How much crimp?

[seabee23]

I just loaded up my first batch of 5.56 to go out and test. I have decided that since they will be shot out of my AR, that I would go ahead and crimp. I am crimping a rem 55gr fmj w/c using a Lee fcd. I set it up in reference to the directions. I know there are many different opinions on this forum as to how much crimp is good. My question is, is there such a thing as too much crimp if you are not damaging the bullet. I have noticed that on a couple different brands that the there is enough crimp that you can see a ring, and the brass has some small marks from the crimp die. Thanks for the help. Just want to make sure that this wont cause the pressures to Jack way up.

[RiggerJJ]

check the crimp by pulling a few bullets. I set mine up by adding crimp until I see a dent in the bullet, then back it off just a slight amount...

jj

[kamikaze1a]

You could also let your groupings tell what your bullet/barrel likes. I marked my die for indexing reference and shot groups with different amounts of crimp. Crimping with the Lee FCD to almost full crimp gave me a slight advantage.

[pjb45]

You are using a taper crimp right?

I put a loaded round in the shell plate, ran the head down with the die in the loosest position. I screwed the die down until I felt a slight resistance of the die contacting the shell. Then I ran it down another 1/3 turn. My brass shows a small band around the top where the taper crimp compressed the brass. It burnishes the top .003 of inch of the brass.

Too much crimp is a bad thing. I am running about 2900 fps so I do not want to see any pressure signs on my primer.

If you have a bullet puller you can guessetimate if you have too much. If you have to bang it many times and you can see drag marks on the bullet, the crimp is too much.

WHATMEWORRY has calibrated fingers, freshly trimmed brass will have a well defined edge. The taper crimp just relieves the edge enough to make it feel smoother. WHATMEWORRY has the tools to actually measure the crimped amount. PM him and ask his advice.

[seabee23]

I am using a Lee factory crimp die.

[kamikaze1a]

There are some who feel the FCD is bad...try it out. Let your groups decide for you.

[BillL223]

I do not use any crimp on any rifle load. Many thousands of rounds and no issues.

[Paul-the new guy]

I used the Lee factory crimp die on 100 .223's that I loaded last night. I followed the instructions to the letter and the amount of crimp seems to be excessive. I am almost affraid to shoot them.

[RiggerJJ]

I used the Lee factory crimp die on 100 .223's that I loaded last night. I followed the instructions to the letter and the amount of crimp seems to be excessive. I am almost affraid to shoot them.

just use them for short range blasters. the excessive crimp should not cause any pressure problems with 223, IMHO...

jj

[kamikaze1a]

I used the Lee factory crimp die on 100 .223's that I loaded last night. I followed the instructions to the letter and the amount of crimp seems to be excessive. I am almost affraid to shoot them.

If you feel the crimp is excessive, back out the die partially. Go shoot some groups with full crimp, partial crimp and no crimp...let your results dictate what your barrel/load likes. Personally, running some sort of crimp with a self loader is a good choice. If your neck tension is not enough, the bullet slamming into the feed ramp could give you bullet setback. With some loads, bullet setback could result in excessive pressure.

[mike_pinto]

I do not use any crimp on any rifle load. Many thousands of rounds and no issues.

What he says.

[Kyle O]

I use just the right amount of crimp without any issues, also many thousands.

[kamikaze1a]

I do not use any crimp on any rifle load. Many thousands of rounds and no issues.

What he says.

Glad to hear that. I crimp and have had an incident of bullet setback. Fortunately, the round did not feed right and discovered the setback before pulling the trigger. Probably would not have gone kb but none the less, glad I did not pull the trigger...

The proper crimp, good insurance with no negative impact on grouping.

[Paul-the new guy]

I used the Lee factory crimp die on 100 .223's that I loaded last night. I followed the instructions to the letter and the amount of crimp seems to be excessive. I am almost affraid to shoot them.

If you feel the crimp is excessive, back out the die partially. Go shoot some groups with full crimp, partial crimp and no crimp...let your results dictate what your barrel/load likes. Personally, running some sort of crimp with a self loader is a good choice. If your neck tension is not enough, the bullet slamming into the feed ramp could give you bullet setback. With some loads, bullet setback could result in excessive pressure.

My 20" AR rifle seems to like the aggresive crimp. I shot multiple 10 rd groups and all of the best ones came from the rounds that I cripmed in the Lee FCD. I don't really like the looks of the necks on the brass though, the crimp marks are still very evident.

[kamikaze1a]

I used the Lee factory crimp die on 100 .223's that I loaded last night. I followed the instructions to the letter and the amount of crimp seems to be excessive. I am almost affraid to shoot them.

If you feel the crimp is excessive, back out the die partially. Go shoot some groups with full crimp, partial crimp and no crimp...let your results dictate what your barrel/load likes. Personally, running some sort of crimp with a self loader is a good choice. If your neck tension is not enough, the bullet slamming into the feed ramp could give you bullet setback. With some loads, bullet setback could result in excessive pressure.

My 20" AR rifle seems to like the aggresive crimp. I shot multiple 10 rd groups and all of the best ones came from the rounds that I cripmed in the Lee FCD. I don't really like the looks of the necks on the brass though, the crimp marks are still very evident.

You did right by trialing the performance. As with just about everything, what works for one might not for another...so I am sure, crimping would not work for everyone.

I too found that crimping with the Lee FCD improved my groups and that a moderate crimp with the same gave me better groups than a mild crimp or no crimp. You could back out the die a bit and try various levels of crimp for comparison. Mark the die with a marker and you can use the mark to index the amount of crimp.