Crimp as a final step.

[Ben]

Maybe it is all in my head, but I like to place a crimp ( on rounds that are appropriate for a crimp ) as a separate step and a final step. Other reloaders seat the bullet AND place a crimp on the round all in one step.

I'll throw the charge, seat the bullet ( without a crimp ) to the appropriate OAL and then move to the last die and place my crimp on the round.

This is how I have my 45/70 dies set up now.
The Lee Turret Press with 4 holes makes this easy and convenient.

 

[Brad]

I far prefer to crimp as a separate step. I really like Redding profile crimp dies for handguns, as long as you are using a "normalish" size bullet. The rifle Lee factory crimp dies do well for me as well.

I can't tell you the last time I seated and crimped in a single step.

 

[Ian]

If you spec a shallow crimp groove when you order an Accurate mould, and use a good RCBS roll crimp die, it's possible to to a good job seating/crimping low-pressure revolver cartridges in one step. For +P loads, I still prefer one step. Taper-crimping practically requires a separate step, such as with .45 ACP (my way, anyway). For .44 Magnum long-range loads, I treat them like rifle ammo and so a very careful and firm roll crimp as a separate step.

 

[Rick]

Like Brad I can't even remember the last round I seated and crimped in a single step, been decades.

 

[gman]

I too crimp as a final step.

 

[KHornet]

Depends on the ctg. For handgun ctgs, I seat separately. For some rifle
ctgs with cast, I will put a tat of crimp only on ctgs like 30-30 when seating.

 

[JonB]

Yes, I prefer to seat & crimp in separate steps and do so, most of the time.
BUT,
I have an old Lee econo turret, (3 holer) and I load 9 and 45 with it...seat and crimp in same step...it seems ok for plinking semi-auto pistol ammo.

 

[RicinYakima]

I never crimp handgun ammo except full-house 357 Magnum loads and over book pressure 32/20 loads (for the S&W Target and Browning M92) loaded with 2400. Then I use a Redding profile crimp in a separate step. I do crimp bullets, jacketed in the .275 Rigby I made on a 1903 Springfield and the 450 Watts as recoil will push bullets in the magazine back into the case.

How do I get away with this you ask? Fast powders, large diameter bullets and low recoil loads. When I gave up shooting the Ruger 44 magnums, I found out the crimp didn't do anything for me but make group sizes bigger, so just left out that step. Now I just set the dies with straighten cases or just the tiniest hint of inward curl. Works for me and everyone I shoot with, as none of us put a crimp in as heavy as Ben shows.

 

[Chris]

I always crimp as a separate step. It's a principle for me.

 

[Ben]

I only loaded 5 rounds for the " photo shoot ".
I think I'll back off that crimp die a bit.

Ben

 

[RicinYakima]

Why would you crimp revolvers at all, unless you: are shooting high recoil revolvers that would pull bullets or are burning too slow of powder and the bullets are exiting the cylinder before it all burns? I'm not being funny I just don't understand, but why? it seems like such a rarely needed technique?

The 45 Auto Rim case on the right is the most I have ever crimped.

 

[Chris]

To expand the concept a bit: for tubular mag rifle shooters the crimp is there to prevent bullet setback. We all know that, just pointing out that crimps aren't just for pistols and revolvers. Real heavy rifle shooters need to crimp to prevent setback in the magazine.

Question is what kind of crimp, how heavy, and when do we apply it.

 

[RicinYakima]

If you don't have brass that is within a couple of thousandths in equal length, as a separate step.
On the 450 Watts, nothing beats the Lee FCD used solidly into the cannelure in the jacket.
Lever guns with smokeless powder loads, the thickness of the brass down into the groove measured with a micrometer. With black powder loads, enough to keep the bullet from popping out the front from powder compression, about twice the smokeless crimp.
JMHO of course, guys.

 

[Rick]

I've posted this several times but it seems valid for this thread. Even in top end revolver loads it is not the crimp that makes the load work, crimp is a precaution against bullet movement prior to powder ignition/combustion. It is the uniformity of the neck tension that does this even with slow powders, perhaps especially with slow powders. With the slow powders heavy for caliber bullets are a big plus.

Crimp Tests - THIS IS A FREEDOM ARMS ONLY LOAD

FA 357 Mag 9”
RCBS 180 GC Silhouette @ 192 gr. (WW HT @ 18 BHN)

16.0 gr. H-110
Winchester brass
CCI 550 primer
Temp 70 Humidity 38%

All chrono tests 10 shots

1> My normal profile crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1518
S.D. 9

2> Roll crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1520
S.D. 9

3> No crimp, second firing of WW brass, Carbide die sized, very slight bell
E.S. 30
A.V. 1528
S.D. 9

4> Light profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1532
S.D. 8

5> My normal profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1536
S.D. 8
.

 

[35 shooter]

In the few instances i've used a crimp, it's in a seperate operation.

 

[RicinYakima]

Rick, the numbers are really consistent! Did you shoot them on paper and measure the results?

 

[Rick]

Yep, that is an extremely accurate load. The purpose though is the consistency of the numbers across 5 different tests with 5 different crimps ranging from heavy to none. I used this load/revolver in long range silhouette revolver class.

 

[358156 hp]

One thing I've noticed about handgun crimping dies is the variance of the actual profile of the roll crimp. Some dies roll the edge of the case mouth in a rounded fashion to various degrees, and some look more like really hard taper crimps, almost 45 degrees in appearance. I preferred the later style with Keith design bullets for example, the case mouth would lay against the bevel in the crimping groove, and the crimp seemed more uniform. The actual roll type crimp seemed more practical with bullet designs that simply had a rounded groove in the bullet for crimping, sort of like a really small lube groove. I never did get around to testing the different crimp profiles to see if there was any practical difference in performance and grouping. My free time was pretty short back then, and most of my range time was limited to about an hour or so a week. Then even that went away, and I eventually sold off my big revolvers.

 

[oscarflytyer]

I crimp ALL my rifle loads (that I crimp) separately. For 45 ACP, seat/taper one op. For my big bore handguns, I seat/crimp in one op. Done that for years. Started sep op crimping rifle when I started shooting cast AND after crushing a few 35 Rem shoulders.

 

[Ian]

Ric, the reason I crimp revolver cartridges is so they feed better in their companion leverguns. I use the absolute minimum I can get by with, just barely turn the mouth inward past straight. One thing I simply detest is the bullet designs that have a crimp groove that is deeper and longer than even a lube groove needs to be. Like Rick has demonstrated, the case tension on the bullet should be doing the work, crimp is more or less just lipstick but for a few exceptions.