Shadow 2 mold?

[Bird]

chris,
I don't do the PC coating, but bullet sizing should be the final step. I have sizing dies, .356, 357, 358, and depending on alloy hardness/mix, and thus bullet spring back, I select the appropriate die that gives me .357''. Also the length of time after casting will change bullet hardness and spring back.
.355'' at the bullet base is too small. You will need to expand the case neck, but be careful of running the expander in too deep as to affect the chambering of the brass.
Assemble a dummy round, and seat the bullet out to an oal of 1.160'' and see if it will pass the plunk test. Use a magic marker all over the bullet. If it will not plunk, keep repeating a few times and then look and see where the bullet contact is. This will show you what size bullet you need and how deep to seat it. Do this with the LRN bullets, as the have a larger bearing surface.
I made a mistake in my earlier post my mold is mp 125 rn.

[44Blam]

That's very interesting, I didn't think about the chamber face scraping off the PC. I did pull some of my rounds that have a mild crimp, the case has scraped off the coating where it was crimped so I will try no crimp with 357 and see how that goes. Now would it be better for me to cast, size 357, PC and resize 357 or cast, PC and size 357? The coating measures .002" thick, the bullets drop at 358.

I also noticed the pulled bullets measure .355 up to the scraped part so looks like they are getting sweged down a bit when seating.

It's frustrating, it shoots jacketed like a laser.

This is why you need the NOE pass through expander - it expands the inside of the case by a few thousandths and bells the neck.

[chris in va]

I don't know if it's the same thing but I do have a LEE case mouth expander, I mainly use it for 7.62x39 cast bullets. I see NOE sells expander plugs, which one would you recommend?

Last night I sized a few to 356 and was able to plunk at 1.09. The 358's plunk at 1.04 which is stupid short and they were making contact with the chamber lip, so I suspect the powdercoating was getting scraped off. I will try to fire

[Bird]

you need an expander plug and die .001 to .002'' smaller than your measured bullet diameter. If you are going to try your 356 diameter bullets then get expander plugs .354 and .355. If you need to go up to a 357 bullet diameter, then you can use the .355 expander plug.
Have you actually measured your sized bullets? Just because the sizing die says 356 or 358, your bullets will not be that diameter.
Two plugs listed below. The first is not for auto pistol. Give them a call, and tell them what you are doing.
https://noebulletmolds.com/site/shop...54-p-exp-plug/

https://noebulletmolds.com/site/shop...p-ap-exp-plug/

The above plugs are used with this die which you will need if you dont have one already https://noebulletmolds.com/site/shop...-case-exp-die/

[chris in va]

UPDATE!

You guys are awesome, turns out the sizing was the issue as you suggested. When it was at 357 the chamber face was scraping off the powdercoating, sending the bullets tumbling. Once I sized to 355, I could seat to 1.09" which snugs the bullet into the rifling.

I made several different loads wth the .355 and none keyholed. I did try a few .357 and a couple went in sideways so now I know!