Is there such a thing as too far off the lands?

[bob4]

Pretty much a hypothetical question and for no rifle in particular just a general question. I loaded a nice accurate load for a friends rifle (30-06) and it was 130 off the lands. The other loads were all closer. It just got me to wondering if there is such a thing as too far off the lands. Other than watching for pressures from compressed loads are there any other risks from being too far off the lands?

 

[tbrice23]

For my very short throated 300wsm and 270wsm when all of the bearing surface is inside of the case neck, thats too far!

I like to experiment with seating depths but these WSM chambers won't let me go further than .040 off with Bergers.

Ideally I like chambers built so that the bearing surface and boat tail Junction is right above the shoulder /neck Junction.

As far as risks go, with the ogive inside the neck it could cause feeding or chambering problems. Also it hampers case capacity.
Anyway, hope this helps???

 

[PGJPJ]

When my Remington 700 had it's factory 270 barrel, the throat was just huge. So I'd have a bullet seated to around 3.34, and easily have .150" jump to the lands. There were only a few bullets I could seat very close at all to the lands.

But, that barrel was still a good 0.7 to 1.0 MOA.

 

[Bravo 4]

Don't have an answer for that, but this is from Weatherby's website:
What is the throat length (free bore) on your Weatherby rifles chambered for Weatherby magnum calibers?
Cartridge Throat length (free bore)
.224 Weatherby Magnum .162
.240 Weatherby Magnum .169
.257 Weatherby Magnum .378
.270 Weatherby Magnum .378
7MM Weatherby Magnum .378
.300 Weatherby Magnum .361
.340 Weatherby Magnum .373
.375 Weatherby Magnum .373
.378 Weatherby Magnum .756
.416 Weatherby Magnum .239
.460 Weatherby Magnum .756
.30-378 Weatherby Magnum .361
.338-378 Weatherby Magnum .361

 

[Code4]

Not if its accurate.

 

[Corey Schwanz]

Eventually if you go "too far" off the lands, the bullet will be sitting very deep in the case neck and could get the ogive below the mouth. As long as seating depth is good in the neck and pressures are in a safe area, jump the bullet whatever it has to be jumped in order to be accurate. A lot of factory rifles have huge jumps, especially with off the shelf ammo. Its scary sometimes how far that bullet travels before its actually in the barrel.

 

[bob4]

Thanks everyone.

 

[Greyfox]

I have owned three Milpec Reminton 700's in 308. All were around .150" off the lands with 168
Fed Match as well as my optimum hand loads. All were .25-.5MOA, at spec velocity and ES under 15FPS . I agree with the other posts that as long as you don't intrude too much with the case capacity, it doesn't matter.

 

[MagnumManiac]

The measured distance from the rifling has no bearing on how accurate a barrel will be, but, if the bullet is too far into the case neck, it MAY cause pressures higher than normal just the same as a jammed bullet does.
There is no set in stone rule that a small jump is more accurate than a very long one. My Kimber 8400 Classic select, with mag box max COL 3.390" with a 180gr Accubond, has a jump of .145". It's accuracy is not affected by this because if I load 200gr Accubonds to be .020" off the rifling, shoots the same size groups, then if I load them at 3.385", groups open a little, but still good for a hunting rifle.

If you look at SAAMI specs, all cartridges have a maximum COL, which is not as important as long as the bullet isn't jammed, then there is a minmum COL, this is more important for the reasons outlined above.

Cheers.
gun)

 

[Varmint Hunter]

The simple answer is - No.

My buddy shoots Weatherby Mark V rifles which have long throats. It is fairly common for him to load bullets a full 1/4" or more off the rifling. He also manages to get these rifles to shoot quite well.

Many rifles will require bullets to be .150" or more off the rifling just to fit in the magazine.

Too deep in the case is a totally different matter.