Bullet seating depth

[Jnestle]

I have been reloading for 4 years for handgun plinking and hunting rifle. I would consider myself average when it comes to expertise in handloading. For my hunting rifle rounds I don't do anything but go "by the book" on everything which has been fine. I end up with ammo affordable and accurate enough for my hunting purposes. My question is about tweaking these hunting rounds A's it relates to bullet seating depth. I read frequently people mentioning the bullet being x distance "off the lands" etc. How do you determing what distance off the lands is appropriate? While I am at it what is the philosophy behind deciding these seating depths?
Thanks

Jn

 

[rcmodel]

Right or wrong, I was never one to chase rifling with seating depth.
I load mostly to standard length that works in any rifle I pick up.

If you stop to consider it, the most accurate factory loaded ammo you can buy for any price (Match & Varmint) is loaded the same way.
It's shoots well in any barrel, regardless of throat length, rifling leade, etc.
And it fits any magazine.

If you do everything else right, and find a powder charge your rifles like, you will only gain a small percentage of more accuracy by playing with seating depth / OAL.

While burning out your barrel testing loads.

Thats MY story, and I'm sticking too it!

rc

 

[creeper1956]

If you do everything else right, and find a powder charge your rifles like, you will only gain a small percentage of more accuracy by playing with seating depth / OAL.

I could be mistaken, and although I don't believe rcmodel has ever competed in benchrest, F-class or Palma matches... he's been around the racetrack more than a few times, and is actually quite correct in his, short but to the point, comment.
For hunting and plinking and normal ranges, there's not much advantage to playing with seating depths, unless you just want to experiment... and as rcmodel said, "While burning out your barrel testing loads".
For shooting competitions where smallest group and smallest aggregate win, and finishing second can be a .001" difference, competitors will do and try anything within the rules to gain advantage... including spending thousands of dollars a year on barrels.

You can play with it if you like Jnestle. Because you're a "by the book" guy... get a good gauge rather than the DIY gauge method (you might look into this method later down the road) and read some of the reference material both on-line and in print about the art of customizing bullet seating depths. I say art because there is no hard and fast rule, and what works for one gun and load seldom work in another. See "burning out barrels".

You don't have to go nuts to start. .050" off the lands is a safe & decent place to start... and tweak from there as you get the hang of it.
Bear in mind, if you don't have competition grade rests, optics and shooting skills, you may be wasting your time... because your aiming errors might be greater than the potential improvement in accuracy.

Word of warning... do not play around with close seating depths for hunting ammunition until you have a complete understanding of what you're doing and why. Wouldn't want your trophy elk to walk away because you chambered a round, un-chambered a round and had the bullet pull out of the case, filling your fire control with propellant... 5 miles from the nearest tools to disassemble and clean the works.

Cheers,
C

 

[rcmodel]

I could be wrong, and don't believe rcmodel has ever competed in benchrest, F-class or Palma matches...

You are right.
I haven't done any of that.

What I have done though, is build 1,000 yard National Match rifles, and sniper rifles for use in Vietnam while with 5th. Army AMU a long time ago.

I doubt rifle barrels have changed remarkably in the years since.

You can burn out a barrel throat chasing that last 5% of accuracy potential with seating depth that is wrong for every other rifle.

And then get to re-barrel the rifle and start all over chasing seating depth again with a new barrel & chamber.

rc

 

[creeper1956]

I apologize if I offended you RC... it was not my intent. I have nothing but respect for your knowledge and good nature. I simply wanted the OP to have a bit more understanding of the why or why not of adjusting seating depths.

Cheers,
C

 

[BYJO4]

Loading to standard specs is good enough for me. Perhaps if I had a high price target rifle and shot long range competition, the small increase in potential accuracy might be worth it.

 

[rcmodel]

I apologize if I offended you RC

Oh no!

No offense, and I certainly didn't intend to imply there was one.

I was just saying that other then Palma & benchrest, which I never competed in, F-class came along long after I was even competing.

I just meant that barrel life probably hasn't changed much through those years, and you can wear a barrel throat slick chasing that last semi-frog-hair of accuracy potential playing with seating depth if you aren't careful.

And if you aren't shooting high-level competition of some discipline, it makes not one whit of difference anyway.

1.5 MOA will kill a deer just as dead just as fast as .15 MOA when the deer is 200 yards away.

rc

 

[Walkalong]

You can burn out a barrel throat chasing that last 5% of accuracy potential

Exactly right. You have to experiment a little, get real close, and then go shoot matches. Fine tune it from there. A little tweak here, a little tweak there. The more experienced you get, the easier it is to get nearly there quickly.

 

[rcmodel]

And a lot of practice with the ammo that brung ya makes more winning scores or dead deer then a lot of experimenting with seating depth too.

rc

 

[Jnestle]

I really appreciate the info. Under the circumstances I will keep with what I have been doing. One less thing to worry about is a good thing.

 

[WNTFW]

It even depends on the bullet. In my opinion, some of the guys I know that worry about it have more pressing problems that would yield bigger dividends.

What I have found as a good rule of thumb is the amount of bullet in the case should be equal to the diameter of the bullet.

Bear in mind I am shooting stock OEM barrels. I guarantee you the points I drop, poor groups or bad shots aren't because of seating depth.