Being a beginner, I ran into a few issues.
First, look through the tutorial section and do a few searches. There are some great threads with pics that helped me a ton.
My biggest mistake was over heating. Once it gets too hot and boils, you have to let it cool and re-melt. Otherwise, you get Swiss cheese. Lots of goods and holes.
That's a pour that was too hot...See the holes?
I cut out my design and then under-cut the bottom edge so it would help lock it in place.
I then drilled some small holes in the stock to achieve the same.
Like was said, a graphite pencil is said to help it flow. I did it. Can't say if it helped or not, but it's recommended.
I then used a minella folder to make the mold.
One piece around the stock and another in the barrel channel. Mine was a half stock with an entry pipe so it was a little different than typical.
Heat the barrel in the area of the pour. If the pewter hits cool metal, it solidifies and stops the pour. You want to get 1 quick, clean pour. I'd say once you start pouring, keep it flowing quickly to finish it. Don't try to pour it slow.
Be careful. Moulten metal is no joke. I'm "accident prone" and managed not to get burnt.
Here's the pour I ended up using. Wasn't perfect. But I was able to use it.
Wish I took pics of the card stock tapped on the stock.
Do NOT use modeling clay for a dam. Lol. I used modeling clay on one of my attempts. "Doesn't harden" or something "sold" me on it. Figured it would work perfect....Well...It melted. I had a volcano of moulten clay and pewter spewing everywhere. I used black clay too...It made a MESS.
It's not difficult. If you don't have pewter, you can use solder. Not sure if mine is purchased pewter or if it's solder lol. It took me a couple attempts. Some I recycled but some, like from the clay mess, wasn't able to be recycled. I'd guess mine is a mix of both lol.
It cuts and files pretty easily, so I didn't mind mine being overly large. I had it shaped pretty quickly.
Again, I'm no pro. But ran into many issues along the way. Mine turned out and is tight on the stock.