Hunters Supply makes a cast canelured 125gr bullet for the 357sig. Although the loaded cartridge exceeds SAAMI max o.a.l., I am thus far pleased with the performance.
Long have I been troubled to find a satisfactory inexpensive bullet for my Glock 31. Two issues haunt the search. The bottleneck 357sig case has a small neck area to grip the bullet. The satisfactory bullet profile is truncated-cone-on-cylinder. Round nose bullets are not held securely.
Glock pistols barrels have polygonal rifling. Word on the street is polygonal rifling does not grip and seal well with lead bullets; copper jacketed, or at least plated, should be used for accuracy and to avoid leading the barrel.
I early on found the Speer #4362, designed and sold for the 357sig, works well. But it aint cheap. I tried plated bullets from the usual sources but found them wanting in accuracy; ok for 9mm, but not at 357sig speeds.
While looking over bullets on Midway's web catalog a few months back I noticed a 125gr cast flat point bullet with canelure, listed for 9mm and 357sig.
CANELURE? Not seen a canelured 9mm/357sig bullet before. That would need a roll crimp die.
I chucked a blank 357sig case in the press and mashed it with the RCBS 357sig seat/crimp die. Sure looks like the RCBS die puts in a roll crimp.
What about HEAD SPACING? Word on the street is the 357sig headspaces on the case mouth, like other auto pistol cartridges. I had long believed however that it headspaced on the bottleneck shoulder like rifle cartridges.
I sacrificed an empty 9mm case, and milled it down to where it seated in the 357sig barrel, stopping on the case mouth, with the case head flush with the barrel face. The case length measured 0.720. That would be the depth to which a 357sig case would also seat, if it seated on the case mouth.
I took an empty 357sig case, 0.857" long, and slipped it into the barrel. If it seated on the case mouth, then the case head should be (0.857 - 0.720 = ) 0.137" above the barrel face. The distance measured 0.155".
The 357sig case seated on the bottleneck shoulder, leaving 0.018" open in front of the case mouth.
I ordered some of the Hunters Supply 357sig bullets.
First off I seated one in an empty case to check the C.O.A.L. - something which had eliminated other promising looking bullets. Crimped at the canelure, C.O.A.L. measured 1.155"; well beyond the SAAMI 1.140" limit.
OK, too long according to spec, but it still might work.
I loaded a couple of dozen rounds with 10.0gr of BlueDot (my 357sig powder of choice for three reasons: it fills the case and thereby ameliorates the bullet set-back issue; it gives top-end velocity, and after all if y'r not after top end velocity then why not just go with 9mm; and it gives a whooping long blue flame).
Took them out to test.
..feeding was fine; over-spec cartridge length seemed not to be a problem.
..average velocity 1360 fps, standard deviation 26; about what expected; quite satisfactory
..too windy for good test of accuracy, but certainly promising; 2.5 inches at 10 yards, hand held standing; excepting one flyer
..no noticeable leading in the barrel.
I think I'll back off the powder a bit, looking to stay close to but below 1300 fps; I am happy with the bullet.
Long have I been troubled to find a satisfactory inexpensive bullet for my Glock 31. Two issues haunt the search. The bottleneck 357sig case has a small neck area to grip the bullet. The satisfactory bullet profile is truncated-cone-on-cylinder. Round nose bullets are not held securely.
Glock pistols barrels have polygonal rifling. Word on the street is polygonal rifling does not grip and seal well with lead bullets; copper jacketed, or at least plated, should be used for accuracy and to avoid leading the barrel.
I early on found the Speer #4362, designed and sold for the 357sig, works well. But it aint cheap. I tried plated bullets from the usual sources but found them wanting in accuracy; ok for 9mm, but not at 357sig speeds.
While looking over bullets on Midway's web catalog a few months back I noticed a 125gr cast flat point bullet with canelure, listed for 9mm and 357sig.
CANELURE? Not seen a canelured 9mm/357sig bullet before. That would need a roll crimp die.
I chucked a blank 357sig case in the press and mashed it with the RCBS 357sig seat/crimp die. Sure looks like the RCBS die puts in a roll crimp.
What about HEAD SPACING? Word on the street is the 357sig headspaces on the case mouth, like other auto pistol cartridges. I had long believed however that it headspaced on the bottleneck shoulder like rifle cartridges.
I sacrificed an empty 9mm case, and milled it down to where it seated in the 357sig barrel, stopping on the case mouth, with the case head flush with the barrel face. The case length measured 0.720. That would be the depth to which a 357sig case would also seat, if it seated on the case mouth.
I took an empty 357sig case, 0.857" long, and slipped it into the barrel. If it seated on the case mouth, then the case head should be (0.857 - 0.720 = ) 0.137" above the barrel face. The distance measured 0.155".
The 357sig case seated on the bottleneck shoulder, leaving 0.018" open in front of the case mouth.
I ordered some of the Hunters Supply 357sig bullets.
First off I seated one in an empty case to check the C.O.A.L. - something which had eliminated other promising looking bullets. Crimped at the canelure, C.O.A.L. measured 1.155"; well beyond the SAAMI 1.140" limit.
OK, too long according to spec, but it still might work.
I loaded a couple of dozen rounds with 10.0gr of BlueDot (my 357sig powder of choice for three reasons: it fills the case and thereby ameliorates the bullet set-back issue; it gives top-end velocity, and after all if y'r not after top end velocity then why not just go with 9mm; and it gives a whooping long blue flame).
Took them out to test.
..feeding was fine; over-spec cartridge length seemed not to be a problem.
..average velocity 1360 fps, standard deviation 26; about what expected; quite satisfactory
..too windy for good test of accuracy, but certainly promising; 2.5 inches at 10 yards, hand held standing; excepting one flyer
..no noticeable leading in the barrel.
I think I'll back off the powder a bit, looking to stay close to but below 1300 fps; I am happy with the bullet.
