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Joined: Dec 2009
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OP
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How do you guys work up a COL, to get your bullet kissing the lands.... Thanks
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Joined: Jan 2006
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Campfire Outfitter
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Campfire Outfitter
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Marks-a-lot is your friend. Seat a bullet, color it with a marker, chamber the bullet and look for the spots on the bullet where the lands knocked off some of the marker.
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Joined: Dec 2004
Posts: 17,226
Campfire Ranger
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Campfire Ranger
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Lots of ways to do it with tools, but I just press a small dent in the casemouth, press fit a bullet, and chamber it. The lands will usually push the bullet back. Try it a few times and measure the OAL, as the lands may sometimes grab the bullet when you retract the round and pull the bullet back out a bit. Then I load a dummy round a bit longer than that on my press and try to chamber that. If it won't chamber, I bump the bullet seating down a bit at a time until it will chamber. If it sticks, I tap it out with a cleaning rod. Once it will close with a bit of resistance, I mark the ogive with a sharpie and chamber agan to see the marks that the lands leave. You can wipe off the sharpie with alcohol and repeat while shortening the depth until you get very short marks, indicating that there is just a bit of land contact. That's your new dummy round and the OAL to work from....
Now with even more aplomb
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Joined: Feb 2001
Posts: 24,239
Campfire Ranger
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Campfire Ranger
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And then put that info on a sticky label in your die box .
Never holler whoa or look back in a tight place
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Joined: Mar 2006
Posts: 17,289
Campfire Ranger
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Campfire Ranger
Joined: Mar 2006
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I use a fired case, resize only about an 1/8 of the neck. insert a bullet by hand, color it with a magic marker, chamber the dummy round, carefully remove and measure. Repeat several times to verify COAL. The key thing is having a bullet that is held by a minimum ammount of neck tension.
Then I fully resize a case, seat a bullet to the COAL, chamber it, look for the marks from the lands and then start seating the bullet deeper in .005 increments and look to see where full contact is, partial contact and no contact. This will absolutely show where the lands are for a given bullet in your rifle.
There are tools that make the job easier and faster but results shouldn't be any different.
To avoid pressure issues, I don't seat bullets into the lands.
fish head
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Joined: Dec 2004
Posts: 17,226
Campfire Ranger
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Campfire Ranger
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And then put that info on a sticky label in your die box . Or you can have a windowsill full of labeled dummy rounds next to your load bench.  When it is time to load again, spin the seater stem out, run the dummy up in the press, snug the seater down on the dummy, and you are there....
Now with even more aplomb
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Joined: Sep 2003
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Campfire Ranger
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Campfire Ranger
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I do the sharpie method on non-grooved bullets. I look for "square" marks on the bullet.
I can't see chit with all the grooves on the tsx bullets though.
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Joined: Mar 2006
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Campfire Ranger
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Campfire Ranger
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I do the sharpie method on non-grooved bullets. I look for "square" marks on the bullet.
I can't see chit with all the grooves on the tsx bullets though. That's strange. The ogive to lands contact point should be well foward of the grooves. ? ? ? fish head
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Joined: Jun 2004
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Campfire Outfitter
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Campfire Outfitter
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For each cartridge I load, I form a case and then split the neck with a Dremel tool--two cuts 180 degrees apart. This puts just enough tension on the neck that you can slip a bullet into the mouth, chamber it, and just measure the length of the dummy cartridge.
Be not weary in well doing.
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Campfire Regular
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For bolt action rifles, I use two cleaning rods; the bullet I intend to load; some masking tape; and a set of calipers.
I plug the hole in one of the cleaning rods to make it a more accurate reading.
Close the bolt
Take the rod with the plugged hole and run it down the muzzle of the rifle.
Place a piece of masking tape around the cleaning rod right at the crown.
Next, remove the bolt and place the bullet in the chamber.
Using the other cleaning rod, hold the bullet against the lands. No need to apply a lot of pressure.
Now take the first cleaning rod and again insert it into the muzzle until it contacts the bullet; mask off your second reading.
The distance from bottom of the masking tape from first reading to the bottom of the masking tape of the second reading is the OAL. From that number I'll subtract .030 as my preferred distance from the Lands.
I usually load my '06 to an OAL of 3.250. When I measured a 150gr Sierra GK SP, the measurement came out to be 3.285. Subtract .030 and I'm at 3.255. Load up 37grs of RL17 behind the GK's and I got a group that measure .401 at 100 yards. YMMV
HaYen
Remember, not everyone has a happy ending, so be happy when you can
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Joined: Jan 2001
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Campfire Ranger
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Campfire Ranger
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Used to use a Stoney Point OAL length gauge (aka comparator) with their modified cases.
Now use that comparator in conjunction with a once fired case from the rifle I'm loading for that has been deprimed and neck sized. I cut a lengthwise slit in the case neck but any of the above methods for holding the bullet will work.
