Variance in OAL

[Rujack]

[fx1974]

[tabascoz28]

High pressure is only possible when loading max to over max. Jams possible when loading to magazine length. So simple answer is yes, possible.

Consider this, pro competitors are sorting and measuring to ogive, not OAL. Seating dies may not seat the tip of a bullet depending on die either. And the ogive may not be consistent either. Some people push the limits, I'd rather get a accurate and safe bullet.

[Rujack]

[FLIGHT762]

Your .010" difference is not an issue if you're using published reloading data from the bullet manufacturer of the bullets you''re using, use their recommended COAL for that bullet. You don't have to worry over that .010" tip difference.

For seating to an OAL that will fit in your magazine, just do a measurement of a sample of your bullets and set your seating die to seat the longest bullet to under OAL max length.

Bullets are seated off of the ogive of the bullet in your seating die, not the tips. Bullet OAL can vary some, but the real measurement that makes a difference is from the ogive. That will determine if the bullet is seated too long into the lands of your rifle chamber.

To find uniformity in rifle bullets, you can measure off of the ogive. If they vary a lot, they can be culled into groups to stay uniform.

To make the most accurate ammo, precision reloaders will buy tools to measure bullet ogive.

Since you are just starting, there's a lot of information on the net to educate you on beginner reloading to making accurate ammo with the basic tools.

You don't need to measure off of the ogives to make accurate ammo. Go with the bullet manufacturers COAL recommendation.

If you later want to get into advanced reloading for making the most accurate ammo, you can do that.

[FLIGHT762]

No, the Hornady headspace comparator bushing set is to measure the "datum" length off of your fired and F/L resized cases so you can set your F/L die not to over size your fired cases.

Hornady does make a "bullet comparator" measuring bushing set that fits the bushing holder in your comparator set to measure bullet ogive length.

You should try to find an experienced reloader who can help you understand the tools, how they are used and what you are trying to accomplish.

[Dirtlaw]

Handloading

I am going to somewhat repeat what is stated above. First, understand what you are measuring and how to measure it. Next, measure once, measure twice, then measure again (strive for accuracy). That's the rule used by woodworkers and machinists. Next, understand what the measurements mean. Your biggest concern is pressure which in turn means safety. The desirable byproduct of the foregoing is accuracy on the field.

[Rujack]

[Dirtlaw]

Like the other old-timer I make my own measurement tools.

[FLIGHT762]

No, just get close to it. We are talking about .010" right? Even if you're .010" over, you're not going to get into any issues. At 2.735" you're still well below 2.800" maximum COAL for the cartridge you're using. You're loading for 308 Win. I assume?

If you went over 2.800" you can get into two issues. 1) you would be over max COAL and your ammo may not fit into your rifle's magazine. Too long. 2) You could be getting close to or jamming your rifle's lands with the ogive of the bullet, causing pressure spikes. You wouldn't know this unless you have the tools to measure bullet to chamber land length (this is another type of measuring tool).

Go with the reloading data length for the bullet. You're fine @ 2.725" to 2.745". You're over thinking this. .010" under or over is not going to cause issues.

[Rujack]

👌 Thank you

[baih777]

Are you using name brand bullets ?
Use calpers and measure your bullets. They should be +- .001
The hornady bullet comparator tool comes in handy when this happens.
You can tell if you got a bad bunch of bullets.

If everything measures ok. If your using digital calipers. Put a new battery in.

[LynnJr]

Bullet length variation is largely dependent on the type of bullet your using.
Tipped bullets with copper bronze aluminum or polymer tips tend to be pretty consistent.
Spitzer type bullets with a lead tip tend to vary more and hollow point match bullets tend to vary even more.

For the average reloader this small variation doesn't mean much unless your having magazine issues. You pick a happy medium and use it.

For a long range competitive shooter the meplat variation which is at the center of your length issue translates into BC variation and vertical stringing as the distance is increased.
You can trim the meplats to uniform the bullets and help with the length issues.

[boyguan]

when i use sierra 168 grn they are near perfect off the ogive. When i bought some midway 168 blems, its all over the place even from the ogive.

[JagerDog]

cautionary guidance against deviating from exact recipes/specifications.

Not really a thing with metallics. Every rifle is different. Start light and work up in YOUR rifle (with your variances).