Hi all, I'm new to reloading and I have a question reguarding OAL. I'm loading 165 BTips for my .30-06 and 120 BTips for my 7mm-08. I checked for proper bullet seating depth per page 42 - 43 of the Nosler Manual fifth edition. With the bullet set at about .050 longer than SAAMI max. I didn't see any marks from the rifling in either rifle. Based on this, I seated the .30-06 ammo at 3.335 OAL and the 7mm-08 ammo at 2.795 OAL. These dimensions are .005 less than SAAMI max. and function through the magazines. What do you think? With their streamlined shape, is it normal for BTips to not touch the rifling? Do you typically set the bullet longer than I did when you check for contact with the rifling? Thanks.
OAL Question
- Thread starter racerx36
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I personally like to create a "dummy" of new cartridge/bullet combinations. I use the rifle itself, if a bolt gun, to do this. Just seat a bullet down just enough in an empty, unprimed case to hold it straight, then get a sharpie marker and color all over the copper of the bullet jacket. Then place the round in your bolt gun, and chamber it, slowly. You will feel a lot of resistance. When you finally close the bolt, then open it back, and hopefully the bullet will come out in the case. If it does, then measure the OAL and that is the full freebore of the chamber with this particular combination. If it sticks in the rifling, get a cleaning rod, put a cotton ball or some other padding on the tip, and gently rap the bullet out of the bore. Take a look at it, and you will see the sharpie marker section is discolored where the bullet went into the case. Re-seat the bullet in the empty case up to that line, and then measure. If you have a comparator you only need to do this once, as you can use that measurement across the board, by the way.
As far as seating deeper or shallower than SAAMI spec, just try not to get it too deep. Generally, I seat longer than SAAMI spec, because it is out closer to the lands, and generates more even start pressure. Deep seating can, in some small capacity cartridges (especially pistol cartridges) create a dangerous over-pressure situation, based on the overall reduction in case volume from the bullet occupying more of the case when deep seated. Just my way of doing things, your results may vary. But work up carefully when using anything other than the exact specs in the manual, and the exact components. Work up carefully then, too, just to be sure.
As far as seating deeper or shallower than SAAMI spec, just try not to get it too deep. Generally, I seat longer than SAAMI spec, because it is out closer to the lands, and generates more even start pressure. Deep seating can, in some small capacity cartridges (especially pistol cartridges) create a dangerous over-pressure situation, based on the overall reduction in case volume from the bullet occupying more of the case when deep seated. Just my way of doing things, your results may vary. But work up carefully when using anything other than the exact specs in the manual, and the exact components. Work up carefully then, too, just to be sure.
- Oct 30, 2004
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The way I establish overall length is by seating the bullet "out there" in a dummy round and using your bolt to ram the bullet into the lands. This will give you the max length wthat the bullet can be seated or the bullet is kissing the lands. Now you know exactly how far off the lands you're at. You can then choose to seat the bullets 10, 20 30, etc tousands off the lands. If it is longer than Saami but still work though your mag you're good.
- Thread starter
- #4
I used the method you both described. I guess I didn't have the bullet protruding from the case enough to contact the rifling. I was concerned that I might not have got an accurate measurement. I think I'll be OK with the OAL that I've chosen. Can't wait to get out and give them a try at the range. And then on a couple of antelope this November.
rick smith
Handloader
- Apr 6, 2005
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I normally use a modified case, Stoney Point, to get the max OAL. If you use the method described by POP be aware of two things. First you can easily push the bullet 20 thousants into the lands. Second the lands may hold the bullet and move it partially out of the case giving you a very incorrect measurement. If you get your measurement, pull the bullet and seat it at your depth. Polish the bullet with 4/0 steel wool and rechamber the round. When removing the case don't let it hit the side wall of the receiver. Look at the bullet under good light with a magnifying glass. You are looking for square/rectangular marks on the bullet approximately where the bullet makes caliber. These marks will correspond to your rifling. You need to reseat the bullet moving it deeper into the case by at least 5 thou. Repolish the bullet, rechamber and look again. This may take several tries. Once you get the marks to a fine line, you are now just making contact with the rifling. Now you can seat however far off the lands you want to be. Be sure to check the round in your mag box for fit and function. You may also hear about splitting the neck and seating a round in the chamber. This is just a variation of POP's method.Rick.
