Thread: Anyone crimp

22 Hornet from lymans cast manual.

I had a .22 Hornet for a while, ordered some .223 bullets in specially for it. Stupidly I checked them with the mic - no difference to the .224 bulk pack ones I was using prior to getting them in. I had used half of the pack at that stage - from that I'm not really sure that the 0.001" difference is actually that important if you work up the load properly. Fairly soft bullets, and the bullet has to mash into the rifling etc so I guess it all comes out in the wash...

As far as the question, crimping for subsonics - found it makes quite a difference to the velocity spread. I think that the primers create a wee bit of pressure and with lubed cast bullets it's probably shifting the bullet forwards on some of the rounds and altering the ignition.

I did the same for my ZKW Hornet. 223 projectiles weren't easy to find. Now I just use 224 projectiles. My rifle hasn't blown up yet and accuracy was the same 223 v 224.

I load a lot of Pistol calibres and also a few rifle, modern and older. Got advice/comments from a bunch of forums, and read plenty of opinions etc.

Result for me was
- any case mouth that gets flared to accept a projectile, e.g. an over diameter cast bullet, needs to be crimped at least back to straight.
- Pistol calibres are typically flared by the powder funnel in powder drop die to facilitate the seating of the projectile without shaving lead or catching and distorting the case mouth. With calibres such as 45ACP, the crimp die is used to reset the case mouth to level but not actually crimp. Reason being the 45ACP headspaces off the case mouth not the rim.
- Pistol calibres used in revolvers are usually flared to seat the bullet and are always crimped to remove the flare then more to lock the projectile and stop it from recessing or losening in the cylinder and jamming the gun. Crimping with a roll or taper crimp also helps with feeding a round into the cylinder smoothly/quickly. The Pistol bullet seating die traditionally seats and crimps on the same stroke using a taper or roll crimp depending on manufacturer/brand. Amount of crimp is determined by depth of the die in the press. RTFM.
- Pistol calibres used in lever actions are always crimped for the same reason as in revolvers except the recoil affects projectile security in the tube magazine. A bullet may become seated deeper with each shot to the point that when it is fired pressure rises alarmingly. Rifle calibres for LA rifles using jacketed bullets are also heavily crimped, eg 30-30, for this reason. The Lee FCD does a great job on these.
- Early black powder rifle cartridges may or may not have been factory crimped as a matter of course. I am a bit unclear on this. I think with black powder the case was filled so the bullet seated on the powder which prevented recession, and was held firmly enough by the thin brass at the neck not to require a crimp in rifles - e.g. cals such as 45-70, 38-55, 32-40, 22 Hornet etc. I don't know about revolvers but suspect crimp would be used to stop the bullet moving forwards, and the same cartridges would be used in LA rifles. In the latter, seating on a blackpowder charge would mean a crimp was superfluous and only there because of potential use in a revolver. But I'm no authority on this (well, on anything really)
- with the advent of smokeless powder, cases designed for BP present bullet security issues where the case is not filled. E.G. 38-55, 44-40, 22Hornet etc. There is no one rule for them because a straight wall case (45-70) differs from a bottleneck (22 Hornet, 44-40), differs from a tapered case, (38-55). I have 22 Hornet and 44-40 brass, nitro powder factory loaded that feature a cannelure style crimp in the brass neck that the base of the bullet is seated against to stop recession. I've never had an issue with 22 Hornet, the neck seems to be small enough diameter to easily retain a seated bullet in place. 44-40 has been problematic for me and I got a lot of advice of this forum and the dedicated 44-40 website. A standard crimp with say a Lee bullet seating die followed by a firm Lee collet die, FCD, crimp works well. Others have extolled different brand dies tapered crimps etc but I have not gone there. A novel idea was proffered on this forum where a small tube cutter was modified to blunt the cutting wheel and then used to make a cannelure style crimp in the brass neck of the 44-40. This is a PITA process but works really well.
- the tapered rifle case presents different issues. The 38-55 I found a challenge. The thin brass wall does not respond well to a Lee FCD unless annealed to just the right amount of brass softness/hardness to allow the crimp to happen without the thin case wall springing back or crushing. The best solution I found was given on this site which was not to resize the fired brass but to seat the bullet as fired, with the fingers even. Its tricky. Most cases this works well enough. The problem is the taper so that the narrowest place is the mouth, the further in the bullet is seated, the less the tension grip. This is a load I feel would most benefit from a neck cannelure but I have not got there yet. If you load BP there is no issue as the bullet sits on the powder. And no, do NOT use case fillers. Research this well if you don't believe me.
- Lyman and others offer specific separate dies by calibre to flare case mouths- Lyman M Die typically used for rifle calibres with cast bullets. Lee Pistol Calibre Lee Loader sets have a little whackamole flaring tool. Lee also makes a universal flaring die with two inserts that cover most calibres. Possibly not as precision as a dedicated Lyman M die but a small fraction of the cost for multiple calibres and does a good job coupled with the Lee Factory Crimp Die, (FCD)
- finally, I have tried Lee FCD crimps for jacketed bullets on the likes of 303B, 30-30, 308Win, 7x57mm with the idea of uniforming neck tension..I'm not convinced that on its own the crimp determines neck tension uniformity. For me, if the rifle is in good nick and all else is on par the only need for a crimp is if using cast and the mouth needs closing after seating. With older rifles of more dubious accuracy I found a crimp could help even on jacketed projectiles - but I have no science around that. There are so many factors especially in an older worn rifle that affect accuracy. Isolating the effect of crimp/no crimp I found to be tricky.

Anyway, hope this is of interest to someone.