PDA

View Full Version : Finding CBTO/COAL with Cast Boolits



Wolfdog91
02-03-2021, 10:36 PM
Little video of me loading up my first 50 cast Boolits and how I found my CBTO. Lemme know what y'all
think.

https://youtu.be/OuOltEJejNw

Rcmaveric
02-04-2021, 11:47 AM
Not bad bro. I used to use the split case neck method to find max COAL. Its PITA though. Now I measure my actual chamber. Frankford Arsenal has these cleaning rod clip on deals. There are also 3D designs if you want to print them your self. I use a dowel rod the diameter of a cleaning Rod.

1)close the bolt
2) drop the cleaning or dowel down the barrel.
3)mark it at the muzzle with a plastic clip or pen while holding firm against the bolt face.
4)open the bolt.
5)Drop a bullet in the chamber.
6) hold the bullet gently in the throat with a pencil.
7) drop the cleaning rod/dowel down the barrel.
8) Hold it against the bullet in the throat.
9)grow a third hand and mark the dowel.
10) measure the distance between the 2 marks.
11) subtract .004 off that for for your finnal COAL. Reason for the. 004 is for leeway and tolerance.

I have never had good performance seating jammed into the lands. Me playing with Quickloads and personal experiences it causes a massive pressure spike with no gain in velocity or accuracy. The pressure spike caused me leading reduced accuracy.

Now load up a couple dummies. Make sure the pace the plunk test. Plunk it in the barrel and close the bolt. It should be easy. Then load a mag and manually cycle the bolt to make sure they all feed reliably. Any issues noted then seat .002 deeper until its reliable.

Next let's talk about that press mount... I saw it flex. I can promise you. One day your going to have issue with rounds chambering. I had problems with my 260Rem chambering. Trouble shot for a month. Finnaly discovered my press was flexing like your was. When I full length resized I wasn't consistently hitting the shell holder. So it wasn't pushing the shoulder back and caused tight bolts and improper head space. Mount that thing firmly to a solid heavy base. If you have tight space and room restrictions get something like the Lee press stand or bench grider stand.

You did well. Only other 2 cents is your notes. Good work keeping them. I encourage you keep that note book and write it all the time. Everything you do and all your ideas. Also get a second note book. Dedicate a new note book for each subject. Now every so often. Read through the note book and copy your notes into their dedicate books. It has saved me doing that. Sometimes we think faster than we write. So reading over them and copying them a subject specific book helps us add those conclusions and observations we over looked. Also helps keep everything organized. Also creates a back up.

I used a paper noted book and then at the end of the day I read over my notes and type them into a computer program file.I have a program that organizes notes in a hiarchy style with folders and subfolders. I have an excel file to track my reloads. I have lost my notes before (coffee and rain and cats) and I have confused my self with my notes. So those are what I have done to prevent that. Nothing worse than trying to read your notes from a month ago only to realize you didnt. put in enough to remember what was going on. I used to us Microsoft One Note for my notes. My subscription expired and I went to a program called Notebooks. Now I run Linux and use a program called CherryTree. Cherry Tree is free and runs on Linux and window.

I would have referenced the Lyman Cast Bullet handbook before I reference the one you pulled out.

Sent from my SM-N970U using Tapatalk

Wolfdog91
02-06-2021, 12:05 AM
Not bad bro. I used to use the split case neck method to find max COAL. Its PITA though. Now I measure my actual chamber. Frankford Arsenal has these cleaning rod clip on deals. There are also 3D designs if you want to print them your self. I use a dowel rod the diameter of a cleaning Rod.

1)close the bolt
2) drop the cleaning or dowel down the barrel.
3)mark it at the muzzle with a plastic clip or pen while holding firm against the bolt face.
4)open the bolt.
5)Drop a bullet in the chamber.
6) hold the bullet gently in the throat with a pencil.
7) drop the cleaning rod/dowel down the barrel.
8) Hold it against the bullet in the throat.
9)grow a third hand and mark the dowel.
10) measure the distance between the 2 marks.
11) subtract .004 off that for for your finnal COAL. Reason for the. 004 is for leeway and tolerance.

I have never had good performance seating jammed into the lands. Me playing with Quickloads and personal experiences it causes a massive pressure spike with no gain in velocity or accuracy. The pressure spike caused me leading reduced accuracy.

Now load up a couple dummies. Make sure the pace the plunk test. Plunk it in the barrel and close the bolt. It should be easy. Then load a mag and manually cycle the bolt to make sure they all feed reliably. Any issues noted then seat .002 deeper until its reliable.

Next let's talk about that press mount... I saw it flex. I can promise you. One day your going to have issue with rounds chambering. I had problems with my 260Rem chambering. Trouble shot for a month. Finnaly discovered my press was flexing like your was. When I full length resized I wasn't consistently hitting the shell holder. So it wasn't pushing the shoulder back and caused tight bolts and improper head space. Mount that thing firmly to a solid heavy base. If you have tight space and room restrictions get something like the Lee press stand or bench grider stand.

You did well. Only other 2 cents is your notes. Good work keeping them. I encourage you keep that note book and write it all the time. Everything you do and all your ideas. Also get a second note book. Dedicate a new note book for each subject. Now every so often. Read through the note book and copy your notes into their dedicate books. It has saved me doing that. Sometimes we think faster than we write. So reading over them and copying them a subject specific book helps us add those conclusions and observations we over looked. Also helps keep everything organized. Also creates a back up.

I used a paper noted book and then at the end of the day I read over my notes and type them into a computer program file.I have a program that organizes notes in a hiarchy style with folders and subfolders. I have an excel file to track my reloads. I have lost my notes before (coffee and rain and cats) and I have confused my self with my notes. So those are what I have done to prevent that. Nothing worse than trying to read your notes from a month ago only to realize you didnt. put in enough to remember what was going on. I used to us Microsoft One Note for my notes. My subscription expired and I went to a program called Notebooks. Now I run Linux and use a program called CherryTree. Cherry Tree is free and runs on Linux and window.

I would have referenced the Lyman Cast Bullet handbook before I reference the one you pulled out.

Sent from my SM-N970U using Tapatalk

Thanks ! Yeah I really need to add a support under the presses mounting arm to make it more ridgid honestly just haven't gotten around to it yet lol. As far as the dowel method I've tried it but honestly its a real head ache for me ( I'm fairly clumsy lol) . And yeas the second note book is in the works because I'm having problems with this one lol.
Thank you for the critiques!