Finding distance to lands

[Thisguy65]

I saw the video of opening/closing the bolt to find the distance to the lands. I went one step further and color the ogive to make darn sure the number I was getting were as accurate as can be.

Action is TL3. The two ways I was using, were by seating the bullet until the bolt fell under it's own weight and there was no extraction camming felt from pulling the bullet out of the lands. (seen here

)

and then using sharpie to color the ogive and looking for marks. I was using both because I felt that you still could touch the lands but not get any felt report on the bolt during extraction. 1.765 showed this. However I only got 2 of the 4 lands. Sharpie added 0.0005, which is very very tricky to measure I understand.

Picture one through three show different seating but also show the rifling marks on the bullet. 1.763 hardly show rifling on the bullet but was scratching.

So my question is at 1.763 the light mark, would you still consider this touching the lands. Remember the camera blows the mark area up. It was hard enough getting the camera to focus on the small mark on 1.765/63. At 1.760 I had zero marks, 1.761 I had a very very faint mark. A good friend of mine using the same bullet, different reamer (6 dasher) but same freebore was 1.768 (touching the lands). Using splitting the case neck with a dremel method. (http://www.larrywillis.com/OAL.html)

 

[Richard Jones]

What kind of action?

 

[Thisguy65]

Big horn TL3. During the test the firing pin assembly was removeed

 

[powderbrake]

You have a number between 1.763 and 1.767. What difference does it make?, Aren't you going to do test loads that range to less than 1.763, and more than 1.767 ? I have always considered the point where it touches the lands a reference point for subsequent actual load tests.

 

[fguffey]

I make transfers, I transfer the dimensions of the chamber to the seating die, after adjusting the seating die to the transfer I zero the seating die.

F. Guffey

 

[butchlambert]

I have a gizzy that I use for ea. chamber. Take a barrel stub and run the reamer into it to include the shoulder. You can use it to verify your shoulder bump and bullet protrusion.

 

[fguffey]

I have a gizzy that I use for ea. chamber. Take a barrel stub and run the reamer into it to include the shoulder. You can use it to verify your shoulder bump and bullet protrusion.

I do not have a grizzy, I do have take off barrels and I have barrel stubs but to tie all of them together I must know the case head protrusion in the chamber I am loading for. Or I transfer the dimensions of the chamber o the seating die and skip the comparator, Hornady/Sinclair tool etc.

F. Guffey

 

[butchlambert]

I do not have a grizzy, I do have take off barrels and I have barrel stubs but to tie all of them together I must know the case head protrusion in the chamber I am loading for. Or I transfer the dimensions of the chamber o the seating die and skip the comparator, Hornady/Sinclair tool etc.

F. Guffey

Mr. Guffey,
I have not a clue what the 'ell your talking about. Do you?

 

[fguffey]

Mr. Guffey,
I have not a clue what the 'ell your talking about. Do you?

Butchlambert. you have no clue? That is Ok, I place no obligation or demand on anyone to even try. When the bolt closes the chamber is a dark place for most, judging by the responses I believe it would be safe to say the chamber is a dark place for all with one exception.

I know there is a tool that is called a chamber gage, my opinion the chamber is a Wilson case with less case body clearance. Problem? I make chamber gages with case head protrusion. Back to the Wilson case gage, it is possible to determine the diameter of a case with the Wilson case gage; can I convince anyone that it is possible and do I know what I am talking about? Convincing anyone it is possible is not my job. If they do not believe it can be done who am I to argue with them.

F. Guffey

 

[butchlambert]

Butchlambert. you have no clue? That is Ok, I place no obligation or demand on anyone to even try. When the bolt closes the chamber is a dark place for most, judging by the responses I believe it would be safe to say the chamber is a dark place for all with one exception.

I know there is a tool that is called a chamber gage, my opinion the chamber is a Wilson case with less case body clearance. Problem? I make chamber gages with case head protrusion. Back to the Wilson case gage, it is possible to determine the diameter of a case with the Wilson case gage; can I convince anyone that it is possible and do I know what I am talking about? Convincing anyone it is possible is not my job. If they do not believe it can be done who am I to argue with them.

F. Guffey

Freddy Freddy Freddy, Pictured below are some of my gizzys. They are cut with the reamer that cuts my chambers. From the git go:
#1-put your headspace gauge or proper headspaced brass in the gizzy and measure to the base of your case. This will tell you how to set the HS on your size die.
#2- seat a bullet a little long and take a measurement. This will tell you how much you need to move your booolit back into your case.
Do you understand?
Tommy, do you comprehend?

