Hornady 140gr .357 FTX in a .357 Sig?

H3LLC4T1 · December 18, 2023, 11:52 PM

Evening everyone. I purchased a Gen3 Glock 23 a few years ago and a barrel to convert it to .357 Sig. I hadn't had much luck with it, due to feed issues causing bullet setback. I just put the factory .40S&W barrel back in until I figured out what was causing the problem. While doing some research, I came to the conclusion that the problem was probably my mags, and I recently purchased a pair of new Glock 31 mags. The problem seems to have resolved itself (I hope), but .357 Sig seems pretty hard to get my hands locally, so instead of buying online, I would rather spend the money on bullets and reload my own.

I'm still fairly new to reloading .357 Sig, but I have reloaded a few. Mostly with Hornady 125gr .356 HAP JHP and Hodgedon CFE pistol. I like the idea of the Hornady Critical Defense, but not at $1.50/rd. I did manage to get my hands on 1 box of Hornady Custom 147gr bullets to load one of my mags and I contacted Hornady and was told they are not selling the FTX bullet they use in the critical defense/Duty rounds separately at this time. The only FTX bullet they do list in the .355-.357 range is the 140gr FTX bullet that they use in their .357 Mag LEVERevolution.

I tried doing a search prior to registering, but didn't really find an answer to my question. Has anyone successfully used this bullet in a .357 Sig case? I'm tempted to buy them anyway, simply to load .357 Mags for my Henry Big Boy or possibly 350 Legend rounds.

Thank you for the insight,
H3LLC4T1

labnoti · December 19, 2023, 12:18 AM

It's not the best idea for two reasons.

First, 357 SIG is based on 9mm projectiles which are 0.355" or possibly 0.356" whereas 357 Magnum uses 0.357" or 0.358" diameter projectiles. Putting a 0.357" projectile through a bore with dimensions suitable for 0.355" projectiles will create a lot of additional pressure. Take note that 350 Legend is also a .355" bore and not .357".

Second, the 140 grain FTX is an especially long projectile for 357 SIG. It is 140 grains which is considerably more massive than the 125 grain bullets typically used for 357 SIG. The FTX also has a long ogive that results in it seating more deeply into the case than shorter bullets. The 357 SIG case does not have the length to seat it without a lot of additional pressure. You will notice that even in 357 Magnum, FTX bullets typically call for less powder to avoid excess pressure due to the longer bullets seated more deeply.

Note that Hornady does not use an FTX bullet in 357 SIG Critical Duty/Defense. It is a Flexlock bullet. It is only 135 grains and the Flex Lock has the plastic tip down inside the hollowpoint and flush with the meplat. FTX have a long, soft, flexible, conical tip. The heavier bullet and conical tip would result in a bullet that is too long for 357 SIG.

ligonierbill · December 19, 2023, 07:09 AM

I'll offer my experience with a Glock 23 and a Lone Wolf 357 Sig barrel. I never had any feed issues using the Glock 40 S&W mags. This with a variety of bullets: Speer GD, Sierra TMJ and JHP, and commercial Federal and Speer GD (all 125s). I did find that the Glock ran consistently 100 fps slower than my Sig P226.

All these bullets, plus some Hornady 147s that I only ran in the Sig, are specified by their makers for 357 Sig. And yes, despite the marketing nomenclature, they're all 0.355. All a truncated cone profile.

rc · December 19, 2023, 09:34 AM

357 Sig is a fickle one. Bullet set back is a well known problem for the caliber due to the bottle neck case that requires the right shape bullets and just the right amount of neck tension. Cool round, but not for me personally due to the known problems with reloading. The classic 38 super or 9x23 are much better choices for reloading hot 9mm.

December 18, 2023, 11:52 PM	#1
H3LLC4T1 Junior Member Join Date: December 18, 2023 Posts: 1	Hornady 140gr .357 FTX in a .357 Sig? Evening everyone. I purchased a Gen3 Glock 23 a few years ago and a barrel to convert it to .357 Sig. I hadn't had much luck with it, due to feed issues causing bullet setback. I just put the factory .40S&W barrel back in until I figured out what was causing the problem. While doing some research, I came to the conclusion that the problem was probably my mags, and I recently purchased a pair of new Glock 31 mags. The problem seems to have resolved itself (I hope), but .357 Sig seems pretty hard to get my hands locally, so instead of buying online, I would rather spend the money on bullets and reload my own. I'm still fairly new to reloading .357 Sig, but I have reloaded a few. Mostly with Hornady 125gr .356 HAP JHP and Hodgedon CFE pistol. I like the idea of the Hornady Critical Defense, but not at $1.50/rd. I did manage to get my hands on 1 box of Hornady Custom 147gr bullets to load one of my mags and I contacted Hornady and was told they are not selling the FTX bullet they use in the critical defense/Duty rounds separately at this time. The only FTX bullet they do list in the .355-.357 range is the 140gr FTX bullet that they use in their .357 Mag LEVERevolution. I tried doing a search prior to registering, but didn't really find an answer to my question. Has anyone successfully used this bullet in a .357 Sig case? I'm tempted to buy them anyway, simply to load .357 Mags for my Henry Big Boy or possibly 350 Legend rounds. Thank you for the insight, H3LLC4T1

December 19, 2023, 12:18 AM	#2
labnoti Senior Member Join Date: April 2, 2018 Posts: 252	It's not the best idea for two reasons. First, 357 SIG is based on 9mm projectiles which are 0.355" or possibly 0.356" whereas 357 Magnum uses 0.357" or 0.358" diameter projectiles. Putting a 0.357" projectile through a bore with dimensions suitable for 0.355" projectiles will create a lot of additional pressure. Take note that 350 Legend is also a .355" bore and not .357". Second, the 140 grain FTX is an especially long projectile for 357 SIG. It is 140 grains which is considerably more massive than the 125 grain bullets typically used for 357 SIG. The FTX also has a long ogive that results in it seating more deeply into the case than shorter bullets. The 357 SIG case does not have the length to seat it without a lot of additional pressure. You will notice that even in 357 Magnum, FTX bullets typically call for less powder to avoid excess pressure due to the longer bullets seated more deeply. Note that Hornady does not use an FTX bullet in 357 SIG Critical Duty/Defense. It is a Flexlock bullet. It is only 135 grains and the Flex Lock has the plastic tip down inside the hollowpoint and flush with the meplat. FTX have a long, soft, flexible, conical tip. The heavier bullet and conical tip would result in a bullet that is too long for 357 SIG.

December 19, 2023, 07:09 AM	#3
ligonierbill Senior Member Join Date: May 20, 2007 Posts: 2,460	I'll offer my experience with a Glock 23 and a Lone Wolf 357 Sig barrel. I never had any feed issues using the Glock 40 S&W mags. This with a variety of bullets: Speer GD, Sierra TMJ and JHP, and commercial Federal and Speer GD (all 125s). I did find that the Glock ran consistently 100 fps slower than my Sig P226. All these bullets, plus some Hornady 147s that I only ran in the Sig, are specified by their makers for 357 Sig. And yes, despite the marketing nomenclature, they're all 0.355. All a truncated cone profile.

December 19, 2023, 09:34 AM	#4
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,775	357 Sig is a fickle one. Bullet set back is a well known problem for the caliber due to the bottle neck case that requires the right shape bullets and just the right amount of neck tension. Cool round, but not for me personally due to the known problems with reloading. The classic 38 super or 9x23 are much better choices for reloading hot 9mm.