I have never tried this method...have you?

Guys, I think what Wilber was trying to say as..... "it is just a number".

Most Benchrest Shooters have their gunsmith make them what we always called a "thingy". It's just a piece of barrel drop with your reamer run in just far enough to establish the shoulder. Simply put a loaded round in, give it a twist, and it tells you what your bullet depth is at in a brand new chamber. Work from there to find out what the barrel/bullet combo likes.

Good video.

http://benchrest.com/attachment.php?attachmentid=17234&stc=1&d=1452475308
 

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Well, I tried it, and using the feel of the bolt handle touching the extraction cam seems to my inexperienced hand the more sensitive of the two possible ways to do this, the other being the feel of the handle closing, or rather falling. I got a falling handle quite a bit before I got to just feeling the root of the bolt handle make contact with the extractor cam. I sized a case, with a one piece Hornady FL die set to make sure that I was not feeling the case at all. The shoulder was bumped well out of the way. I tried the case by itself... absolutely no feel at all. I worked the Wilson die shortening the loaded length in small increments, and at the last was making adjustment of .001. When I made what I thought would be my final adjustment, I checked myself by seating the bullet .001 deeper and got nothing on the cam, and no mark on the bullet, this with the bullet likely textured with 0000, and looking at the marks with a low power, over the head binocular magnifier. Having been through this once, I would expect that I will gradually shorten up the time that it takes considerably. I was measuring the combined length of the stem and cap (non-micrometer die) each time. All this time in shooting, and I had never run across this method before. IMO it is the most precise method for finding touch that I can imagine. I will color the case and keep it in my PPC loading kit. Just out of curiosity, I resized the case, seated the bullet long, measured the tip to head dimension, chambered it, and remeasured it. It had shortened, the neck tension was .002 and the difference between the barest touch and jam was .020. The barrel is a rechambered Rock Creek with 5R rifling. The rifle has no ejector. For the last two checks I put the rim under the extractor and inserted the combined dummy round and bolt into the action, feeling for the point where I could start to close the bolt, and just after starting rotation, keeping rearward pressure on the handle as I closed the bolt. If I were working with spring plunger ejector, I would have to do something different. I might sacrifice a case, cut away one section of the head to make clearance for the ejector, and load the case on the bolt face every time that I made a measurement. Understand, I would never bother with all of this for any field application, having gotten perfectly satisfactory results using less demanding methods, but for those situations where I want to leave no stone un-turned, this would be one of those stones.
 
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Boyd -
Welcome to LR methods..... many have been doing this for years.
15-ogive VLDs never worked well to the Jam method, and is why this and the similar "hash mark" methods have been popular in LR for years.
To chase the lands equal to the rate of erosion, this rules the roost (gizzy's<>thingy's only tell the lands location when the throat is fresh).
Donovan
 
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This'll be useful for determining touch in my .224 Clark with the 90 grain Berger VLD. Even though they like a lot of jump it's good to have a set reference point to start from (and I agree, the jam method is tough on that high an ogive).

-Lee
www.singleactions.com
 
zfastmalibu said:
Men,
I made the video to help those who don't have a consistent way to do this.
Click to expand...

Boyd Allen said:
If I were working with spring plunger ejector, I would have to do something different. I might sacrifice a case, cut away one section of the head to make clearance for the ejector.
Click to expand...

Guys, why remove the ejector (as in the video) or bypass the ejector (as Boyd mentioned)? Is it to be sure the ejector doesn't push the bullet into the lands? If that's the reason, given that the ejector will be in place when shooting, it seems that removing the ejector may prevent you from actually finding the "touch" point under actual shooting conditions.
 
