how do you determine when bullets are seated "to the lands"?
- Thread starter Ranman
- Start date
Close the bolt on your rifle, put a cleaning rod down the barrel until it touches the bolt, threaded end down, mark by putting a piece of masking tape on the rod at the muzzle.
Next, put a bullet (not cartridge) in the chamber and hold it in firm against the lands with the eraser end of a pencil. Next, put your cleaning rod in threaded end first until it reaches the bullet, then mark the rod with a piece of tape at the muzzle. Measure with calipers between the tape marks and you have your OAL to the lands.
Do this twice two confirm.
You should do this anytime you change bullet brands, weights, or styles.
Next, put a bullet (not cartridge) in the chamber and hold it in firm against the lands with the eraser end of a pencil. Next, put your cleaning rod in threaded end first until it reaches the bullet, then mark the rod with a piece of tape at the muzzle. Measure with calipers between the tape marks and you have your OAL to the lands.
Do this twice two confirm.
You should do this anytime you change bullet brands, weights, or styles.
superd222
CGN frequent flyer
You could purchase the tools to do it. Eg: Hornady Lock-N-Load OAL Gauge
OR
I use the following method:
1. Remove firing pin from bolt (or use an unprimed/resized case)
2. Load a bullet in the case seated about 200+ thousandths (0.200") longer than suggested. DON'T USE LIVE AMMO FOR THIS - NO POWDER OR PRIMER !!!
3. Chamber this (bullet + case only) round
4. Push the bolt closed - this seats the bullet "into the lands"
5. Remove this test cartridge and examine length of rifling marks on bullet (magnifying glass helps). This is how far into the lands the bullet was pushed.
6. Measure OAL and now you can determine (calculate) various OAL's eg: into the lands, just at the lands, 0.010" off the lands etc...
7. Load a few more rounds using this procedure to verify the starting OAL.
BE CAREFUL !!!
Some rifles shoot well 'just into the lands' - some rifles shoot well with a 10-20 thou jump.
I NEVER (OK...Rarely) seat bullets to an OAL that puts the bullet in the lands. I try to keep them 0.010" or more off the lands depending on the rifle and application.
This is the method I use which may not be appropriate or safe for all firearms.
Always refer to your reloading manual.
Good Luck - and - BE CAREFUL !!!
SD
OR
I use the following method:
1. Remove firing pin from bolt (or use an unprimed/resized case)
2. Load a bullet in the case seated about 200+ thousandths (0.200") longer than suggested. DON'T USE LIVE AMMO FOR THIS - NO POWDER OR PRIMER !!!
3. Chamber this (bullet + case only) round
4. Push the bolt closed - this seats the bullet "into the lands"
5. Remove this test cartridge and examine length of rifling marks on bullet (magnifying glass helps). This is how far into the lands the bullet was pushed.
6. Measure OAL and now you can determine (calculate) various OAL's eg: into the lands, just at the lands, 0.010" off the lands etc...
7. Load a few more rounds using this procedure to verify the starting OAL.
BE CAREFUL !!!
Some rifles shoot well 'just into the lands' - some rifles shoot well with a 10-20 thou jump.
I NEVER (OK...Rarely) seat bullets to an OAL that puts the bullet in the lands. I try to keep them 0.010" or more off the lands depending on the rifle and application.
This is the method I use which may not be appropriate or safe for all firearms.
Always refer to your reloading manual.
Good Luck - and - BE CAREFUL !!!
SD
Please explain? The gauges do not take in to account the different bullet shapes and styles which results in inaccurate seating depths. Take the ogive of a Barnes TSX and compare it to the ogive of a Hornady Sp.
The style that you give is more open to fault, I use to use a form of this method. You need quite a bit of pressure on your bolt to force a bullet into a sized case, then the bullet will "stick" into the lands and pull back when you extract giving you a longer OAL reading.
thats exactly how I do it. it is very accurate. you need a good set of calipers to measure the marks.
I just don't think you can place tape to very good accuracy. I did reread your post and I have to admit it will probably work decently. After all any method is just to get close and then experimentation finalizes it for accuracy on target.
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+1. I made a total investment of about $60 for the depth tool + comparator set + predrilled cartridges that screw onto the depth tool and **just** hold a bullet enough to move into the case on the slightest touch at the lands. It's easy to use and accurate...and no big fuss to redo when using a different bullet type, and quick to calibrate multiple rifles. I also learned a trick on these forums, use a cleaning rod in from the muzzle to push back against the bullet, then you can move the bullet back and forth by feel and fine tune the 'touch' at the lands.
The piece of mind of using a tool designed to do the job right is worth the $$, to me.
Derek__Erickson
Regular
- Location
- Kamloops BC
Use a felt pent, or a lighter, get the bullet so it has black on it, if you use a bic lighter, you can get some black residue, that works great
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take a spent case, ( a bullet should slide down the neck with room to spare) press edge of neck on hard surface to dent it. Make the dent as small as possible to apply a very, VERY light squeeze on the bullet, push bullet into neck so it sticks out as far as possible. gently chamber the round as though it was a single shot. close bolt open bolt and close it again. gently remove round and measure. this is your distance to the lands with this particular bullet.
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I think I'll try this method before I go and buy any tools to do so! It sounds like it will produce an OAL with the bullet seated just to the lands that I can work with to test different seating depths.
I usually seat a bullet to the longest length that will fit in my magazine. Try to chamber it, usually if it is hitting the lands it will give some resistance when closing the bolt. Extract the cartridge and often the OAL will be the 'kissing lands' distance. Back it off .020" or so for some wiggle room and reseat. Retest and it usually is good to go
I use Spitzers method - it works well. I use a wooden dowel, and mark it with a fine mechanical pencil. Also, ensure the rifle is cocked when the bolt is closed - this forced the bolt rearward - otherwise you can introduce an error.
Finally, as you are measuring to the (possibly defomed lead) tip of the bullet, measure two or three bullets before you start, and pick a representative sample. Mark it with a magic marker for future reference - eg if you have any another rifles in the same calibre, you must do a survey for each rifle, and load to the tightest one.
This is the biggest drawback to loading close to the lands for hunting rifles - its rifle specific, and bullet lot specific. I've found significant variations in ogive profile from box to box of Hornady bullets! This can make the effort very time consuming. I've gone back to fairly conservative margins ie 30 - 40 thou, as it makes life easier, and the groups havent gotten any larger.
Finally, as you are measuring to the (possibly defomed lead) tip of the bullet, measure two or three bullets before you start, and pick a representative sample. Mark it with a magic marker for future reference - eg if you have any another rifles in the same calibre, you must do a survey for each rifle, and load to the tightest one.
This is the biggest drawback to loading close to the lands for hunting rifles - its rifle specific, and bullet lot specific. I've found significant variations in ogive profile from box to box of Hornady bullets! This can make the effort very time consuming. I've gone back to fairly conservative margins ie 30 - 40 thou, as it makes life easier, and the groups havent gotten any larger.
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create various differnt depths and cover the bullet with a black perm marker.. go from shorter to longer, and insert/close each one.. you will see the black marker getting rubbed of and see that pattern of the lands when the length starts to hit it, and rub off and it's forced against them.
