OAL ?

[goosedowner]

What are you guys using to measure the OAL of your reloads? I use calipers but after reading a thread about OAL yesterday I now see how different bullet shapes can change how far i need to seat my bullets and I think I need a better way to measure them.

[JakeMartens]

I don't know of any other way other than with calipers

[Amerflyer48]

OAL is measured by calipers,.. and yes projectiles will change your OAL dimension...

I usually start out with a RN and load a new projectile (SWC TC etc.) so that it stays within the outline created by the RN then adjust as needed..

A fellow shooter uses his mags... he loads 10 or so dummies so that they will load without binding starts long and sets back until they will fit then shortens OAL by a few thou. records OAL then hand cycles them in the intended firearm..

OAL by caliper is the most repeatable,.. you just have to find each projectiles "magic" OAL welcome to the joys of reloading....

John

Edited March 10, 2011 by Amerflyer48

[noylj]

Quote: A fellow shooter uses his mags... he loads 10 or so dummies so that they will load without binding starts long and sets back until they will fit then shortens OAL by a few thou. records OAL then hand cycles them in the intended firearm. Unquote

You should always make up at least one inert "dummy" round (used to set-up your dies, verify feeding and chambering, and use if/when you need to set-up the seating die for that bullet again) and start long. The COL in manuals is either the SAAMI requirement (so manufacturers' ammo can fit in all properly chambered guns) or the minimum recommended. In both case, the reloader should try longer COLs.

[Action Pistolero]

If you were loading for a rifle, you could get an adapter for the calipers that measures the bullet from the ogive. The adapter has bushings that are used for the caliber of the rifle. To my knowledge, they do not make the bushings in pistol calibers. Measuring from the ogive eliminates the differences between JSP, JHP or RN.

With pistol bullets there are two factors that determine overall length for any given bullet. That is the chamber and the magazine.

Make up a dummy cartridge. (no primer or powder) Barely seat the bullet in the case. Take the barrel out of the gun and drop the round in the chamber. The rim of the case should be flush with the barrel hood. Keep seating the bullet a little at a time until it fits flush.Take note of it's OAL with the calipers. Now make up 5 more dummy rounds. Load them in the mag. If they are too long for the mag all 6 of them will not fit in the mag. If they are all fit your done. That is the longest cartridge that you can load for that gun with that bullet. If you change bullet styles you will have to do this again.

Edited March 10, 2011 by Action Pistolero

[Popsmoke]

I use two methods on determining OAL:

1st - measure the overall length with calipers. I feel this isnt too accurate, because the tip of a bullet nose can vary with shipping, drops, and manufacturing variances.

This method is useful for determining if a shell will fit into a magazine.

2nd - use a bullet comparator nut. This wont measure true overall length, but what I call Ogive Overall Length. It measures from a repeatable place on each bullet with out regard for the quality of the nose. This method is useful for comparing one shell to another, and more importantly, when optimizing length for bullet jump to the lands in your specific rifle.

[Pro-Pain]

As was said, watch out for manufacturer variations. Make sure you're not testing one bullet and changing the die set. If you increase the sample size, say to about 10 bullets or so like what was mentioned, you should be able to get a good estimate of where you're at. Just remember not every bullet will be the same, but you may be off only by thousandths.

To remind yourself, barely open the calipers to 3-4 thousandths and look and see how much space that actually is, you can barely see through the calipers...

Also, try not to run the line. If you're gun can handle up to say 1.130, don't set your bullets at 1.129, as some might not make the cut. Give yourself some leeway so that even if a bullet is a few thousandths off, it can still cycle the bullets and won't bind up, jam, etc.

Or, pick up Revolver Division where OAL is not so finicky

[MARKAVELI]

I use Calipers and case gauge, I make 10 dummy rounds (no powder no primers) check to se if they fit in my mag s, rack em through my weapons (WITH NO FIRING PIN)! Using the same brass no mix brass and it should be just about perfect.. Good luck.