Help! Distance to the lands

[Oklahunter1]

To start, I am a rookie when it comes to reloading. I am getting ready to load the Berger 156 Elite Hunter for my 6.5x284. I used the Hornady device to measure my distance to the the lands. It gave me a distance of 2.618” to the bullet ogive. I then thought I would try something I saw on YouTube to decide how much jump you need to load for. I loaded up a dummy load with the bullet seated way out. I colored the bullet with a magic marker, I then chambered it. When I got it out it measured 2.645” to the ogive and 2.566” to where the marker was messed up. My question is how can these two methods be so different?

 

[The Oregonian]

There may be more to it but part of the problem is getting to Hornady tool to seat the bullet the same way every time. Is it jammed, just touching, etc. The Alex Wheeler method seems to be the best but it can take a little bit to get the feel for what you are trying to feel for.

 

[cajun]

Take a coated cleaning rod put it in the muzzle. When you push the hornady tool forward push back with the rod. You will be able to feel the bullet going in the lands.

 

[cajun]

Also when you seated the bullet long and chambered it the bullet is going to be hard into the lands or jammed.

 

[QuietTexan]

Were you jamming it in there with the Hornady tool? Or trying the back-and-forth light tough way? I don't mess with the delicate method, I jam the heck out of the bullet into the lands with the Hornady tool and get repeatable results down to the thousandths, and I back off 0.010" from that.

Generally with a hunting load you don't want to stick a bullet in the bore and fill an action with powder if you have to open the action right, right? And Berger tells us the VLDs can handle jump and have a range 0.030-0.040" wide for seating depth, so you should be able to find longer jump node, so why jam them into the lands anyways? If your measurement is off in absolute terms, it doesn't matter because you're only coming back away from that point, not going in deeper.

Start at 0.010" off your hard jam, back out by 0.040" intervals, bracket the best group, done. Then shoot it way far out there to actually confirm the load.

 

[Sockeye66]

Stand the rifle on it's pad when using the oal gauge, seems to be more accurate for me that way. If there's one thing I'm truly an expert at it's breaking the head of of aluminum tube. I do like using a piece of brass with a thin cut vertically along the neck and chambering a long seated bullet. I then look with a magnifying glass to check for marks.

 

[Ted Sierocinski]

To start, I am a rookie when it comes to reloading. I am getting ready to load the Berger 156 Elite Hunter for my 6.5x284. I used the Hornady device to measure my distance to the the lands. It gave me a distance of 2.618” to the bullet ogive. I then thought I would try something I saw on YouTube to decide how much jump you need to load for. I loaded up a dummy load with the bullet seated way out. I colored the bullet with a magic marker, I then chambered it. When I got it out it measured 2.645” to the ogive and 2.566” to where the marker was messed up. My question is how can these two methods be so different?

Just choose one and go with it. Do a ladder test to see which seating depth your rifle likes.

 

[Oklahunter1]

Also when you seated the bullet long and chambered it the bullet is going to be hard into the lands or jammed.

Cajun, that’s the way I do my hornady tool too. Just seems like almost .040 is a lot of difference. If I use the hornady method distance and started .020 off the lands could I actually be .060 off?

 

[Mikecr]

I used the Hornady device to measure my distance to the the lands. It gave me a distance of 2.618” to the bullet ogive. I then thought I would try something I saw on YouTube to decide how much jump you need to load for. I loaded up a dummy load with the bullet seated way out. I colored the bullet with a magic marker, I then chambered it. When I got it out it measured 2.645” to the ogive and 2.566” to where the marker was messed up. My question is how can these two methods be so different?

Method difference: The Hornady tool takes datum from shoulder contact in your chamber, while jamming is w/resp to bolt face.

Whatever you seen on youtube cannot tell you how much jump you need to load for..
The only way to determine best cartridge base to ogive (CBTO) is through full seating testing.
That best result is not 'predictable' by anyone.

Also, Jam length does not produce touching, which distance off the lands (OTL) is based on.
Someone mentioned Alex Wheeler's method. He didn't invent it or anything, it's old tried & true.
But he did put out a great video for it:

Myself, I use a cleaning rod method to find touching. I only do it intially(new barrel) to give me a starting point for my range of seating testing. I don't ever do it again with a given barrel, and I never care where touching or jam really is.
All I care about is the CBTO that testing tells me is best.
CBTO is not w/resp to lands, so that's why I don't care about what my land relationship is.
Honestly, we make way too much of finding touching land relationship with dead nutz accuracy, as it really doesn't matter at all..

 

[cajun]

Look at it this way. Round the hornady tool to 2.620. You got 2.645 jammed. So .025 difference. Not hard to be .020 from touch to into the lands hard. I would just roll with the 2.620.

 

[Oklahunter1]

Thanks for everyone’s replies. I appreciate it! I’ll just start .020 off the hornady method and go from there.

 

[Crunchy]

I use the Hornady method and take 5-10 different measurements and write them down. Use the shortest number, and take .010 or .020 off from that to start. Remember different lot bullets will measure differently.

C out

 

[swampbug]

The exact measurement is not that important. It is just a place to start.

 

[MontanaJack]

I work the bullet in and out of the lands using the Hornady tool and a carbon fiber cleaning rod from the muzzle end of the barrel, pushing the bullet back and forth engaging the lands with the bullet with the Hornady rod and dislodging with the cleaning rod. Before locking down the Hornady tool, I make sure the case is jammed into the chamber. I repeat this process a half a dozen times and use the average and subtract 0.010 to start. I'm shooting lots of single hole groups with many rifles, mostly at 0.010 off the lands with VLD bullets. Works for me. Good luck!!