How to calculate OAL?

[JRHawkins1118]

I’ve been watching several videos on how to determine OAL on YouTube.

I’ve seen several doing plunk test. Then tapping on it while it’s in chamber to make sure it doesn’t stick or ride the lands.

I’ve also seen one video that demonstrates how to actually calculate what the OAL should be.

What would you suggest for a guy new to the hobby? I don’t want to load to factory because my CZ cartridges were too long.

Thanks in advance!

 

[indyblue]

It sure doesn’t take me much longer than it took him to calculate just by dropping the round into the chamber and see if I can rotate it making sure it’s off the lands.
If not, I simply crank seating in 5 to 7 thousanths, it takes me between 90 seconds and two minutes to get it, right.

 

[shootersix]

Micrometer is what I use!

Remember coal and plunk are different!

My reloads are 1.13 coal, and will drop into my sigs no problem at all!

But they stick in my shadow 2! They won’t even chamber!, the slide won’t close!…but they will fit in my case check gauge!

I had to adjust my taper crimp to get them to work in both my legion and my shadow!

 

[JRHawkins1118]

Micrometer is what I use!

Remember coal and plunk are different!

My reloads are 1.13 coal, and will drop into my sigs no problem at all!

But they stick in my shadow 2! They won’t even chamber!, the slide won’t close!…but they will fit in my case check gauge!

I had to adjust my taper crimp to get them to work in both my legion and my shadow!

Thanks. I had been reading that it’s good not to crimp 9mm. Do you always crimp?

 

[Creedmoor]

Thanks. I had been reading that it’s good not to crimp 9mm. Do you always crimp?

I always crimp for autoloader pistols.
I use a firm Crimp with Dillon Taper Crimp dies.

 

[shootersix]

The last die in my Dillon is a lee taper crimp! So every round is crimped!

 

[Wabatuckian]

Thanks. I had been reading that it’s good not to crimp 9mm. Do you always crimp?

I use Lee Factory Crimp Dies on pistol rounds that I'm not loading lead bullets into.

 

[BigRed]

Crimp was the bane of my existence...until I started figuring out some stuff (full discloure...I do not fully understand crimp)

After I started figuring out some stuff, I learned crimp matters.

Still have to figure out how to get it dialed in.

Hell, seems crimp remains the bane of my existence!

 

[Creedmoor]

I always crimp for autoloader pistols.
I use a firm Crimp with Dillon Taper Crimp dies.

I taper crimp jacketed and lead bullets.

 

[indyblue]

I’m not sure that I crimp 9mm per se, I set the die just enough to take the bell out.

Am I doing it wrong? No problems with feeding or setback that I know of so far.

 

[Jarvitron]

For pistol stuff I Lee factory crimp just enough to see/feel (maybe 1/8th a turn over touch) and then just plunk. I have never felt the need to find max oal for pistol (on rifle I use modified cases and a caliper/comparator set to find the lands)

 

[cobber]

I reload based on my CZ chambers. If it chambers in my CZs then it will chamber in everything else. YMMV

 

[JRHawkins1118]

I reload based on my CZ chambers. If it chambers in my CZs then it will chamber in everything else. YMMV

Thanks. I’m going to try these out this morning.

 

[cobber]

Thanks. I’m going to try these out this morning.

(And mind your minimum OAL, while you’re at it. )

 

[JRHawkins1118]

For pistol stuff I Lee factory crimp just enough to see/feel (maybe 1/8th a turn over touch) and then just plunk. I have never felt the need to find max oal for pistol (on rifle I use modified cases and a caliper/comparator set to find the lands)

Thanks. I was using RCBS crimp. But I noticed a lot of people mention the Lee. So I ordered one yesterday. We’ll see how it goes!

 

[russc2542]

I plunk with my CZs (short leade). If it fits them, it'll fit anything.

I run 9 through a lee crimp die because I have a Bond Arms Bullpup, it's basically a bullet puller when it cycles so they need a good firm crimp.

 

[92FSTech]

I plunk with my CZs (short leade). If it fits them, it'll fit anything.

Pretty much this. CZs have tight throats and I typically use my son's PCR barrel to set my seating depth. Barsto makes a barrel with a pretty tight throat as well, and surprisingly so are the Gen 5 Glock 9mms.

 

[92FSTech]

Crimp was the bane of my existence...until I started figuring out some stuff (full discloure...I do not fully understand crimp)

After I started figuring out some stuff, I learned crimp matters.

Still have to figure out how to get it dialed in.

Hell, seems crimp remains the bane of my existence!

Try a Lee Factory Crimp Die. It's cheap and it'll make the whole process easier to set up and yield more uniform results.

 

[indyblue]

I believe any die that crimps should work, it's all in the setup. Sometimes need to play with the "ratio" of seating plug depth to the taper crimp portion of the die to control crimp. i.e. I seat to desired OAL, then back the seating plug out and dial in the amount of crimp, then turn the seating plug back down to proper seating depth.

This is why you should make some dummy rounds (no primer or powder) to set up dies first.

I use Redding dies exclusively so I may be talking out my azz (but can't imagine dies vary that much? They should all be at least sammi spec).

I crimp just enough to remove the bell and a tiny bit extra.

 

[92FSTech]

I use Redding dies exclusively so I may be talking out my azz (but can't imagine dies vary that much? They should all be at least sammi spec)

The Lee FCD crimps as a standalone process, so you don't have to simultaneously adjust seating depth and the depth of the die to get proper bullet depth and crimp. It breaks that out into two separate stations, and allows for very quick and precise crimp adjustment.

The other benefit is that it passes the case body through a carbide sizer ring inside the base of the die which corrects any bulges or other anomalies in the case that may have occurred since your re-sizing step.