Setting OAL just off the lands

[wrench459]

I used this very method. It was consistent...

I use about the same method with my 9mm handgun.

 

[D.B. Cooper]

Okay. So here is what I have so far. I bought the Hornady tools (OAL gauge w/ modded case and bullet comparator.) Using those, I've established:

Ogive to lands = 2.275"

I seated the bullet at .010" off the lands. (Totally arbitrary number, buts "seems" like a good starting point.)

COAL = 2.722 This is .012" longer than Lyman's specification of 2.71" maximum COAL, however, it easily chambered and ejected from my rifle.

Problem: Projectile (Speer 80 grain Spitzer) length is 0.870" My best measurement of how much bullet is protruding from the case mouth is 0.669" This indicates a seating depth of only 0.101" which is about .142" LESS than what people here have advised (minimum depth = projectile diameter.)

What should I do about this? The projectile is firmly seated. I can't twist/rotate it in the case, and I can't pull it out of the case by hand. It cycled in the rifle okay. Should I leave it and see what happens? (What are the negative ramification of this?) Or should I just seat it down to at least specified COAL regardless of the lands. (This would seem to defeat the entire purpose of this procedure.)

Thoughts?

 

[ArchAngelCD]

You are loading for a .243 hunting rifle. All these tricks to squeeze out a little tighter group are unnecessary for a hunting round. The deer will be just as dead if you are off 1/4" from where you aimed. After all, the kill zone is ~ 8" on most deer. Also, not all rifles need the bullet to start just off the lands to be accurate . Example? Weatherby rifles. Most Weatherby rifles have very long leads and there is no way to come closed to the rifling yet those rifles are considered to be extremely accurate. How can that be?

 

[wrench459]

.. All these tricks to squeeze out a little tighter group are unnecessary for a hunting round. ...

Just went through with this with a friend of mine.
He has a light mountain gun barrel chambered in .308.
Talked him into just shoot the friggin deer.....it will go down "IF" your doing your part.

 

[D.B. Cooper]

You are loading for a .243 hunting rifle.

Sort of.

This was my NRA Hi-Power match rifle for many years. pillar bedded stock and action. Very light and crisp trigger. Modified magazine and follower. I routinely shot 1/4-1/2 inch 100 yd, groups (off the bench) with Sierra Match King bullets. But you're correct. I am repurposing the gun back to hunting. (Caribou - I have a bit more than 8") But I see no reason no not to use the gun to its maximum potential, even if it's simply a learning process. Besides, 243 is stretching it for caribou, and the one I got last year was 312 yards out when I pulled the trigger. I'll take everything I can get.

 

[RussellC]

Just saw a Youtube posted by Natureboy in this thread that is well made, should you choose the route. It really is idea to do it this way.

Yes it is indeed. The Hornady tools allow you to push to far in, even with the dowel stuck in the muzzle sandwiching the bullet. Using the video method, then comparing the feel using the lock and load or Sinclair tools allows you to get a much greater feel. As others have said, each different shaped bullet will give a different number. Some bullets begin to stick in some of my guns freebore (Savage) before getting to the lands...

Russellc

 

[quest4perfection]

Yes it is indeed. The Hornady tools allow you to push to far in, even with the dowel stuck in the muzzle sandwiching the bullet. Using the video method, then comparing the feel using the lock and load or Sinclair tools allows you to get a much greater feel. As others have said, each different shaped bullet will give a different number. Some bullets begin to stick in some of my guns freebore (Savage) before getting to the lands...

Oops. Lost my thread...back again:
Same issue of sticking in freebore in two of my BRs. Carbon remover cleaned it up nicely.

 

[RussellC]

Oops. Lost my thread...back again:
Same issue of sticking in freebore in two of my BRs. Carbon remover cleaned it up nicely.

These are brand new guns, thoroughly cleaned to be sure. No difference.
Anytime I measure a chamber, step one is cleaning it really, really good. Otherwise you are wasting time.

Russellc

 

[quest4perfection]

These are brand new guns, thoroughly cleaned to be sure. No difference.
Anytime I measure a chamber, step one is cleaning it really, really good. Otherwise you are wasting time.

Russellc

I just had a 22br rethroated and the lands had very sharp edges. Had an issue with them catching the bullet with very little pressure. So I used a dowel to rock bullet bak and forth until I felt it just touch.