The 54r Bond Improved is based off the 7.62x54r Russian. The cartridge has been changed to an overall larger size, increasing the case capacity to approx 70grains of water.
With a case capacity now exceeding the 30-06, the performance is also increased with appropriate powders.
The reamer print# at PTG is 50771. The throat on this reamer is the same as a standard 54r throat. So to get the full potential from this case with the heaviest of bullets, extending the throat with a throating reamer may be desired.
This reamer was designed for the .311 but is being used successfully with .308 barrels as well.
For my .311 barrels: To fireform cases, I purchase 150gr PPU loaded ammo and shoot it in the Improved chamber. Thats the easiest way I get fire formed brass with a 99.9% success rate. (Very rarely I get the occasional cracked shoulder).
For my .308 barrels: Since I cannot find loaded brass ammo with .308 bullets, I buy Lapua and Norma NEW brass and use the 'cream of wheat method'. Ive also loaded new brass with standard Lyman published 54r loads to fire form.
You CANNOT shoot steel surplus ammo in this Improved chamber. The steel cases crack badly at the shoulder, because the steel case cannot stretch nearly as much as a brass case, before it fails.
This process is certainly not for everyone. If you only shoot a couple hundred yards with your Mosin, and are perfectly happy, thats awesome. Plus, you'll save powder. :)
When I started, my intentions were to shoot 1000yds with my mosins, accurately.
However, the most accurate long range bullet in the .311 catagory is the 174gr HPBT MatchKing (or Hornadys version). And to maintain optimal accuracy at that long of range,
it is important to keep the bullet supersonic for as long as possible.
But the 54r case just fell short on powder capacity to keep those 174gr bullets going fast enough.
So, I studied existing cases on the market, (mainly the 300 winmag) and wanted to model this one loosely after that, by removing the case taper, increasing shoulder angle, and moving the shoulder forward. Some might consider the neck length short. I made it that short, simply because that is the only amount of neck I ever used on my standard 54r loads, which were very accurate. No sense in leaving more neck than I was going to use.
I knew VERY little about 'Wildcatting'. I knew nothing of Ackley, but knew a few people working with the .358 Hoosier.
With the help of a good friend Mark Pitt, I drew up a print and sent it off for a reamer to be made at PTG.
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