10mm Magnum Revolver

porklard · May 10, 2018, 08:05 PM

In November I bought the new Ruger SRH Revolver in 10mm Auto. In April I got a 10mm finish reamer from Dave Manson and converted the cylinder to 10mm Magnum. It's a great shooting piece of steel.

I have been working up loads in H110 and AA#9 and just finished a workup in AA#7 and Longshot. I was disappointed in the H110 - it doesn't increase velocity through the workup from 20 to 21 gr. The AA#9 went up nicely though, finishing at 18gr and 1485 fps. There were no signs of overpressure so I will push that a bit more.

Does anyone have any pointers?

agtman · May 11, 2018, 06:33 AM

I assume you've seen Taffin's 10mm Mag load data (?) here:

http://www.sixguns.com/tests/tt10mag.htm

http://www.handloads.com/loaddata/ta...Powder&Source=

Propellants that work well in the 10mm AUTO should work equally well in the 10mm Magnum, the latter cartridge being simply an "extended" or longer-cased 10mm.

Possibly try magnum pistol primers if you haven't already.

Probably more than you want to know, ... but the 10mm Magnum is a distant derivative of the ancient Herter's .401 'Power Mag', which once briefly competed with Elmer Keith's then-hot-new 'police cartridge,' the .41 Magnum. Think very early 1960s. Then it faded.

Dimensionally and ballistically, Herter's .401 is similar to the 10mm Magnum, except the .401 cartridge was designed for use in a single-action revolver, whereas the 10mm Mag was designed for use in IAI's old AutoMag IV, a 1911-ish semi-auto pistol.

Here's a link to a good review of the details and history of Herter's .401 cartridge, with load data that bears some interesting proximity to 10mm Mag load data. You'll note the similarity of bullet-weights and propellants used, and the velocities obtained, in relation to Taffin's 10mm Mag data. Might be helpful in extrapolating loads.

The .401 load data follows the review. Again, just FYI:

http://www.gunblast.com/Fryxell_Herters401.htm

**Mike Irwin** · May 11, 2018, 07:26 AM

Moving this to the reloading forum.

GarrettJ · May 12, 2018, 07:29 PM

Quote:

Originally Posted by porklard

The AA#9 went up nicely though, finishing at 18gr and 1485 fps.

What bullet weight are you using?
And what barrel length?

agtman · May 12, 2018, 07:50 PM

The 10mm SRH has a 6.5" barrel.

porklard · May 16, 2018, 04:31 PM

I use 180gr HAP and XTP since all my 10mm was for my Glock 29. I tried some AA#7 from 14 to 15gr in .2 increments - 1343 fps. I tried Longshot from 8.2 to 9 in .2 increments but it is slow at 1068 fps plus it left the cartridge cases blackened - I think that means the pressure is not high enough to expand the case and seal the chamber. It also doesn't fill the case much.

I did look at the .41 Mag - I have a Blackhawk and load 210gr bullets for it. I think I could get some 200gr HAP and XTP and extrapolate the 41 loads - that seems to be what agtman was thinking (and thanks for the tip about the Power Mag.). I had some Blue Dot but it meters so poorly I used it up and wasn't going to buy anymore but I think now I should.

Thanks for all the really good info so far!

porklard · May 16, 2018, 04:36 PM

agtman, I just took another look at Taffin and he used magnum primers - that is likely why I don't get the chrono numbers he posts. Here comes another hazmat fee...

GarrettJ · May 16, 2018, 09:29 PM

Quote:

Originally Posted by porklard

I use 180gr HAP and XTP...I tried Longshot from 8.2 to 9 in .2 increments but it is slow at 1068 fps plus it left the cartridge cases blackened - I think that means the pressure is not high enough to expand the case and seal the chamber. It also doesn't fill the case much.

I think you're right. Especially since Hodgdon's website lists 8.5 to 9.5 gr. of Longshot for a "regular" 10mm. So loading 9.0 gr. in a longer case with more internal volume would reduce pressure and velocity noticeably.

