"Factory Crimp Die"

[Pdvdh]

I would say yea. I didn't pull any of the 225s but the press pressure is very light.
Both dies felt about the same. I used my calipers to measure the dip.
I'm getting .308" at the hearing surface behind the crimp. And getting .307" at the crimp. The shiny copper reflects the light very well. So it looks worse than it is.

I pulled one of my .224 Vmax bullets and measured the indentation in the baring surface at the location of the crimp. I measure about .0022" reduced diameter at the crimp. Just for others general information. They shoot much better than no crimp... for what it's worth.

 

[Pdvdh]

Some of us should do a BC comparison at ,say 600 or 800 yards with a heavily crimped vs non crimped bullet. Just to say we did it.

I'm a bit OCD. I'll admit to weighing out 3,600 .223 casings and entering each individual weight in an Excel spreadsheet on my computer
But I won't admit to trying to measure a changed BC value for a bullet with a 0.002" indentation!

Messing with ya, but I feel certain you could file 0.002" off the tips - the most BC critical location on the bullet - and still not measure or detect any affect on BC value.

 

[Pdvdh]

Just crimped some 280 AI shells. Had to grind the LEE collet down 0.040" in length because I'm using Lapua 30-06 brass, which is 0.040" - 0.050" shorter case length than 280 brass.

Crimped 11-162gr Amax, and 6-160gr Accubonds. Could feel the extra resistance crimping the Accubonds. Thicker, stouter jackets on the Nosler bullets.

 

[orangediablo]

I've never felt comfortable crimping any bullet that doesn't have a cannelure. However, I recently tried the Lee FCD in my LR260 when doing a load development with 123 Amax and Varget. The results were great. My next loading I forgot to crimp again because I never do it in my regular loading steps. The groups were definitely worse.
I have put a ( PROPER ) Lee FC on a bullet and then pulled the bullet to see if there was any visible deformation, I couldn't tell at all by my eyes. I'm sure one could go overboard on a crimp by setting the die up wrong and deform a bullet but the die is pretty easy to set up correctly.

I'd say its worth a try.

I had pretty much the same result. Loaded and crimped a bunch with the Lee FCD, and did the same without a crimp (I don't turn necks or do anything with neck tension) and noticed a reduction in accuracy. Still fairly new to this world, but prefer a light crimp on a ll my rounds. I'm under the assumption crimping will give a more consistent tension than not crimping.

 

[fiftybmg]

Crimp is mainly for preventing setback of the unfired rounds, either in the mag or tube.

Single shot rifles don't need a crimp as there is no unfired round to be impacted [ compacted ] by the recoil.

 

[Pdvdh]

That's one purpose for the crimp on heavy recoiling rifles and revolvers.

That single cause doesn't explain why ammunition manufacturers crimp factory ammo with cartridges that don't generate recoil sufficient to set bullets back under recoil? Surely they know those cartridges will never set the bullets back in the case necks in the magazines under recoil force.

 

[WildRose]

I had pretty much the same result. Loaded and crimped a bunch with the Lee FCD, and did the same without a crimp (I don't turn necks or do anything with neck tension) and noticed a reduction in accuracy. Still fairly new to this world, but prefer a light crimp on a ll my rounds. I'm under the assumption crimping will give a more consistent tension than not crimping.

It's not just an assumption.

The more I mess with crimping bullets the more consistent my loads are all the way around.

 

[ButterBean]

I've tried it with several different types of bullets in three different calibers.

On those that don't have a cannelure or drive bands I'm using just a very gentle crimp so as to not damage the bullets by adjusting the crimp die to where I can just see that it has marked the brass.

It definitely seems to improve the consistency of my neck tension and tightened up my groups.

I arrived at this by comparing loads that were exactly the same other than one being crimped and the others not shooting three and four shot groups through the .260's, .300 RUM and 7mm STW.

Rose, I use the Lee F/C on everything load I and you know me well enough to take it from there, the one thing I will say that i found is the 25-06 responds to the F/C like no other, I have used it to fine tune a bunch of Two Bit 06's that folks said wouldnt shoot

 

[WildRose]

Rose, I use the Lee F/C on everything load I and you know me well enough to take it from there, the one thing I will say that i found is the 25-06 responds to the F/C like no other, I have used it to fine tune a bunch of Two Bit 06's that folks said wouldnt shoot

I was completely shocked at how big a difference it made with the .260. The more I use it on different calibers and types of bullets the more utility I see in doing so.

I pulled a bunch of bullets a few weeks ago and instead of resizing I just seated a new bullet and crimped it. No question about it, the neck tension was next to zero except for the rim right where I applied the crimp and they all shot exceptionally well.

 

[fiftybmg]

That single cause doesn't explain why ammunition manufacturers crimp factory ammo with cartridges that don't generate recoil sufficient to set bullets back under recoil? Surely they know those cartridges will never set the bullets back in the case necks in the magazines under recoil force.

In case the loaded rounds get dropped ?

The side effect of crimping is better powder burn. Not much, but enough to produce measurable effect in some cases. Powder burns better under pressure.

There will be reloaders who have recorded no benefit to crimping for their platform.

 

[RockyMtnMT]

In case the loaded rounds get dropped ?

The side effect of crimping is better powder burn. Not much, but enough to produce measurable effect in some cases. Powder burns better under pressure.

There will be reloaders who have recorded no benefit to crimping for their platform.

I agree with this. I have developed some great loads without a crimp. Not sure that a crimp would have helped or hurt, didn't try to know. So far, for me, I have not found it to hurt yet. If I were to guess, at some point I will find a better load without a crimp. I have not done enough to know but my guess is that in precision full custom rifle the crimp may not help. In that scenario I am thinking brass would need to also have perfect neck for uniform neck tension. I don't know about anybody else but I really don't like neck turning brass. If a simple crimp does what neck turning does, I'll take the crimp.

I still think it is kinda funny that crimping is a new thing for most. I've been loading for over 25 years and just started crimping for the first time this last year.

Steve

 

[Reloader222]

I use the Lee Factory Crimp Die on my 9mmP for my Beretta Pistol and 357M for my Marlin Rifle. Excellent invention it smooths thing up. Zero hick-ups!

 

[Deleted member 46119]

I now have a Lee F/C die to try out.

 

[Pdvdh]

There will be reloaders who have recorded no benefit to crimping for their platform.

There will also be reloaders that find crimping improves the precision of their current, carefully developed hand loaded ammo in their rifle. All for a whopping $10.

But neither statement, both being true and correct, provide meaningful value for the active or prospective reloader.

What provides value for me, is a $10 tool that substantially improves the precision of loads I've spent days, and sometimes weeks, developing.

In the substantial time I spent researching the use and effect of the LFC die, it improves precision more often than not, and it rarely degrades precision.

To further qualify my findings: The only reports I've read proclaiming degraded precision were from reloaders that had never crimped.

You can lead a horse to water, but they may not drink. I seem the fortunate one, as it's been decades since it ever mattered to me.