Overall case length per bullet manufacturer

[Skubasteve]

This is my first post, I've been gathering very useful information as I started reloading and begun to shoot long range, so thanks for helping me not blow myself up!


Anyways back to the post, so I've been trying to find the best way to measure OAL for each bullet and haven't found anything really consistent till I started playing with my caliper. I know I'm not the first but let me know it this is an accurate way of measuring out to the lands. Ill be using a Nosler 165gr BT chambered in .308 as an example:

- Remove bolt, Drop a bullet down the barrel (wiggle it around) then measure from a set point on the bolt entry to the bullet (needs 6"+ caliper)- 6.606"

- Drop a fired casing in and measure from the same point to the rear of the case- 4.822" (this number will not change between bullets)

- so now subtract these two numbers (1.784") then add in the length of the bullet (1.215") which gives you a final result of 2.999 for max OAL

I've tried the marker,smoke, and loose bullet techniques but this is the only way I got the same number everytime. Let me know if this method seems accurate. And also where should I start my load length at? I always hear " back off a little" but could use some actual numbers, thanks



Measurements done on Remington 700 ADL .308 SA 26" barrel

 

[Supergyro]

You may try posting this in the reloading section for more knowledgeable answers. I've never heard of the method you use (that's not to say it is inaccurate). Most just say to use a jig for finding lands (don't remember who makes them) that goes into the back of your brass and measures how much the bullet moves when the lands bump them from being seated long.

 

[Layton]

Read this thread in the reloading section and it will give you a start. Many of your questions will be answered there. The ones that aren't just post those and someone will jump in.

L

edt: And howdy btw.

 

[dinc]

Follow Layton's link. The links method (bullet tip to bolt face) will give more consistent oal than what you are doing (bullet base to case base). I think it's because of case head space variation and they way they drop into the chamber when you measure. All of it's adds up to chasing a couple of hundredths that aren't going to make much difference.

The hope is that if you find the perfect bullet seating depth your MOA+ gun will suddenly shoot 1/10" groups. Not happening. Factory Remington chambers are notoriously long, you won't be able to seat to touch.

Adjusting seating depth is searching for a barrel vibration node that is more repeatable. Like adjusting powder charge up and down tenths of a grain. Climate shooting conditions will change through out a day and day to day that will have just as big an effect. You're chasing your tail.

Make the gun accurate: good bedding, good trigger adjustment, good scope mount, check the crown. Shoot accurate ammo: load a good bullet with consistent methods.

Then shoot. A lot. And remember practice does not make perfect, perfect practice makes perfect. Take a class from a qualified instructor, get a plan, follow it. The shooter is the biggest variable in anything you are trying to measure and improve. Practice will improve your shooting more than anything else.

 

[Skubasteve]

Awesome thread suggested, thanks guys. I'm new to the forum so I didn't know where to post

 

[Supergyro]

You may also find that searching your question first can yield multiple threads on almost any topic. I recommend the google snipershide search engine that some members have in their sig line, or just google site:snipershide.com -insert topic of choosing here-.