"Can I add tss to commercial shells?"... no.

[Dave in AZ]

Someone PMed me this question, thought it was a good one that folks new to this might ask so posting reply for others:

"...
I recently found the forum in hopes of learning more about reloading. I also enjoy your blog posts. I am a complete beginner when it comes to reloading, other than some dove loads several years back. My question to you is, could I open up some factory shells I have and add heavyweight or tungsten to create a duplex load and recrimp them? Or could this cause pressure issues? Any thoughts would be appreciated. Thanks"

So, the answer is NO, you can't ADD tss to a commercial shell and recrimp. Adding any payload will increase pressure. However, REPLACING payload with a more dense shot, such that total volume in the hull is DECREASED, seems like it has a reasonable chance to be safe. To be clear, this meansfor example taking say a 1-1/8oz commercial steel load, removing 50 grains of steel shot and replacing it with exactly 50 grains of tss shot, then recrimping.

Yes, I THINK it would be safe pressure wise and would reduce pressure. But as with all things reloading, making any changes or deviating from recipes, you are 100% on your own to assess and accept the personal risk. I pressure test anything I intend to shoot a few of, personally. Basically, I never want someone thinking, "this dude Dave on the internet told me this was OK". I want them thinking that some unknown internet guy gave them one more opinion from which to form their own personal decision for which they accept all risk

[mchughcb]

Thanks Dave for the thread,

Until last week I had zero experience with loading TSS. 30 years ago I used to reload 12 gauge and now I just reload about a dozen or so rifle calibres up to 416 Rem Mag so I'm cautious when it comes to reloading.

I have just posted on this website a video of what I did. What I'm after is not what is typical load in the USA but more typical of fox hunting down under. If you replace a lead load with TSS but under the weight of the factory lead load and repack it with enough mylar and re crimp I didn't have any problems. My experience of letting them off in my Beretta SP1 20 Gauge is that that actually had less kick than the normal lead load and no I don't have the means to pressure test them, hell even getting wads is an issue but the barrels look good with my hawkeye bore scope, there was no gas escaping from the primers, the primers didn't look flattened, the shots sounded normal and the pellets whacked the target. I doubt I was even close to 10,000 PSI. I will eventually get them over a chrony but my old one was retired when it was coming straight for me with my combo gun and the magno unit is a bit awkward on shotguns.

Infact I'll be doing some more testing of a similar ilk on my 12 gauge Beretta SP and I'm going to borrow a 410 and do some testing with that as well. I can tell you if you think things are tough in the USA getting quality shotgun reloading components, down here is neigh on impossible.