C.O.A.L. vs O.A.L.

My hope is the forum will create a "sticky" clearly defining these two terms so we are all using the same dictionary.

Here is a SUGGESTED starting point: "C.O.A.L." defines the length of the cartridge from the base of the brass to the TIP of the seated bullet. "O.A.L." defines the length of the cartridge from the base of the brass to the OGIVE of the seated bullet using a caliper with a Comparator Gauge mounted and re-set to 0.000". Resetting the caliper to 0.000" will remove the length of the Comparator barrel from the O.A.L. measurement.

What think ye?

Ooops

COAL and OAL are the same thing......making them separate by how they are measured will just confuse more people. It's all relative anyways. There are too many variables involved for one person to take a OAL figure from another and try to use it in their rifle. (potentially dangerous too)

Find the length to the lands for each barrel/bullet YOU have and go from there. You'd be better off sticking with what works for others as far as how far off the lands the bullet is.......even then there will be quite a bit of play with the figures.

example: say I'm using an OAL of 2.350" which is .025" off the lands in my rifle. taking my OAL of 2.350" and loading up rounds for your rifle could cause some problems. on the other hand, using the .025" off figure will give you a good starting point....as long as you know what your length to the lands is.

HTH

Ok...I'm just slow. Any diagrams, cut away drawings? I'm a visual guy.

On the visual side and being new to reloading, are there any good sites with diagrams that I can visit for this stuff. I'm in dial-up land and all I seem to find are videos on the subject.

Thanks

Garett

The term for the measurement from the base to ogive already exists. It's just that nobody uses it.

Cartridge Base To Ogive... CBTO.

Admittedly confusing topic. Hornady makes a Lock-n-Load OAL Guage. Excellent product. But it does NOT measure OAL whatsoever. It alloes you to measure the afformentioned maximum CBTO in a given gun with near perfection and is highly recomended.

And Hornaday makes a bullet comparator as well. But so does Redding, Sinclair and others, to the best of my knowledge. And while they may all be conceptually the same or similar, it would dangerous to use them interchangably.

All these precision products allow a handloader to perfectly measure and reproduce details for a given gun. They don't allow numerical comparisions between different users and different guns, in my opinion. What they can do, is allow us to clearly descibe the "jump" that was optimal in a given gun, such that another user can dumplicate that same jump, if they have the tools. Whether it will yield similar outcomes is a different matter.....

What is the best and or easiest way to measure your chamber? I'll look into the Lock-n-load oal, as I am just interested in my rifle(s). Actually I'm working on a Switch barrel 22-250 and 6.5 cm.

Thanks for the help,
Garett

Grott, If I recall, there have been a number of very informative threads regarding measuring chambers. Do a search in this forum and you will probably find all the info you need. If not, I would suggest you start a new thread on that topic. Many participants here will enjoy helping you.

Best wishes and good luck.









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Quote:

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Originally Posted by Grott

What is the best and or easiest way to measure your chamber? I'll look into the Lock-n-load oal, as I am just interested in my rifle(s). Actually I'm working on a Switch barrel 22-250 and 6.5 cm.

Thanks for the help,
Garett

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The Hornaday LnL OAL gauge can be had for about $34 from places like Grafs. You'll then need a modified case for each cartridge type you load (anywhere from $5.60 to just over $12, depending on the case) and a comparator with an insert for each bullet caliber (not cartridge type). If you load more than one bullet caliber the most cost effective comparator solution is one of Hornady's sets ($29 for a comparator with a set of 6 inserts, or $49 for a set of 14 inserts).

Not cheap overall (about $60 even if you load only one cartridge type), but worth it if you're serious about squeezing accuracy out of your loads.

Thanks for the help guys, this is good. I think I'm going to see a long cold winter up here in the north country. Lots of time for reloading, bench time is limited though.

Garett