So along the lines of what you're doing, and since the cylinder on my Blackhawk will accommodate it, I started working up some 10mm loads at standard length, and then went to a longer OAL.

I worked a Hornady FMJ-TC up to 9.0 gr. Longshot at 1.270" (1326 fps.), and then I started at 9.0 gr. and moved the OAL out to 1.395". This is roughly half way between regular 10mm and 10mm Magnum.

At this length I have so far worked up to 10.6 gr. Longshot (1377 fps) with no signs of excess pressure. I expect I can go up a fair bit more on the charge weight without issue. I just need to load some and go try them out. With your longer case and OAL, you should be able to safely work your way up quite a bit from where I've gotten to.

porklard · May 18, 2018, 05:48 AM

GarrettJ, Thanks. I was using the Hornady 10th and it shows 8.2 gr Longshot max for 10mm Auto, but I must have used the Hodgdon data in the past because I have recorded 9.2gr Longshot at 1211fps in the Glock 29. That works to help confirm much of what agtman wrote. I bought some LP Magnum primers and loaded 21.0gr H110. Where I recorded 1239fps with CCI LP Primers, I got 1320fps with the CCI LP Magnum primers.

As long as you are using Longshot I will go back to it for some more workup. I wasn't aware Ruger had a 10mm chambering for the BH. Nice.

Also, I loaded 18.5gr of AA#9 but it went backward to 1395fps. I will load that with Mag primers and see what it does. I haven't been concerned about accuracy yet, nor have I begun to compare any of my 41 Mag load work to see where the 10mm Mag fits.

agtman · May 20, 2018, 04:27 PM

Good to hear ...

I figured you'd get better 10mm Mag velocities with the magnum primers. I use the CCI mag primers in my heavy 10mm AUTO handloads.

Quote:

I did look at the .41 Mag - I have a Blackhawk and load 210gr bullets for it. I think I could get some 200gr HAP and XTP and extrapolate the 41 loads - that seems to be what agtman was thinking (and thanks for the tip about the Power Mag.). I had some Blue Dot but it meters so poorly I used it up and wasn't going to buy anymore but I think now I should.

Actually, for extrapolation purposes, I'd be studying the load data posted at that link to the Herter's .401 Power Mag, rather than the .41 Mag. Dimensionally, the 10mm Magnum cartridge is closer to the .401 P-Mag than it is to the .41 Mag - especially if you intend to shoot hardcast bullets of the same or similar weight as were cited in the .401 data.

Good luck!

agtman · May 20, 2018, 04:56 PM

Here's a link to a YouTube vid of Jeff at 'Gun Blast' reviewing Ruger's new GP-100 Match in 10mm. It uses moon clips like the S&W 610s.

However, Jeff then sent the revolver to Tyler Gun Works in Texas to have the chambers of the cylinder reamed to 10mm Mag specs, along with a couple of other goodies.

He talks about that work and some of his 10mm Mag handloads in the vid. Jeff mentions that factory 10mm Mag ammo is available from Double Tap. (The DT load he fired in the vid used the light, 135gn bullets).

Moon clips shown are loaded with .40S&W, 10mm AUTO, and 10mm Magnum cartridges.

Just FYI:

https://m.youtube.com/watch?v=CsrbCI...e_continue=278

porklard · May 22, 2018, 09:47 AM

Thanks agtman! Excellent video. I am having a lot of fun with this project.

I watched a friend shoot my Redhawk 44Mag and the SRH 10mm Mag - the 44 is still a bigger blast, but the 10mm Mag is as much fun. I will continue loading up and get some 200gr XTP and post my results as I go.

agtman · May 22, 2018, 05:22 PM

Quote:

Thanks agtman! Excellent video. I am having a lot of fun with this project. I watched a friend shoot my Redhawk 44Mag and the SRH 10mm Mag - the 44 is still a bigger blast, but the 10mm Mag is as much fun. I will continue loading up and get some 200gr XTP and post my results as I go.

