Death Jam

[IDescribe]

Garmil, on a progressive, the shellplate flexes a little differently as the plate fills up at the beginning of the loading sessions.

Personally, I pull my first five bullets for the practice bin.

[peterthefish]

Changing your OAL is quick, free, fool-proof, requires no additional tools, and is most importantly -- reversible. Reaming your barrel is none of those.

Reaming a barrel isn't reversible, but it's not the end of times either. Running a throating reamer a few turns in a barrel of mine allowed me to run my 9mm major ammo at a safe OAL and had no impact on accuracy - I didn't even have to change zero. Best $45 I ever spent.

[IDescribe]

There are reasons to ream your CZ. Yours is a good one. If I wanted to run major in a 75, I would do the same thing.

That's not what this guy is doing, though. This guy is trying to account for the variations in the first and last five bullets off his progressive press by making a permanent alteration to his firearm. It makes no sense.

[IDescribe]

ZHunter, another way to look at this is this:

The eerw who responded earlier in this thread is a grandmaster shooter who is a CZ specialist, works for CZ Custom, and stands to make money when people are looking to have their CZ barrels reamed. His recommendation was for you to load shorter. Food for thought.

[longbeard]

I struggled with loading shorter as well because I wanted to share ammo with my other guns. I came close to reaming, but am glad I just moved to a shorter OAL. I've never looked back and my other guns eat the shorties just fine.

Note that it's definitely profile dependent. 147FP have to be shorter than RN.

[LeviSS]

I am going to throat the barrel a bit to give some leaway but will not change my OAL

That's like cutting off your toes to get your shoes to fit.

That made me laugh.

IDescribe - every time you post, I pick up something that helps me understand reloading more clearly. I've read a lot of manuals, but none of them make it as clear as you do. Thanks for all the tips.

[JRM83]

Also, try to figure out why the OAL of that round was so out of spec. User error or something in the setup? Reaming will help but it really masks the issue.

Usually one of the last rounds through the press in a run. Without a case being sized exerting pressure on the opposite side of the shell plate OAL can grow a bit. Easy enough to set aside and plunk test the first and last 5 rounds out of a batch.

I have noticed the opposite effect. The case being sized and going through the powder measure creates more distance between the shellplate and dies. When those cases aren't there the last round gets seated a bit shorter.

In the rifle world accuracy is usually found loading closer to the rifling rather than farther away. Unless you need the rifling out farther so you can stuff more powder in the case there is just no reason to ream the chamber. More accuracy, less powder, and the rounds are guaranteed to chamber in any gun with a longer chamber. Short isn't bad, its good.

Edited November 10, 2015 by JRM83

[IDescribe]

I have noticed the opposite effect. The case being sized and going through the powder measure creates more distance between the shellplate and dies. When those cases aren't there the last round gets seated a bit shorter.

Different users, different presses, different dies, different station setup, different press cusomizations, different results. My Dillon 650 with a Redding Expander (which works like an M-Die, takes much more force than a regular expander) at station 2 and a Hornady powder drop at station 3 is going to flex the shellplate differently than someone with a Dillon powder drop and PTX expander at station 2 and a powder cop or bullet feeder at station 3. Then there's differences from press to press from different manufacturers and models.

You can, will, and should experience different results from others.