silly question. Bullet setback

[harkamus]

Am I correct in my assumption that as long as your reloaded ammo is ~.015 inches less than the overlength measure, that you should never encounter bullet setback? I just stumbled upon this revelation when I thought about it a sec. Just wanted to make sure I was correct. If I am correct, than in theory, reloaded ammo should never have set back since the projectiles never engage the rifling prematurely due to the ~.015 margin for jump gap prior to engaging rifling.

[Wobbly]

Bullet setback could be caused by numerous issues. Overly long OAL is probably number 1 in CZs, but certainly not the only cause.

For instance, if your expander sets the case inside diameter too big, then the bullet will be loose in the case neck and walk in and out as the cartridge gets slammed around.

 

[harkamus]

Bullet setback could be caused by numerous issues. Overly long OAL is probably number 1 in CZs, but certainly not the only cause.

For instance, if your expander sets the case inside diameter too big, then the bullet will be loose in the case neck and walk in and out as the cartridge gets slammed around.

 

I forget the name of the die, but shouldn't the reloader tighten the neck again after priming, charging, and seating bullet? I mean that seems common practice at least in my mind. I know I have a die for this. In fact when I measured over length, I was using resized brass, which made things a bit more difficult but a bit more accurate. I couldn't push the bullets in with hand strength. I had to actually seat the bullet deeper and deeper using my press, always measuring the length and doing the drop test. Made several bullets this way to confirm my measures. Anyway, just thinking out loud. I do see your point though.

[Wobbly]

No, the reloader should load the ammunition correctly to begin with, and then leave it alone. The more you squeeze and squooze on the neck of the cartridge the looser the bullet gets in the case mouth.

If you have the famed Lee "Factory Crimp Die" (FCD), then you need to be aware that is causes as much trouble as it cures. It's a huge double-edged sword.

A ton of information already exists on this web site about 9mm and taper crimp. Some reading would be in order.

 

[harkamus]

No, the reloader should load the ammunition correctly to begin with, and then leave it alone. The more you squeeze and squooze on the neck of the cartridge the looser the bullet gets in the case mouth.

It you have the famed Lee "Factory Crimp Die" (FCD), then you need to be aware that is causes as much trouble as it cures. It's a huge double-edged sword.

A ton of information already exists on this web site about 9mm and taper crimp. Some reading would be in order.

 

Gotcha. Always willing to educate myself. Will do more reading after I finish priorities. Grad school stuff.

[1SOW]

As the man said,  when your bullet is seated  the flare on the case mouth is  removed with a taper crimp either on the seating die or a separate taper crimp die.
Either way, what secures the bullet in the case is "NECK TENSION" gained by a properly sized case.

[harkamus]

As the man said,  when your bullet is seated  the flare on the case mouth is  removed with a taper crimp either on the seating die or a separate taper crimp die.
Either way, what secures the bullet in the case is "NECK TENSION" gained by a properly sized case.

Yea, mine seem to be fine so far after several thousand reloads of 9mm and a couple thousand of .45. I guess for me the Lee FCD has worked fine thus far. But I will do more reading about that sort of thing when I get a chance.

[1SOW]

I use the LEE FCD with complete confidence.  I think it can also be 'mis'-used if not adjusted properly.

[grapnel]

I use the FCD so I can seat and crimp in two steps. Haven't had it do anything but remove the slight belling I apply, and my plated bullets remain intact just like my jacketed, so I think I like it.

[1SOW]

My experience in 9mm'only:
The LEE FCD carbide "sizing ring" is criticised by many as SQUEEZING the case & BULLET to a smaller diameter, damaging the bullet in the process.  That diameter they are talking about is the SAAMI max. 9mm cartridge diameter.

I load and shoot on average 1K+/month 9mm for years using the FCD  for the vast majority of those loads..  The only bullet damage I've witnessed is when the FCD crimp adjustment is set too small for the bullet diameter and case thickness.  That is one of the reasons I sort by headstamp.   With mixed headstamps and the taper crimp set for a thin case, it can indent the bullet when it's in a thicker case.  (say a 5X shot FC/CCI case=thin  vs a once fired WIN/WCC case = thick)

Can loaded cartridges exceed SAAMI max?  YES, AND they can feed and fire in some pistols/carbines. 

Before I reloaded I used and stocked up on reloaded ammo from a reputable licensed company, 124gr plated RN bullets at 1075 ft/sec.  After some time using these,  I got an order that wouldn't feed reliably.  The company sent me replacements and they wouldn't feed.  I started reloading.

Much later on, I ran those 'oversize diameter bullets' through the FCD with no crimp.  It did lessen the diameter and they fed and shot fine.  The cartridges were originally too big for the CZ 75B.  I don't recommend this procedure,  but it does illustrate what the FCD WILL SQUOOSH,  cartridges that exceed SAAMI max.

YMMV and that's OK too.

P.S.  I STILL had some of that ammo in the closet and shot it in a Colt carbine recently.  Shot great!


 

[Wobbly]

The biggest FCD issues are reported by users who load over-sized lead bullets. The FCD can smush (that's a highly technical term we mods use) the bullet as well as the case. So you could order and seat .358" bullets (specially sized to your barrel), then have .355" bullets coming off the 'production line'.

Also, some early models of the FCD were recalled because they were way undersized.

You do need to be careful. 

[harkamus]

I don't load lead cast lead bullets. I prefer minimizing lead exposure as much as possible even if the lead bullets are coated. In fact, I've only loaded Montana Gold JHP.

[Wobbly]

You'll get more lead in your body from your tumbler than handling lead bullets.

[1SOW]

As a kid (and some of us even now), didn't you squeeze split shot closed with your teeth when you went fish'n?

[harkamus]

You'll get more lead in your body from your tumbler than handling lead bullets.

I know most of the lead is from the primer, but the bullets also have lead. I figure I'll minimize it as much as I can. I mean, why not?