Is anybody loading the 300gr HP .44 from Matt’s Bullets

[BKS]

I bought a box of these to try in my S&W 629s. Based on the other 300gr lead data I’ve found, If I seat it to book COL it won’t fit in my gun. It has two crimp grooves.

I’m afraid if I seat it to fit the pressures will be too high.

https://www.mattsbullets.com/index.php?main_page=product_info&cPath=70&products_id=285&zenid=b7km2ob4da94crbs2bic7lhou5

[megasupermagnum]

That looks a lot like a NOE mold to me. https://noebulletmolds.com/site/shop/432/434-319-rf-aa3/434-319-rf-aa3-rg2-cavity-gc-brass

According to Matt's description, 900-1000 fps is the sweet spot. You will easily be able to get that velocity unless your barrel is very short. This would be a perfect job for bluedot powder, although 2400 would probably work just as well. My guess is starting loads of H110 will be over 1000 fps.