I have had problems with gas blowing by the primer on my STW with Remington brass starting about the 3rd to 4th reload. With some research on this forum and others I learned that you can fireform STW brass from 300 H&H. I couldn't find any STW brass anywhere so I figured what the hell, I'll give it a shot.
Started with standard H&H cartridges from Norma.
Step 1 - Anneal the necks. Standard torch. Turned the lights out in the room. Heated them evenly using a power drill to spin them about 5-7 seconds until I could see a slight glow from the necks with no lights on in the room.
Step 2 - Resize the necks down from 30 cal to 7mm.
Step 3 - Prime the case with a small rifle primer. I didn't have any of these and F210 was all I could find so that is what I used this time.
Step 4 - Fill case to the top with Red Dot powder. Pour it out on a scale and weigh it. Came to 42.6 gr. Took 5% of that which turned out to be 2.13gr. Seemed a little low to me and I was being safe anyway so I rounded up to 2.5 gr to start with.
Step 5 - Loaded the first prepped case with 2.5gr Red Dot. Filled the rest of the case with Cream of Wheat. Capped the case with soap plugged in the end to prevent spilling.
Step 6 - Fired the cartidge.
This didn't provide the desired results. It blew the shoulder area out OK but the full body was still incomplete.
So I repeated the steps above increasing the load charge to 4.5gr and then 6.0gr of Red Dot. 4.5gr did the job pretty well but 6.0 made the case body just a little more concentric and filled out so I went with that for the rest of the cases. No pressure problems at all in my gun with 6.0 grains of Red Dot.
After that I loaded up a 180 over 78.8 gr of H-1000 and fired it to complete the comparison. From left to right in the picture in case you can't read the sharpie writing is a new case from Remington in STW, new Norma 300 H&H, annealed 300 H&H, 2.5gr Red Dot fireformed, 4.5gr Red Dot fireformed, 6.0gr Red Dot fireformed, 78.8gr H-1000 shot through fireformed case w/ 6.0gr Red Dot, and a 4x fired Remington case from my old recipe with the 180 VLD.
All in all I think it went well. I'm going to load a few more rounds this weekend and begin working up a load again. I use to shoot the VLD's but I'm going to try the Hybrid's and see how they do on targets and animals. I do think this brass will yield much longer life in the primer pocket area. There is a decernible difference in the pressure required to put the primers in these cases as compared to Remington. No suprise to most I guess.
I know I didn't do anything ground breaking here that is worthy of acclaim. Just thought I'd share my info for any other novices like myself that might find it useful.