Lee Factory Crimp vs. Redding Profile die?

[W.R.Buchanan]

You got me thinking so I went and measured my C&H .44 mag dies. .4495 on the ID of the carbide sizing die. I rotated the die arouind the calipers to check roundness also. Right on.

I then ran 12ea mixed brands of Special and Magnum cases thru that die. All of them measured exactly .4495 when done . I don't know how many times each of these cases had been fired but I'm pretty sure it was more than once.

All measured exactly the same and there was no variation between the spec and mag cases. Which I would expect since they were pushed thru the same hole.

I don't know what you guys are doing to get these results? They make no sense.

The only thing I can suspect is that your calipers inside and outside measuring surfaces are not calibrated together. A .001 difference in the OD and ID surfaces would generate a .002 difference in OD and ID measurements. Also a .001 diference on a set of chinese calipers would not be unusual at all. I have seen much more expensive tools that had as much or more discrepancy. I used 2 sets of 12" Mitutoyo calipers and a 6" set of Tesa brand (Swiss) and I can calibrate them with ring gauges of known sizes and Jo-blocs which are exact. I use them in my machine shop every day.

Also when taking an inside measurement you must hold pressure on the calipers and rotate the item until you get the calipers exactly square to the measured surface. The reading will stabilize while you are rotating the part. You will end up with the highest measurement you can repeat.

Same holds true on OD measurements on a round piece. UNless the calipers are perfectly square to the piece you will get bogus measurements. You also want to avoid the ends of the caliper jaws as the jaws flex to some degree, measure in closer to the middle of the jaws. On OD measurements you take the lowest measurement you can repeat. Just clamping the calipers onto a piece one time is not a valid test. You must get the same reading several times to confirm that you got a good one.

Also on an OD measurement on a round piece you need to rotate the piece to check for roundness. This would be especially true of a brass case as it would be very easy for it to be out of round and measure a few thou either way when readings are taken at 90 degrees to each other. You could then average the two readings and come up with the actual diameter.

It took me several years to be able to take accurate measurements with dial calipers, and I scraped a lot of parts due to bogus reading of my instruments. I finally learned that I needed to take the same measurement several times to make sure what I got was what was actually there.

This is my only explaination for what is happening with your guys springing brass. I cannot make it spring in my shop.

Randy

[W.R.Buchanan]

Of course You can't push a bullet or a case into a sizing die by hand,,, there is zero clearance!

The ID of the die is the same as the OD of the case or boolit. Think about it.

You can damn sure shove them back in with the press and the size doesn't change. You can't tell me the spring back is constant and stays the same if you size that case several times in row. It would have to change because everytime you stuff a bigger case into a smaller die it work hardens a little more and since the hardness is changing the spring back would have to change as well. Right? But the size doesn't change does it?

Also when you bend "Some" metals there is spring back. The spring back on brass is so small you don't even allow for it, it is virtually non existant.. I just built a fuel tank for my Jeep last week from 6061 T4 which is dead soft aluminum. There was no spring back at all. took a 100 ton press brake to make the bends The steel skid plate was another story and we had to go 2-3 degrees past 90 degrees to yeild a true 90.

Built this entire vehicle from scratch,,, there is no other like it on this planet.

Been doin' this for a while.

Randy

[hylander]

My Calipers are accurate, I check them with known size parts.
I am measuring correct and get the same reading each time.
Again I know nothing about this springback thing, only what I am getting for measurements.
I have another set of .44 Dies coming Saturday and will measure them as well and see what I get.

[W.R.Buchanan]

I guess we'll have to just agree to disagree on this point. It is pointless to argue over a distance when we can't get together to measure each others parts and check to see what is going on.

If we could do it together we could figure exactly why everyone doesn't get the same measurements off the same parts. And we could measure each others parts with different tools.

You guys may be getting spring back in your brass. I have never seen it.

As indicated I measure everything as I load to check for consistancy. I can only report what I see and know as fact. Your results may vary.

As with anything, nobody knows everything and Richard Lee was no different, he did some good things and some not so good things, and opinions on him are as varied as the weather.

Just ask what Dave at C&H thinks about Richard Lee. He gets down right ornery about that subject.

Randy

[r1kk1]

Just ask what Dave at C&H thinks about Richard Lee. He gets down right ornery about that subject.

Randy

Yeah I know. I call Dave the Vampire. He mainly works nights. His son Bryan and Beth run the front. I can't remember the guy in the back.

He told me he built a post sizing die for 223. I personally don't like post sizing but it's my opinion. What shocked me is the year - 1970. He is helping me revamp a three station ch press. Thank God for parts. I currently trying out a taper crimp for a big bore single shot. I'll see how that works. The man knows his stuff. I think I have a box of dies marked 4-D somewhere.

Very nice guy to talk too. So is Gary Reeder and Kase Reeder of Reeder custom guns.

