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...bullet=40-180B

https://www.accuratemolds.com/bullet...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.



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.



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.



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...

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[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.

[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/...PC-500x500.JPG

http://arsenalmolds.com/bullet-molds...it=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.