Is the 10mm Magnum a good revolver cartridge?

[Captain O]

Back during the 1990's a Customer Service Representative at S&W relieved the chambers of his 6 1/2" barreled Model 610 to accept the 10mm Magnum Cartridge. He stated that the handgun withstood the pressures of the Magnum cartridge without so much as a hiccup.

This modification allows the 200-grain bullets to reach 1450 fps and 954 fpe from that 6 1/2" barrel. (This is solidly in .41 magnum territory).

Thoughts, opinions?

[The_Shadow]

This data was from Accurate Arms from 8" BBL

[sqlbullet]

I am a huge fan of the 10mm auto.

Never saw the point of the 10mm magnum.  All the drawbacks of the 41 Magnum but only 90% of the performance.

[Mike D]

I've considered buying the super red hawk and punching it to 10mm magnum.

That load data above is very conservative. I've seen days that pushes the 200 grain XTP very close to 1600fps.


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[TonyRumore]

Extend it, neck it to .357, and rechamber a Coonan barrel.

Tony

[Walking Bear]

OK Tony you make it and I will test it out.  Sounds like something Gary Reeder would tackle

[The_Shadow]

This was originally about the revolver conversion to 10mm Magnum.  Seeing the mention of the Coonan here are some things to look at...

I had posted a letter to Coonan awhile back about the 357 Coonan being made into a 10mm Magnum and also a barrel for the 9X30 (10mm Magnum necked down to 9mm like the 9x25 Dillon).
No response was made to my e-mail letter.   

It should be fairly straight forward for conversion.  The slide's breech face should be OK as is with the 357 case rim being .440", Extractor should work but might need one slightly modified to hold the 10mm magnum casing tighter to the breech face.  Barrels should be easily cut to fit the existing slides, however the slide may require some work at the the nose of the slide for barrel fitting of the barrel or barrel bushings mad for the difference in barrels.  Magazines should be an easy modification considering the 357 mag case and rim...

Would truly be interesting gun chambered for 10mm magnum and 9x30

Left to right 9x25 Dillon 9x30Dillon and rimmed 40 caliber


This was Randy Shelley's 9x30 AMT gun  See the info at this link; http://10mm-firearms.com/wildcats/welcome-mr-randy-shelley-designer-of-the-9x25dillon-cartridge/


357Magnum case length is 1.290" with a COL of 1.590  case rim is 0.4400"

10mm Magnum case length is 1.225" with a COL of 1.555"  case rim is 0.4250"

[TonyRumore]

If you went with a .357 bullet instead of a .355" bullet, you could just rechamber an existing Coonan barrel.  With 9x30, you would have to make a whole new barrel.  It just makes a lot more sense to do it in .357 rather than 9mm due to the speeds it's going to hit, especially for hunting uses.

You could either leave the case length at 1.225 and design the chamber reamer to run some free bore (lead), before you hit the throat, or just make a longer case from 6.8spc.
Since the 357 Mag headspaces on the rim, the existing chamber won't have a square sharp edge on it at the case mouth so the bullet shouldn't be disrupted much going from the shorter case, through the lead and into the throat.



Tony

[hollywood63]

Shadow what are you using for the rimmed 40 case?  I just fire formed a hand full of 30-30 cases

[TonyRumore]

It would be a lot easier to just use Herter's 401 PowerMag cases.  The brass isn't that hard to come up with.....it's on GunBroker all the time.

The 401 PowerMag is one of those items that is Rare, but not Scarce, because it has no Desirability.  It takes all three to be really Collectible.  Rarity + Scarcity + Desirability = Collectability. 

Most guys that have 401 PowerMag guns, dies, brass, ammo, etc, could care less and it's always for sale, because no one else wants it either.   

Tony

[The_Shadow]

Hollywood63, that was not my forming of the rimmed 40 casing, that was done by Randy Shelley himself for his project.  When we talked last he didn't mention what parent casing he used.
Randy info;

I took a Ruger 38-40/10mm convertible, opened up the 10mm cylinder to shoot either 10mm magnum or my rimmed version, 40 cal. magnum. Project started in 1997 still not fired yet.

[shottist]

I have a S&W 610 with a 6.5" barrel.  Bought a reamer and reamed the cylinder for 10MM Magnum ammo.  Bought lots of 10MM Magnum cases & Starline 10MM auto cases. Bought lots of "moon clips".  I shoot 40 S&W, 10MM auto and 10MM Magnum interchangeably with the moon clips.  Also have a Witness for the 10MM auto.  Have "too many" guns, so don't shoot it often.  Easy to manage, very accurate, sort of like to a 22 short, long or long rifle.  Love the gun.  Use a LBT LFN mould for 200 gr. bullets and Lee mould for 165 gr. cast bullets, cast from wheel weights with added tin, sized 0.401  Also have "too many" S&W 44 magnums, so not short of energy here.

Still have the reamer if anyone needs it.

[The_Shadow]

Welcome to the forum Shottist.  I just posted some Accurate Arms 10mm Mag data in the 10mm reloading section.
I shared it on several other forums over the years...
Best regards...