The OAL to touch the lands is written down and placed into the die box with the id of that particular rifle. It helps to recheck this occasionally as in high volume rifles the leade will wear and a couple of times I've found that ogives for a particular brand and style of bullet will have changed slightly from lot to lot.
Also - measure at least two or three different bullets in a lot to check for consistency. I bought a pile of Speers at a gunshow but the guy did not bother to mention they were factory seconds. Their ogive profiles were all over the place so OAL to touch the lands varied by a good .050".
Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!
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Joined: Nov 2005
Posts: 335
Campfire Member
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Jpro- Are you from Farmerville or Marion area ? For an old country boy you have good ideas. I have used the same methods for years. Sometimes I look at the book COL and add some then close the bolt slowly , then seat some more and check bolt. When it closes with a slight touch of the bullet it shoots USUALLY.I have some long chambers that I shoot single shot because they are to long for the magazine when I find that spot. I would rather shoot 1/2" with 1 shot than have 4 more rounds that I usually don't need . Oh yeah I know where the Tiger Bend , Loutre Runs and the Rocket Crossing Is. Been to Alabama Landing and duck hunted Moss Lake Too.
Last edited by rvp; 02/16/10.
SHOOT STRAIGHT AND OFTEN. Hunt with your kids. Teach them not to shoot anything that they are not going to eat. Have respect for all ANIMALS.
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Joined: Mar 2007
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Campfire Regular
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Campfire Regular
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Just use a Sinclair or Stoney Point OAL gauge!
405wcf
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Joined: Mar 2005
Posts: 26,199
Campfire Ranger
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Campfire Ranger
Joined: Mar 2005
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I use a fired case, resize only about an 1/8 of the neck. insert a bullet by hand, color it with a magic marker, chamber the dummy round, carefully remove and measure. Repeat several times to verify COAL. The key thing is having a bullet that is held by a minimum ammount of neck tension.
fish head That's how I do it too....... Casey
Casey
Not being married to any particular political party sure makes it a lot easier to look at the world more objectively...
Having said that, MAGA.
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Joined: Jan 2007
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Campfire Outfitter
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Campfire Outfitter
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For bolt action rifles, I use two cleaning rods; the bullet I intend to load; some masking tape; and a set of calipers.
I plug the hole in one of the cleaning rods to make it a more accurate reading.
Close the bolt
Take the rod with the plugged hole and run it down the muzzle of the rifle.
Place a piece of masking tape around the cleaning rod right at the crown.
Next, remove the bolt and place the bullet in the chamber.
Using the other cleaning rod, hold the bullet against the lands. No need to apply a lot of pressure.
Now take the first cleaning rod and again insert it into the muzzle until it contacts the bullet; mask off your second reading.
The distance from bottom of the masking tape from first reading to the bottom of the masking tape of the second reading is the OAL. From that number I'll subtract .030 as my preferred distance from the Lands.
I usually load my '06 to an OAL of 3.250. When I measured a 150gr Sierra GK SP, the measurement came out to be 3.285. Subtract .030 and I'm at 3.255. Load up 37grs of RL17 behind the GK's and I got a group that measure .401 at 100 yards. YMMV
HaYen +1 Doc
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Joined: Dec 2004
Posts: 17,226
Campfire Ranger
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Campfire Ranger
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Jpro- Are you from Farmerville or Marion area ? For an old country boy you have good ideas.
Oh yeah I know where the Tiger Bend , Loutre Runs and the Rocket Crossing Is. Been to Alabama Landing and duck hunted Moss Lake Too. I'm only about half as old as I look in my avatar. (grin) Of my two main hunting spots, one is currently flooded by Bayou DeLoutre and the other is a stone's throw from Alabama Landing, so you are right on the money....
Now with even more aplomb
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Joined: May 2005
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Campfire Tracker
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Campfire Tracker
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How do you guys work up a COL, to get your bullet kissing the lands.... Thanks Kissing the lands will not guarantee accuracy. OAL should be set by first determining the shape of the groups. The initial OAL does not matter. If the group is a large equilateral triangle, seat out further in 1/4 turn increments. If the group puts 2 together and the 3rd out there, seat deeper in the reverse method. The only obstacle to this method is where an internal magazine dimension prohibits increasing OAL for scenario one. John
When truth is ignored, it does not change an untruth from remaining a lie.
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Joined: Jan 2010
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Campfire Member
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Campfire Member
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AussieGunWriter, may I ask were or how you came about your seating depth adjustment technique?
I've never heard of seating deeper to cure shots that go out there as you say from the main group.
I'm not critizing, just looking to cure some of that problem I am having with 2 rifles right now that are doing that.
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Campfire Regular
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Campfire Regular
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BTT
Also curious about AussieGunWriters answer.
Remember, not everyone has a happy ending, so be happy when you can
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Campfire 'Bwana
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A wise man is frequently humbled.
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