Load Manual OAL vs Push Test Results

[Wobbly]

Thank you, Wobbly! I need to educate myself before starting reloading - things are more complicated than I expected.

• It's not really that complicated, it's just that the European 9mm barrels make you do a few more calculations before starting to make sure you're safe. I'd much rather have people start on 45ACP, but they typically confuse the small size of 9 for "easy".

• But even then the calculations never take more than 3-5 minutes. It's a lot more 'common sense' than 'rocket science' !

• What I'd suggest you do with ammo you didn't load yourself (factory new or factory reloads) is slip about 10 consecutive rounds into the naked barrel. Let them head space on the end of the chamber, and then see if the cartridge will rotate smoothly.

I know that many favor Berry's 124gr RN for reloading, but Lee manual says OAL: 1.115 for 124gr RN plated bullets, some recipes I found online for Berrys 124gr RN even say 1.116.

• The stated OAL is a report of the length used in the test, NOT a recommended OAL. Please look around the Lee data. Nowhere does the word "recommend" show up.

• The bullets from Berry Mfg are the exception rather than the rule. They use such a slender ogive that they have NO issues in the CZ 9mm barrel. You can use any OAL you like with Berry, but it is NOT that way with other RN bullets in the CZ chamber. All other bullets need to be measured on an individual basis. There simply are no 'rules of thumb' or guidelines for guessing what the OAL might probably be. It's all explained here: https://czfirearms.us/index.php?topic=103620.0

But, from the other side - CZ barrel needs less OAL, so how it is possible to accomplish? Reducing powder charge?

Most common powders, especially modern powders, don't fill a 9mm case. What you want for reloading is one that fills about 1/2 to 2/3. That way a double charge completely fills the case, and probably even overflows, thus giving a visual indication of trouble.



And although it's not a great practice, it's even OK to 'compress' most of the powders now sold. As you can see in the photo above, the bullet will occupy all the empty space, thus making a nice tight cartridge construction.

Hope this helps.

[daved20319]

And check magazine fit/feed, etc., too.

I was loading some .45 acp (230 grain LRN) for that new XD 5" Tactical .45 I bought last spring.  Pulled the barrel, adjusted/tested (plunk test) till I got what I wanted and load a box for the next range trip.

Started trying to load the ammo in the magazines and I'd get 4 or 5 of them in before they'd hang up.  Overall length just fine for the chamber - too long for the magazine.  I've never run into that problem before.

Check both.  Chamber and magazine.

Yeah, I have the same issue with my SIG and truncated cone bullets.  No issue with chamber fit, but the mags are a PITA.  My 97 BD eats everything (so far).

[CzechnoWizard]

As Wobbly has come so very close to explaining, the oal listed in the load manual has nothing to do with assuring a particular load will feed thru the geometry of your pistol and into the chamber. It is actually published as a minimum oal to be heeded when working near or at the listed max load. Reducing oal drives pressures up. Doing so on a load already at max can be quite dangerous. If you need to run a shorter oal than listed  (presumably to obtain proper fit and headspace in your particular chamber), then you need to stop your load development  at some point lower than the published max. Exactly where is hard to predict so you will have to rely on other signs or commission some kind of lab tests to determine pressure with your reduced oal. Best bet is to try a different combination of powder and or projectile until you find a combo that chambers without having to reduce the oal into that realm where you cannot trust the published data

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