I would be looking for a true dimension from where the bullet touched the lands to the bolt face...as a reference. Yes, the ejector pressure would probably force the bullet into the lands just a little bit, just as the force and speed with which the bolt was run forward as a round was chambered might have some effect when there is an ejector. What I am looking for is a constant starting place from which to adjust, and a reliable way to get there. Now that I have this method, it would be interesting to compare the setting that it gives me with others, like using a case with a split neck, using my Stoney Point (now Hornady) tool, or my Sinclair tool that has a rod and stop collars. One thing that I am going to try is a clamp piece to go on a split case neck to clamp the bullet in position after a reading has been taken so that it will not be accidentally be moved in the process of measuring. I have one that I got with a prototype of a seating depth tool for .222 that someone sent me back in the 90s when I was writing for Shooters News. It is a short piece of rod with a hole in it for the case neck and a set screw. The fellow did not produce his seating depth tool because he was told that it infringed on the patent on the then relatively new Stoney Point tool.
 
No, I wasn't kidding. Maybe I didn't understand the purpose of doing that.

So, everybody shoots their bullets seated at that precise length??
 
Wibur I talked to a shooter at Shamrock this pass year who previously
shot on US shooting team. He said he shoots from both ends just
touching lans and working into lans and hard jam ,working out of lans.
He indicated resuts could be good using both ways. Checks each new installed
barrel like this.
 
Wilbur said:
No, I wasn't kidding. Maybe I didn't understand the purpose of doing that.

So, everybody shoots their bullets seated at that precise length??
Click to expand...

Wilbur, no it is just a starting point. It is a good spot to avoid actually. All my record holing barrels have shot somewhere within 10 thousands of there though, so I find it useful.

Tom
 
I can't say this without sounding like a dummy but I will anyway. That's just a method to find a spot that you may not use....?
 
Let's say that we have found a good seating depth that we want to get precisely back to as the the throat wears. It could be so many thousandths longer than the point where the bullet touches, or the bullet could be jumping by some amount. Whichever it is, we would like to have the most precise and repeatable way of locating my starting point. I believe that this method would stack up very well in terms of consistency, but only time and repeated use will tell. Right now I have a non micrometer 6PPC seater set for touch, by this method, and have recorded the precise stem and cap combined length that produces it. Since I have never used that setting, but some have reported good results there, the next time that I venture forth to the range, I will do some charge testing, and once I know what the best powder measure setting seems to be I will do some seating depth testing, around touch, to see if I can find some improvement. At the end of all of this, after I have put 50 rounds or so through the barrel, I will check to see if my throat has moved, using the same method. There are a lot of ways to skin this particular cat. I may try this one and abandon it after testing. The reason that I put the link to the video up was that the method was new to me, and I wanted to know if others are doing it that way, and if they are, or have in the past, what their opinion is. If I can do a more precise job of finding my reference point. perhaps I can do a better job of staying in tune over time, as barrels wear.
 
Wilbur,
A lot of guys shoot .010 off the lands. Some barrels like you to chase the lands. So you need an accurate way to keep the bullet .010" off the lands. I check the throat every time I load, some do it every target. Theses dashers can be pretty picky at 1k. Its similar to you guys chasing the powder charge all day.
 
Boyd, you just stated one of the benefits and something it does not help me in any way to TELL my competition. I'm 3 for 3 on barrels since adopting the method in the video. These barrels have had a node jumping, and 2 of them in the lands. If the throat moved 1 thousands on Saturday, I advanced the bullet on Sunday 1 thousands. 3 of 3 have stayed on tune doing this. I know a lot of forum members here don't shoot long range, but our seating window to keep a dasher on its TOP tune is ridiculously small. And if the trend I mentioned above holds, and I don't have to shoot "test" groups to find it every time something changes..... well, then that is important, and will lead(already has) to better aggs.

I would like to hear how finicky or non finicky is seating in the short range game?

Edit... I see Alex can type faster than me, hmmmm

Tom
 
Thanks guys. This is exactly the kind of information that I was hoping for when I started this thread. I am learning, and that is fun.
 
No one would even think of beating a Find Outstanding Young Gentleman
like you Wilbur. They know Better
 
When I'm breaking in a barrel to find what it likes I do exactly what the video shows. I like a hard jam then I only have one way to go back. Then after a few hundred rounds if the rifle is not shooting the way it was I recheck to see if I need to go forward again to bring back the accuracy. Same stuff I guess!

Joe Salt
 
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