458 SOCOM and cast: fast or regular twist?

Elkins45

Active Member
I’m getting ready to buy a 458 SOCOM barrel and bolt from Tromix. My only use will be subsonic suppressed with heavy cast lead bullets. They offer the 10” barrel in both 1:10 and 1:14 twist. I’m wondering if slow heavy bullets might be better served by the faster barrel. Thoughts?
 

Ian

Notorious member
Honestly? Ask Tony. He had a good reason for offering the 10" ROT in the shorter barrels, I just don't remember exactly what it was. My Tromix 10.5"/14" ROT with suppressor and 495-grain Lee bullets shoots quite well to 100 yards, farthest I've tested it, nice round holes.
 
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fiver

Well-Known Member
I think 1-16 is the faster twist on the 450's.
IMO 1-10 would be for 550-700gr 900 fps type stuff.
 

RBHarter

West Central AR
Over there , there was a guy that had an adjustable mould that wanted to see real world how heavy a 45 cal 1-16 would go . I' dont remember the particular cartridge it may have been a 458 WM but I'm more inclined to think it was a 45-70 #1 , but he stopped at 900 gr because the "fun" in his scientific research had stopped around 750 gr . At 900 gr he still had round holes and all of them on an 8.5×11 at 100 yd . 1-32 goes away in 452 someplace around 330 gr depending heavily on nose shape and that shape being short . My Mountain Molds 453-350 makes 45° ovals but the Lee 457-340 @354 shot about 5" @ 50 yd and round holes . Ive shot a number of bullets in a Marlin 45-70 including a NOE version of a 458132 Postell down to whatever 12 gr of Unique does at an OAL of 2.455" which is slow probably 950-1000 fps . I believe that's a 1-20" , round holes 4" at 50 without strenuous target hold or load work more of a feasibly test ....I chickened out because of the long jump to the first band even paper patched to soak up some of that length .

A 300 gr Barnes TAC-X duplicated in cast with the HP cavity partially filled sans plastic tip is right at 400 gr a exact duplicate sans tip would be 384 + cast dia and nose fill . The RCBS 45-500 FN is scarce and that pointy 457-500 Lee didn't shoot well for me but in it's new home and PC it shot fine to 1500 fps .

The 458132 according to the Strelok calculator app with an MV of 1100 fps zeroed at 150 yd is 8" high at 100 , 8" low at 200 and hauls 1000 ftlb past 350 yd with just 7' of hold over . In case you had any inclination to go that way .

That's 4 yr of 45-70 , 45 Raptor , 45 Colts carbine rough and greens applied data in 1-16 , 1-20 , and 1-32 twist , dia .450 , 452 and .4575 finished , with bullets 300-535 gr .
 

Intel6

Active Member
I shoot a RRA upper with a 1-14" twist with a few different cast bullets. I regularly shoot a NOE 354 HTC bullet and a NOE 500 SPHTC bullet out of it with decent results for cast bullets with either a PC or HiTek coating. I was on the group buy for the NOE MOAB mould which casts a 600 gr solid or a 570 gr. HP and I could not get any acceptable results from it. I don't know if the the 1-10" would be better for the 500+ gr. bullets but I know they didn't shoot well in mine. I guess it depends on what bullet weight you plan on shooting?

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Ian

Notorious member
I don't know if the the 1-10" would be better for the 500+ gr. bullets but I know they didn't shoot well in mine.

Tony had a very good reason for sourcing the expensive 10" ROT barrels for the SBR versions, I think you discovered it. Like you, I have no problems with the 14" ROT up to 500 grains subsonic/suppressed, even with 10.5" barrel length.