No doubt about it, at very low velocity, caliber wins the day overall. There are special designed small caliber bullets that are very good in this arena, but not suitable for day to day use.
Now, I am going to make some Assumptions on this, I assume we are talking about deer/pigs for the most part, here in the Carolinas.
So I’ve been pondering putting a night twist rate 16”-18” 458 SOCOM barrel on a Howa mini action,
I am not very familiar at all with a Howa Mini Action, I plead nearly complete ignorance here. I have looked over on GunBroker, and there are no Howa bolt guns chambered in 458 Socom listed anywhere. So Again, I Assume one would have to build or chamber a barrel to fit the Howa for this cartridge. I do see Howa's in other cartridges, running $550 or better, then the cost of conversion added to that...... Depending on who/where/what, a conversion and barrel is going to be anything from $500 to much more I believe, and especially trying to find a faster twist barrel, which will probably have to be special order. In .458 caliber, I believe down to 1;12 may be available without special order? I know 1:14 is. Not sure about faster twists. But, for this application, I believe 1:14 will suffice and not be an issue at all...........For sure go with 16.25 inches....... case capacity does not require more barrel to burn at all.......
There are hundreds of different types of .458 caliber bullets to choose from, .458 is a wonderful caliber, one that is dear to my heart. You can get 45/70 type bullets, in the case of 458 Socom, 300 gr cheap HP's are great at 1500-1800 fps, various 400s are great at even lower velocities, thinking the Remington 405 is just great at 1200-1500 fps. Lots of cast bullets mostly cheap, and at subsonic would work fine...... There is no down side in .458 caliber that I can see in any way.
Break open gun? No, I despise those bastard things. Not for me. Lever gun, 45/70 would serve fine, but lever guns are very expensive these days, they have jumped through the roof. Probably not that much heavier than a bolt gun, but again I am not familiar with the Howa Mini? The slow twist rates in the Lever guns, I really don't think is an issue in this case, in these calibers. Think about it, there are still extreme long range matches with the big Sharps and 1885s in 45/70 and such cartridges shooting out 500+++ Yards, getting extreme accuracy........all those have very slow twist rates.......1:18 or even slower.......
Maybe other options in .458 caliber would give more versatility in addition to the SubSonic. 450 Marlin comes to mind, which can be put on a bolt gun, I have no experience with the 450 Marlin, which the 458 American (shortened 458 Winchester) preceded the marlin cartridge. Some minor tweaking would get you big fat heavy bullets at SubSonic without issue, and then later if you wanted to up the ante some, it would have more versatility than the 458 Socom.
Then of course another option and trying NOT to toot the B&M horn any is the 458 B&M Super Short. It can easy do SubSonic, I have used it to test various bullets down to 800 fps with no issue at all. Then of course, you can get very serious with it running super 300 Premiums to 2400-2500 fps, and the mighty 250 Socom from CEB at 2700 fps. The down side of this is cost. Requiring a Winchester M70 WSSM action, and about $1200 to convert. So not a cheap option at all. But no build is going to be cheap to begin with, unless you have the ability to do it yourself, a talent that I do not possess.
Yet again, here is an option that might come out to the good. I see plenty of those 450 BushMaster bolt guns on GunBroker, prices from $450-$550, some higher just depending. Ruger, Savage and seems some other makes and models available. I believe many are already threaded? Yes, caliber drops to .452 caliber, or basically 45 Colt caliber, handgun. But, the primary mission of this rifle is SubSonic, so this is just not an issue at all with bullet selections and there are just about as many .452 bullets available, if not more than even .458 caliber. If one wanted to up the ante with higher velocity, there are bullets that will do the job and hold together well at even 2000 fps or better.........Then there are piles on top of piles of bullets available for that 1200-1500 fps range. Lots of cast bullets for cheap shooting at SubSonic...........Still poking .45 caliber holes.........not enough difference in caliber between .452 and .458 to take notice.
Hmmmm............. We, as shooters, do all sorts of great and wonderful, fun, sometimes not practical, projects! Guilty as charged......... But if I was just looking at the goals mentioned, and the "For The Money Factor", I would have to check out one of those "ready made" bolt guns in 450 BushMaster..... I could get by with .452 caliber, and it might be a bunch of fun, at less cost than a build.........I don't know? Fun to build, god knows I have built a plenty.......and still do.......
