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Posted: 4/29/2024 9:45:47 AM EDT
Link Posted: 4/29/2024 9:51:19 AM EDT
[#1]
Link Posted: 4/29/2024 10:22:22 AM EDT
[#2]
A taper crimp helps keep the bullet from setting back into the case when chambering in a semi-auto, it was never intended for a revolver.  The recoil of a revolver causes the opposite to happen.  This is why factory 9mm ammo tends to have issues in revolvers.  A roll crimp is the answer, but there aren't many jacketed bullets for the 9 that have a cannelure to roll into.  I had a Ruger convertible 357/9, but never did use the 9mm cylinder.  It just wasn't worth the hassle.
Link Posted: 4/29/2024 5:07:16 PM EDT
[#3]
I have literally shot untold 1000's of 45 ACP through 625's since the late 80's & "No" problem with a good taper crimp using swaged, hard cast lead, plated, jacketed, and now hi-tek coated hard cast bullets.  
And, none of that lee carbide factory crimp stuff either.  Dillon or Redding taper crimp dies.  

And, NEWS flash......most standard handgun dies come with a roll crimp style seater.  Hornady only makes the 9/40/45 sets with taper crimp and that has not been all that long.  Same for some of the RCBS handguns sets.  I have played with a S&W 986.  And, had no troubles with bullet jump.  

Some factory loaded ammo comes with cannalure in the case wall to help with bullet set back in some cases.  

But if there were a problem a compromise may well be the Redding profile crimp die.  Sort of a hybrid design.

Link Posted: 4/29/2024 5:45:32 PM EDT
[Last Edit: Trollslayer] [#4]
The way I understand it is this -

If the cartridge headspaces on the case mouth (45 ACP, 9mm Luger, etc), then it is supposed to be taper crimped.  A proper taper crimp leave the case mouth fully exposed.  Taper crimp minimizes bullet set back and aids in preventing OAL growth.

If it is a rimmed (or revolver) cartridge that headspaces off the rim, then it gets a roll crimp, preferably into a cannelure.
Link Posted: 4/30/2024 10:06:33 PM EDT
[#5]
Speer's old No. 11 Manual (think it was 11) had 9mm data that stated something to the following effect:  In a small case like 9x19mm, bullets that end uo seated deeper than specified can have dramatically higher pressures.  It was a significant number.    The warning was basically "ensure you taper crimp enough that bullets wont be seated deeper when they are fed from magazine into barrel (feed ramp contact)".

Based on that kind of scared advisory, I crimp a lot.  My routine is simple.  Load and crimp a few.  Load them in a magazine. Insert in firearm and retract slide.  Let slide slam home, chambering a round.  Eject the round.  Reload into the magazine a repeat again.  I'll feed a few rounds through the gun three times.  If three cycles does not change seating depth, my crimp is good.

No guarantees, but I have a suspicion more crimp would solve this revolver issue.
Link Posted: 5/1/2024 11:31:49 AM EDT
[#6]
No guarantees, but I have a suspicion more crimp would solve this revolver issue.
View Quote


Actually, a different crimp.  A roll crimp works far better than a taper crimp when it comes to bullet "pull".  Recoil causes the opposite of setback.
Link Posted: 5/1/2024 5:29:47 PM EDT
[#7]
https://revolverguy.com/ruger-9mm-lcr-field-report/

I came across another article on a Ruger 9mm revolver, this one is about the LCR.
I can't tell if the Farnam article is about one of the other models since Ruger has done this with the SP101 and the LCRx version, but all of these are short run offerings that are not very common.

I like my 45 ACP revolvers very much and considering the 230 grain projectile, I am not sure what is up with the examples we see in these 9mm articles.

In the labs, we can both measure the dynamics of the weapons, and we have "drop sleds" we use to create standardized shock tests for the ammo.
We would have needed to run tests of both the pistol and the ammo to have an opinion of the margin of safety that would mean something, but here we don't have a clue.

All I can say is I will bring a set of calipers with me the next time I play with the S&W 929 which is an N-Frame series 8-shot design that runs moon clips and is popular in ICORE competition circuits.
This S&W 929 weighs roughly 44 ounces and the Ruger LCRx weighs roughly 17.4 ounces, not to mention the inertial mass properties would be just as dramatically different.
Since I brought that up, the SP101 shows 25 ounces.
Could be that the LCRx puts that much more acceleration on the ammo, or it could be that some ammo is low quality with respect to neck tension, IDK.

Since the 9mm Luger is over 100 years old and the standards committee had to herd cats because there were so many versions and inputs from all over the world, my opinion is that Ruger should take on the problem of rating the ammo to determine the risk in their design and advise their customers what to avoid and what they recommend as well. It would be harder to force the ammo market to meet a new and more difficult standard requirement compared to sorting out the needs of their revolver design. But this is just my opinion.

I didn't turn on to the moon clip revolvers till later in life, and regretted waiting so long. I realize trends in guns and ammo change with generations, and these days revolvers are not for everyone.

If I go to the range with the S&W 929, I arrive with the ammo already on the moon clips and none of the brass hits the ground. If you shoot it, it just puts a smile on your face and many folks went out and got one after trying it.
It is a great teaching gun for rookies in my view. It has an excellent trigger, long sight radius, is very accurate, and very gentle for folks who are just learning recoil.
I will warn you these are not cheap and easy to find either, but worth the trouble. YMMV
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