Crimping coated or plated bullets

[Captaingyro]

This thread:

http://www.thehighroad.org/showthread.php?t=796964&highlight=crimp

got me wondering: how much roll crimp can you use on coated (or plated) bullets before the curled-in edges of the case mouth start to affect the coating. Is it possible that the coating will be partially or totally stripped off as the bullet exits the case? I realize that this is a difficult question to test because it involves recovering bullets, but I'm wondering if anyone has ever experimented along these lines?

 

[340PD]

They certainly can be crimped, but rupturing the plating is probably not a good thing. I use a taper crimp die on all my plated bullets and have never had any problems including .357 mag. If there is a crimping grove on my coated bullets I very lightly apply the crimp.

I love slow reloading so I am just using a 50 year old single stage press so I have four steps to a round.

 

[tcj]

I use coated bullets exclusively now and only taper crimp lightly on 9, 45, etc.

On my 357's I use a coated bullet with a cannelure that I roll crimp into.

As long as you don't cut the coating (light impression is fine) it works great.

FYI I use the blue bullets for all of my taper crimp bullets and bayou for the cannelure ones only because blue doen't make one with a groove.

They all work well - I just find less odor while shooting with the blues vs the hytek coated bullets.

 

[Rule3]

For the OP

Revolver or Semi Auto.???

Hi Tech coated is pretty amazing stuff. Crimp as you normal do. Take a bullet and smash it with a hammer and see if it comes off. It doesn't. They are regular lead bullets underneath.

Plated bullets, can be taper crimped and very light roll crimp but if the do not have a cannelure then pretty much all you can do is neck tension and taper crimp. I do not use them so can't really say more.

 

[gonoles_1980]

I use a tapered crimp on both my 357 and 44 mag CP bullets. I was using a roll on the 44 map until, a little piece of the copper plating was left behind.

 

[joem1945]

I only crimp enough to remove the bell unless they have a crimping groove and I'm loading magnum calibers.

 

[mdi]

I too taper crimp plated and coated/PCed bullets that have no crimp grooves. For my home PCed bullets, all have a crimp groove that I roll crimp into...

 

[Walkalong]

The roll crimp I am using on the coated 158 SWCs in full power .357 loads doesn't seem to harm anything accuracy wise. That is with two different makers. Both are HiTek coated.

For a Power Bond plated 125 in medium to high level .357 I used a hard taper crimp. No roll crimp for plated.

 

[PO2Hammer]

I use taper crimp for plated and coated. With plated 158 grain FP's with no cannelure, I taper crimp into the side of the bullet, with coated 125 grain RN bullets I seat them deep enough so that I can taper crimp on the nose.
I used to use a profile crimp on plated, that worked too.

 

[Captaingyro]

The original question specifically said "roll crimp", and thank you to all who addressed that. I am specifically curious about bullets that have a crimp groove or cannelure, because those bullets allow a crimp to close the case mouth down to smaller than bullet diameter.

The concern is that, as the bullet exits the case mouth, the crimped edge will be scraping along the length of the bullet, potentially damaging the coating (or copper plating).

Walkalong, thanks for the incredible pics. I'm doing pretty much what you're doing with plated .357's (X-tremes in my case), but the fact that the crimp brings the case mouth down to less-than-caliber diameter is what I'm concerned about. I do wonder if we're damaging the plating on firing, but I can't figure out a way to prove it one way or the other. (Obviously your accuracy isn't suffering).

 

[Rule3]

The original question specifically said "roll crimp", and thank you to all who addressed that. I am specifically curious about bullets that have a crimp groove or cannelure, because those bullets allow a crimp to close the case mouth down to smaller than bullet diameter.

The concern is that, as the bullet exits the case mouth, the crimped edge will be scraping along the length of the bullet, potentially damaging the coating (or copper plating).

Walkalong, thanks for the incredible pics. I'm doing pretty much what you're doing with plated .357's (X-tremes in my case), but the fact that the crimp brings the case mouth down to less-than-caliber diameter is what I'm concerned about. I do wonder if we're damaging the plating on firing, but I can't figure out a way to prove it one way or the other. (Obviously your accuracy isn't suffering).

You asked about two different kinds of bullets. Coated and Plated
So there are different answers.

Hi Tech coated can be crimped just like regular lead it is not going to come off.

Plated bullets are soft inside and plating can be really thin or some are a bit thicker. If it has a cannelure it can be crimped lightly so not to break through.

That is pretty much it.

 

[Rule3]

Here is a picture of a Bayou Bullet 9mm bullet smashed with a hammer.

Do you think crimping is going to hurt it??

I also torched one with a propane torch and the lead melted inside but the coating remained until a pin hole opened and the lead flowed out!

 

[RealGun]

The concern is that, as the bullet exits the case mouth, the crimped edge will be scraping along the length of the bullet, potentially damaging the coating (or copper plating).

I don't think you accounted for the case expanding to the chamber dimensions under pressure, readily releasing the bullet. In any case, if I was going to routinely use plated bullets in a revolver cartridge (or the FMJ with no crimp groove), I would buy a taper crimp die. That is not to say that a light crimp before it rolls would nor be sufficient, actually just removing any expansion and belling. I would think a taper crimp would snug up better, but I don't know.

 

[Walkalong]

I don't think you accounted for the case expanding to the chamber dimensions under pressure, readily releasing the bullet

Agreed

 

[Captaingyro]

Rule 3...good demo on the hardness of Hi Tek. I never woulda' thunkit. I feel better about roll-crimping coated revolver bullets now.

As far as plated bullets go, I'm still kind of wondering. I'm sure the case mouth blows open under pressure...I've never seen a roll crimp survive firing...but I'm just not sure about the timing. I can imagine the crimp scraping off some of the plating before the gas (which is behind the bullet in the case) gets to it. In other words, is the harm done by the time the gas forces the crimp to open up? Hard to tell.

 

[Rule3]

Rule 3...good demo on the hardness of Hi Tek. I never woulda' thunkit. I feel better about roll-crimping coated revolver bullets now.

As far as plated bullets go, I'm still kind of wondering. I'm sure the case mouth blows open under pressure...I've never seen a roll crimp survive firing...but I'm just not sure about the timing. I can imagine the crimp scraping off some of the plating before the gas (which is behind the bullet in the case) gets to it. In other words, is the harm done by the time the gas forces the crimp to open up? Hard to tell.

Anytime, I guess I should have grabbed a 158 gr 38.357 bullet But it is the same. I actually smashed it on the nose first made it a flat nose and nothing came off and then hit is several times to flatten it.

Needless to say I do not use plated bullets, have not for a long time.

They used to be a bargain but I can buy FMJ 9mm for almost the same price so why bother with them?

 

[Havok7416]

Here are some bullets that I shot for a test awhile back (posted here on THR).
While these were taper crimped and you did ask about roll, it should give you a decent idea on the durability of the coating. Also with the coating it's the back of the bullet that makes the most difference. I will go more in depth when I have more than just a few minutes.