Lee Factory Crimp vs. Redding Profile die?

[UNIQUEDOT]

Uniquedot: first I must ask you what manual mentions case springback and I need the Manual name and page # where it states this information.

The reason why I insist on this exact reference is because several people on this thread have stated that they read this in a manual or Handloader Magazine. Or "so many manuals state this."

Yet when I look at the articles mentioned there is NOTHING IN THESE REFERENCES WHATSOEVER that says or even implys that this problem exists. It's like somone is not understanding what they read.

I got out a few of my manuals so that i could provide you with the information, but by golly it ain't in a single manual i looked through. No doubt that rather than reading it in various manuals i have read it on various forums, or the only other explanation i can offer is that i was perhaps thinking of the opposite of what is being discussed such as the spring back in the chamber after firing the round.

Colorado4wheel, as i stated to W.R.Buchanan when asking him a question... i ask you this question to get legitimate knowledge and not to continue an argument. If you have male and female parts of the EXACT same size would it even be possible to fit them together without force? it seems to me that there would have to be at least some minute tolerance between one or the other in order to fit them without forcing.

[MtGun44]

Measuring with a caliper that is good for +/-.001 proves little.

If you have fully annealed brass, the springback is at the minimum. As the brass is cycled
it work hardens and the harder brass will spring back more than the soft brass.

In the end, the springback IS occurring. Whether you can measure it or not is an interesting
experiment, but it has nothing to do with the facts of how metals behave, only the particular
situation and set of tools you are using.

If your point is that your brass doesn't spring back much. OK, fine, you may have
soft brass and inadequate measuring capability. Again - very soft annealed brass
has a very low yield stress, which means that it will have a small elastic range, and this
can make the springback small enough to be hard to measure. It does not mean that it
is not there. Note the practical effect and move on.

If your point is that brass does not spring back at all, you are wrong no matter what you say,
think or do. The science is extremely well settled and not open for adjustment based on your
measurements.

Bill

[Doughty]

Randy,
I don't think you really read my post before you replied to it.

"Doughty: It would seem that the Lee dies were sizing the cases a bit smaller and as a result they would chamber up in the rifle mentioned. RCBS now makes "Small Base dies" for .223 and .308 that size the cases about .001-.002 smaller in dia at the base than their regular sizing dies. This is supposedly to facilitate them chambering in Automatic rifles easier."

I didn't say anything about chambering in a rifle or about the cases being too large and therefore needing a die that sized bases smaller. I said that a RCBS case mic was used to measure headspace. And the point was not about just sizing something smaller than necessary to get it to fit, but about CONSISTENT sizing and about how being below, at, and passed the point of elastic/plastic deformity might effect things.

A small thing perhaps, but then small things are what we're talking about.

[Colorado4wheel]

If you have male and female parts of the EXACT same size would it even be possible to fit them together without force? it seems to me that there would have to be at least some minute tolerance between one or the other in order to fit them without forcing.

Fair question. PM sent.

[UNIQUEDOT]

I dug a little deeper and found an interesting article on cartridge brass in the ABC's of reloading 6th edition.

On page 27 it says " A second problem that still crops up is brittle brass. After cartridge brass is formed it gets a final heat treatment called stress relief. This process involves less heat than annealing and is done to bring the brass to the optimum degree of springiness".

I have found this argument interesting and also confusing! but I'm willing to bet that someone at starline brass could clear this argument up for all of us with a simple phone call. A second opinion from a metallurgist would be reassuring as well.

[W.R.Buchanan]

Doughty: Indeed, I responded to what "I thought you were asking?" And admittedly after reading your second post I was not answering your question accurately.

As far as what you are actually asking, I think the amounts of difference in how the individual cases respond during their life, IE: thruout the variance in elasticity. I would have to say that the effects are relatively negligable. And most reloaders 99.99%, would be oblivious to the changes.

However, the whole regime of change to the cases could be compensated for by Sizing Dies that are under the Nominal size of dies for that caliber.

Plus,,, I don't know how you would quantify how much change in elasticity there would be during each sizing event throughout the life of a given case, and I think that even if you could somehow chart this change over the life of a given case that those results would be pecular to that particular case and not necessarily indicative of any other case outside of the given run of brass that, that specific case came from. And (to go one step further) maybe not even the same as the rest of the cases from that given run either.

I think there is just too many variables in play to come up with a truly empirical answer.

Whew, I had to read and re-read that last paragraph several times to make sure it said what I thought I wanted to say. I hope you can understand what I am trying to say, cuz I'm not sure if I said what I meant.

In reality I think the short answer is that "it doesn't make any difference in the real world." And if It does somehow rear it's ugly head, then the Small Based Dies would be the only availalbe solution to the problem.

Does any of this make sense? I'm trying really hard!

Randy

[Colorado4wheel]

www.6mmbr.com/catalog/item/1433308/1464783.htm

Forester says it's .002"

[MtGun44]

You are right when you say "It doesn't make any difference in the real world." Lots of
things are that way - absolutely, provably true, but in many situations, not important to
real world results.

Bill

[Colorado4wheel]

It's a academic conversation. I find them interesting. Unless your the guy in the link above ordering a sizing die to a specific size it really doesn't mater. Well the people who sell/buy the U-Die also care. But that would be crazy for lead bullets anyway.

[Petander]

I stumbled on this thread,searching for Redding Profile Crimp.

I don't like pulling bullets with the hammer so I run the to-be-pulled rounds in a sizing die. The sized-down bullets can be picked with bare fingers then.

[azrednek]

I might be a bit off subject but Redding's profile crimp die for 45 Auto Rim is a godsend. Heavy 230-250gr slugs often backed out with a taper crimp. Been using the profile crimp die for years and I can't recall a slug backing out since.

[azrednek]

I stumbled on this thread,searching for Redding Profile Crimp.

I don't like pulling bullets with the hammer so I run the to-be-pulled rounds in a sizing die. The sized-down bullets can be picked with bare fingers then.

Petander thanks for that advise. Never thought about that method but I'll never forget it.

[1hole]

Giving this a little thought, I would have lean to the Springback side of the debate.
Seeing how when you fire a loaded round the brass expands tight against the chamber walls then quickly retracts a few thousands.
Unless I'm missing something there.

You are missing nothing.

Like lead, dead soft brass has very little, if any, spring back. However, if cartridge brass didn't have elastic spring back it wouldn't have any grip at all after the necks are forced to expand when bullets are seated, nor could fired cases be easily extracted; obviously neither of those are what happens.

It's interesting to measure neck inside diameter before bullets are seated and again after the (unfired) bullets are pulled. Depending on caliber and number number of times the case has been used, I find a spring back of 1 to 2.5 thou below bullet diameter after pulling.

Lee's handgun FCD "post seating" sizer ring die has a single purpose; it insures we have ammunition that chambers everytime. I really like that. Many factory handguns have largish chambers with plenty of clearance to chamber thick neck cases loaded with oversize cast bullets so not every handgun needs the FCD.

So, to each his own but I think everyone should understand what his tools are actually doing. I've seen a lot of web expert BS posted about Lee's FCD but if you ever need one, just once, for your defence loads and you don't have one you may never need it again. My wife's .357 Blackhawk needs it, my surplus 1911 doesn't so I load accordingly.

[Petander]

I might be a bit off subject but Redding's profile crimp die for 45 Auto Rim is a godsend. Heavy 230-250gr slugs often backed out with a taper crimp. Been using the profile crimp die for years and I can't recall a slug backing out since.

Thanks for this,I'll get one for the 500S&W.