If you're buying a suppressor buy an appropriate indicator rod!

1. Go here: http://www.mcmaster.com/#tool-steel-rods/=121c1fv

2. Click 'Multipurpose O1 tool steel'

3. Scroll down on the left frame and click 'Precision Ground'

4. Click '36"'

5. Select your desired rod diameter, preferably 0.010" to 0.020" smaller diameter than your bore, e.g. 0.308" = 0.2810" If you don't KNOW your bore diameter check your cartridge SAAMI specs! It only takes 30 seconds, go ahead and do it anyway.

6. When your rod arrives grab some automotive sand paper or a whet stone and round the sharp corners off the ends, and give the whole rod a good cleaning and oiling.

7. Indicate your configuration and know you won't be wrecking your suppressor.

Just in case some of you folks don't know, these are cheap and easy to acquire steel rods that are excellent for determining if you're going to have a catastrophic failure (aka a real bad time) with your suppressor.

I grabbed a handful in late 2015 for under $30 shipped total:

• 0.2031" for 0.220" (22LR/223/556)
• 0.2188" for 0.224" (223/556) ^
• 0.2500" for 0.264" (6.5mm)
• 0.2810" for 0.308" (30cal)