Playing with the 401 Powermag single action has me thinking

[magnumwheelman]

I have a S&W 610 that has been reamed for the 10 mm Magnum... I'm wondering how close the grooves at the base of the case are, & if I couldn't massage the custom made 40 caliber Magnum cases to fit the Moon clips... or if I would even need to ( thinking I'll have excessive headspace on a moon clip gun without a clip, but??? ) however I haven't tried putting a 401 in my 610 cylinder yet... but my Accurate Reloading manual states that the 10 mm Magnum is literally a rimless 401 Powermag, & I'm actually using 10 mm dies to reload the 401... might be kinda cool to be able to shoot those in that gun will be looking into it more this week

[tinkerpearce]

I'm intrigued...

[tinkerpearce]

This might sound like a dumb question- at least not to folks familiar with caliber designations- but what caliber is .401?

[magnumwheelman]

my Accurate loading manual says the 10 mm Magnum is essentially a rim less 401 Powermag... the 10 mm Magnum case is just like a longer ( magnum length ) 10 mm auto case... so the 401 is... ( 40 caliber / 10 mm )

I'm loading it using 180 grain 38-40 bullets right now, since they have a crimp groove... I could also use any of my 10mm bullets with light enough loads to keep bullet creep under control

my S&W 610 was originally chambered for 10 mm with the use of a moon clip ( 40 S&W can also be fired in these guns ) I deepened the chambers to fit the unique & obscure 10 mm Magnum, which I originally bought into, for an Automag in my collection... in this case the Automag 4 chambered in 10mm Magnum...

I still haven't ( hoping to tonight ) try slipping a 401 cartridge into the S&W 610... only issue I really can see, is if the extractor star won't work with the rimmed cases of the 401... ( & of course the possible headspace issue mentioned in my original post ) if the extractor star is the case, I may be able to fit the extractor star to the 401 cases, & still have it work fine for the 40 S&W / 10 mm / 10 mm Magnum, with the moon clips

S&W 610 in foreground



some cartridges






will get a few pictures of the 401 Powermag cartridges tonight

[magnumwheelman]

Pictures coming in the morning... no problem with the extractor star... but 2 possible issues, although not unsolvable... the 401 Powermag cases made from the Starline 41 Magnum cases are longer, I purposely left the Powermag cases as long as possible, to use as much of the cylinder length as possible... so since the chambers were cut, so that the 10 mm Magnum case would headspace on the case mouth, the 401 cartridges do not insert far enough to fully insert into the cylinder, so that the cylinder will close... and 2nd, the head space gap is wider than the rim, since this is a moon clip gun, there is more space than normal between the back of the cylinder, & the recoil shield... a bigger groove could be machined into the base of the 401 cases, that could fit the moon clips... more thought required... but I am interested in the possibility of having the 1st double action 401 Powermag

[magnumwheelman]

a couple pictures from last night...

S&W 610 with a 10 mm Magnum & 401 Powermag cartridge



the S&W 610 cylinder with a 10 mm Magnum cartridge headspaced on the mouth ( space allows for a moon clip ) & a 401 Powermag cartridge inserted to where the crimp hits the throat... auto cartridges get a taper crimp, & get a more solid & dependable fit at the mouth... the 401 has a crimp from a Lee 10 mm factory crimp die, which does lock into the crimp groove slightly... I'll likely still have to headspace on the case mouth rather than the rim, or there will be excessive headspace, due to the fact that this gun was designed to run with a moon clip... I may put a deeper groove in the base of the 401 case, so they can fit into the moon clips, & then can possibly put a heavier roll crimp on the case, & not worry about the cartridge going into the chamber too far, or pushing in, causing soft primer hits... depending on what my machinist buddy thinks, when I discuss this with him later???



No problems with the extractor star or ratchet

[needsmostuff]

Silly , obvious question. Will the 10mm mag drop in and fire in the single action or is there a rim thickness /headspace issue.

[magnumwheelman]

if you are talking one of the Ruger 10 mm guns, for example... since there is no rim, the single action guns headspace on the case mouth, so case length is critical, & so the 10 Mag cartridges are too long for the 10 mm chambers... this is why I had the extra 10 mm Magnum cylinder made for my Buckeye, in the single action thread

[needsmostuff]

Ooops ,sorry ,not a well worded question.
What I meant was will a 10mm reload work in a 401 Single Action like a Herder's or your custom Buckeye.
I think I misread the pictures and concluded the 10mm had a semi rim (I've never seen one) . If it has NO rim there would be headspace issues I'm sure.

[magnumwheelman]

the regular 10 mm cartridge would slide into the chamber of the 401 too deeply to fire, as it is not a semi rimmed cartridge... the new 10 mm Ruger Blackhawks ( I was just looking at those on their website ) have conventional spacing at the back of the cylinder, so those headspace on the case mouth, much like the old 30 carbine Blackhawks did... the new Super Redhawks being double action, have a bigger space to allow for the moon clips, so they "group eject" the same as any double action... the single actions get by without the moon clips, as they only eject 1 case at a time...

I'd be interested in looking at the Charter Arms 40 S&W Bulldog, & see if those could be modified for the 401... but there are likely pressure & cylinder length issues with the 40 caliber Charters

[okiehoosier]

Since the 10mm and 40 S&W obviously don't headspace on the case mouth, headspacing with the extractor clip instead, why not simply bump the chamber out a bit more with a reamer so the .401 rims sit flush?