close
Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Hunting > Long Range Hunting & Shooting

Long Range Hunting & Shooting Nightforce Optics

Reply

Need help with odd caliber

LinkBack Thread Tools Display Modes
  #1  
Unread 08-23-2011, 07:13 PM
Junior Member
 
Join Date: Aug 2011
Posts: 2
Need help with odd caliber

Anyone ever hear of a 7mm Apollo Mach IV?

It's the caliber of a rifle I recently inherited. It was made by Apollo Custom Rifles in the 70s on a Austrian Voere action and barrel. At the time, it was a competitor to Weatherby (and I guess we all know who won that competition) with its own line of wildcat cartridges. It was a premium rifle guaranteed to shoot 1" groups. Here are a couple of pics:





I luckily found an original 1970s owners manual and discovered that the impressive-sounding cartridge is a 300 Win Mag simply necked down to 7mm. Sounds a lot like the 7mm Practical!

I have several problems in trying to handload for this baby. The handbook makes a lot of the fact that the barrel has some freebore and as such, can be loaded hotter than without it. Still, the recommended max loads with a 139 gr bullet of 74 gr of 4350 (3380 fps) or 78 gr of 4831 (3500 fps) seem way too hot. I'm thinking of using near max 7mm Weatherby Magnum load data as a start.

It also says that the 7mm Apollo Mach IV has a case capacity of 89.2 gr of water. That's weird because this cartridge starts out as a 300 Win Mag, and that is listed as having a case capacity of 83.2 gr of water! How can squeezing the neck down to 7mm increase case size?

Now the real problem: I bought an RCBS 7mm neck sizing die and some new Remington 300 Win Mag brass. When sizing, it was VERY difficult pulling the neck expander ball back through the case neck, so I removed it. Now I have 20 cases with an inside neck diameter of 0.262 inches and an outside neck diameter of 0.297 inches. And I when I put the expander ball back into the neck sizing die, I can't force it through the necks!

As you might have guessed, I'm a raw beginner when it comes to reloading, and this hassle may force me to just sell the rifle and go with something simpler.

Anyone have any advice?
Reply With Quote
  •   #2  
    Unread 08-23-2011, 08:46 PM
    Platinum Member
     
    Join Date: Jan 2011
    Posts: 2,206
    Re: Need help with odd caliber

    Yeah, you can not work the brass that much, your going to have to turn the case necks probably .008-.010" to get the outside around .319" and about .283" inside.
    Reply With Quote

      #3  
    Unread 08-23-2011, 10:45 PM
    Official LRH Sponsor
     
    Join Date: Feb 2011
    Location: N. Texas and S. Africa
    Posts: 7,314
    Re: Need help with odd caliber

    Quote:
    Originally Posted by backwoods83 View Post
    Yeah, you can not work the brass that much, your going to have to turn the case necks probably .008-.010" to get the outside around .319" and about .283" inside.
    Yep... .
    __________________
    Without the First and Second Amendments the rest of The Constitution is Meaningless.
    Reply With Quote
      #4  
    Unread 08-23-2011, 11:47 PM
    Official LRH Sponsor
     
    Join Date: May 2010
    Location: Bozeman, MT
    Posts: 387
    Re: Need help with odd caliber

    Why not use a Sinclair or PMA Tool 7mm inside neck expander and then turn the outside of the necks to remove the excess material?

    These expanders are designed specifically for this task and are tapered to make the work easier than the ball on your sizing die.

    My .02 for what it's worth.

    On the capacity... does the body taper less on this cartridge than the 300 win mag? That could explain the extra internal room.

    Keep us posted! Sounds like a fun cartridge!
    __________________
    The Tikka Performance Center Team
    www.tikkashooters.com
    www.tikkaperformance.com
    Reply With Quote
      #5  
    Unread 08-24-2011, 02:37 PM
    Bronze Member
     
    Join Date: Jan 2011
    Location: PA
    Posts: 36
    Re: Need help with odd caliber

    Try Hart's gunsmithing in PA. He has a ton of experience with odd calibers and may be able to get a proper set of Reading dies. If he has a reamer he can make a set of dies and guide you on what to do. Bob is a great guy. Good luck. As far as case volume it's probably like the Ackley's with the shoulder further forward with a shorterneck,w and less taper.
    Reply With Quote
      #6  
    Unread 01-20-2015, 01:28 PM
    Junior Member
     
    Join Date: Nov 2009
    Location: aloha oregon
    Posts: 10
    Re: Need help with odd caliber

    Maybe punch it on out to 7stw...!!
    Reply With Quote
      #7  
    Unread 01-21-2015, 06:20 AM
    Platinum Member
     
    Join Date: Dec 2005
    Location: Tucson Az
    Posts: 1,983
    Re: Need help with odd caliber

    I did some searches and found some more information for you:

    7mm Apollo Mach IV???????????? - 24hourcampfire

    Long range rifle PACKAGE! [Archive] - Reno4x4

    Long-range masterpiece! [Archive] - Reno4x4
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes


    Similar Threads for: Need help with odd caliber
    Thread Thread Starter Forum Replies Last Post
    What caliber 7mm Rem Mag or 300 Win Mag theicon2u Long Range Hunting & Shooting 78 06-09-2012 11:57 AM
    help with a new caliber Booney Long Range Hunting & Shooting 22 04-08-2010 08:38 PM
    What caliber? 7 Mag or 300 win? texan79 Rifles, Bullets, Barrels & Ballistics 9 03-30-2010 09:04 PM
    best caliber jmeier1981 Rifles, Bullets, Barrels & Ballistics 8 01-31-2009 05:26 PM
    WTS: Rem 700 PSS 223 caliber Like new bearclaw46 Guns For Sale 0 03-17-2003 10:51 PM


    All times are GMT -5. The time now is 01:57 AM.


    Powered by vBulletin ©2000 - 2016, Jelsoft Enterprises Ltd.
    Content Management Powered by vBadvanced CMPS
    All content ©2010-2015 Long Range Hunting, LLC