I read alot about loading certain bullets just off the lands to get best accuracy. how do people do this? what I do is use my press to very slowly seat a bullet into an empty case (starting long), try to load it using the bolt. any resistance, I try to seat the bullet alittle deeper until the bolt just closes like it is supposed to. this is the cartridge length I use as my starting point for off the lands. is this the correct way or am I doing something drastically wrong? is there a tool/guage available to do this and make this simpler?
That method will get you close. You will typically end up with a cartridge that is a little longer than the lands, since you've touched the lands and likely embedded the bullet a couple thousandths into the lands.
There are several methods that can be used, with tools and without. For years, I used a method very similar to yours, however, I would blacken the bullet with either a candle, black Sharpie marker etc. So I could tell when I got it short enough not to touch the lands.
Once you find the lands, you can use a Stoney Point to measure the case base to ogive distance and write that in your reloading manual. Then if you change bullets you can still determine the correct seating depth by just measuring the loaded bullet. Because many bullets will have an ogive to tip variation caused by the meplat forming it is preferrable to use the ogive as a reference.
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It is a 30-1/2", .187" diameter steel rod. One end is threaded and has, what appears to be a brass tip, .25" diameter x 1" in lenth, threaded onto the end. On the rod are two steel sliding rod stops with set screws.
1. Check to insure firearm is unloaded.
2. Close the bolt and insert the rod down the bore till contact is made w/ the bolt face. (Small end for .22-.26 bores, large end for .27-.45 bores)
3. Slide both gauge stops down the rod until in contact with the muzzle. Tighten set screw on the top gauge stop (the one farthest from the firearm), the remove the rod. (I just slide it out about 10")
4. Select "a" bullet from the box to be fired, with an undamaged tip, insert the bullet into the chamber to firmly contact the rifling. Using an unsharped pencil or wooden dowel, hold the bullet against the rifling.
5. Reinsert rod, same end as before, till contact is made w/ the bullet. Slide the guage stop down to contact the muzzle. Tighten the set screw. I perform this several times, getting an average measurement.
6. Remove the rod and using dial or digital calipers, take an "inside" measurement between the two gauge stops. This is the maximum cartridge overall length for this particular bullet in this rifle.
7. Use the "same" bullet and seat into a dummy cartridge case so the OAL is the same as the measurement you just took.
8. Then use some kind of OAL gauge. I use the Stoney Pt. comparator. Take the meaurement and write that # down in your reloading log. This is your "dead length" (DL) seating depth and all further depths should be adjusted from here. Example, my 30-06 Ackley IMP "DL" with the Nosler 180 BT is 3.760" w/ the comparator yet 3.393" bullet tip cartridge base. Last month I performed a seating depth test for accuracy by shooting 3-shot groups starting w/ my depth at 3.765", or .005" into the lands. I then worked my way "in", away from the land, in .005" increments, finding a sweet spot .015" (3.745") off the lands. Groups were running 1/2" to 3/4" MOA out to 300 yds.
1. Use the same bullet and dummy case to set up your seating dies.
2. Make sure your OAL will fit into your magazine box.
3. Once you find a seating depth that works well, keep the accuracy at top notch by tracking the wear of the rifled lands by checking the running 1-6 again about every 300-500 shots. You might need to adjust the seating depth of the COL longer by a few thou to keep that "just perfect" distance to the lands.
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