 

[bobinpa]

I have those same gizzys for some of my guns and it works perfectly. Not that it matters, but I follow what you are doing.

 

[dkhunt14]

I make transfers, I transfer the dimensions of the chamber to the seating die, after adjusting the seating die to the transfer I zero the seating die.

F. Guffey

Explain that procedure and explain what it has to do with finding seating depth.. Matt

 

[dkhunt14]

I do not have a grizzy, I do have take off barrels and I have barrel stubs but to tie all of them together I must know the case head protrusion in the chamber I am loading for. Or I transfer the dimensions of the chamber o the seating die and skip the comparator, Hornady/Sinclair tool etc.

F. Guffey

Can you explain how this finds seating depth. Matt

 

[dkhunt14]

You have a number between 1.763 and 1.767. What difference does it make?, Aren't you going to do test loads that range to less than 1.763, and more than 1.767 ? I have always considered the point where it touches the lands a reference point for subsequent actual load tests.

I like to know the exact touch point so I can keep track of how much to move the bullet to chase the lands. 40 rounds from now I can check again and if I gained .020 I can adjust my seating die to move my bullets. 020. When trying to shoot really small groups at any long distance 600 yards plus, some guns are touchy to what seating depth they really want. Sometimes the difference between shooting good and shooting records can be as little as .003 seating depth. Then I find what depth the gun likes.
See Alex Wheelers video of Tom Mosel's way of checking seating depth. It is the most accurate way of doing it. Matt

 

[Luke Miskol]

I saw the video of opening/closing the bolt to find the distance to the lands. I went one step further and color the ogive to make darn sure the number I was getting were as accurate as can be.

Action is TL3. The two ways I was using, were by seating the bullet until the bolt fell under it's own weight and there was no extraction camming felt from pulling the bullet out of the lands. (seen here

)

and then using sharpie to color the ogive and looking for marks. I was using both because I felt that you still could touch the lands but not get any felt report on the bolt during extraction. 1.765 showed this. However I only got 2 of the 4 lands. Sharpie added 0.0005, which is very very tricky to measure I understand.

Picture one through three show different seating but also show the rifling marks on the bullet. 1.763 hardly show rifling on the bullet but was scratching.

So my question is at 1.763 the light mark, would you still consider this touching the lands. Remember the camera blows the mark area up. It was hard enough getting the camera to focus on the small mark on 1.765/63. At 1.760 I had zero marks, 1.761 I had a very very faint mark. A good friend of mine using the same bullet, different reamer (6 dasher) but same freebore was 1.768 (touching the lands). Using splitting the case neck with a dremel method. (http://www.larrywillis.com/OAL.html)

 

[Luke Miskol]

I take one downer brass, cut the neck with a small cut-off wheel in a Dremel; lengthwise just the neck. Then size it. Start a bullet in the case and close action. As soon as the bullet engages rifling there just enough tension to push bullet to C.O.L with out forcing anything or jamming it to far into lands. Had a old gunny Sargent show me that trick.

 

[mikecr]

IMO, the R-P tool is/was the best for finding touching w/resp to your bolt face. Its a version of the 'cleaning rod method'.
Look over Woods post here for pics and instructions: http://www.reloadersnest.com/forum/topic.asp?TOPIC_ID=9027
Maybe you can make or find a version today.

Personally, I've stopped testing with land contact seating, as off the lands some amount has been better with my loads, and I would no longer be willing to rely on eroding land contact. I'd run with different bullet, powder, neck tension, or cartridge, before accepting that situation.

 

[6MMsteve]

I see FGuffey has given his wisdom to you guys, Go Guffer your koolaid is toxic lol

 

[6MMsteve]

I make transfers, I transfer the dimensions of the chamber to the seating die, after adjusting the seating die to the transfer I zero the seating die.

F. Guffey

 

[Sheldon N]

You have a number between 1.763 and 1.767. What difference does it make?, Aren't you going to do test loads that range to less than 1.763, and more than 1.767 ? I have always considered the point where it touches the lands a reference point for subsequent actual load tests.

As much as I care about the OP's question (I've got a TL-3 Dasher on order myself), ultimately this is the correct answer.