Crimp or no crimp? - .223 loads w/ SMK 77 gr

[mark5pt56]

So, I lucked out and found 1 pound of Varget and 4 of H4895. I have some more SMK 77's w/cannelure enroute. Question is, I haven't crimped in the past with these, haven't had issues. Does anyone use the Lee Factory Crimp Die? I just picked one up, mainly to have.

Reading the Lee book, test state that the inconsistancies were less with a crimp vs. no crimp.


Thoughts ?

Mark

[Artos]

I'm loading 75 hornady's and have not seen any need to crimp yet....I can tell I have good neck tension when seating & always prefer to not crimp coming from a benchrest background.

[ra2bach]

you like 4895 for .223?

[sinister]

If you're going for precision you should use a neck-sizing die (I'd recommend a Redding S-die with a .245 bushing).

Crimping case mouths into bullets or merely squeezing the case necks into the bullet jacket causes inconsistencies in the jacket and core -- exactly what the bullet manufacturer was trying to PREVENT if they were making match-grade projectiles.

A properly sized neck will provide enough neck tension that you will never need to worry about bullet set-back and will be consistent enough to give uniform pressures.

[chadbag]

What kind of gun?

[mark5pt56]

This is an AR, so that neck sizing is out, well aware of that for the bolt guns.

I'll do some test, just got the crimp die. So far without crimp, I'm getting .5 to .6 with the 18" Stealth. Two different charge weights of Varget and 69/77 SMK's

I'm trying the H4895 since there's no Varget around. I called Sierra today and got the data for the 2 bullets weights.

The only other powder I've used for .223 is 748(to temp sensitive) and 4320, worked great and accurate (69 gr SMK/Oly Ultra Match)

Mark

[99merckx]

If you're going for precision you should use a neck-sizing die (I'd recommend a Redding S-die with a .245 bushing).

Crimping case mouths into bullets or merely squeezing the case necks into the bullet jacket causes inconsistencies in the jacket and core -- exactly what the bullet manufacturer was trying to PREVENT if they were making match-grade projectiles.

A properly sized neck will provide enough neck tension that you will never need to worry about bullet set-back and will be consistent enough to give uniform pressures.

This is what I have learned.

[MustangGreg66]

Interesting topic and lots of opinions and info here. I started loading Hornaday 55gr FMJs for my AR earlier this year and never crimped, then recently started using my Lee crimp die, setup to just barely touch the cases.

I'll have to do some accuracy testing between crimped and non crimped and see what holds out for me. I'd be interested to see what you guys discover through range testing as well.

[Nightvisionary]

I don't crimp and from the research I did before deciding not I didn't find any reports from actual shooters that experienced any bullet setback or other issues from not crimping.

[markm]

I don't crimp and from the research I did before deciding not I didn't find any reports from actual shooters that experienced any bullet setback or other issues from not crimping.

That's specific to each loader and his equipment. There's a ton of variables to consider. But I agree that set back is rare. I find set back rounds at the range all the time. But those rounds were factory crimped and were a weapon problem, not an ammo problem.

For bulk practice ammo, there's no downside to crimping. And the position is there on the progressive for me. So I put a light factory crimp when running regular bulk 55 gr FMJs.