Just curious if anyone has shot one this short, and if so, what kind of numbers were you seeing?

Bet it is noisy!

I've shot 20" and really liked the rifle. Don't know the numbers. "Enough" suited my needs well.
Actually I shot factory ammo just to see what it was like, but generally used handloads instead. The handloads I used were 400 gr and not maxed out. I used faster burning powder, which I think helped with the muzzel blast. I estimate 2000-2200 fps. For my use - very good loads.
KB

PM Michael458. He has all sorts of big bore, short barreled rifles built by SSK for him. He knows his stuff!

have a 20" 458 AR ... its interesting if you are burning a lowish pressure-but-fast-powder load ... fireball!

works, aint REALLY a flame thrower, WILL need h335/rel7 in it

remember, the revered 45/70 and 450 marlin come in 18" barrels

I have a Whitworth that some idiot cut back to 19" ! I had Tip Burns build and install an extension to regain its balance and proportion. He did a beautiful and damn near undetectable job. It is a 4", slightly overbored extension. I loaded up one of my old favorite loads with Norma 202 and a 500 grain Hornady soft, by the Norma info, it was 3 grains below max and filled the case up. I was shocked when I shot it over the Chrony and it showed 2026 fps! I have used this same load in other .458's I have had and it was over 2050. Never any pressure signs. I was amazed and shot several more to verify it, so I would say, if you use the right powder and handload, you can probably duplicate the original factory specs, even with a short barrel.

My 19 1/2 " barreled 458 Win Mag .gets the same velocities as any other 458 Win I have had up to 25 " . I pretty much only shoot 4198 and AA 2230 for powder ..... Have you shot any high intensity straight wall case after dark ? they all have a big muzzle flash .

Thanks guys! I liberated an interarms mkx off of gander mountain for a steal of a price in excellent condition. Looks like it has upgraded sights and very nice wood. I believe its the factory stock, but one of those rare gems that somtimes pop up with fine figure and grain. I have no use or desire for a full size 458 win, as I'm having a 10.75x68 built on a M70 classsic for eventual DG hunts. I figure ill either sell it to someone who wants it the way it is, or cut it down and use it as my big bore brush gun, loaded down to moderate/heavy 45/70 loads. I may have another barrel put on for that however so I don't ruin its resale value.

Sounds like a good job for an Adams and Bennet barrel from Midway . . But you will NEED to put a 2nd recoil lug on it and bed it in tight . The 458 will eat a stock for breakfast ....