpled eastern bloc cases of both 5.5mm and 6.5mm primers, but for 6.5mm (.254) primers (7.62x54), a bushing must be swaged from something like 1/4" soft copper tubing which can be easier than might be thought. For cases with 5.5mm (.213-.215) primers (all 8X57 I've seen), the following process will work to completion: The Eastern Bloc cases all have that dimple on the inside of the case between the flash holes which marks the center of the anvil. I use a 5/64 "aircraft" length drill bit (5") to reach down inside the case, get centered on the dimple and drill until it starts to grab and spin the case in my hand. At this point, the tapered anvil is drilled nearly through and very thin and the case can be deprimed with a conventional decapping pin which breaks off the tip of the anvil and punches out the berdan cup. A carbide primer pocket uniformer (Lyman, I think) is chucked up in the hand drill and used to remove the remainder of the anvil and cut the pocket to the correct depth. By the way, the eastern dimpled cases fortunately have pocket depths of approximately .120, handily allowing depth uniforming to .125 for boxer primers. Some foreign cases have pockets considerably deeper (see below). Now we have a clean pocket that's .213-.215 dia. or so which must be reduced to properly fit a .210 primer. This can easily be done by clamping a long 5/16 punch (Harbor Freight) in the vise with the end of the handle resting on the vise screw housing for support and the punch sticking straight up out of the jaws. The case is inverted and dropped onto the punch and a fat center punch (too big to slip into the pocket and ground to a shallow 30-45 degrees) is centered on the primer pocket and struck to upset the brass around the pocket into the pocket to reduce its diameter to less than .210. It doesn't take much - a good crack with a 4 oz. ball peen hammer will do. Pockets are then swaged to uniform diameter with a primer pocket swage tool (mine is RCBS) just like swaging out primer crimps and they are now ready to be primed. I've done this conversion with both brass and steel cases, using them at full power and have gotten good service from both. Having three flash holes doesn't seem to have any noticeable affect on pressures or accuracy. Most of my shooting is done with .311-.312 cast boolits paper patched with three wraps of drafting vellum, bringing them to a .325-.326 diameter, perfect for the 8mm. A PP'd 175gr 311041 cast of WW over 48gr of Rel 15 speaks with some authority and shows promising accuracy, but could probably use some tweaking, which is yet another thing on the overloaded to-do list. Sometime before Fall, hopefully.

    Two things about Turkish, Egyptian and other cases from non-eastern-bloc sources: The Berdan priming system does not rely on uniform pocket depth for proper function, rather the relationship between the anvil height and the priming pellet-and-cup thickness, so the pocket depth can often be deeper than .125. Some I've attempted to convert (Turkish) resulted in seated primers being .020 below the case head and unreachable by the firing pin, thus needing a disk of material to be pressed in place to make the pocket workable with boxer primers. Nice cases, but another step I'm not willing to do unless the cases are something exotic. Also, these generally do not have the dimple between the flash holes, so they must be converted by another process - hydraulic or mechanical depriming, center drilling with a flash hole drill guide which fits into the pocket for centering purposes, etc. (A 1"-1.25" 1/4-20 set screw with a friction nut set .125 back from the end with the threads spin-filed to .210 diameter x .125 long and bored through for the 5/64 flash hole drill makes a dandy drill guide. Insert into primer pocket over the tip of the anvil with the nut against the headstamp and you're ready to drill the flash hole.) British Radway Green 7.62x51 cases are high quality and have good pocket depth, so they can be converted by this method, but boxer 7.62x51 is ubiquitous and too easy to get. I haven't gone there beyond proof of concept experimentation.
    Last edited by yeahbub; 01-07-2019 at 01:35 PM.

  2. #42
    Moderator
    Texas by God's Avatar
    Join Date
    Mar 2016
    Location
    Texas
    Posts
    14,315
    That is very interesting information but it certainly makes me glad Boxer 8x57 brass is readily gotten at present and readily obtained by reforming .270,.280, or 30-06 when it's out of stock!

    Sent from my SAMSUNG-SM-G930A using Tapatalk

  3. #43
    Boolit Master
    Join Date
    Aug 2007
    Posts
    791
    DOH!! I'm mortified to realize I posted the conversion info in the WRONG THREAD! Okay, anyone know how to move it to the "Converting Berdan brass to Boxer" thread? . . . . Yeeesh, what in the world was going on there I wonder, what th'. . . dang computers mrrmnnr, harrumph, grumble snort. . . . I need a computer that does what I want it to, not what I tell it to do. . . .

  4. #44
    Moderator
    Texas by God's Avatar
    Join Date
    Mar 2016
    Location
    Texas
    Posts
    14,315
    That's hilarious! I feel your pain....

    Sent from my SAMSUNG-SM-G930A using Tapatalk

  5. #45
    Boolit Master


    Join Date
    Oct 2009
    Location
    NH
    Posts
    3,783
    Think Past Recoil Shield!!!

  6. #46
    Boolit Master



    Join Date
    Apr 2007
    Location
    Alturas, California...where the west still lives!
    Posts
    2,255
    Quote Originally Posted by RedneckRob View Post
    I thought the 88 GEW bore was .318 or was this one that was rebored to .323 ?
    If there is an "S" stamped on top of the receiver ring, it was rebored to accept the .323 spitzer bullet. This does NOT mean you should use military full pressure loads, even thought the Germans thought it was safe. They shoot cast boolits beautifully though.

  7. #47
    Moderator
    Texas by God's Avatar
    Join Date
    Mar 2016
    Location
    Texas
    Posts
    14,315
    Weren't they just enlarged in the neck and ball seat and the bore left @.318"? And marked "S" with stripper guides soldered on and a bullet notch in the front rec. ring? I've just described the 88/05 haven't I? A Bit Confused- maybe I am.

  8. #48
    Moderator
    Texas by God's Avatar
    Join Date
    Mar 2016
    Location
    Texas
    Posts
    14,315
    No pics but I fired a single 3 shot group from both NOE boolits @100yds with the 10.5 gr Unique load. Less than 3" so considering the heat I'm pleased.

  9. #49
    Boolit Master RU shooter's Avatar
    Join Date
    Nov 2006
    Location
    SW Pa.
    Posts
    2,928
    Quote Originally Posted by Texas by God View Post
    No pics but I fired a single 3 shot group from both NOE boolits @100yds with the 10.5 gr Unique load. Less than 3" so considering the heat I'm pleased.
    Try upping the unique loads some in my experience it seems to do do better the warmer the loads. 13-14 gr range was the sweet spot for a few different bullet weights for me .
    If you find yourself in a fair fight, your tactics suck!

  10. #50
    Boolit Buddy Eddie1971's Avatar
    Join Date
    Dec 2016
    Location
    Modern Day East Germany
    Posts
    256
    Quote Originally Posted by roverboy View Post
    That's a mean looking boolit.
    I use the same head powder coated and gas checked in my 88's and have been having great results with 30.5-31.5 grains of Winchester 748 using a magnum primer. They are sized to .323, bores slug out to .321.

Page 3 of 3 FirstFirst 123

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check