I used conical baffles for the 510 whisper silencer so I could reconfigure it for my 45 acp Enfield rifle by removing the spacers and stacking the baffles at the end of the can. My first three cans (300 whisper, 510 whisper, 22lr) were make from K or conical baffles. I prefer K baffles, but still use a conical baffle for the blast baffle as I think it make lead to less turbulence in the blast chamber and less disruption to the bullet path. But I do not have data to back this up.
I normally make the baffle with as large a cone as I can on my lathe. I space the baffles about the distance of one bullet length apart. I make a bearing surface on the conical baffles at least a half inch long to help keep the baffle aligned properly. K baffles align themselves. I make the baffle bore .025” to .070” larger than bullet caliber. Larger for the baffles farthest from the muzzle. If the barrel is not very straight or I can not be certain of very good alignment of the silencer to the bore, then I make the baffle bore larger. The silencer external dimensions are based on cartridge capasity and how much bulk I am willing to have added to the firearm.
I use aluminum and steel. Aluminum is good for most pistol and low pressure rifle silencers like the 300 whisper and 22lr. I use stainless for muzzle brakes and blast baffles most times. I use 4130 tubing for high pressure silencers like 5.56 and .308 because it is straight, stronger, cheaper and comes with a smooth finish inside and out.
½-28 means half inch wide and a thread pitch of 28 threads per inch. ½-28 is common for 22 caliber barrel threads at the muzzle. 5/8-24 is common for 308 and some that are larger.
I bought a grizzly lathe ($1500), wire feed welder ($400), band saw ($60), bench grinder ($50) just to make silencers. I learned how to operate the lathe while making my first silencer, it was easy to learn the basics, but I am still not very good at it. I recommend paying as much as you can afford on the lathe. The cheap 12” hobby lathes are a bad choice. If you plan on using the lathe for years, then get a good one, not like the cheap one I bought. I bought most of my stuff online or at Home Depot. Be very careful when ordering online; make sure the machine they ship matches the specs they list.
I made an excel spreadsheet to determine the volume a baffle would take up inside of the can and to estimate the more difficult internal measurements to make. I use trig equations to determine volume of the baffle based on a few easy to make measurements. It also showed me the weight of the finished product. Its biggest asset was to show me that the baffles and spacers needed to be very thin in order to not take up too much expansion volume in the can. After gaining some experience on the lathe, I did not use the spreadsheet to determine dimensions.
Ranb