...to CRIMP or not to crimp?

[stinsonbeach]

All my friends - shooting comp buddies - tell me to roll crimp .45's as I was having some problems w/ feeding & extraction.

Everything I read tells me NO CRIMP but a moderate taper crimp.

Had lots of trouble w/ my favorite gun - very finicky to begin w/ - but not w/ some others that are notorious for being temperamental (STI's for example).

Shoots store bought - the gun I'm having problems w/ - just fine.

Simple question: crimp or no crimp? I realize the round headspaces on the case, but . . .

Thanks,

-jb

[Jman]

I taper crimp. Add your bullet width and your case wall thickness X 2. Example .451 + .022 = .473

A light taper crimp would be something like .002

Your finished round will measure .471 and should run like a scalded cat.

Unless of course something else is wrong.

[stinsonbeach]

...actually all the non-sense started w/ me "fine-tuning" the friggin' thing!

Thanks for the #'s - I appreciate precision...tho you'd never know it w/ some of the hair-brained things I do!

-jb

[The Happy Gila]

Dillon told me "all .45 ACP should be taper crimped to .470" to which I've adheared and had no problems. Granted, I shoot jacketed 230 gr RN or 200 gr FP exclusivly, but for those bullets, the .470 taper crimp works like a charm for me.

[stinsonbeach]

Dillon told me "all .45 ACP should be taper crimped to .470" to which I've adheared and had no problems. Granted, I shoot jacketed 230 gr RN or 200 gr FP exclusivly, but for those bullets, the .470 taper crimp works like a charm for me.

Thanks - I shoot 185 HP but I think I'm going to change to 230 for this one gun.

I've got some figuring to do.

-jb

ps oal ? ...'er loa? ...or whatever is in vogue at the moment!!!

Edited July 31, 2010 by stinsonbeach

[Phil G]

I taper crimp to my 45 ACP with lead 200 gr SWC to .469 - .470 and the rounds feed perfect and shoot well. A roll crimp could allow the round to chamber at an improper depth and create ingition and/or extraction problems.

Phil G

[stinsonbeach]

I taper crimp to my 45 ACP with lead 200 gr SWC to .469 - .470 and the rounds feed perfect and shoot well. A roll crimp could allow the round to chamber at an improper depth and create ingition and/or extraction problems.

Phil G

...& I think that has been my problem of late. Thanks.

-jb

[Mattog22]

I'm glad I stumbled onto this thread. Just yesterday I loaded some of my first cast bullets 230gr RN and had a few feeding problems where the case mouth got caught up on the edge of the chamber. I had crimped to .473, maybe some were .474 because of mixed headstamp. I thought my solution would be to crimp a little more, now hearing most of you are crimping to .470 I think I have my problem figured out. Thanks guys.

[Jman]

Pay close attention to your crimp firmness with bare or moly coated lead. Lead has no "memory" when squeezed. It maintains it's compressed diameter. Brass has some "memory". It can loose it's compressed diameter a little. Adding these two equal little or no crimp.

So...just sayin'...don't get all gorilla on the crimp. Especially with cast or coated bullets.

[Mattog22]

Pay close attention to your crimp firmness with bare or moly coated lead. Lead has no "memory" when squeezed. It maintains it's compressed diameter. Brass has some "memory". It can loose it's compressed diameter a little. Adding these two equal little or no crimp.

So...just sayin'...don't get all gorilla on the crimp. Especially with cast or coated bullets.

Not arguing here as I am still really new to the cast bullet thing, just trying to learn. My thought was even if the crimp is deep you are only effecting the part at the case mouth, the rest of the bullet in the case should still be at a larger diameter right? I may be confused, are you talking about worrying about bullet setback due to the crimp not holding the bullet? I could see the problem if you were using a LFCD and sizing the whole thing thus the brass springing back a little and the lead not but I don't quite understand on the crimp.

[Jman]

My thought was even if the crimp is deep you are only effecting the part at the case mouth, the rest of the bullet in the case should still be at a larger diameter right? Not necessarily with an overly tight taper crimp because it involves more brass and bullet area. Some what more possible with a roll crimp. I may be confused, are you talking about worrying about bullet setback due to the crimp not holding the bullet? Exactly. I could see the problem if you were using a LFCD and sizing the whole thing thus the brass springing back a little and the lead not but I don't quite understand on the crimp. A tight roll crimp for example is needed with a heavy recoiling revolver. A light taper crimp and consistent OAL are key to safe and reliable semi-auto reloads.

[stinsonbeach]

Pay close attention to your crimp firmness with bare or moly coated lead. Lead has no "memory" when squeezed. It maintains it's compressed diameter. Brass has some "memory". It can loose it's compressed diameter a little. Adding these two equal little or no crimp.

So...just sayin'...don't get all gorilla on the crimp. Especially with cast or coated bullets.

Not arguing here as I am still really new to the cast bullet thing, just trying to learn. My thought was even if the crimp is deep you are only effecting the part at the case mouth, the rest of the bullet in the case should still be at a larger diameter right? I may be confused, are you talking about worrying about bullet setback due to the crimp not holding the bullet? I could see the problem if you were using a LFCD and sizing the whole thing thus the brass springing back a little and the lead not but I don't quite understand on the crimp.

...remember: .45's headspace on the case-mouth

-jb

[Mattog22]

My thought was even if the crimp is deep you are only effecting the part at the case mouth, the rest of the bullet in the case should still be at a larger diameter right? Not necessarily with an overly tight taper crimp because it involves more brass and bullet area. Some what more possible with a roll crimp. I may be confused, are you talking about worrying about bullet setback due to the crimp not holding the bullet? Exactly. I could see the problem if you were using a LFCD and sizing the whole thing thus the brass springing back a little and the lead not but I don't quite understand on the crimp. A tight roll crimp for example is needed with a heavy recoiling revolver. A light taper crimp and consistent OAL are key to safe and reliable semi-auto reloads.

