Sierra 243 Win seating depth question

[Propbndr]

Will do but it is not my method, it the method used by Frankford Arsenal.

I will look at what you send. Maybe it will work with what I have on hand.

 

[Kracken McGraw]

https://www.brownells.com/reloading...lair-bullet-seating-depth-tool/?sku=749004650
These are out of stock at the moment but have given me results very close to the bolt firing pin removal method.

 

[Propbndr]

https://www.brownells.com/reloading...lair-bullet-seating-depth-tool/?sku=749004650
These are out of stock at the moment but have given me results very close to the bolt firing pin removal method.

That is similar to what I can make with what I have on hand. What I have can be used with that method or the Frankford Arsenal setup.

 

[Propbndr]

I will look at what you send. Maybe it will work with what I have on hand.

Thanks for the pm.

 

[Kracken McGraw]

That is similar to what I can make with what I have on hand. What I have can be used with that method or the Frankford Arsenal setup.

The Sinclair goes through the receiver and the Frankford may go down the barrel.

 

[Propbndr]

The Sinclair goes through the receiver and the Frankford may go down the barrel.

After a second look at the Sinclair setup, I have no way of duplicating it. With what I have, I can duplicate the Frankford Arsenal setup.

 

[Propbndr]

I ended up using the Hornady OAL gauge with a homemade modified fire formed case, using touch vs jam. I was able to get repeatable measurements With less then .002 between different bullets. I was not able to get repeatable measurements with screw collars on my cleaning rod (Similar to the Frankford Arsenal setup). I did try using blue loctite with a fire formed case and bullet. The results were almost identical to the Hornady gauge. Based on my measurements, the rounds I was concerned about have a CBTO about .040 off the lands.

And for those who may be wondering about loctite blue ruining the components, you can pull the bullet. They clean up beautifully with alcohol and a swap.

Thank you for all the suggestions.

 

[McGrew]

As suggested in a couple of posts, my problem may be with the Hornady modified case and or my technique. I have decided to make my own case and redo the measurements. While I have not stuck a bullet, I don’t want to take a chance of that ugly scenario. All I have to do is find a 5/16 - 36 tap.

I am cheap and after spending a lifetime in machine shops decided to make my own gauge for finding the lands. BTW, 5/16-36 taps are not common. I’m sure Hornady or McMaster will sell you one. I am shooting 223 and took a fired case from my rifle and drilled and tapped it for 10-24. I would have preferred 10-32, but did not have a screw long enough. I found the 10-24 works fine. I insert the modified case with the bullet I plan to shoot into the chamber. I use a dental pick to hold the case in the chamber and turn the screw with a long screwdriver. When the case starts backing out I stop. Pull out the case and bullet and measure the COL. I found it to be repeatable if you are careful. This tool cost nothing and should work in bolt guns as well as single shots. This might be another way to check your measurements. Danny

 

[Propbndr]

I am cheap and after spending a lifetime in machine shops decided to make my own gauge for finding the lands. BTW, 5/16-36 taps are not common. I’m sure Hornady or McMaster will sell you one. I am shooting 223 and took a fired case from my rifle and drilled and tapped it for 10-24. I would have preferred 10-32, but did not have a screw long enough. I found the 10-24 works fine. I insert the modified case with the bullet I plan to shoot into the chamber. I use a dental pick to hold the case in the chamber and turn the screw with a long screwdriver. When the case starts backing out I stop. Pull out the case and bullet and measure the COL. I found it to be repeatable if you are careful. This tool cost nothing and should work in bolt guns as well as single shots. This might be another way to check your measurements.

I never thought about trying that method. I was able to find a tap and drill set on Amazon for about $12. Not the best set but, it worked. As I don’t have a lathe, I used my drill press to drill the case. The challenge was how to hold the case securely without damaging it. I was able to hold it tight enough with the rubber clamps on my workmate. I feel that I will have no problem making cases for 308 & 30-06‘s. 223 might be a challenge due to the small diameter of the case.

 

[Zero333]

As long as the the bullets are not getting JAMMED (Stuck) in the rifling, you're go too go.

Just do a usual load work up and look for pressure signs..

 

[dryhumor]

I use this method from time to time.

Take a FL sized case trimmed to length and make two slits in the neck 180 degrees apart. A dremel tool and cut off wheel work well.

Seat a bullet a bit longer than max chamber spec and mark the bullet base even with the case mouth with a sharpie. Chamber the round, close the bolt, extract the round keeping it aligned to the bore with your finger.

You can see in the pic, the bullet has been pushed back from contacting the lands. Not a hard jam, just a firm contact. Measure COAL. You can pull the bullet and spin, remark, and repeat to verify results.

I measure both COAL and case base to ogive, and go from there.

 

[Propbndr]

I use this method from time to time.

Take a FL sized case trimmed to length and make two slits in the neck 180 degrees apart. A dremel tool and cut off wheel work well.

Seat a bullet a bit longer than max chamber spec and mark the bullet base even with the case mouth with a sharpie. Chamber the round, close the bolt, extract the round keeping it aligned to the bore with your finger.

You can see in the pic, the bullet has been pushed back from contacting the lands. Not a hard jam, just a firm contact. Measure COAL. You can pull the bullet and spin, remark, and repeat to verify results.

I measure both COAL and case base to ogive, and go from there.

What is the purpose of the mark? Does it indicate if the bullet stuck slightly?

 

[dryhumor]

What is the purpose of the mark? Does it indicate if the bullet stuck slightly?

Just a visual indicator that the bullet has touched the lands. It the mark hadn’t moved, then you would pull the bullet and spin a bit, remark it, reseat farther out and try again.

Not every chamber has the same amount of freebore. Howas and Weatherbys come to mind with longer chambers.