Is OAL an inaccurate measurement given different available bullet shapes?

[shinbone]

OAL doesnt take in account for length of ogive, shank and seating depth, which I believe are much more critical measurements for reloading. Seating depth would translate to how much case volume is available which determines charge.. remaining length of shank exposed is important for the point at which where the bullet engages the rifling. It seems OAL is really only important for magazine fit and the bullet tip clearing the bullet ramp. Why hasn't modern reloading data upgraded to include these measurements? That way we wont need to rely on "named" bullet shapes and alot of load data discrepancy.

[1lostinspace]

Your right. But who knows, it makes sense to me.

[G-forceJunkie]

Critical for what? Reloading manuals are recipies for safe loads the fall within the range that they were designed for (pressure and size wise), not accuracy. Any tweeking you do after the fact of getting a load within the proper perameter is up to you due to many factors the reloading books have no controll over. Things such as the size and qualilty of the chamber, amout of freebore, depth and angle of the throat, etc. 100 rifles will have different numbers for those things, numbers that were chosen to be an "all around acceptable." number, not the best number for a particular bullet.

OAL doesnt take in account for length of ogive, shank and seating depth, which I believe are much more critical measurements for reloading.

[bohoki]

oal is only critical to magazine fit to me

[choprzrul]

Detemine how much jump to the rifling you need for optimal accuracy for a given bullet. Once you find that, use a comparitor that locates off of the ogive of the bullet. Record the measurement/method and set dies accordingly. This will need to be done for each load/bullet/powder combination with zero magic formula available as generally, each gun is different. The fun is in the journey and the reward awaits you at the destination.

.

[30Cal]

I don't see it as critical for the purposes of publishing data. OAL doesn't require additional tools. Comparators, necessary for measuring other reference points on the bullet are manufactured with tolerances; variation in comparators will amplify errors in seating depth. Specifying all that other stuff adds a huge burden of complexity for no real benefit. If you one chooses to measure and adjust bullet jump, it's easy enough to do with only a seating die and calipers.

[wizdumb]

OAL is important to ensure that the cartridge will fit inside your magazine, which may not matter at all if you only have a single-shot firearm.

Once you have your dies set for the desired seating depth (based on the ogive rather than meplat, which is typically more consistent) and you've verified that your OAL is within magazine specs, you're good to go.

[robert101]

For pistol I just make certain the round will chamber without hitting the lands.
For rifle (my LR308) I make certain the round will chamber without hitting the lands.
Yea, that's about it. It's not like I'm a match shooter.

[damndave]

For pistol rounds I measure COAL, but for my rifle rounds I measure base to ogive to get an exact measurement on where the bullet contacts the lands.

[Mikeb]

The Lyman Manual lists OAL for each different bullet wieght and shape.
take care
Mike

[Bhobbs]

That's because OAL is the standard for that round. All rounds in that caliber are loaded to less than or equal to that length so they will function in standard firearms. Outside of that is up to you as the loader to tune the rounds to your rifle. Each chamber is different so that is why you have to measure and load the rounds to the proper seating depth. That may or may not exceed the standard OAL.

[noylj]

[24Sailor]

That's because OAL is the standard for that round. All rounds in that caliber are loaded to less than or equal to that length so they will function in standard firearms. Outside of that is up to you as the loader to tune the rounds to your rifle. Each chamber is different so that is why you have to measure and load the rounds to the proper seating depth. That may or may not exceed the standard OAL.

^^^ Yes this I've found true...Tune your OAL to your particular rifle..Be carefull when you work up to hunting loads. Use a chronometer and watch for pressure when you do. Bullets on the lands create a double edged sword on pressure. And under charging a case with the OAL too long does the same. I use .040 changes ( both progressively up and down ) in OAL to get my accuracy, and 1 to 1.5 gr. powder escalation, in 30.06, .308 and .243 calbers after that. I always start with about 2% above minimum for powder if I'm starting a little long.

Hopefully you feel competent and have been reloading awhile....OTHERWISE IGNORE THIS ADVISE and stick to the manuals!!

[Whiterabbit]

Critical for what? Reloading manuals are recipies for safe loads the fall within the range that they were designed for (pressure and size wise), not accuracy. Any tweeking you do after the fact of getting a load within the proper perameter is up to you due to many factors the reloading books have no controll over. Things such as the size and qualilty of the chamber, amout of freebore, depth and angle of the throat, etc. 100 rifles will have different numbers for those things, numbers that were chosen to be an "all around acceptable." number, not the best number for a particular bullet.

To add to this, I have never found a load that shot most accurately when one factor was pushed to the max. It's always a few clicks back from max, or a few clicks up from min, in the middle, etc. But never pushing it.