300 BO Molds?

[Aunegl]

RCBS 130 sp and 165 sil works in my AR pistol.

[waco]

I like the Lee 155 for supers and the NOE 230gr for subs.

[whisler]

Waco: love your signature line. I still remember the inscription over the doorway of the Catholic grade school I attended "come children and I will teach you the fear of the LORD". They were not kidding either.

[waco]

Waco: love your signature line. I still remember the inscription over the doorway of the Catholic grade school I attended "come children and I will teach you the fear of the LORD". They were not kidding either.

Amen!

[Wisest.fool]

i have tried the lee 309-230-5R but in my 16" cmmg 300BO upper it does not cycle properly powdercoated at 1050fps with imr 4227. It may be fitment. these seem to drop right at .3085. Its very close to cycling properly, but not picking up next round every time. If i add more powder i may go super.... kind of defeats the purpose. doesnt lead the barrel though.

[Burnt Fingers]

i have tried the lee 309-230-5R but in my 16" cmmg 300BO upper it does not cycle properly powdercoated at 1050fps with imr 4227. It may be fitment. these seem to drop right at .3085. Its very close to cycling properly, but not picking up next round every time. If i add more powder i may go super.... kind of defeats the purpose. doesnt lead the barrel though.

What buffer are you running?

[bld451]

Hey there. I managed to take care of the "lead ring" problem by polishing the transition from the end of the chamber into the throat with some 1500 paper and a dowel. It was pretty sharp there and I thought I'd just break the edge there without changing the dimensions of either chamber or throat. It did the trick! No lead ring and got through about 150 rounds with no lead or coating buildup.

I thought I'd put this up to maybe inform any decisions about molds and ask for folks to chime in. Not advocating for anything, just posting for informational purposes. My photos here are through a microscope, so take that into account. The features look huge, but in fact they are very small. I was curious to see if there was any gas cutting on these recovered bullets. I have not experienced any leading with these loads after polishing the chamber mouth as described above and my bore cleaned up with one Hoppes brush and a couple of patches.... nice.

Anyway, these are the bases of the Noe 153 HTC, and 2 of the MP 311-235's.

Both of the black colored bases are the 235's (one pc'd black and one Ford dark blue) loaded sub with 11.7 grs of AA1680. The clean blue one is the 153 at 1700 or so fps with 16.5 grs of 296.

Here is one of the subs for scale


It's base


Other 235's base

[bld451]

Here's the NOE 153. It fared a little worse, as we would expect.


Interesting, it seems there was gas cutting on the leading edge all the way along the rifling track in some places. I have really only heard of trailing edge issues.
also note where I crimped. There is no crimp groove provided on the bullet, just crimped this one in there. Gas cutting apparent around the circumference there, too.

For those who coat in a pile and are ok with the "boogers" that result, here is a pre, and post as near as I can tell.



Sorta making me think about a PB checkmaker...

[bld451]

Here is a little better image of the cutting along the leading edge..

[sutherpride59]

I’ve been very happy with the NOE 311299 which is a 206 grain mold for subs. I have a MP311-130 mood for supers. Both are very accurate and cycle just fine.

[popper]

Base below the shoulder.