Have fun and good luck. Don't forget to try the heavy hardcast boolits - 200, 220 & 230gns.

My current favorite is SNS Casting's 220gn 10mm poly-coated HC slugs. The poly-coating prevents the barrel from leading up.

In the Glock 10mms, the poly also makes the round 'slick' for easy-feeding going up the ramp. That's not a concern in a wheelgun, but keeping the barrel from leading up is an obvious cross-over benefit as between the two platforms.

Still am impressed with Taffin's honesty in comparing the 10mm & .41 Magnums:

Quote:

The 10mm Magnum has definite applications as a hunting pistol and a long range silhouette pistol. Shooting informally at long ranges of 100 to 200 meters and using rocks as targets convinced me of this. Anything the .41 Magnum can do, the 10mm Magnum can also do and perhaps do it even a little faster and a little better. That is a tough confession for an old sixgun man to make.

Ruger45LC · May 25, 2018, 12:35 PM

Taffin is entitled to an opinion or two, but in no way will a 10mm Mag equal or out-do a .41 Mag.

**Unclenick** · May 25, 2018, 04:45 PM

Porklard,

I know you are done with Blue Dot anyway, but for others considering it, I would avoid any load of Blue Dot in your 10 mm Magnum. In late July of 2008, Alliant issued a warning they say was based on their ongoing product review testing to stop using Blue Dot behind 125-grain bullets in .357 Magnum and to stop using it altogether in the .41 Magnum, even though they had previously published loads for it.

Alliant has never explained the nature of the problem they found. Modern transducers display the full pressure curve, where the old ones only registered the peak, so they may have seen something funny with that. Or they may simply have found the pressure standard deviation in those loads was outside of SAAMI standards and could predict some percentage of their customers were going to be on the high tail of the bell curve and could experience a kaboom. Any SD outside the SAAMI standard is probably a liability red flag for them, anyway.

Of course, people used Blue Dot for a lot of years in the warned-against combinations and most never experienced an issue during that time. So those who used it a lot will probably harumph and declare it's all nonsense because they don't understand the statistical nature of it. Their odds, as individuals, of seeing a problem may be low, but Alliant has large numbers of customers firing a much larger number of rounds, so the odds of it happening to one or more customer at some time may not be so small. You just don't want to be the unlucky one.

Anyway, I don't know if your 10 mm Magnum is close enough in powder space shape and size to the .41 Magnum that it should be considered affected. I would just assume the warning should be applied to it by extension unless you contact Alliant and they specifically tell you it is OK.

agtman · May 26, 2018, 07:38 AM

Quote:

Taffin is entitled to an opinion or two, but in no way will a 10mm Mag equal or out-do a .41 Mag.

How do you know?

Did you perhaps test a 10mm Mag IAI AutoMag IV head-to-head against a Desert Eagle .41 Mag?

Dude, did you even read Taffin's article and his load analysis? The guy's shot more magnum cartridges, including the .41, in more types of handguns, than any other gunwriter alive today.

But regardless, ... even if the 10mm Mag merely equaled the .41 Mag's ballistic output (fps/fpe), it still has the advantage of being able to use a much wider range of bullet-weights and styles, including hardcast boolits, than the .41, the selection for which is quite limited.

And that advantage exists before you even consider the versatility of the platforms: Ruger's 6" 10mm SRH and, now, the 4" 10mm GP-100. Post-conversion, both wheelguns can load and fire three different cartridges using the same moon clips, which by design facilitate quicker loading and extraction than the default finger-fumble method.

agtman · May 26, 2018, 07:51 AM

Quote:

I know you are done with Blue Dot anyway, but for others considering it, I would avoid any load of Blue Dot in your 10 mm Magnum. In late July of 2008, Alliant issued a warning they say was based on their ongoing product review testing to stop using Blue Dot behind 125-grain bullets in .357 Magnum and to stop using it altogether in the .41 Magnum, even though they had previously published loads for it.

