Is this too much crimp?

[gregshin]

Using .355 147gr Extreme plated bullets.

Left side is a pulled bullet and the right side is unloaded.

there is a line from the crimp but the plating has not been compromised.

should i back off or just load up and test shoot?

[bowenbuilt]

If you have crimped enough to put a line on a plated bullet it is too much. This is the main reason everyone complains about how inaccurate plated bullets are. They are so soft that a line indicates the front portion of the bullet has been sized. I would back it off and try for no line and I will admit it's tough to get right but it will be worth it when you try to shoot groups. Don't ask me how I know.....

[al503]

I actually leave the lip about .001" larger than the rest of the case holding the bullet.

[aahunt03]

Thats a good picture. I also struggle with crimping. I never really get it right so I always just keep it as minimal as possible and can tell no difference in the rounds I have crimped and ones I haven't.

[Hi-Power Jack]

You have enough "crimp" - actually just removing the bell - if the case enters the chamber fully.

[kaech]

Using .355 147gr Extreme plated bullets.

Left side is a pulled bullet and the right side is unloaded.

there is a line from the crimp but the plating has not been compromised.

should i back off or just load up and test shoot?

Too much crimp

[kevin c]

As far as setting the die to remove flare but not leave a crimp mark on the bullet, it's worh noting that brass thickness varies a bit from brand to brand, so that at any given setting the die will force the case mouth into the bullet more or less with more or less case wall thickness.

You will probably get the most consistent results using single headstamp brass, but hardly anybody I know is quite so OC (except mebbe yours truly ;^D). If you use mixed HS brass, you will have to put up with some variation, which may or may not be enough to affect load performance.

[RePete]

That looks good to me.

[phidelt208]

NO way, Bownbuilt has it right, with a plated bullets there should be no or very very slight marks on the bullet.

The bullet on the right looks ok, I assume it hasn't been crimped or seated?

Edited August 21, 2014 by phidelt208

[tk71]

I use x tremes also and noticed mine had very slight circle on the bullet. I pulled some winchester factory fmj target ammo and it had a worse indention than mine.

[truborshooter]

Crimp is a function of case wall thickness, case length and case springiness.

Factory ammo figures in crimp in their loading formula. But they use virgin brass all the same length and spring,

They also tend to have very short oal to work in all chambers like the short CZ, so their crimp bearly intrudes on the bearing surface of the bullet

We load to fit our specific chambers so we can get into the 1,130- 1.150 range in 9mm where crimp can really effect bullet barrel performance.

You can get close to factory crimp with products like the Lee Factory Crimp die

[seanc]

Crimp is a function of case wall thickness, case length and case springiness.

It is this as best of my understanding.

That said, I just crimp to .379 on everything and call it good. I believe 100% this produces variable accuracy when you start moving out though, no question.

For major match ammo where there are going to be longer shots, I cull out single headstamp as best as possible...

[bowenbuilt]

A taper crimp die will very easily produce a tapered bullet. On a "plated" round nose bullet you don't have a lot of bearing surface to start with and you don't want half of that to be undersized even by a small amount. Most plated bullets are almost as soft as straight lead so you have to be extra careful not to over crimp them or they will live up to their bad name for accuracy. A jacketed or factory bullet has a much tougher jacket and therefore are much more forgiving to this. How many times do you read on here that "I tried the plated bullets and my group size opened up by 4". If you treat a plated bullet right it will give groups as good as any other bullet. If it is round with a consistent weight and diameter with a flat base there is no other reason a plated bullet would not be as accurate as any other bullet unless you over crimp it. When it comes to plated and coated you can forget factory crimp measurements unless you enjoy larges groups, smoke and barrel fouling.

The OP's bullet is very close, he could turn out the crimp die a quarter turn and as long as it feeds reliably he should be there. The consistency with range brass is nearly impossible but there is a sweet spot you can get to even with range brass as long as it feeds and chambers reliably.

Edited August 21, 2014 by bowenbuilt

[Laughingdog]

If you check your reloading book, it will list 0.380" as the spec for the case diameter at the lip. As long as you're at 0.380, you're good, especially since the round headspaces on that lip anyway.

For a minimum, it's been pointed out repeatedly on this site that the way to figure that out is to add the bullet diameter and twice the case thickness at the lip of the case. Anything smaller than that deforms the bullet.

[Brooke]

As has been explained an infinite number of times, the term crimp is a misnomer. The "crimp" station is just a place to remove the bell (flare) put in earlier to avoid shaving the bullet during insertion (seating).

