Crimping the 5.7x28mm

[curlysir]

I used a 22 hornet FCD as the starter for modification and my shell holder is a hornady. My final collet length was 1.075" which gave me about 20 to 30 thousandths on the crimp. Since you are using a different FCD start by sticking a resized/trimmed piece of brass in the shell holder and measure the length of the brass sticking beyond the holder. Then add about 75 thousandths to that for a starting length. You can then grind off some as you test to get the crimp width you want – better to start long and trim down (I trimed to much on mine initially). However, if you trim too much you can always bond/weld a thin piece of shim material to the bottom to thicken it back up (what I did). You can also check the thread viewtopic.php?f=19&t=1438" onclick="window.open(this.href);return false; for FCD modification.

Thanks for the the reply. Right now somewhere around 1.083" +/- appears to be what I am shooting for based on my collet. My 218 Bee collet is 1.292" long which is .053 shorter then the 1.345" case length. Using the same reasoning for the 5.7 X 28 the length should be 1.135" - .053 = 1.082" +/-. Using your method of adding .075" to the length of the shell above the shell holder gives me 1.008" + .075' = 1.083". I think I will start at 1.100" and trim from there based on crimping results.

[starfury]

Sounds like a good plan! If I remember from the other threads the bee FCD might have issues with hitting the case shoulder if it is shortened too much - so move up on it slowly and stop when you get a good looking crimp. Good luck!

[curlysir]

Here is what I have ended up with. Lee 218 Bee FCD. Collet Length 1.093", Threaded collar Length 2.0".

This gives me a crimp length of between .030 and .040" depending on case length with a diameter reduction of between .002" and .003". This is with a Lee Turret Press.

Is there a "Idea" crimp length to try for?

[starfury]

My final crimp length is about 0.030" and has worked fine. I think you are good to go!

[s64woody]

I bought a Lee 218 Bee Factory Crimp Die to modify for use with the 5.7. The collet slots ended up being more than short enough to allow it to be shortened to function with the 5.7 case. I THINK we ended up taking .235 inches off of both the collet and body.
A lath is a wonderful thing.

[s64woody]

The Lee Factory Crimp Die mentioned above ended up producing very nice .030 inch wide crimps on my cases.

I am now curious just how much effort should be expended on the crimp? On my first attempt I think my caliper shows about .004 inches reduction in diameter after the crimp is in place. Is this enough, too much or what?

The bullet being crimped is a Sierra 40 gr. Hornet, #1200, which does not have a cannelure.

[DAVADAR]

I hope not to step on anyone's toes, but I found out a while back while looking for a Lee factory crimp die for my .300rsaum (Lee factory crimp dies, in my opinion, is lees best invention. They have some other good stuff, but most companies have better, though you definitely pay for it.) that you can get a custom made factory crimp die from Lee for $25, just send two empty shells of the required caliber, I assume trimmed to optimal required length. I've never had a problem with a Lee fcd, and seem to give better accuracy than without.

[empty_head]

I prefer to follow the following reloading premises on crimping bottleneck cartridges:

First: Try seating your bullets without expanding the neck. Depending on the elasticity of the batch of brass your cases were made from that should do the trick. Watch the first few bullets going in to make sure the copper jacket is not being shaved.

Second: If the jacket is shaving then set the neck expander ball to open the top .005 of the case just enough to stop the shaving. The bullet will push its way in and should have sufficient neck tension. Normally this should be the end of experimenting with crimps. A crimp's only purpose is to keep the bullet from coming out under recoil. I believe most readers would agree recoil is close to nonexistent.

Third: If your neck expander always opens the case mouth too much, fix it. Remove it from the die and caliper the diameter. If the diameter of the expander ball is larger than .226 it is time to get out the 1200 grit carborundum paper. DO NOT USE A DREMEL TYPE TOOL. Hold a small square of sandpaper in your off hand. Using virtually no pressure on the paper rotate the expander a short time. Wipe the expander clean and caliper it again. Be careful to keep the expander as round as possible. After sanding your expander down to .226 start over at the First step until your bullets seat without shaving. The best carborundum paper I have found is at Harbor Freight. It is made in India on a yellow backing paper.

Fourth: To salvage cases that have had the mouth opened too much, slowly adjust in a very slight taper crimp. NEVER use a roll crimp on a rifle cartridge. You do not really want to crimp the case, you just want to restore the shape of the brass as close as possible to original.

Remember, using a crimp increases pressure, reducing velocity and accuracy. These are only my opinions and information I have taken from others. These guidelines have served me well up to .308. Use them at your own risk. Crimps should be used only when called for. I have never crimped a 5.7 case except to repair carelessness with the Third step. Thanks for listening and snipe at will.

[satellitedr3ams]

Lee makes a factory crimp for the 5.7 now. I will do a review once I use it. till then, anyone else feel free.

http://leeprecision.com/fact-cmp-die-5.7x28-fn.html" onclick="window.open(this.href);return false;

[Rapier1772]

I'm too skeered to crimp my 5.7 loads, too easy to overpressurize it. I've never crimped a bottle-necked round, just the roll & taper crimps on straight cases.
Good luck y'all.

[satellitedr3ams]

Took the lee crimp all apart and cleaned up the metal flakes in the slits of the collet and just smooth any rough parts seen with some files & flitz. Seems to work just fine.

[Kiran04]

If I'm going to try crimping my loads, how much do I need to lower the charge?

[DoubleJ]

I recently got the Lee FCD and I"m pretty happy with it with my cast loads. Haven't used it for anything else, quite a neck on the 5.7. Unless you're up near max, I don't think it'll give you any pressure issues putting a crimp on. Maybe do a known safe low charge, ten crimped and ten not, see what your velocity difference is. Theory says your ES should drop also, but I hear that's not always the case.

[panzermk2]

A good crimp, min 5k psi increase and your pressure spike is sooner.