IMO, if you are reloading for accuracy you want to eliminate any variable you can. I don't know how the Lee die works but I don't see how you can get a consistent crimp if the cases aren't pretty darn close to the same length.

Chambered221 brought up a good point too. If the cases get so long that the mouth is forced into the lead, not allowing it to release the bullet right, you're going to get high pressures.

Once again, I'd follow manufacturers' recommendations. According to the Lee Second Edition manual, page 46, "Remember, cases do get longer and must be trimmed or they will pinch the bullet at the end of the gun's chamber. This will cause higher and possibly dangerous pressures."

I guess first of all you need to understand how the Lee FCD works. But I have to go out and blow snow for a few hours.

Since the sun is shining here, I will explain that the FCD from Lee is a collet crimp that will squeeze to a specified diameter no matter what the length of the case ( within a +/- .010) it puts a uniform crimp around the brass. If you set it real tight it will even "cannelure" your bullets. This is why Speer said not to use it with thier bullets.

Since we are on the subject of a consistent crimp...........

Also keep in mind that different brands, batches, and lots of brass will have a different wall thickness also.

This is how/why I got onto the Lee FCD.
I found that using a variety of headstamps gives a inconsistent outside diameter of a loaded round. Combine that with another 1 or 2 thousanths of a lead bullet and things start to get tight in the chamber. American brass with a lead bullet will jam my 45 evrytime. Cost me a match one day. ( it was only a local match, nothing big )
After jamming the gun up about a dozen times, the culprit was finally found.

After talking to some friends about the problem someone suggested the Lee FCD. He explained it like this: "The Lee FCD is a resizing die with a crimp built into it." Don't know if he's right but it seems to work that way.

The FCD is a good tool for anyone using a mixed bag of headstamps in their pistols.

Chamber21 and all those interested. Go to your loading bench. Pick up your favorite calipers and measure a few case wall thicknesses. I think you will find that the difference is nominal and really won't count for anything. You might try weighing a few different cases too. I have found that they are very close with a few non-military lighter then the civilian cases. Maybe in the old days wall thickness and case weight was a factor, but I doubt that it is now...I could be wrong...Sooo go weigh and measure a few...So miniscual I don't even pay any attention to it anymore...Load'em-shoot'em-load'em again...

Sorry Bushy can't do that........... Don't have a ball micrometer...............

Reason I don't have one is the reason you stated for the most part. Don't need it. Brass today is pretty consistent.

My troubles were from a mixed bag of brass that was military and commercial together. Alot of it was from a buy out deal from a guy who had some of it around for the last 35+ years.

Dawgdad wrote:

Since the sun is shining here, I will explain that the FCD from Lee is a collet crimp that will squeeze to a specified diameter no matter what the length of the case ( within a +/- .010) it puts a uniform crimp around the brass. If you set it real tight it will even "cannelure" your bullets. This is why Speer said not to use it with thier bullets.

Thanks Dawgdad, I couldn't have explained any better.

We had a blizzard overnite and until 2 pm and my driveway and sidewalks around my house (corner lot) as well as in the fenced yard had several feet of snow on them. I had to get the driveway clear so when the wife gets home from work at 6pm she could get into the driveway. All I can say is, Thank God for snow blowers.

Just a note about Lee FCD dies.

Rifle dies use a collet.

Pistol dies do not, they have a carbide sizer.

Bushmaster wrote:

Chamber21 and all those interested. Go to your loading bench. Pick up your favorite calipers and measure a few case wall thicknesses. I think you will find that the difference is nominal and really won't count for anything. You might try weighing a few different cases too. I have found that they are very close with a few non-military lighter then the civilian cases. Maybe in the old days wall thickness and case weight was a factor, but I doubt that it is now...I could be wrong...Sooo go weigh and measure a few...So miniscual I don't even pay any attention to it anymore...Load'em-shoot'em-load'em again...

I have 200 WW brass and 300 Remington brass for my .45-70 and the remington brass weighs 195.2 gr on avg and the WW weighs 168.9gr on avg.

I use the Lee Factory Crimp die on my .243 Win and it is great. I will never go back to a roll crimp or rely on neck tension again. The good thing about the FCD is every round will have the same tension on it , regardless. Accuracy did improve as soon as I started using the FCD though.

According to the blurb that comes with the FCD, quote "Trim length is not critical" unquote.

I use Remington 80gn SP bullets and they have a cannelure from the factory, however prior to that I was using the Speer 70gn SP without a cannelure. I could not discern any drop off in accuracy when using the FCD...even when crimping tight enough to form a cannelure.

One of the things that Lee claim is an improvement in accuracy with bullets that do not have a cannelure if tightly crimped. Accuracy is one thing, but performance as intended by the manufacturer is another. I cannot say that the bullets that were "crimped" would perform exactly as intended. Having said that, I couldn't imagine that there would be any significant change in expansion or weight retention after being crimped by the Lee FCD...but then again, I could be wrong...I have been once or twice in the past...but I certainly couldn't notice any difference.

For those that haven't seen a Lee FCD I have included some pics below.

Cheers, Vince

Thanks Vince. I assume that the inner piece moves up and down with the case and is squeezed in as it comes up?

1895ss...Like I said "I could be wrong" That's why I told everyone to weigh cases themselves. I just knew you would go out of your way to prove me wrong. Bet that took some time out of your life. Just how old are those .45-70 cases?

Chamber21...You reload and you don't have a caliper? Calipers are kind of a universal measuring tool. They are capable of measuring inside, outside, thickness and depth.

Vince pictured a rifle (collet) FCD. Here is a FCD for .38/.357 revolver...

Bushmaster wrote:

1895ss...Like I said "I could be wrong" That's why I told everyone to weigh cases themselves. I just knew you would go out of your way to prove me wrong. Bet that took some time out of your life. Just how old are those .45-70 cases?

Bushy, but no I didn't have to go out of my way at all. I had that info in my reloading notes. I keep records of all my reloading activities, loads, components etc. The WW case are 9 years old and have been loaded three times and the Remington cases are 7 years old and have been loaded twice. I use the Remington brass for high power loads and the WW brass for lighter loads.
Ops almost forgot, I also have 60 remington brass, from factory loads, that has been loaded 3 times. I bought three boxes of factory loads when I first got my 45-70 and reloaded them until the new WW brass I had ordered arrived. I haven't used them since I guess that's why I forgot them.

I see the pistol FCD is different. When crimping, does that inner piece move up and down as well?

There ya go...The lighter ones are worn out. That's why they are lighter.
Yes, it moves as to where the adjusting knob is set. You adjust the amount of crimp with the knob on top of the die. The ajusting knob is hollow so it won't disturb or move the bullet. What's interesting is if you want a very light crimp, you will get a roll crimp. If you want a heavy crimp you will get a taper crimp from this die. Go figure.


In summary and back on topic. As far as I'm concerned the "case length is critical" in the manufacturing ammunition if for no other reason then the fact that you are inspecting the case one more time...

Bushmaster wrote:

I just knew you would go out of your way to prove me wrong. Bet that took some time out of your life.

Yep Ok, I'll go back to my life now ...............