Just Curious

[DonHowe]

How many crimp cast bullet rifle loads vs neck tension?

Revision:
After reading the first reply I realized I had been thinking at the time I started this I was thinking of bottleneck cartridges but did not make that clear.

[mehavey]

Unless . . .

It's a single-shot BPCR w/ bullet in contact with the lands
-- or --
It's a straightwall-headspace on-mouth cartridge . . .

...always roll crimp

[JonB_in_Glencoe]

I do both, lots of factors involved.
Semi-auto, or not semi auto?
boolit seated to lands? or boolit jump?
tight chamber/throat, or loose/worn/eroded throat?
Are you counting on Obturation happening?
a Crimp is a good way to bump pressure a little bit, do you want that? or would you prefer it not happen?
Sometimes it's desirable to not only "not" crimp, but also leave the flare, to center the cartridge for that perfect launch.
...and there are more things...

[AndyC]

The only rifle caliber I cast for currently is .300 Blk - I don't crimp because the neck-tension is pretty massive. In my J-word .308 pills through semi-autos and bolt-guns, I don't crimp either - I don't recall ever having had an issue caused by lack of crimp.

[onelight]

I crimp in tube fed lever guns , and semi autos.

[mdi]

I agree with all posts above. JonB is the closest, same as my thinking, in other words, depends...

[WebMonkey]

i use a lee factory 'crimp' collet style die on my .308 loads.

i do that because it makes my novice loading more consistent.
it also allows me to rough handle the loaded cartridges without worry of unwanted projectile movement.

i hunt under 200 yards on my own land and cloverleaf my rounds at 100yds.
so for me, my useage of the FCD is most acceptable.

good luck!

[DonHowe]

Unless . . .

It's a single-shot BPCR w/ bullet in contact with the lands
--

When I shot BPCR Silhouette a few guys I knew did not even resize their cases before reloading with black powder, the bullet just being a slip fit and finger seated. That never suited my thinking but the one gentleman (he'd like that) wS usually near the top of the scoresheet so his method worked for him.

[Winger Ed.]

I'm only shooting .308, .30-06, .30-30, and .45-70 rifles with cast now days.
The brass is all trimmed, and I put a slight roll crimp on them.

Handgun calibers aren't trimmed, and they all get a taper crimp.

[charlie b]

I try it both ways to see which is more accurate for the bullet, cartridge and load combination.

[GregLaROCHE]

It all depends. I always try to crimp the minimum possible, because I think doing so, increases case life. If I am loading hot rounds in a tube fed magazine I normally crimp hard, however, the same round I may only taper crimp, if I know I will be loading them individually.

[rbuck351]

I just remove the flair enough to ensure good feeding except for revolvers that have boolit creep. I put a very heavy crimp on the wifes lcr in38spl. But on the other I don't crimp on my 454 Puma as they want to seat deeper instead of creeping out and they are are already a compressed powder charge.

[Jim22]

Crimping can also help the powders combust properly. Especially with spherical, double base powders. The folks who make spherical powders like these control burning rate by applying rather thick coatings. That makes them meter through powder measures better but also makes them a bit hard to ignite. I discovered this with my rifle in .357 MAX. I was using regular small rifle primers and got vertical stringing in groups. The groups were about an inch wide and three or so inches tall. I switched to small rifle magnum primers and applied a rather heavy crimp from a Lee Factory Crimp die. Groups settled right down.