[Colorado4wheel]

The sizer is smaller then the cartridge. It's just common sense. Anytime you bend metal you band it past the point you want it to spring back to. Every metal has a different elasticity. You can Google it and get the number. If it was zero clearance as you say you could overcome it with your hand. You need a press to overcome it because it's not zero, its negative. This is just obvious if you just step back and look at the elasticity and information right on your bench. Even a coat hanger would prove it if you just fiddle with bending it. You have to go past the point you want it to return to. It's just the way it works when you bend metal. Every metal is different and you can look it up if you really want to. Those numbers will show lead is much less so. So if you move a cartridge into a FCD the brass can spring back (its more elastic) and the lead can get sized. Perhaps if I am bored I will find the post by Richard Lee (maker of the FCD) about it. Don't hold your breath. A lot of FCD threads on GT and I don't remember his screen name. I do know someone on the forum who is friends with him. He doesn't like me because I don't like the FCD.

[Char-Gar]

I have two pair of high end Starrett calipers, one digital and one mechanical. I don't trust either of them to give absolute precision measurments. I use a high end Starrett micrometer if I want that. I have used calipers and micrometers side by side for many years and know what each tool will do.

So when folks talk "spring back" or whatever in the same paragraph with calipers, I take it all with a grain of salt.

[Colorado4wheel]

So when folks talk "spring back" or whatever in the same paragraph with calipers, I take it all with a grain of salt.

You don't need dial calipers to know it's there.

Top right corner of page two, about 8 sentences down and into page three.

http://www.olinbrass.com/companies/f...ta%20Sheet.pdf


Also

http://wiki.answers.com/Q/Difference...ic_deformation


This is not that complicated.

Elastic deformation returns to it's original shape after a strain is applied.

Plastic deformation returns to a deformed shape after a strain is applied.

I am calling it spring back to make it more understandable. When i do a corrective alignment on a bent suspension part I have to bend the part WAY past the point I want it to return to. For example, you can measure the bend and see that bending it 1 inch doesn't change a thing, but bending it 1.125" will change it .125". . I have flown around the country doing this exact thing for people about 50 times on race cars. People pay my flight and time to do this. Cartridge brass behaves the same way. It's in the first link I provided.

Just try pushing a piece of brass in your die. You can see with your eyes that the brass is bigger then the die even after sizing.

[1bluehorse]

All very interesting, and I for sure have no idea of the answer ( I was lost at "springback"). So I just did a little check on 45 colt dies and brass. I also have no idea if this is relevant or has much meaning, just for S&G's.
Lee dies: ID of the sizing die measured .4675 (.468 gauge wouldn't enter but the .467 pin was a little loose so I just intropolated the extra 5)

unsized (fired) Starline brass ID .448 after sizing .445
RP brass ID .450 after sizing .446
Win ID .450 after sizing .446

should have added that they were all .478 OD before, .470 after sizing. (must have pretty good chambers in the Bisley)
Now this was measured with calipers so +or-, my mic's getting checked so couldn't use it.

The Win. and RP brass thickness measured .11, while the Starline measured .12 (this was measured with the same set of calipers)

Oh, by the way the LCFCD ID measured .477 (not sure how this die would "swage" a .452 bullet) All the ID measurements were taken with a set of decent minus pin gauges..

Like I alluded to above, I have no idea if this is useful in any way, but was kinda interesting to do anyway..

[Colorado4wheel]

unsized (fired) Starline brass ID .448 after sizing .445
RP brass ID .450 after sizing .446
Win ID .450 after sizing .446

What was the O.D.?

[1bluehorse]

What was the O.D.?

I just edited the post to add that. .470..measured with calipers.

[Colorado4wheel]

.470 - .4675 is .0035.
.0035 spring back. Close to my .003 I said it would be.

[1bluehorse]

.470 - .4675 is .0035.
.0035 spring back. Close to my .003 I said it would be.

Could be even closer, calipers aren't the best for that measurement either..as you all know...

[Colorado4wheel]

Larger cases have more spring back. But it varies from about .002 to about what you got. It's hard to measure consistently to. 001 in a piece of brass that is not always straight or round.

Thanks for doing the test.

[W.R.Buchanan]

I went back and sized 35 more .44 cases. I measured all before sizing at .454 I measured all after sizing and they are .4495 which is exactly what the ID of the sizing ring in my die is..

I ran one case thru the die 12 times and it still measured .4495 at the end. The second pass thru was slightly easier than the first pass thru as no sizing was taking place. All subsiquent passes took the same pressure and did not change the dia at all.

I was able to start the sized cases into the die and push them in about half way with hand pressure but I can't get it any further. So there is very little if any spring back ON MY CASES!

My cases are nearly perfectly round after sizing, mainly becasue the die is round and the brass is being formed by the die.

You can measure to .001 easily with calipers if you rotate the part in the caliper jaws while pressure is on. I do it everyday I own a successful machine shop and this is what I do.

