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Other Ammunition Calibers => Factory Ammo pull-downs => Topic started by: The_Shadow on March 28 2013 01:46:45 PM MDT

Title: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: The_Shadow on March 28 2013 01:46:45 PM MDT
Cartridge is from Ammo Manufacture: Underwood 125gr Bonded FMJ
Ballistics Information: 357 SIG
Muzzle Velocity: 1475 fps
Muzzle Energy: 603 ft. lbs
Brass Make/Headstamp: Star Line-Brass
Bullet Make/Weight/Construction/Info; Length 0.5400"/Dia. 0.3555":
125gr. JHP Actual weight 125.6 grains / 124.2 grains / 124.6 grains
C.O.A.L.: 1.1240" / 1.1235" / 1.1330"
Primer: Brass color
Case: Diameter 0.4220" all
Crimp Diameter 0.3785" / 0.3790" / 0.3790" crimp medium
Length 0.8600" / 0.8610" / 0.8600"
Powder Description/Positive ID/Type/ LongShot
Charge Weight:     9.8 grains / 10.0 grains / 10.0 grains

(https://s20.postimg.cc/9awzw9ai3/IMG_0670_zpsf56597e6.jpg)

(https://s20.postimg.cc/o6vj3utml/IMG_0672_zps1f921696.jpg)

(https://s20.postimg.cc/x1wdedq4t/IMG_0674_zps8bdd8117.jpg)

(https://s20.postimg.cc/gqw9i2lct/IMG_0675_zps34425bf6.jpg)

(https://s20.postimg.cc/ygxy346nh/IMG_0676_zps0868f5b1.jpg)

(https://s20.postimg.cc/4c9hhr9a5/IMG_0677_zps754db5c9.jpg)

Hodgdon data shows 124gr Hdy XTP using 9.3 grains LongShot @ 1429 fps 37,900 psi (inside MAP)
Max average pressure for the 357Sig is 40,000psi
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: Intercooler on March 28 2013 02:03:40 PM MDT
LongShot goes a long ways  ;D
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: The_Shadow on March 28 2013 02:03:40 PM MDT
In the last picture one cartridge was damaged by something putting a dent into the casing...even though Underwood's ammo is over the book listed data of Hodgdon, I don't think that alone was the cause for the KA-Boom.
I still think the incident was related to bullet set back, which in turn caused a sever pressure spike, that resulted in the catastrophic failure of the gun!
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: Intercooler on March 28 2013 02:20:06 PM MDT
This is the ammo from the blown up Glock? The one pictured looks like it has been chambered or something in a bad way. Mark on the front, dent in the middle and marks on the headstamp.
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: The_Shadow on March 28 2013 10:36:51 PM MDT
BTW- a review of my notes shows that Double Tap was using 10.0 grains of LongShot under the 125 Speer Gold Dots Loaded in the 9x25Dillon, these ran 1525-1475 fps from my S&W1006 5" conversion :o
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: REDLINE on March 31 2013 04:26:00 PM MDT
Interesting.
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: The_Shadow on March 31 2013 04:48:51 PM MDT
BTW the SwampFox 40S&W Ammo 165gr GDHP loading that blew-up another Glock 29 with a 40S&W conversion barrel, was also loaded with 10.0 grains LongShot powder, this being a sever case blowout.
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: REDLINE on March 31 2013 05:19:35 PM MDT
Wow.  Wish we knew what pressure those were loaded to.
Title: Re: Underwood 357Sig 125gr Bonded FMJ pull-down
Post by: Pctechdude on August 13 2015 11:15:23 PM MDT
Oddly enough, I've loaded plenty of 357 Sig. I've always used AA#9 and 800-x. With a Speer gold dot 125gr bullet, and 10gr 800-x it's compressed. Virtually eliminates set back and achieves 1450fps from a 4" barrel without going over on pressure.
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