Alliant has never explained the nature of the problem they found. Modern transducers display the full pressure curve, where the old ones only registered the peak, so they may have seen something funny with that. Or they may simply have found the pressure standard deviation in those loads was outside of SAAMI standards and could predict some percentage of their customers were going to be on the high tail of the bell curve and could experience a kaboom. Any SD outside the SAAMI standard is probably a liability red flag for them, anyway.

Wasn't aware of that info, so thanks for the heads-up.

I checked the load data (@ the GunBlast link) for the Herter's .401 PowerMag, which is closer to the 10mm Mag than the .41, and didn't see any reference to loading with BlueDot.

http://www.gunblast.com/Fryxell_Herters401.htm

**Unclenick** · May 26, 2018, 12:31 PM

This is the text of the original warning, which we can post as it asks to be distributed. They want the warning to get out.

Quote:

ATK Commercial Products
900 Ehlen Drive Anoka, MN 55303
www.atk.com

July 25, 2008

Dear Functional Wholesaler:

Please distribute this letter to all of your customers immediately with instructions for them to do the following:

• Post this letter in a highly visible area of their establishment
• Distribute to their customers as soon as possible

Alliant Powder Blue Dot® Product Safety Notice

Alliant Powder® periodically reviews and tests their published reloading data to verify that recommended recipes have not changed over time.
During the latest review Alliant Powder discovered that Alliant Powder’s Blue Dot® should not be used in the following applications:

• Blue Dot® should NOT be used in the 357 Magnum load using the 125 grain projectile (Blue Dot® recipes with heavier bullet weights as specified in Alliant Powders Reloading Guide are acceptable for use).
• Blue Dot® should NOT be used in the 41 Magnum cartridge (all bullet weights).

Use of Blue Dot® in the above cases may cause a high pressure situation that could cause property damage and serious personal injury.

We apologize for any inconvenience that this may cause and appreciate your understanding and cooperation in this matter.
Thank you for your cooperation and if you have any questions or concerns please contact me at [email protected] or call me at 540-639-8503.

Dick Quesenberry
Alliant Powder
Product Line Manager

Filthy Harry · May 27, 2018, 09:19 PM

I don't see how the 10mm Magnum can outperform the 41 Mag. It'll probably come close, but if I'm not mistaken the 41 Magnum case is bigger. Bigger case more powder more power at the same pressure. Most 40 caliber bullets are designed for the 40 S&W's and are already stressed at 10mm velocities. They also top out at 200 to 230 grains so I honestly would't use bullet choice as an advantage.

Ledslnger · May 27, 2018, 09:32 PM

Elmer Keith said the .41 outperformed the .44 Mag due to it’s speed. I can’t see the 10mm being able to beat the .41 if the .44 Mag can’t. And, Elmer Keith had a little bit of experience to pull from. Has at least a couple bullets named after him. Might be a bit of knowledge there I bet.

Filthy Harry · May 27, 2018, 10:15 PM

Is bullet jump an issue with these hot 40 caliber revolver loads? I mean there's gotta be a reason revolver bullets have crimp grooves.

porklard · May 29, 2018, 11:23 AM

Lots of interesting ideas... I haven't looked at bullet jump but I do crimp pretty hard.

My results for the 41 Mag are invariably higher speed though I only have 210 gr bullets and it doesn't need a magnum primer to get there. I won't argue for the 10mm Mag outperforming the 41 Mag. But a deer would never notice... though a bear??

I am trying some interesting things, all with Hornady .401 180gr HAP bullets and new Starline brass, bullet seats to 1.555 inch COL:
18.5 gr AA#9 CCI primer 1395fps
18 gr AA#9 CCI primer 1428fps
15 gr AA#7 CCI primer 1343fps
11.4 gr Longshot CCI primer 1358fps

The only magnum primer I have shot so far is H110 at 21 gr for 1320fps.

I have some loaded with Mag primers and AA#9 at 18.5 gr I will shoot soon.

