testtest

Took a Political Break - Range Trip w/Glock 27.5 with KKM .357 Sig Conversion Match Barrel

Lab4Us

Lab4Us

Master Class
Those that read my posts over at Glock know I’m a big proponent of .357 Sig caliber. Something about the “oomph” of sending those rounds down range! Anyway, I had previously picked up al conversion barrel for a Glock 23.5 MOS and loved everything about it. Figured what the heck, I’ll try it in my G27.5. The advantage for both of these is the slide is significantly more stout than the G32.4 and G33.4 slides.

I posted my range report here if you’re interested. https://www.glocktalk.com/threads/g27-5-357-sig-conversion-range-trip-and-a-question.2010197/

The question is why the Freedom Munitions X-Def HP 124 +P ammo was shooting 4-6” + high compared to the Speer 125g TMJ and Golden Saber 125g, both of which hit at POA (my shooting skills notwithstanding).

Any you slice it, range time beats political discussion time by leaps and bounds!
 
I don't have any compacts or smaller (excluding the 4" m/p 10mm) so not familiar with slide weights and dimensions. I love the 357sig round compared to +p and +p+. I have a p226 and g31 gen4 and converted a 4.25" m2 40s/w to 357sig. What was required is increasing the spring pressure even when using a comp.
 

Attachments

  • 20240803_013523.jpg
    20240803_013523.jpg
    1.2 MB · Views: 52
  • 20240803_013340.jpg
    20240803_013340.jpg
    1.3 MB · Views: 47
  • 20240803_013235.jpg
    20240803_013235.jpg
    1.4 MB · Views: 47
Last edited:
Lab Us said:
Those that read my posts over at Glock know I’m a big proponent of .357 Sig caliber. Something about the “oomph” of sending those rounds down range! Anyway, I had previously picked up al conversion barrel for a Glock 23.5 MOS and loved everything about it. Figured what the heck, I’ll try it in my G27.5. The advantage for both of these is the slide is significantly more stout than the G32.4 and G33.4 slides.

I posted my range report here if you’re interested. https://www.glocktalk.com/threads/g27-5-357-sig-conversion-range-trip-and-a-question.2010197/

The question is why the Freedom Munitions X-Def HP 124 +P ammo was shooting 4-6” + high compared to the Speer 125g TMJ and Golden Saber 125g, both of which hit at POA (my shooting skills notwithstanding).

Any you slice it, range time beats political discussion time by leaps and bounds!
Click to expand...
I am not a fan of the .357Sig, but when I was still working at my sheriff dept, the chief had G32 in it, he really liked it a lot, I did a bunch of upgrades he wanted, I was still at that time a Glock Armorer
 
Did you chronograph them in your gun ? What are the respective advertised velocities?

At first glance , it would point to greater muzzle rise while the projectile is still in the bbl . Or significantly Different pressure curve , giving Different slide acceleration, giving more "snappy " muzzle flip .

Or your shooting .

Or just one of those unexplained freak things to tell your gun buddies .
 
Biggfoot44 said:
Did you chronograph them in your gun ? What are the respective advertised velocities?

At first glance , it would point to greater muzzle rise while the projectile is still in the bbl . Or significantly Different pressure curve , giving Different slide acceleration, giving more "snappy " muzzle flip .

Or your shooting .

Or just one of those unexplained freak things to tell your gun buddies .
Click to expand...
If this was in answer to my OP, the advertised velocities were 1325 and 1350, which is why I posted I didn’t think 25 fps at muzzle would make such a difference. And I really doubt I forgot all fundamentals for 50 rounds, since the 100 before and the 50 after were centered.

Negative on the chronograph, don’t own one. Maybe pressure curve to muzzle rise 🤷‍♂️, it’s just the first time in 10s of thousands of rounds in dozens of different handguns I’ve ever seen such a difference just by using different branded ammunition. And the high shooting ammo was +P, so maybe you’ve nailed it. Just know I won’t be using that ammo in this gun since all other ammo in all other weights/bullet types hit POA.

Thanks for your thoughts.
 
First Follow up thought :

The actual velocities, from your gun , with that bbl length , with the conditions on that day , varied by a lot more than 25fps .

Usable and useful chronograph start at under $100 . Once you have one , you'll kick yourself for not getting one years sooner .


OR , you have a cool story for your gun buddies over hot coffee / cold beverages .
 
Also remember that the .357 Sig is a bottle neck cartridge. With the chamber being so big in relation to the bullet size, it almost HAS to feed. I think the recoil and blast is much less than a 125 grain .357 Magnum load; semi auto probably helps that. Frequently in the winter where it is easier to hide a larger platform I reach for my Commander size Sig. I love the Ed Brown developed round butt and the checkering on the front strap. Personal preference, I wish it had finer cocking serrations. These wide ones remind me of a Philippine born 1911 and don't look right to me. But the sights and the trigger won me over. I like this a lot...just wish it looked like a Garrison with a round butt and checkered front strap!
 
You must log in or register to reply here.
Back
Top