I'm planning to built a new bolt gun, one that spans the gap from subsonic plinker to high powered hunter.. hoping to spark some conversation and get recommendations from folks that have either used one of the calibers I'm considering, have recommendations on the gun smithing needing to be done or can give real world experience with other cartridges/calibers.

Here's the goal:
  • Box fed bolt action (would love to do a box fed lever, but the BLR is the only real option there, and limited to 4 rounds
    • I'm leaning towards the 10 FCP-SR but am open to the right firearm platform for the round I go with (based on the feedback I get here)
    • The ideal goal is an intregally suppressed, box fed bolt rifle that I can run medium to heavy weight bullets through

  • Used for subsonic plinking within 100 yards (possibily some hunting) as well as high powered hunting up to (max) distances of 200 yards (deer, hogs, etc.)
  • .44 - .50 caliber bullets in weights from ~200 to ~?? (would love to have a round capable of 200-500 grain bullets)
  • Once I've selected a cartridge I'll purchase the bolt action and have a gunsmith do any needed work: re-barreling, reaming, etc. also making sure twist rate is appropriate for bullet weights.


SIDE NOTES -
I'm all about real world application and prefer reliability over 'features': I'd rather have a heavy, flat front bullet than a HP that might/might not expand, depending on velocity. Terminal Performance is the primary measure I look at and, especially for subsonic, I know 100 yards will likely be the max distance - I'm fine with that. I'd rarely take a shot over 200 yards unless it was just ringing steel for fun.
I've considered 45-70 but for subsonic work there's just too much case capacity and everyone that I know who reloads it has stories to tell about bent brass at the case mouth - also costs more (brass, powder charge, etc.)


Here are the calibers I'm debating over and their potential application:

44 Magnum: capable of sending 200-320 gr pills down range from subsonic to high power. (200 gr to 320 gr)
Pros:
Great bullet selection and reloading data available
Can also be used in a sidearm - eg. Super Black Hawk, etc.
Lesser expensive brass/powder than the other cartridges on my 'list'
There are some lever guns available in this caliber
Cons:
Only bolt gun, that I know of, that's chambered for it is the Ruger 77/44
Rimmed case might not lend well to a custom bolt gun (that's not made for feeding it)
Difficult to suppress the lever gun options - no integral option so I'll have a can hanging off the end of an already long rifle
45 Long Colt: capable of powder puff rounds up to some very stout loads - as long as new, stronger brass is used. (230 gr to 360+ gr ?)
Pros:
Highly available and good bullet selection
Can also be used in a sidearm
Very affordable brass and components
Same as the 44 magnum regarding lever guns
Capable of heavier bullet weight than the 44 mag
Cons:
I don't know of any bolt gun chambered in it
Rimmed case might not lend well to a custom bolt gun

500 S&W Magnum: Not too familiar with this round, not having shot it before.. but, very capable cartridge (275 gr to 500+ gr ?)
Pros:
Decent bullet selection
Capable of heavier bullet weight than the 44 mag or 45 LC
Possible to carry in a side arm, though very unlikely I'd carry one this size
Seems very capable and looks to have great potential based on data available
Cons:
More expensive components
More of an 'unknown' for me, as I don't have real world experience with this round

45 Raptor: interesting round. .308 bolt head so basing the rifle on a .308/7.62 bolt gun would be as simple as new barrel, reamed for the cartridge (simple, not easy)
Pros:
Performance seems to be excellent with this round
Greater bullet weight range (160 gr to 400+ gr)
.452 Caliber bullet options are plentiful and most are designed to work great at moderate velocities (eg. works well for subsonic)
Uses standard .460 S&W reloading dies and .308 shell holder lowering cost of 'wildcat' reloading components
Cons:
Interest and availability of this cartridge is yet unknown
Mimics/Close performance to other existing cartridges, though would be easier to chamber/feed this round, potentially

Other options I've through about, but have no personal experience with:

450 Bushmaster (250 gr to ??)
Not sure how 'simple' it would be to convert say a 10 FCP-SR to chamber this round

458 SOCOM (250-600+ gr)
This is actually one of the rounds I really like the performance of... the cost is a downside to entry
Again,.. not sure of the practical ability to convert the rifle

So, there it is.. the near sum total of the research I've done regarding a cartridge that I can reload for both subsonic (preferably above 300 grains, heavier == better), that uses SWC style, large meplat bullets and is still capable of running 'lighter' bullet weights at high velocities for better range, when needed. I'd prefer to run a rifle with an integral suppressor and will have one made for the chosen platform, as long as it'll handle the hi-velocity of the cartridge selected. In a perfect world, I'd be able to throw 300, 400, 500+ grain (?) hard-cast lead rounds down range at @ 1050fps with the integral suppressor providing little more than a 'poof' for a sound signature (from what I have seen from the 44 mags, anyways) and still be able to throw 250-300 grain bullets at full velocity through the integral without damaging it. IF I have one made, it'll be made for easy cleaning/disassembly and strong. I'd gladly trade the slight addition of weight over a bull barrel to get the sound reduction.


Looking forward to hearing your comments, suggestions and ideas !!


References: