charlie brown

No, one bullet is not larger in diameter than the other. They should both have a MAXIMUM diameter of .284, but depending on the ogive of the bullet, one will reach that diameter at a different point from the nose of the bullet, and will be .284" in diameter for a different length of the bullet. A .284" bullet should touch the lands where the bullet is actually .276" (I think, if the lands are .004'' deep). A .308" bullet will touch the lands where the bullet is .300" in diameter, and so on. The reason for the differences is that the deep part of the rifling of a 7mm rifle should be .284", and with .004" deep rifling, you have a total of .008", which makes the distance across the lands .276."

firstshot

Ok......so if I want to seat these bullets 10 thousants off the lands, I would seat the Game Kings to 2.255 amd seat the Accubonds to 2.290.......

and I would need to measure a new "distance to the lands" for every type of bullet that I load.

Is this correct?

firstshot
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Make your first shot count!

charlie brown

Yes, if that is how far they are, every rifle is different, and I don't own a 7-08, and I don't have a load book handy, so I don't know what the COAL is of that cartridge. But, I am guessing, then, that your lengths for each bullet were 2.265 and 2.300?

firstshot

Yes the lengths for each were 2.265 and 2.300.

Thanks so much to all of you for your help!!!!!!!!

firstshot
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Make your first shot count!

Slamfire

The head to lands distance actually is the same, as it is the dimension of the rifle's chamber. What you are measuring is the length of your cartridge, which as the others have so aptly put it is different for every make of bullet.

bigcountry

I notice that this is the first place new reloaders get caught up. then after loading for several calibers, they quickly forget about it. If not done right, it can cause you all kinds of issues. I have seen new reloaders seat so far out that only .15" of the bullet is in the case, and the bullet is easily knocked around. I have seen them with severe pressure spikes on occasion due to jamming in the lands. Seen guys on hunting trips that worked hard on reloads to show up in the middle of nowhere that find out they can't put thier bullets in the magazine cause they never did tried it.

I mean its a good question to ask and find out. But I highly suggest you don't sweat it too much. Its the least of the your worries. Just make sure your not in the lands for one, and make sure you can fit your bullets in the mag two.

James B

Now you have it figured out. A guy never stops learning about reloading. When I first started reloading it meant finding another rock for my slingshot. I am still learning

rost495

FWIW land depth is not the same on all barrels either so there is really not a math formula you can use. Buy a stoney gauge and a dummy shell for each caliber you load in. You will most likely have different readings for each different type bullet you use.

Like the rest said, most likely they'll all be different and as such just learn to accept and live with it.

BTW just touching is often the worst place you can seat bullets too. A very good rule of thumb to follow is to either stay at least 10th off the rifling or at least 10th engaged(or more in either case). Just touching may well be that with one bullet but the next may jump etc... they are not made perfect and this can play heck with accuracy and pressures.

Jeff