Reddit mentions of LEE PRECISION 90798, Universal Neck Expanding Die.25 to .45 Caliber

Rifle dies have an expander ball that sizes the neck to .002 under the bullet size. This ensures that the bullet is held snugly. This works well with typical jacketed rifle bullets. It does not work well with coated bullets.

Lee makes a universal case expanding die that will flare the case mouth so that you can start a coated bullet. Use the minimum amount of flare that will allow you to start the bullet.

I expand my case mouths (not just flare) when using cast bullets. Lyman makes an "M-Die" which actually expands the case mouth and works well. An alternative would be to buy a cheap Lee universal expander die and replace the expander inserts with the NOE M die styled inserts and expand your case mouths to the right diameter to avoid shaving lead or swaging bullets down. As far as making bullets harder, you can always add some wheelweight alloy to it, or something with tin and antimony. I like to use old printing press lead (linotype, foundrytype, monotype) to make my alloys harder. I usually buy mine from a guy on facebook, but you can buy it from rotometals or even scrap yards.

Link to lee universal expander die: https://www.amazon.com/Lee-Precision-Universal-Flaring-Die/dp/B000N8N538/ref=sr_1_1?ie=UTF8&qid=1522945634&sr=8-1&keywords=lee+universal+expander+die

Link to NOE M-die styled expander pieces: (sorry, looks like my work is blocking it now)

What I ended up doing is resizing a bunch of 223 before I chopped them, I used the 300 resizer and took out the primer punch, worked pretty good. This trimmer may be a good idea, I've been looking at getting it for myself, you can read the reviews and decide if its for you. And heres a jig if you dont want to make one.

For powder/bullets, I use AA1680 and Palmetto Projectiles 208gn for Subsonics. Dont use them for Supers. Also, if you're running a progressive and loading lead coated projectiles, you'll need an expander die of some sort to prevent the brass from cutting up the lead projectiles.

Also, sub/xpost to /r/300BLK

I had the Mr. BulletFeeder for about 2 weeks now. It works really well. Easy set up if you follow the instructions on the website; it doesn't come with any directions. And following the directions, you have to expand the neck before seating. The Lee Universal Flaring Die works great for that.

I just thought of something else I thought I'd pass along. I went ahead and added a universal expanding die to my case prep to flare the case mouth just a hair. I'm not sure how much that has made a difference or if I'm just better at initial bullet seating but I have found that my bullet alignment seemed much better afterwards.

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https://www.amazon.com/gp/product/B000N8N538/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Use a Lee universal expanding die, it's super handy.