Seating shallow or "jamming" into the lands.

[Tcox]

Hey crew,

I picked up some Berger hybrids and will start load development again. I have a 6.5 creedmoor built on a LONG action, therefore mag length doesn't exist to me. Here begs the question: how far into the lands can I safely seat? It seems that the further out I seat, the more case capacity I gain, right? On a dummy case, I loaded all the way out to 2.950 (0.150 longer than specs) and even out this far, my projectile is not being pushed into the case any measurable amount. There is also no additional resistance when closing the bolt. Other than potential pressure from the projectile contacting the lands, is there any reason that I couldn't load this far out or longer?

 

[7stw]

What length are your lands ? I have a couple of rifles that I seat all the way out until they're touching the rifling. An increase in pressure and if you want to unchamber a round the bullet will nine times out of 10 pull from the case and the powder makes a hell of a mess in the action. But in one of my stw's it's also where I find the best accuracy. Other rifles I own like to be seated a couple thousands off the lands. A couple even prefer quite a bit of "jump" to the lands for the best accuracy. Bergers in my experience like very little jump. So the longer generally the better. But every rifle is Different in regards to seating depth.


Sent from NSA wire tapped device.

 

[dennishoddy]

My 06 is just touching the lands and that is where it gets its best accuracy too. Its the only rifle I have that does that.

 

[DRC458]

I never, EVER, "jam" a bullet against the lands. I always give a couple thousandths clearance. Most of the time that is where I will get the best accuracy. I suppose I could have some rifles that gave better accuracy with the bullet touching the lands, but I will never know because I just won't do it.

 

[Tcox]

I begin touching lands at approximately 2.840 or atleast that's where I begin seeing slight impressions on the projectile. Is it common to feel zero resistance when I'm seated this far out? As I said, I feel zero resistance and when unchambering the round the projectile is retained in the casing and OAL is unchanged.

 

[OKCHunter]

I never, EVER, "jam" a bullet against the lands. I always give a couple thousandths clearance. Most of the time that is where I will get the best accuracy. I suppose I could have some rifles that gave better accuracy with the bullet touching the lands, but I will never know because I just won't do it.

This ^^^. When making loads with this increased OAL, I feel little or no resistance when seating the bullet.

 

[DRC458]

I begin touching lands at approximately 2.840 or atleast that's where I begin seeing slight impressions on the projectile. Is it common to feel zero resistance when I'm seated this far out? As I said, I feel zero resistance and when unchambering the round the projectile is retained in the casing and OAL is unchanged.

Then you are probably just touching the lands and you would feel no added resistance. You're probably perfectly safe there, but I personally wouldn't go any longer. That's just me. YMMV.

 

[dennishoddy]

I coated my bullets with dykem. Its a spray that machinist use to blue metal plates so they can scribe a line on the plate. Just kept moving it out until I could see a mark from the lands. Occasionally I'll feel a little resistance when closing the bolt, but if I eject the round, it doesn't pull the bullet.

 

[OKCHunter]

One way to find the OAL at the lands is to create a reference round. I cut two opposing slits in the brass neck and seated the bullet at the maximum OAL that would retain the bullet. I then loaded the cartridge into the chamber and let the bullet "seat itself" against the lands. At that point I added .002 more to the seating depth.

 

[DRC458]

One way to find the OAL at the lands is to create a reference round. I cut two opposing slits in the brass neck and seated the bullet at the maximum OAL that would retain the bullet. I then loaded the cartridge into the chamber and let the bullet "seat itself" against the lands. At that point I added .002 more to the seating depth.

That's basically what I do, but I don't cut the brass. I either leave the round assembled or (most often) just pull the bullet when I've got the measurements I want.