OK, makes sense, but to get to that point wouldn't you really have to be going overboard with the crimp? I would think that crimping to .470 wouldn't introduce any of those problems. Are you talking about this happening with a crimp of less than .470 or are you getting close to a danger with .470 crimp. I ask because that was the next thing I was going to try. Thanks for the help

Edited August 1, 2010 by Mattog22

[Mattog22]

Pay close attention to your crimp firmness with bare or moly coated lead. Lead has no "memory" when squeezed. It maintains it's compressed diameter. Brass has some "memory". It can loose it's compressed diameter a little. Adding these two equal little or no crimp.

So...just sayin'...don't get all gorilla on the crimp. Especially with cast or coated bullets.

Not arguing here as I am still really new to the cast bullet thing, just trying to learn. My thought was even if the crimp is deep you are only effecting the part at the case mouth, the rest of the bullet in the case should still be at a larger diameter right? I may be confused, are you talking about worrying about bullet setback due to the crimp not holding the bullet? I could see the problem if you were using a LFCD and sizing the whole thing thus the brass springing back a little and the lead not but I don't quite understand on the crimp.

...remember: .45's headspace on the case-mouth

-jb

Yes, but I don't remember the diameter but I think you have to go smaller than .470 or .469 to have headspacing problems. If we are all talking about going crazy with the crimp and cranking it down way smaller than the recommended crimp then I agree 100%.

Edited August 1, 2010 by Mattog22

[stinsonbeach]

Pay close attention to your crimp firmness with bare or moly coated lead. Lead has no "memory" when squeezed. It maintains it's compressed diameter. Brass has some "memory". It can loose it's compressed diameter a little. Adding these two equal little or no crimp.

So...just sayin'...don't get all gorilla on the crimp. Especially with cast or coated bullets.

Not arguing here as I am still really new to the cast bullet thing, just trying to learn. My thought was even if the crimp is deep you are only effecting the part at the case mouth, the rest of the bullet in the case should still be at a larger diameter right? I may be confused, are you talking about worrying about bullet setback due to the crimp not holding the bullet? I could see the problem if you were using a LFCD and sizing the whole thing thus the brass springing back a little and the lead not but I don't quite understand on the crimp.

...remember: .45's headspace on the case-mouth

-jb

Yes, but I don't remember the diameter but I think you have to go smaller than .470 or .469 to have headspacing problems. If we are all talking about going crazy with the crimp and cranking it down way smaller than the recommended crimp then I agree 100%.

...which I - embarrassingly - have done!

-jb

[Jman]

Yes, but I don't remember the diameter but I think you have to go smaller than .470 or .469 to have headspacing problems. If we are all talking about going crazy with the crimp and cranking it down way smaller than the recommended crimp then I agree 100%.

You have definitely captured the essence sir.

A tip... when I started loading for semi-autos I used factory ammo to use as a template. As long as the bullet profiles were the same (not hard with ball) I would adjust my dies to match. It will get you close at least.

[Mattog22]

Yes, but I don't remember the diameter but I think you have to go smaller than .470 or .469 to have headspacing problems. If we are all talking about going crazy with the crimp and cranking it down way smaller than the recommended crimp then I agree 100%.

You have definitely captured the essence sir.

A tip... when I started loading for semi-autos I used factory ammo to use as a template. As long as the bullet profiles were the same (not hard with ball) I would adjust my dies to match. It will get you close at least.

I did that too when I first started but always noticed the OAL seemed to be shorter than the books recommended, can't remember on the crimp though. I was always scared of pressure when I started so I just went by the book. So much for that, that's why I'm having the feeding issues, because the book said .473. lol

By the way, I am not condoning straying from the published specs at all, you just need to tailor it sometimes.

[stinsonbeach]

Yes, but I don't remember the diameter but I think you have to go smaller than .470 or .469 to have headspacing problems. If we are all talking about going crazy with the crimp and cranking it down way smaller than the recommended crimp then I agree 100%.

You have definitely captured the essence sir.

A tip... when I started loading for semi-autos I used factory ammo to use as a template. As long as the bullet profiles were the same (not hard with ball) I would adjust my dies to match. It will get you close at least.

I did that too when I first started but always noticed the OAL seemed to be shorter than the books recommended, can't remember on the crimp though. I was always scared of pressure when I started so I just went by the book. So much for that, that's why I'm having the feeding issues, because the book said .473. lol

By the way, I am not condoning straying from the published specs at all, you just need to tailor it sometimes.

.470 works perfectly in my finicky gun...

-jb

[Mattog22]

.470 works perfectly in my finicky gun...

-jb

Hopefully in mine too!

[stinsonbeach]

.470 works perfectly in my finicky gun...

-jb

Hopefully in mine too!

Hopefully - & I'll bet you a beer (or 20) it does!

-jb

[Mattog22]

lol, I'll let you know

[Rolex]

PS: you have been given those exact

specs. over the last year or so with

those you shoot with!

[Mattog22]

PS: you have been given those exact

specs. over the last year or so with

those you shoot with!

Are you replying to me? My buddy just told me about .470 for the crimp just yesterday when I had problems

[Rolex]

Matt. Not to you as we have never met!

It's for jb.

[Mattog22]

Matt. Not to you as we have never met!

It's for jb.

Oh, OK, I was confused!