Some of the data seems a bit anomalous to me with SD values and fps values displaying a wider range than I would have thought. I would not expect values in six shots of individually weighed H110 with mag primer ranging from 1236fps to 1378 (SD 51)

Statistics/Velocity Report

String #: 3
High Velocity: 1378
Low Velocity: 1236

Average Velocity: 1320
Extreme Spread: 142
Standard Deviation: 51
Grains: 180

Velocity # Velocity Power Factor Foot/Lbs
1 1287 231.660 661.959
2 1349 242.820 727.274
3 1378 248.040 758.879

4 1352 243.360 730.512
5 1318 237.240 694.233
6 1236 222.480 610.536

or AA#9 from 1324 to 1470 (SD 52) standard primer

Statistics/Velocity Report

String #: 1
High Velocity: 1470
Low Velocity: 1324

Average Velocity: 1395
Extreme Spread: 146
Standard Deviation: 52
Grains: 180

Velocity # Velocity Power Factor Foot/Lbs
1 1470 264.600 863.592
2 1394 250.920 776.604
3 1324 238.320 700.568

4 1419 255.420 804.709
5 1416 254.880 801.310
6 1352 243.360 730.512

I loaded a case with a 180gr HAP seated at 1.555 COL, weighed it at 260.4 gr then filled it with water and weighed it at 281.4 gr for a case volume of 21 gr of H2O. I thought this might give me an idea where I might get to compressed loads if I were to go there but I find I have no idea

Powder is lighter than water, is that correct?

agtman · May 29, 2018, 01:58 PM

Quote:

Elmer Keith said the .41 outperformed the .44 Mag due to it’s speed. I can’t see the 10mm being able to beat the .41 if the .44 Mag can’t. * * *

Dude, get yourself focused. Try actually reading the posts and the links to the load & chronograph data that were included.

They're not talking about the 10mm AUTO; they're talking about the 10mm Magnum. Different beast.

disseminator · May 29, 2018, 10:29 PM

While there IS a wide range of .40 caliber bullets available, how many of them are suitable for these velocities? To me that is still why I feel the 10mm struggles not to mention the fact that traditional magnums are still generally superior for most game taking applications IMO.

While the 41 Magnum might not have the bullet selection of the other magnums, it has vastly more suitable hunting bullets than the 10mm does.

That said, there is nothing wrong with a 10mm Mag if that is what trips your trigger.

agtman · May 30, 2018, 08:04 AM

Quote:

While there IS a wide range of .40 caliber bullets available, how many of them are suitable for these velocities? To me that is still why I feel the 10mm struggles not to mention the fact that traditional magnums are still generally superior for most game taking applications IMO.

While the 41 Magnum might not have the bullet selection of the other magnums, it has vastly more suitable hunting bullets than the 10mm does.

'Vastly'?

They make 10mm/.40-cal hardcast 'boolits' that are certainly "suitable for hunting" in weights of 200gns, 220gns, and 230gns, and likely others I haven't seen or tried.

Those - and Hornady's XTP-HP and FMJ-FP bullets - will hold up magnum velocities, such as what S&W 610 owners were getting out of their 6.5" tubes by long-loading the 10mm AUTO past its nominal COAL of 1.250", which is the specified maximum for use in an autoloader.

In a revolver, 610 users (like me) were long-loading the 10mm cartridge out to almost 1.400" and getting near 10mm magnum from the 6.5" guns. You can google and find some of these posts on the various gun-boards, like the S&W forum. A few showed up in threads on THR. I was going to have my own 610 converted to 10mm Mag, but it was an early, first generation 610 and I eventually sold it to a local S&W collector for a hefty amount of cash.

Regardless, the 10mm Mag cartridge makes the practice of long-loading the 10mm AUTO unnecessary, since any halfway competent 'smith can ream-out the chambers of the cylinder to Magnum specs.

The real question is barrel length - longer being better for maximizing the ballistic advantages of the 10mm Mag's output, which is what Ruger's 6.5" 10mm SRH can provide - once 'Magnum-tized' - as a pure hunting handgun. Plus it's easily scoped, whereas the old 610s were not.

