40 cal bullets in 10mm shells

lunker · 10-14-2010, 07:20

I have been using 165grain Montana Gold FMJ bullets with various brass. I have been loading to the accepted 1.26 OAL. Visually though, the bullet seems as though it is set too far back in the case. I will be buying the 180 grain bullets next time I order. Has anyone else noticed this phenomenon? I will post a picture or two when I get home tonight.

Kegs · 10-14-2010, 12:48

-How long are your cases?

lunker · 10-14-2010, 12:52

Quote:

Originally Posted by Kegs

-How long are your cases?

I will measure a few when I get home, but they are standard Starline, Winchester, Georgia Arms brass. I discard brass that starts to exhibit signs of wear, so I don't think the length is out of spec.

Kegs · 10-14-2010, 13:02

Well if your brass is .982-.992" and your COAL is 1.26", it should look like pretty much any other 10mm cartridge out there.

Have you calibrated your caliper lately?

lunker · 10-14-2010, 13:35

Quote:

Originally Posted by Kegs

Well if your brass is .982-.992" and your COAL is 1.26", it should look like pretty much any other 10mm cartridge out there.

Have you calibrated your caliper lately?

I would think so too. I was wondering if the MG bullets I was using were more "configured" for 40S&W. Since the 40 has a different OAL, I was thinking that perhaps the design of this bullet was more designed for how much it would protrude from a 40S&W case than a 10mm case.

Kegs · 10-14-2010, 20:21

Quote:

Originally Posted by lunker

I would think so too. I was wondering if the MG bullets I was using were more "configured" for 40S&W. Since the 40 has a different OAL, I was thinking that perhaps the design of this bullet was more designed for how much it would protrude from a 40S&W case than a 10mm case.

That would be the first time I'd ever heard about it. I never had any problem with the appearance of the 155gr. xtps vs. 200 gr. ones - just more of the 200 in the case - but I haven't really used any other bullets other than the XTPs so far - though I have seen the M.G.s loaded in the double tap rounds I purchased a year ago - they didn't really look that much different - until you shot them of course.

lunker · 10-14-2010, 20:52

The picture below has a 165 grain Speer Lawmen round on the left and a 165 grain Montana Gold bullet in a 10mm case. You can see that they differ in how far they are set back in the case.

Kegs · 10-16-2010, 10:10

Quote:

Originally Posted by lunker

The picture below has a 165 grain Speer Lawmen round on the left and a 165 grain Montana Gold bullet in a 10mm case. You can see that they differ in how far they are set back in the case.

The .40 looks short and weak.

anomad · 10-16-2010, 15:35

I load Speer gold dot 180's in 40 and 10mm cases. I seat them out a tiny bit farther in .40, just to be on the safe side.

As long as there are no adverse pressure signs and your magazines feed reliably I'd say you're good to go.

_The_Shadow · 10-16-2010, 21:40

Bullets for the 10mm do seat deeper inside the casing of the 10mm as compared to the 40 Short & Weak. (exposed bullet that is) That being said that is how they get more powder space for the short 40S&W.

Compare your to factory 10mm and you will see you are at the correct cartridge lenght 1.250" to 1.260". People have loaded longer but that is their personal preference which fits their particular weapon. If they swap to another weapon it may not work the same...

lunker · 10-16-2010, 22:27

Quote:

Originally Posted by _The_Shadow

Bullets for the 10mm do seat deeper inside the casing of the 10mm as compared to the 40 Short & Weak. (exposed bullet that is) That being said that is how they get more powder space for the short 40S&W.

Compare your to factory 10mm and you will see you are at the correct cartridge lenght 1.250" to 1.260". People have loaded longer but that is their personal preference which fits their particular weapon. If they swap to another weapon it may not work the same...

Thanks Shadow. That is the missing piece. I really need to look at some factory 10mm ammo. At least I don't feel like. I might be screwing up my loads any more.

**texas 48** · 10-23-2010, 18:50

I have loaded 3000 MG in 10mm from 1.250 to 1.260 no issues. Here is some data on different 10mm bullets.
165 MG JHP .58 inches. 165 REM Golden Saber .57 Inches. 155 Hornady XTP .55 Inches. 150 Nosler JHP .53 Inches. 135 Nosler JHP .49nches. .40 is 10MM and vice versa

herdingcats · 10-29-2010, 11:24

The pic you posted looks fine to me. I've loaded TONS of MG 155gr and 180gr JHP into both 40S&W and 10mm. I've kept my OAL to spec and have not had any issues. MG makes great stuff in my book.

Unfortunately, I have not loaded the specific bullet you're referring to... the 165grain Montana Gold FMJ. So I have no info on that one.