Measuring Lands?

[Reece123]

2nd time using a Hornady oal tool to measure the lands on a rifle. First one is a 243 tikka with 103 eldx. When I did it, it was easy to push and then hit the lands hard and stopped. Pretty straightforward. On my seekins 6.5 prc im measuring with 147 elmd and 156 Bergers. With both of these bullets, it seems a little mushy and then hits the lands hard. Do I stop when I feel the slight resistance or when it gets firm?

 

[wapitibob]

You can run the bullet thru a wax candle flame to smoke it and you'll then see where the lands touch.

 

[JRay]

Videos | wheeleraccuracy

www.wheeleraccuracy.com

Watch the Finding your lands video. I use this and it works very well. You have to disassemble your bolt and it takes some time, but it is accurate.

 

[EdP]

I use the Hornady tool. 9 readings are taken, 3 with the brass knob at TDC, 3 at 90 deg CCW of TDC, and 3 at 90 deg CW of TDC. The readings are generally within a few thousanths and any that differ significantly are tossed and retaken. The 9 readings are averaged, or I may toss the high and the low and average the remaining 7.

 

[Castle Rock]

Gently, if you push firmly you are well into the rifling

 

[Caseknife]

2nd time using a Hornady oal tool to measure the lands on a rifle. First one is a 243 tikka with 103 eldx. When I did it, it was easy to push and then hit the lands hard and stopped. Pretty straightforward. On my seekins 6.5 prc im measuring with 147 elmd and 156 Bergers. With both of these bullets, it seems a little mushy and then hits the lands hard. Do I stop when I feel the slight resistance or when it gets firm?

Brand new rifle or has it been shot? What does the bullet look like when you remove it from the chamber? Does it have scuff marks or is it pristine like the others in the box of bullets? If it has scuff marks, you are pushing it through a carbon ring and then hitting the lands.

 

[WeiserBucks]

I use the Hornady tool. 9 readings are taken, 3 with the brass knob at TDC, 3 at 90 deg CCW of TDC, and 3 at 90 deg CW of TDC. The readings are generally within a few thousanths and any that differ significantly are tossed and retaken. The 9 readings are averaged, or I may toss the high and the low and average the remaining 7.

I bet 7 members of this forum know what TDC is without a Google search.

 

[Axlrod]

I bet 7 members of this forum know what TDC is without a Google search.

I only used that term when I was building BBC's

 

[North of 60]

Top Dead Center

 

[WeiserBucks]

I only used that term when I was building BBC's

Unfortunately I bet 97% of our membership knows what a BBC is

 

[Reece123]

Brand new rifle or has it been shot? What does the bullet look like when you remove it from the chamber? Does it have scuff marks or is it pristine like the others in the box of bullets? If it has scuff marks, you are pushing it through a carbon ring and then hitting the lands.

its got about 30ish rounds on it without being cleaned. They are scuffed. I bet it is a carbon ring then.

 

[Axlrod]

Unfortunately I bet 97% of our membership knows what a BBC is

Mopar guy

 

[Reece123]

I bet 7 members of this forum know what TDC is without a Google search.

Yea I know what top dead center is but haven't heard that term since I quit building 2 smokers. Certainly never messed with any BBC, or Chevys either!

 

[Reece123]

Gently, if you push firmly you are well into the rifling

I was thinking maybe that was the case, but the bullet is still seated when I pull the tool out. ive jammed the rifling before using other methods and the bullet was barely stuck on the lands.

 

[Caseknife]

its got about 30ish rounds on it without being cleaned. They are scuffed. I bet it is a carbon ring then.

Clean it good and then retest. Shouldn't be a carbon ring forming with only 30 rounds though.

 

[WeiserBucks]

Carbon ring is the new covid, you have it and it's gonna kill us all.

 

[Axlrod]

Yea I know what top dead center is but haven't heard that term since I quit building 2 smokers. Certainly never messed with any BBC, or Chevys either!

A BBC IS a Chevy

 

[WeiserBucks]

A BBC IS a Chevy

Swing and a miss homie.

 

[Silver Wings]

I ran into a similar situation yesterday. Drilled and taped a 6cm case for the Hornady tool. The 109 eldm stops with a coal of 2.705. I marked a loaded cartridge(coal 2.790) with a sharpie and this is how it came back after being chambered. Approximately 400 rounds on this barrel. I tried Hoppe’s on a patch and an underside bore brush from the chamber side…didn’t get too aggressive with it. Nothing changed when I retried with the tool.
In the photo you can see the ink was cleaned off all the around the bullet just above the case mouth. No rifling marks anywhere on the bullet.
Carbon ring???
How aggressive do I get with it and not create another problem?

 

[wind gypsy]

I ran into a similar situation yesterday. Drilled and taped a 6cm case for the Hornady tool. The 109 eldm stops with a coal of 2.705. I marked a loaded cartridge(coal 2.790) with a sharpie and this is how it came back after being chambered. Approximately 400 rounds on this barrel. I tried Hoppe’s on a patch and an underside bore brush from the chamber side…didn’t get too aggressive with it. Nothing changed when I retried with the tool.
In the photo you can see the ink was cleaned off all the around the bullet just above the case mouth. No rifling marks anywhere on the bullet.
Carbon ring???
How aggressive do I get with it and not create another problem?

View attachment 1034653

Signs of a carbon ring and if it is you'll likely want something that does a little better on carbon than hoppes and if anything, a slightly oversized brush putting more pressure on the start of your freebore.