On the other hand, for a general purpose 'field'/'woods'/'trail' gun, the 4.2" GP-100 (once converted to 10mm Mag) wins for portability. In fact I'll wager it would be easier to carry around than my 4" N-Frame .41 Mag Model 58, and yet would yield equal or better ballistics than the 58.

May 10, 2018, 08:05 PM	#1
porklard Member Join Date: March 24, 2014 Posts: 15	10mm Magnum Revolver In November I bought the new Ruger SRH Revolver in 10mm Auto. In April I got a 10mm finish reamer from Dave Manson and converted the cylinder to 10mm Magnum. It's a great shooting piece of steel. I have been working up loads in H110 and AA#9 and just finished a workup in AA#7 and Longshot. I was disappointed in the H110 - it doesn't increase velocity through the workup from 20 to 21 gr. The AA#9 went up nicely though, finishing at 18gr and 1485 fps. There were no signs of overpressure so I will push that a bit more. Does anyone have any pointers?

May 11, 2018, 06:33 AM	#2
agtman Junior member Join Date: July 26, 2001 Location: midwest Posts: 2,374	I assume you've seen Taffin's 10mm Mag load data (?) here: http://www.sixguns.com/tests/tt10mag.htm http://www.handloads.com/loaddata/ta...Powder&Source= Propellants that work well in the 10mm AUTO should work equally well in the 10mm Magnum, the latter cartridge being simply an "extended" or longer-cased 10mm. Possibly try magnum pistol primers if you haven't already. Probably more than you want to know, ... but the 10mm Magnum is a distant derivative of the ancient Herter's .401 'Power Mag', which once briefly competed with Elmer Keith's then-hot-new 'police cartridge,' the .41 Magnum. Think very early 1960s. Then it faded. Dimensionally and ballistically, Herter's .401 is similar to the 10mm Magnum, except the .401 cartridge was designed for use in a single-action revolver, whereas the 10mm Mag was designed for use in IAI's old AutoMag IV, a 1911-ish semi-auto pistol. Here's a link to a good review of the details and history of Herter's .401 cartridge, with load data that bears some interesting proximity to 10mm Mag load data. You'll note the similarity of bullet-weights and propellants used, and the velocities obtained, in relation to Taffin's 10mm Mag data. Might be helpful in extrapolating loads. The .401 load data follows the review. Again, just FYI: http://www.gunblast.com/Fryxell_Herters401.htm Last edited by agtman; May 11, 2018 at 07:20 AM.

May 11, 2018, 07:26 AM	#3
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,390	Moving this to the reloading forum. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

May 20, 2018, 04:56 PM	#11
agtman Junior member Join Date: July 26, 2001 Location: midwest Posts: 2,374	Here's a link to a YouTube vid of Jeff at 'Gun Blast' reviewing Ruger's new GP-100 Match in 10mm. It uses moon clips like the S&W 610s. However, Jeff then sent the revolver to Tyler Gun Works in Texas to have the chambers of the cylinder reamed to 10mm Mag specs, along with a couple of other goodies. He talks about that work and some of his 10mm Mag handloads in the vid. Jeff mentions that factory 10mm Mag ammo is available from Double Tap. (The DT load he fired in the vid used the light, 135gn bullets). Moon clips shown are loaded with .40S&W, 10mm AUTO, and 10mm Magnum cartridges. Just FYI: https://m.youtube.com/watch?v=CsrbCI...e_continue=278 Last edited by agtman; May 21, 2018 at 06:21 AM.