The outer diameter of the top of the casing on a finished cartridge should be 0.378 to 0.380 for 9 mm. This is an important dimension because the cartridge head spaces on this upper casing rim. The so called crimp has nothing to do with holding the bullet in place. That occurs lower down the casing where you clearly can see a diameter change at the base of the seated bullet. There should be no deforming of the bullet.

[truborshooter]

"the cartridge head spaces on this upper casing rim"

sometimes, if the case length matches chamber length or longer,

Fact is many rounds never touch the barrel end of the chamber and just hang, pushed into the bolt face

non concentric to the bore, by the extractor.

[njl]

Measure your brass thickness at the mouth. 9mm tends to be around 0.011" to 0.012". Measure your bullets. 9mm is generally 0.355-0.356". If your crimp measurement on a finished cartridge is less than 0.356 + 0.022 (0.378"), you're almost certainly overdoing the crimp. I tend to aim for 0.379-0.380".

There's a commercial reloader nearby that people have given me samples of ammo from. They crimp their 9mm to 0.369" and their .45acp to 0.465". You should see the crimp rings this leaves on the bullets...just not in your own ammo.

[Red Ryder]

As has been explained an infinite number of times, the term crimp is a misnomer. The "crimp" station is just a place to remove the bell (flare) put in earlier to avoid shaving the bullet during insertion (seating).

The outer diameter of the top of the casing on a finished cartridge should be 0.378 to 0.380 for 9 mm. This is an important dimension because the cartridge head spaces on this upper casing rim. The so called crimp has nothing to do with holding the bullet in place. That occurs lower down the casing where you clearly can see a diameter change at the base of the seated bullet. There should be no deforming of the bullet.

EXACTLY! The best crimp is when there is no crimp! .378 to .379 and chamber checks fine! If you have to go .376 or .377 to get the bullet to chamber check, and you have good accuracy and no tumbling, then do it. If you have issues, then maybe this isn't a good bullet for your gun.

[Laughingdog]

As has been explained an infinite number of times, the term crimp is a misnomer. The "crimp" station is just a place to remove the bell (flare) put in earlier to avoid shaving the bullet during insertion (seating).

The outer diameter of the top of the casing on a finished cartridge should be 0.378 to 0.380 for 9 mm. This is an important dimension because the cartridge head spaces on this upper casing rim. The so called crimp has nothing to do with holding the bullet in place. That occurs lower down the casing where you clearly can see a diameter change at the base of the seated bullet. There should be no deforming of the bullet.

EXACTLY! The best crimp is when there is no crimp! .378 to .379 and chamber checks fine! If you have to go .376 or .377 to get the bullet to chamber check, and you have good accuracy and no tumbling, then do it. If you have issues, then maybe this isn't a good bullet for your gun.

if you have to crimp down to .376 or .377 to pass a case gauge, it's probably not the case mouth that's your problem, since the spec is .380 or .381. Odds are your bullet is pretty deep, and you're crimping that far to take out a bulge farther down the case.

When I load to 1.145" or longer with a RN bullet, and a .380 crimp, I can go thousands of rounds without a single issue passing in a case gauge. When I do, it's generally some oddball brand of brass that I didn't sort out because I'm loading practice ammo instead of match stuff.

Note: I say this as someone who spent years being completely jacked up on what constitutes a proper crimp, based on horrible advice from the person who started me into reloading. I believe his exact words on crimping were "Just crimp until you can't feel the lip of the case when you run your finger down the cartridge. As mentioned by others, that wasn't too bad when I loaded jacketed bullets. But was horrible when I switched to plated and lead to save money.

Edited August 22, 2014 by Laughingdog

[Joe D]

I have been shooting lead bullets through Glocks for years. I load a 160 gr lead bullet in 9mm. IMO the worst device ever made was the Lee Factory Crimp die. I taper "crimp" mine to .379" at the mouth. 1.150" OAL in a G34 and 1.200" in a Range Officer.

Edited August 23, 2014 by Joe D

[grouptherapy]

Most lead cast bullets can be swaged in lee FCD if the bottom sizing ring hasn't been knocked out. I don't see it so bad with any thing else. I like the FCD because it doesn't rely on consistent brass oal aka sorted HS and trimmed brass. I have taper crimp dies and FCDies. I choose FCD. Jmo

Left bullet had too much crimp.

Sent from my iPhone using Tapatalk

Edited August 23, 2014 by grouptherapy