I looked at the links you provided and if you really understand the numbers describing the physical properties of those materials then you could be making much more money than you are working on Jeeps and race cars. I am a non degreed engineer with 30 years in trade and I don't begin to be able to compare the modulus of elasticity to anything. Those numbers are just gobbildy gook designed for metalurgists and nerdy types to bandy about over coffee and donuts.

You obviously will not accept my results, and short of doing a Youtube video of the process showing the results and measuring techniques used, I doubt that would convince you either.
.
I don't know how to do a youtube video, so there is no point in bandying this further.

If your cases spring back then so be it. Mine don't. Good luck

Randy

[hylander]

I'm still enjoying this discussion
Even though the OP was Lee FCD vs. Redding Profile and not
"Spring back VS. no Springback"
I desisded to purchase both Dies to make my own comparisons.
(As far as the usefulness of the dies)

[Colorado4wheel]

I know spring back exist. My entire life of bending stuff tells me you have to bend metal past the point you want it to return to. Think about it. Think about why your brass doesn't go back into the sizing die (even using firm hand pressure). Then get back to me. The science is on my side. It's not that hard to understand. They basically said brass has more elasticity. That is why we reload brass and not steel cases.

[hylander]

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.

[Char-Gar]

I am not a science type and hold no credentials that would enable me to speak to the "spring back vs. no spring back" issue, but I do know a few things about handloading.

If you have a sizing die that is made to proper specs and an expanding plug that is correct for the bullet diameter, spring back, if such exists, is of no consequence. You will run accross the occasional lot of out of spec brass, but that is not common.

This board, and others like it, are a continuing source of amazement to me. Folks keep coming up with issues and theories that have never been a concern to handloaders before now. You would think that somebody would have discovered these things years ago. Folks have too much time on their hands, that would be better spend on the shooting range, where theory doesn't mean much. There, it is all about the hole in the target.

[W.R.Buchanan]

4WD: you need to read my posts a little more closely. Your dubbing in way too much BS trying to make your point.

I said the cases would go back into the die with hand pressure! There is still zero clearance, they don't just fall in, you have to push them fairly hard.

You are trying to compare bending steel to forming brass. They are two completely different animals. This is "common sense."

Brass is the most stable common metal available. If you look at microscopes and other precision instruments they are made of brass and the reason why is because it is both temp stable a stable in ductility. IE it stays where you put it.

When you machine brass you don't have to compensate for push back. You dial in your tool and the cut is taken. When you burnish brass, which is the process where you rub a roller onto the surface to produce a high gloss finish. You set the tool with a guage pin that is the same size as your finished size. There is no spring back because of the ductility of the material. The metal moves to accomidate the tool.

Thread rolling is the same process. Thread rolling taps come in generic sizes that yeild the exact same thread pitches if used in brass, aluminum, steel or stainless steel. All of these materials have different levels of ductility and different cofficients of expansion. Yet these tools are not built oversize to compensate for springback. They are built on size, and that size is what you get in the part..

When is the last time you drilled a hole? Did you drill it oversize cuz the metal would springback and close up on you?

Forming cases with a die is virtually the same process as burnishing . That is common sense where I come from.

I don't know why your brass springs back, but like I have stated above, I suspect you are getting bogus readings from your measuring tools. This is the only logical answer for why your inside and outside measurements have a .003 difference. IMHO

I suggest you take your cases and the sizing die to a machine shop and have someone else measure them with their tools without you present and then compare what they get with what you get. Then have them measure the same stuff again with your calipers. Bet thier results are different than your readings with either tool.

Hylander: Brass forms to the chamber and in cases of very high pressure magnum rounds it does not just spring back, the rifles action must physically extract the case, as it is physically formed to every nook and cranny in the chamber. This is why most all rifle rounds have tapered cases, and this is also why most hotrod magnum rifles are built on bolt actions. They have a higher mechanical advantage to extract the cases than other types of actions. On a Mauser action this camming surface is the angled cut you see at the top of the bolt handle and comes into play everytime the bolt is opened. It is there to physically jack the cases out of the chamber.

Immediately after firing, the cases are so hot they are expanded a significant amount and are effectively wedged into, and stuck to, the chamber walls, so the extraction cam is necessary. Larger the case the more effective it must be. NO big deal on a .223,,, Big deal on a .378 Weatherby Mag! More surface area in contact with the chamber walls to overcome, means more mechanical advantage necessary to execute. More pressure forming the brass to the chamber means more of the same thing.

On pistol rounds the brass gets formed to the chamber, and then shrinks slightly as it COOLS down to yeild clearance for removal. All it needs is <.001 to be free of the chamber. This is temp cycling not springback. Also this happens in a very few degrees of change.

Brass expands much more than steel does when heat is applied, but at room temps 70-100 F it moves virtually not at all. That's why they make the optical parts out of it. If it did move, then your telescope or microscope would change focus with every minute change in ambient temp. This would drive you nuts.

And what Char-Gar said above which really is the bottom line here,,, why is this springback stuff just now being discovered. I have never seen it or heard of it in 35 years of doing this.
Randy