May 25, 2018, 04:45 PM	#15
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Porklard, I know you are done with Blue Dot anyway, but for others considering it, I would avoid any load of Blue Dot in your 10 mm Magnum. In late July of 2008, Alliant issued a warning they say was based on their ongoing product review testing to stop using Blue Dot behind 125-grain bullets in .357 Magnum and to stop using it altogether in the .41 Magnum, even though they had previously published loads for it. Alliant has never explained the nature of the problem they found. Modern transducers display the full pressure curve, where the old ones only registered the peak, so they may have seen something funny with that. Or they may simply have found the pressure standard deviation in those loads was outside of SAAMI standards and could predict some percentage of their customers were going to be on the high tail of the bell curve and could experience a kaboom. Any SD outside the SAAMI standard is probably a liability red flag for them, anyway. Of course, people used Blue Dot for a lot of years in the warned-against combinations and most never experienced an issue during that time. So those who used it a lot will probably harumph and declare it's all nonsense because they don't understand the statistical nature of it. Their odds, as individuals, of seeing a problem may be low, but Alliant has large numbers of customers firing a much larger number of rounds, so the odds of it happening to one or more customer at some time may not be so small. You just don't want to be the unlucky one. Anyway, I don't know if your 10 mm Magnum is close enough in powder space shape and size to the .41 Magnum that it should be considered affected. I would just assume the warning should be applied to it by extension unless you contact Alliant and they specifically tell you it is OK. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

May 12, 2018, 07:50 PM	#5
agtman Junior member Join Date: July 26, 2001 Location: midwest Posts: 2,374	The 10mm SRH has a 6.5" barrel.

May 16, 2018, 04:31 PM	#6
porklard Member Join Date: March 24, 2014 Posts: 15	I use 180gr HAP and XTP since all my 10mm was for my Glock 29. I tried some AA#7 from 14 to 15gr in .2 increments - 1343 fps. I tried Longshot from 8.2 to 9 in .2 increments but it is slow at 1068 fps plus it left the cartridge cases blackened - I think that means the pressure is not high enough to expand the case and seal the chamber. It also doesn't fill the case much. I did look at the .41 Mag - I have a Blackhawk and load 210gr bullets for it. I think I could get some 200gr HAP and XTP and extrapolate the 41 loads - that seems to be what agtman was thinking (and thanks for the tip about the Power Mag.). I had some Blue Dot but it meters so poorly I used it up and wasn't going to buy anymore but I think now I should. Thanks for all the really good info so far!

May 16, 2018, 04:36 PM	#7
porklard Member Join Date: March 24, 2014 Posts: 15	agtman, I just took another look at Taffin and he used magnum primers - that is likely why I don't get the chrono numbers he posts. Here comes another hazmat fee...

May 18, 2018, 05:48 AM	#9
porklard Member Join Date: March 24, 2014 Posts: 15	GarrettJ, Thanks. I was using the Hornady 10th and it shows 8.2 gr Longshot max for 10mm Auto, but I must have used the Hodgdon data in the past because I have recorded 9.2gr Longshot at 1211fps in the Glock 29. That works to help confirm much of what agtman wrote. I bought some LP Magnum primers and loaded 21.0gr H110. Where I recorded 1239fps with CCI LP Primers, I got 1320fps with the CCI LP Magnum primers. As long as you are using Longshot I will go back to it for some more workup. I wasn't aware Ruger had a 10mm chambering for the BH. Nice. Also, I loaded 18.5gr of AA#9 but it went backward to 1395fps. I will load that with Mag primers and see what it does. I haven't been concerned about accuracy yet, nor have I begun to compare any of my 41 Mag load work to see where the 10mm Mag fits.

May 22, 2018, 09:47 AM	#12
porklard Member Join Date: March 24, 2014 Posts: 15	Thanks agtman! Excellent video. I am having a lot of fun with this project. I watched a friend shoot my Redhawk 44Mag and the SRH 10mm Mag - the 44 is still a bigger blast, but the 10mm Mag is as much fun. I will continue loading up and get some 200gr XTP and post my results as I go.

May 25, 2018, 12:35 PM	#14
Ruger45LC Senior Member Join Date: July 24, 2005 Location: Kentucky Posts: 768	Taffin is entitled to an opinion or two, but in no way will a 10mm Mag equal or out-do a .41 Mag.

