10MM/.40Cal Bullet Design *180gr or 200gr"

[robertbank]

I am currently looking at two mold designs from Accurate Molds. I am trying ti balance practice vs serious use. My plan is to use 40cal brass for practice/playing IDPA and carry 10MM brass for serious work using my GP-100 revolver.

The only parameters at this point are the design has to be plain base. I have a Gas check maker from Pat Marlin and intend to apply GC's tp the base of the bullets most of the time. I will be sizing the bullets .401. I will be asking for a min diameter of .402 using WW alloy.

I am looking at two designs right now. the 40-215F and the 40-189B. Not sure if these are the best two and would appreciate any thoughts you guys might have.

https://www.accuratemolds.com/bullet_detail.php?bullet=40-180B

https://www.accuratemolds.com/bullet_detail.php?bullet=40-215F

Take Care

Bob

[popper]

I use a PB 165gr TC PB in 40 autoloader, @ 950 fps goes end to end through 150# hog. Don't know what you are protecting from but 220 in 10mm is 400#-ft vs 350 in the 40. Not a lot of gain.

[Taterhead]

I own or have owned 7 or 8 different 10mm mold profiles. My everyday is an LBT 401-175-TC. The Lee of similar moniker and the Lyman 401638 are also good (although the Lyman mold didn't work well for me). No doubt Accurste has something similar.

https://i.postimg.cc/Z51Wb5vM/20201227_200009.jpg

If long loading in 40 S&W cases, I like this 40-200F. Profile works well for that and also is great in 10mm cases.

https://i.postimg.cc/J44sJtRJ/20210824_103802.jpg

For wilderness carry, this LBT 402-200-WFN is awesome. I have the GC version too at 209 gr. Accurate makes a similar profile designed by our own fredj338: 40-195G.

https://i.postimg.cc/Gtq4XCMp/20210325_110748.jpg

Edited to add that I find a GC in 10mm to be unnecessary for the heavier bullets. Maybe if zipping 135 grainers at 1600+ fps, but not for 180-200+ gr. I load my 203 gr WFNs to 1250 fps and PB and PC is good-to-go.

[10sandxs]

I shoot the lee version of taterheads red ones. Always for plinking as I don't compete in run and gun (I shoot bullseye). I'm running them now in a recently acquired smith&wesson 610 in 40 and they are very accurate, at least out to 50' indoor range I typically shoot at. Haven't shot them in 10mm...

Sent from my SM-G973U using Tapatalk

[Taterhead]

More 10mm bullet pics. Here are some of the 10mm bullets I've cast.

Left to right

Accurate 40-200F
LBT 402-200-WFNGC
LBT 402-200-WFN
NOE 403-180-RF
Lee 401-175-TC
Lyman 401638

Feel free to inquire about my experiences with each.

All shot in Glocks mostly.
https://i.postimg.cc/TwngS1KK/20190206_205321.jpg

[robertbank]

Taterhead what I am looking for is a PB bullet. I have it in my head I might be able to solve the annoying leading I get in the first 1/8th" of rifling when using 40cal cases containing the Lyman 401638 in my 10MM GP-100 by using a PB GC on the PB Bullet. I have a large supply of 40 cases and would like to shoot 40 cal for practice and occasionally for playing IDPA SSR Division. For Wilderness Carry I think I am better served with a 200 gr bullet with a wide meplat in 10MM. That said there is the practical annoyance of budgets and how much I want to invest i this project. I am beginning to think a 180 to 195 gr bullet might well do both. Your thoughts?


Take Care

Bob

[Taterhead]

I don't shoot 10mm in a revolver, but can say that none of the bullets I referenced lead my autoloaders, no matter the base. Mine are all PC or HT.

Are your cylinder throat diameters > groove diameters?

[Burnt Fingers]

Taterhead what I am looking for is a PB bullet. I have it in my head I might be able to solve the annoying leading I get in the first 1/8th" of rifling when using 40cal cases containing the Lyman 401638 in my 10MM GP-100 by using a PB GC on the PB Bullet. I have a large supply of 40 cases and would like to shoot 40 cal for practice and occasionally for playing IDPA SSR Division. For Wilderness Carry I think I am better served with a 200 gr bullet with a wide meplat in 10MM. That said there is the practical annoyance of budgets and how much I want to invest i this project. I am beginning to think a 180 to 195 gr bullet might well do both. Your thoughts?


Take Care

Bob

If the same load doesn't lead using 10mm cases I think you have your answer.

The bullet is most likely tipping in the cylinder and entering the throat a bit crooked. That's going to cause leading no matter what.

[robertbank]

Taterhead Yes to cylinder size, just. Like you, I don't get leading in my 40cal pistol. I do get some in my 10MM resolver when using 40 cal brass Burnt Fingers who posted after you may have the explanation for the leading. I hope not but think he may be right. Once I decide on a FB bullet and cast some I won't know if my GC idea is going to work. I most certainly will post my results here. Right now the 40-315F would seem to be my best bet but I have not made up my mind. I will be back to you on some questions I have regarding your experiences with your bullets early next week.

Thanks to you and the others for your replies. Hope to get a fes more responses before I open the wallets up.

Take Care

bob

[FlyfishermanMike]

I have this one:

http://arsenalmolds.com/image/cache/catalog/403-200%20Gr%20WFN-PC-500x500.JPG

http://arsenalmolds.com/bullet-molds?product_id=161&limit=99999999999

Hard to beat the Lee 401-175-TC for plinking.

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[robertbank]

I did get some leading using the lead bullets in 10MM brass so I suspect Burnt Fingers may have explained the leading issue. I don't yet have a 200 grain mold to see whether it is just the bullet design that is the issue. Time will tell as I am pretty intent on getting a 200 gr mold for the revolver. One other thing to consider is the Ruger cylinder design. It has a very sharp ridge in the cylinder to allow 10MM brass to be used in the gun without the need for clips. Using the shorter 40 cal brass and the pbviosl;y shorter caertridge might result is some slight shaving of the bullet if it were to hit the ridge just right. Just a gues on my part. Any shaving of the bullet might result in some gas cutting.

I think I have more work to do before i decide either to live with a bit of leading in the revolver or just not use 40 cal brass. The story continues. Anyone have any further ideas feel free to jump in. I am not sure how many 10 MM revolver shooters are out there., I suspect not many.

Take Care

Bob

[JAC43]

Have you measured the cylinder throats on your GP100? What were they out of curiosity. Mine pass a.402" minus gauge easily.

[robertbank]

Have you measured the cylinder throats on your GP100? What were they out of curiosity. Mine pass a.402" minus gauge easily.

Mine allow a .401 sized bullet to pass through them with ease. I checked early as my .357 GP-100 had three undersized cylinder throats put of six. When I get my 200 gr 10MM bullet mold I will try loading the bullets long in 40 cases for practice. My idea will be to just get a portion of the side of the bullet resting beyond the step in the chamber.

Take Care

Bob

[Outpost75]

My Accurate designs used in 10mm Ruger Blackhawk are 40-182H, 40-220H and 40-224H. Also use the 40-182H in .38-40 and .40 S&W.