How about a 45 Super face-off?
4586 -vs- 625PC,
semi-auto -vs- revolver,
solid barrel -vs- cylinder gap,
4.25" -vs- 4.0" bbl.
Seems like a pretty close match, or does it?
The 4586 appears to have an edge because it has a slightly longer barrel & no barrel-cylinder gap, unlike the 625.
But the 4586 really only has a 3.29" barrel when you measure from the chamber's shoulder to the muzzle.
And the 625 actually has the barrel's full 4" plus 0.29" of cylinder throat travel, minus .007" of pesky pressure leaking B-C gap, for 4.283 inches of launch runway.
For the "fire in the hole" I'm handloading new Starline 45 Super brass filled with Power Pistol, plugged with Zero 185gr JHPs, seated out to a COAL of 1.220", & sparked by CCI-300 LPPs.
Starline's 45 Super brass is stronger & heavier than their 45 ACP brass (Empty Wt./gr: 87.4grs. -vs- 79.1grs.) and have slightly less capacity, because of the thicker web area, than their 45 ACP brass (volumetric capacity H²O wt./gr.: 26.8grs. -vs- 27.3grs.). External dimensions are the same for both cartridges.
When I first started loading for 45Super in my Colt Govt. Mk.IV, Series 70 I used Power Pistol & found anything over 11.6grs bulged the brass because of it's unsupported chamber, so 11.3grs became my standard max load.
Then Power Pistol became "unavailable" & I switched to LongShot using the same load. After the craze subsided I was able to switch back to Power Pistol & haven't used LongShot since. That's going to be a Part II test, now that I have some on-hand again.
My (6) incremental loads start off where the Sierra VI Reloading Manual stops at 9.9grs/P-P for it's top 185gr 45ACP revolver load, maxxing out at 1300fps from the 7.5" Freedom Arms revolver.
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WARNING:
All data in this thread is non-standard load data & should not be used in any firearm not in good condition or setup for 45 Super.
Do your own research & cross-referencing.
Use at your own risk!
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I'll test (6 of each per gun) at 10.1, 10.4, 10.7, 11.0, 11.3, & end with 11.6 grs (for a total of 72 rounds), since both guns have fully supported chambers, using my LabRadar chronograph.
Things stayed very close right until 11.6grs.
What happened to the 4586's velocity there?
Same thing I've had happened other times I pushed a semi-auto to it's upper limit, it ran out of recoil spring force & couldn't keep the barrel/slide locked up until the bullet left the barrel losing pressure & velocity.
My 4586 has a 20# Wolff hammer/mainspring (#27520), which is standard strength for it, and has a 20# Wolff recoil spring (#47920) instead of the factory strength 17# recoil spring.
Occasionally I've found that a Wolff recoil spring is physically too long for the intended pistol & when the slide is racked fully rearward it stops not on the frame abutment, like it should, but rather on the compressed recoil spring, which isn't good.
This 20# recoil spring exhibited this problem when I originally installed it & I had to cut off (1) full coil to stop it from bottoming out on itself & according to my in-the-gun test it exerted 19# of force when fully compressed in the 4586 after being shortened.
Wolff's next heavier recoil spring for the 4586 is a 22#er (#47922), which I also tried originally. It required having (2) coils cut off of it for proper fitment & afterwards it tested at 21# of force installed in the pistol.
I opted going with the 20# recoil spring at that time, which was still installed for this chrono test.
At this time, since I plan on sticking with 11.3grs/P-P as my max 45 Super load, I see no need to go to the heavier recoil spring.
Next stop, test the same loads using LongShot.
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PS: I did this test a week ago but it took some time compiling the data. Coincidentally, the new Handloader magazine, Issue #339, just hit my mailbox & it has a write-up / test / handloads on 45 Super on page 28 by Layne Simpson. First I've ever seen by a reputable magazine.
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Results using Zero 185gr JHP with a COAL @ 1.220"
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The winner (by one cut-off coil
) at an average of 1314mv & 709me, the 625PC.
A maximum velocity of 1324 fps was obtained twice from the final load in the 625PC.
Ext. Spread: 25.8 fps, & Std. Dev: 10.07 fps
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I started taking a temp/humidity gage with me as I always knew it was humid at the range because of their water trap to minimize lead dust but this is crazy! Most times it's just in the low to mid 90%.
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