May 27, 2018, 09:19 PM	#19
Filthy Harry Junior Member Join Date: April 19, 2018 Posts: 4	I don't see how the 10mm Magnum can outperform the 41 Mag. It'll probably come close, but if I'm not mistaken the 41 Magnum case is bigger. Bigger case more powder more power at the same pressure. Most 40 caliber bullets are designed for the 40 S&W's and are already stressed at 10mm velocities. They also top out at 200 to 230 grains so I honestly would't use bullet choice as an advantage.

May 27, 2018, 09:32 PM	#20
Ledslnger Member Join Date: March 20, 2018 Posts: 60	Elmer Keith said the .41 outperformed the .44 Mag due to it’s speed. I can’t see the 10mm being able to beat the .41 if the .44 Mag can’t. And, Elmer Keith had a little bit of experience to pull from. Has at least a couple bullets named after him. Might be a bit of knowledge there I bet.

May 27, 2018, 10:15 PM	#21
Filthy Harry Junior Member Join Date: April 19, 2018 Posts: 4	Is bullet jump an issue with these hot 40 caliber revolver loads? I mean there's gotta be a reason revolver bullets have crimp grooves.

May 29, 2018, 11:23 AM	#22
porklard Member Join Date: March 24, 2014 Posts: 15	Lots of interesting ideas... I haven't looked at bullet jump but I do crimp pretty hard. My results for the 41 Mag are invariably higher speed though I only have 210 gr bullets and it doesn't need a magnum primer to get there. I won't argue for the 10mm Mag outperforming the 41 Mag. But a deer would never notice... though a bear?? I am trying some interesting things, all with Hornady .401 180gr HAP bullets and new Starline brass, bullet seats to 1.555 inch COL: 18.5 gr AA#9 CCI primer 1395fps 18 gr AA#9 CCI primer 1428fps 15 gr AA#7 CCI primer 1343fps 11.4 gr Longshot CCI primer 1358fps The only magnum primer I have shot so far is H110 at 21 gr for 1320fps. I have some loaded with Mag primers and AA#9 at 18.5 gr I will shoot soon. Some of the data seems a bit anomalous to me with SD values and fps values displaying a wider range than I would have thought. I would not expect values in six shots of individually weighed H110 with mag primer ranging from 1236fps to 1378 (SD 51) Statistics/Velocity Report String #: 3 High Velocity: 1378 Low Velocity: 1236 Average Velocity: 1320 Extreme Spread: 142 Standard Deviation: 51 Grains: 180 Velocity # Velocity Power Factor Foot/Lbs 1 1287 231.660 661.959 2 1349 242.820 727.274 3 1378 248.040 758.879 4 1352 243.360 730.512 5 1318 237.240 694.233 6 1236 222.480 610.536 or AA#9 from 1324 to 1470 (SD 52) standard primer Statistics/Velocity Report String #: 1 High Velocity: 1470 Low Velocity: 1324 Average Velocity: 1395 Extreme Spread: 146 Standard Deviation: 52 Grains: 180 Velocity # Velocity Power Factor Foot/Lbs 1 1470 264.600 863.592 2 1394 250.920 776.604 3 1324 238.320 700.568 4 1419 255.420 804.709 5 1416 254.880 801.310 6 1352 243.360 730.512 I loaded a case with a 180gr HAP seated at 1.555 COL, weighed it at 260.4 gr then filled it with water and weighed it at 281.4 gr for a case volume of 21 gr of H2O. I thought this might give me an idea where I might get to compressed loads if I were to go there but I find I have no idea Powder is lighter than water, is that correct?

May 29, 2018, 10:29 PM	#24
disseminator Senior Member Join Date: November 26, 2016 Location: Minnesota Posts: 960	While there IS a wide range of .40 caliber bullets available, how many of them are suitable for these velocities? To me that is still why I feel the 10mm struggles not to mention the fact that traditional magnums are still generally superior for most game taking applications IMO. While the 41 Magnum might not have the bullet selection of the other magnums, it has vastly more suitable hunting bullets than the 10mm does. That said, there is nothing wrong with a 10mm Mag if that is what trips your trigger.