“The 22 Creedmoor Project”

[Jake Larsen]

Prepping the next test.

I’ll be focused on verifying drop data with the tumbled pieces, and monitoring velocities.

The “no prep” seated with substantially more force (which I expected) and left a small dent in the circumference of the bullet.

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I found the exact same thing with Alpha brass. Used it for two different cartridges now. There’s significant tension if it’s not run across a mandrel. How consistent it is from piece to piece? Who knows…would need one of those computerized tools to measure seating pressure


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[huntnful]

I found the exact same thing with Alpha brass. Used it for two different cartridges now. There’s significant tension if it’s not run across a mandrel. How consistent it is from piece to piece? Who knows…would need one of those computerized tools to measure seating pressure


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That’s pretty much every brand also. They are all undersized quite a bit. It’s not even worth finding out IMO, although they “felt” like they seated with similar pressures. Just plan to mandel virgin cases every time IMO.

I just made a video mandreling the virgin cases without brushing and moly inside the case necks. I’ll upload it and share it tomorrow. There’s a reason I only did 10 of the other prep styles and why I prep them how I do.




That top mandrel has expanded 100’s of necks and is flawless. The bottom mandrel, my 22CM mandrel looked flawless as well prior to expanding the dry necks. This is how it looks after just 10 cases. Scratched and full of brass shavings. And that how the inside of the case necks look as well. Shitty picture because I just zoomed in on the video and screenshot it. I’ll show it better tomorrow. I’m in bed now haha.

 

[T_Widdy]

That’s pretty much every brand also. They are all undersized quite a bit. It’s not even worth finding out IMO, although they “felt” like they seated with similar pressures. Just plan to mandel virgin cases every time IMO.

I just made a video mandreling the virgin cases without brushing and moly inside the case necks. I’ll upload it and share it tomorrow. There’s a reason I only did 10 of the other prep styles and why I prep them how I do.

View attachment 805667


That top mandrel has expanded 100’s of necks and is flawless. The bottom mandrel, my 22CM mandrel looked flawless as well prior to expanding the dry necks. This is how it looks after just 10 cases. Scratched and full of brass shavings. And that how the inside of the case necks look as well. Shitty picture because I just zoomed in on the video and screenshot it. I’ll show it better tomorrow. I’m in bed now haha.
View attachment 805669

I put the mandrel in a drill and Diamond paste on a towel to clean and polish mine up

 

[huntnful]

I put the mandrel in a drill and Diamond paste on a towel to clean and polish mine up

That’s exactly what I’ll be doing as well. I’ve been down this road before haha. I did this one for the people, so they can see for themselves why I prep it how I prep it. It may not even show up on target. But I can see the difference and I can feel the difference. And I don’t like it. Whether I can shoot the difference though…. we’ll see lol.

 

[Matt5266]

Following!

Thanks for doing this. I'm very interested. Look forward to the results!

 

[silasbowhunter]

Interesting! I’ll be following along for the sake of information! Thanks for this.


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[Mhahn2]

To get rid of those rings on your bullets from the seater chuck up a bullet in your drill and get some fitz polishing compound and polish your seating stem until the ring goes away.