New caliber testing soon. .45ACP, .45 Super and .460 Rowland

[Intercooler]

    I sent for a Hunter 6" conversion today and plan on having the barrel reamed for .460 Rowland. I'm pretty sure I can fire all three of these from what I understand. My plan is to run it uncompensated with no brake and a 22lb recoil spring  . I'm trying to see if I can get one even higher or possibly use a 1911 spring in it.

[The_Shadow]

That 460 Rowland is an interesting cartridge, I haven't played with it yet but have some loading data on hand.

[Intercooler]

I can't buy any guns here in this stinking State  :'( I figured I could more or less add a couple this way. You ever hear of anyone running into issues firing all three?

[The_Shadow]

The 460Rowland is a longer cartridge and chamber and the max pressure is set at 40,000 psi.  You would be using the shorter  45ACP and 45Super cartridges, like those using the 40S&W in a 10mm chamber, it would head space on the extractor!  It would work, but there can be issues like the firing pin pushing the shorter casings off the extractor with our without ignition.  Bullets fried from the shorter cases, can strike the end of chamber cut, this can cause some wear and or deposit bullet material and carbon to foul the chamber, this would require a good cleaning prior to shooting the 460's again.

I haven't priced these yet but they may well be more expensive than the 10mm in the long run...

[Intercooler]

  I thought although the .460 uses longer brass it gets the same OAL as .45ACP?

[The_Shadow]

Yes the460's are the loaded to the longer overall length of 1.2750", whereas some 45ACP's are loaded 1.2000 depending on the bullet designs, but the difference in casing length is where the carbon deposits build up from using the shorter cases, like that of 38 spl and 357 magnum, revolvers typically use a tapered end of chamber cut.  Semi auto uses a squared end of chamber cut so the casing headspaces on that cut, therefore trying to shove the 460 Rowland cartridges in the chambers after shooting the shorter 45ACP length cases, may prove difficult without a good cleaning.

[Yondering]

    I sent for a Hunter 6" conversion today and plan on having the barrel reamed for .460 Rowland. I'm pretty sure I can fire all three of these from what I understand. My plan is to run it uncompensated with no brake and a 22lb recoil spring  . I'm trying to see if I can get one even higher or possibly use a 1911 spring in it.

NO!

Do not try to shoot 45 Auto or 45 Super in a Witness chambered for .460. Same idea as 40 in a 10mm; OK in a Glock (because of the short firing pin) but it is not OK in a Witness.

You will have some rounds jump in front of the extractor, and the long firing pin of the Witness will set them off. This can lead to bad things.

This is me speaking from experience.

Also, you will need a brake on that 460 Rowland barrel to slow down the slide. A heavy recoil spring will not cut it. Sounds like you should research this a little more first...

[Intercooler]

   I read about someone doing it with a 1911 and a two polymer pistols with no brake. Dice rollers?

[sstewart]

The kits for 1911s have brake built into barrel.

[Intercooler]

   I asked the Tangfo gurus. Maybe just .45ACP and Super then. I shot Doubletap .45 Super out of my old Beretta PX4 without any issues in stock form.

[Intercooler]

   I confirmed the firing pin issue with shooting the .45ACP. So if it's cut Rowland do you think a Magnaport: http://www.magnaport.com/misc.html and strong spring assembly will make it a go? No longer barrel exists to put a brake/comp on the end of the Hunter.

[Yondering]

No, Magnaporting (or any other barrel porting) is not the same as a brake; it reduces muzzle flip but does nothing to reduce rearward recoil, which is what a brake does to slow down the slide.

45 Super and 10mm are similar power levels; both rounds need pistols set up similarly. The stock Witness setup is marginal for either one IMO; a stronger hammer spring and recoil spring are necessary IMO. The 460 R is on a whole other level, and can't be setup just like a 10mm or 45 Super.

[Intercooler]

    I spoke with  someone who does all kinds of Witness Hybrid builds and his thought was a custom Sprinco setup coupled with the Magnaporting would work. It would take the "Corbon" Sprinco setup which is a PITA to rack the slide and why they don't suggest it except in extreme situations. Since the Hunter rod is longer I would have to send mine in for a custom rework mating the two. Quickly turning into a $1500 upper assembly going that route and the magazines might not work properly as well.
     Maybe soon I will be out of this State and can buy an XDm .45 lower and put a drop-on kit.

[Yondering]

Again, porting does nothing to slow down the slide. The only thing working for you in that setup would be the Sprinco system, which may prevent battering at the rear end of travel, but will put that stored energy right back into the slide when it goes forward again.

If you really want to do a 460 Rowland, you'd be better off with a standard length Witness with an extended barrel and a brake, to do it right.

[Intercooler]

Yea. The same person said if you want .44 ballistics, just shoot a .44