Good way of finding your guns OAL?

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CNDShooter94

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I've been reloading for a year now and for the OAL have just always done what the manual says. But these have just been for plinking and havent needed anything more. I wanna start getting into long range shooting amd will be spending this summer developing an idea target load. I meed some good ways of findingy guns perfect OAL for maxium accuracy! Any tips guys?

Cheers
Brandon
 
1-Using fired case from your rifle-dent the mouth, so that a bullet can barely be seated with finger pressure.

2- Barely start the bullet into the case.

3-Insert case and bullet into chamber, and gently close bolt fully.

4-Open bolt,gently remove case and bullet, and measure COL. That is the COL with the bullet against the lands, in that rifle, with that bullet.

5-Repeat a few times to insure consistent results.

6- Using that particular bullet(not another one from the same box, but that same bullet) set your seating die to provide the distance from the lands that you desire, by shortening the COL by that amount.

You must use the same bullet for all steps, because bullets do vary in length due to variances in the points, and your COL is measured to the point.

As well, in some cases, the bullet may stick in the lands, and be partly or totally pulled out of the case as you extract it from the chamber. If that is an issue, you can mark the bullet with graphite from a pencil, or smoke it over a flame, so you can see how far the bullet was pushed into the case before it was pulled out. Simply push the bullet back into the case to that mark, and measure the COL.
 
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Or, take a sized, UNPRIMED cartridge case (with no powder) and seat a bullet in it leaving a very long OAL. Load the case + bullet only in your rifle. When you close the bolt with a little extra effort, the bullet will finish seating well into the lands. Measure the cartridge OAL then back off the length by your desired amount of jump.

I usually repeat this a few times to get a consistent result.

Good luck and be safe!
 
stubblejumper said:
1-Using fired case from your rifle-dent the mouth, so that a bullet can barely be seated with finger pressure.

2- Barely start the bullet into the case.

3-Insert case and bullet into chamber, and gently close bolt fully.

4-Open bolt,gently remove case and bullet, and measure COL. That is the COL with the bullet against the lands, in that rifle, with that bullet.

5-Repeat a few times to insure consistent results.

6- Using that particular bullet(not another one from the same box, but that same bullet) set your seating die to provide the distance from the lands that you desire, by shortening the COL by that amount.

You must use the same bullet for all steps, because bullets do vary in length due to variances in the points, and your COL is measured to the point.
Click to expand...
:cool:
never knew that. Thanks.

edit

you too SuperD
 
Or, take a sized, UNPRIMED cartridge case (with no powder) and seat a bullet in it leaving a very long OAL. Load the case + bullet only in your rifle. When you close the bolt with a little extra effort, the bullet will finish seating well into the lands. Measure the cartridge OAL then back off the length by your desired amount of jump.
Click to expand...

If your case necks are being sized to provide adequate neck tension, it will be extremely difficult to close the bolt with a sized case. And if you exert that much pressure pushing the bullet into the lands to close the bolt, the bullet will not just be touching the lands, but it will be forced well into the lands. It could easily be forced .020" into the lands, without you even knowing.
 
Loaders nest you will find your rifle load combination
Look around it will get you really close
Click to expand...

The problem is that throat dimensions can vary considerably from rifle to rifle, even if they are the same make and model.

And I guess jump space is just somthing your gunna have to experiment with and see what works best right?
Click to expand...

Every gun is an individual.
 
Seat a bullet into case

Use bullet puller to remove bullet

Re Seat bullet - neck will now be a wee bit looser

Seat long as per surperd222's comment

Repeat for consistency

I find above to be as accurate as either Hornaday or Sinclair tools
 
Since you must be into reloading, save a split case. This is what I`ve done: use a hacksaw to cut two slits in the neck part way down to the shoulder (makes loading the bullet easier by hand). Then do as the first guy said. I`ve noticed quite abit of controversy over the "seating to lands" vs "seating off the lands". Some say that some ammo is better against the lands and some ammo prefer the jump. Its hard to say and alot of bench time is needed I`m thinking.
 
Partial resizing of your case gives about the right tension. Do three tests, and use the shortest as your template. That template round can be used for each loading session where that same combination is being used. With sufficient neck tension, there will be no changes in the OAL. Write sufficient information on the case, as well as some identifiers on that particular lot of bullets, for future reference. Store that template round in the bullet box from which the bullet came from.
When you are completing your final load from that lot, pull the bullet from the template and load it too. You won't need it again as the entire process will be repeated for the next lot you intend to use.
 
darcy32171 said:
Since you must be into reloading, save a split case. This is what I`ve done: use a hacksaw to cut two slits in the neck part way down to the shoulder (makes loading the bullet easier by hand). Then do as the first guy said. I`ve noticed quite abit of controversy over the "seating to lands" vs "seating off the lands". Some say that some ammo is better against the lands and some ammo prefer the jump. Its hard to say and alot of bench time is needed I`m thinking.
Click to expand...

Yea ill probably run a few tests to see which performs better.
 
I have used the "lightly seated bullet" technique a few times with good success. I found that COL really made a difference in accuracy.
 
stubblejumper said:
1-Using fired case from your rifle-dent the mouth, so that a bullet can barely be seated with finger pressure.

2- Barely start the bullet into the case.

3-Insert case and bullet into chamber, and gently close bolt fully.

4-Open bolt,gently remove case and bullet, and measure COL. That is the COL with the bullet against the lands, in that rifle, with that bullet.

5-Repeat a few times to insure consistent results.

6- Using that particular bullet(not another one from the same box, but that same bullet) set your seating die to provide the distance from the lands that you desire, by shortening the COL by that amount.

You must use the same bullet for all steps, because bullets do vary in length due to variances in the points, and your COL is measured to the point.

As well, in some cases, the bullet may stick in the lands, and be partly or totally pulled out of the case as you extract it from the chamber. If that is an issue, you can mark the bullet with graphite from a pencil, or smoke it over a flame, so you can see how far the bullet was pushed into the case before it was pulled out. Simply push the bullet back into the case to that mark, and measure the COL.
Click to expand...


This method depends entirely on neck tension. Chances are on a factory gun, the bullet will fall into the case on fired brass, in which case it needs to be pinched ever so slightly. This method definitely works, but it will be imprecise when it comes to finding just the lands. There will be a component of bullet jamming with this method. A proper OAL gauge is a good investment and i receommend the Sinclair
 
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