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more crimp questions

Post by Aprilian on 9/15/2018, 9:59 pm

I had been working on understanding why I got brass and lead shavings on my single stage press http://www.bullseyeforum.net/t9002-crimp-die-causing-brass-shavings-_-not-sure-why  Unfortunately, the problem came back last week.

Today I polished the snot out of the Redding micrometer crimp die.  Then I measured, loaded and dismantled a lot of dummy rounds today.   I noticed that the crimp die was also sizing the leading edge of the bullet by a thousandth to two.

I went back to the beginning and adjusted the depth of my dies.  I was able to eliminate all lead shavings with even my largest (.453) bullets.  As I played with slowly increasing the crimp level I noticed that the rounds passed the 2 gauges and my barrel far before the .470 that is often listed as the minimum crimp.

My 2 gauges and Kart barrel all accepted a .4725 crimp.  The maximum cartridge diameter was .474 (below the base of the bullet).

I understand that crimp helps build pressure, but will I have other problems if I test loads at a crimp of .472?

I plan to call Redding to ask about the tiny chips I am still getting from the crimp die, but there are very few now.
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Re: more crimp questions

Post by dronning on 9/15/2018, 10:35 pm

.472 seem like a very loose crimp, but maybe not?  I was using .469 for quite a while but I was also experiencing poor powder burn on some lighter loads with certain powders.  It was suggested I try .465 crimp.  I did and got better burn and group size improved slightly.

Brass shavings pretty much went away when I went to the stepped powder funnel, you don't need as much of a bell on the case to seat the bullet.  I still do get some shavings when loading new brass because the edges are sharp.
- Dave

I load with both a Dillon 550 & 1050
Case lube I use Hornady One Shot on new or wet tumbled brass and for used brass a capfull (or2) of NuFinish when dry media tumbled.
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Re: more crimp questions

Post by Jon Eulette on 9/15/2018, 10:49 pm

I didn’t catch this until dronning posted. Are you roll crimping? Truthfully I don’t know how much you can roll crimp down to. But .472 is too big! Even for jacketed.
Jon
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Re: more crimp questions

Post by zanemoseley on 9/15/2018, 11:21 pm

.472" is loose as a goose. I ran .469" for 3 years but have recently moved to .463" to get more consistent ignition. I get fine brass shavings in my Dillon taper crimp die, maybe due to the amount I bell the cases to get a good start for the flat base Magnus #801 bullets. I don't see any reason not to crimp to at least .465".

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Re: more crimp questions

Post by chopper on 9/15/2018, 11:27 pm

Dave, what is a stepped powder funnel, I use a 550 also and the funnel has a step where it flares the mouth. Is this a special funnel? I been crimping at .468", but sometimes I get 1 or 2 that aren't level with the gage or an old kart barrel.
 Ian, I've had some brass shavings and lead smears in the past also, but they seemed to go away when I'd clean my seater and the crimp dies. I now clean those every 100 loads whether they need it or not.
Stan

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Re: more crimp questions

Post by Multiracer on 9/16/2018, 5:37 am

chopper wrote:Dave, what is a stepped powder funnel, I use a 550 also and the funnel has a step where it flares the mouth. Is this a special funnel? I been crimping at .468", but sometimes I get 1 or 2 that aren't level with the gage or an old kart barrel.
 Ian, I've had some brass shavings and lead smears in the past also, but they seemed to go away when I'd clean my seater and the crimp dies. I now clean those every 100 loads whether they need it or not.
Stan

Search "M" dies. They are made by several companies, Redding, Lyman they are also made for the Dillon powder drop. Wonderful tools.

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Re: more crimp questions

Post by Aprilian on 9/16/2018, 8:15 am

Jon, 
taper crimp die.   

Dave, 
in my testing yesterday I wiped all brass, lead flakes, excess lube after the seating - therefore I can be sure that the brass shavings are being created by the Redding crimp die (which I triple checked is set with the ACP side to the cartridge).
I'm using Noe expanders so the case is straight expansion, not belled.
These cases are Federal (your favorite) with multiple firings, with Hornady one shot and not cleaned.

Not that it makes a difference to my original question, but at .453 on these bullets, the .472 crimp's effect on burn and accuracy night be compared to 
.452 = .471 crimp
.451 = .470 crimp
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Re: more crimp questions

Post by dronning on 9/16/2018, 8:31 am

chopper wrote:Dave, what is a stepped powder funnel, I use a 550 also and the funnel has a step where it flares the mouth. Is this a special funnel? I been crimping at .468", but sometimes I get 1 or 2 that aren't level with the gage or an old kart barrel.
 Ian, I've had some brass shavings and lead smears in the past also, but they seemed to go away when I'd clean my seater and the crimp dies. I now clean those every 100 loads whether they need it or not.
Stan

The standard powder funnel just has the flare while the stepped one has a very slight step before the flare.  In the pic. below you see a "step" before the flare on the part of the funnel that goes into the case.  This allows you to get by with less flare and actually helps seat the bullet deeper into the case without damage.

Just recently I bought several PTU's (Powder Transfer Unit) from PhotoEscape on this forum - very nice product!


Image from Ebay, PhotoExcape's page: link to PhotoEscape's PTU's

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Re: more crimp questions

Post by Chris Miceli on 9/16/2018, 8:42 am

what does the PTU expand to in 45acp ?
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Re: more crimp questions

Post by dronning on 9/16/2018, 9:05 am

Chris Miceli wrote:what does the PTU expand to in 45acp ?
.454
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Re: more crimp questions

Post by Aprilian on 9/16/2018, 4:07 pm

dronning wrote:
Chris Miceli wrote:what does the PTU expand to in 45acp ?
.454
Dave,  Is that what the PTU diameter measures?  Brass will spring back depending on metallurgy and thickness - plus it is hard to measure the brass ID accurately.   

It might help to post both diameters.
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Re: more crimp questions

Post by Aprilian on 9/20/2018, 9:23 am

I found what might be the long term cause  - here is what I posted on another site.
I think I may have finally solved the root cause. I watched how the cartridges entered the dies and I had an alignment problem. The Redding #1 Shell Holder was very loose in how it held the case rim. It also didn't go back on the ram far enough to be able to center the fore-aft dimension in the center of the die. 

What was happening was that the case would enter the die, brush against one side and then "cock" in the shell holder.

I grabbed an RCBS #3 shell holder that I have and compared the two. Then I went to the store to get another RCBS #3 and noticed they also had Hornady #45. I carefully opened both packages and compared the two. The Hornady had far less play on a case rim, so I bought it. What I can see is the rim now slides sideways in the tighter shell holder, instead of tipping. I tested 20 rounds and at every step used a black sharpie - no flakes.

I'm hoping this puts an end to my brass dandruff!
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Re: more crimp questions

Post by dronning on 9/20/2018, 9:52 am

Aprilian wrote:
dronning wrote:
Chris Miceli wrote:what does the PTU expand to in 45acp ?
.454
Dave,  Is that what the PTU diameter measures?  Brass will spring back depending on metallurgy and thickness - plus it is hard to measure the brass ID accurately.   

It might help to post both diameters.

I won't waste my time trying to measure - the stepped PTU just works.  Using the stepped PTU with almost no flare the bullet goes just a little deeper into the case and never tips.  Overall I believe you are working your brass less too.  I use a bullet feeder when I load jacketed ammo and without the stepped PTU it is almost impossible to keep the bullet on the case when the press indexes.
- Dave
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Re: more crimp questions

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