Who makes the best concentric checking rod for a decent price? What else would cause a baffle strike?

Different things can cause a strike. Bad threads, loose threads, unstable bullet/twist rate too slow.

What is the host and what can?

From an 'eon' of experience: 'Cheapest' and 'Concentric Rod'
are mutually exclusive terms when it comes to:

your afety, not damaging and junking what cost a $200.00 ATF STAMP plus $400.00+ Can
are in play.

Old Balkan mountain mottos euphemistically said:
A Tight 'Lower Sphincter' flatulates twice.
and I am too poor to by cheap ( disposable) things.


You will never regret saving for a proper Suppressor Alignment Rod:
e.g., << https://geissele.com/tools/suppressor-a ... -gage.html >>

Parking fees in urban city are now $37.00 and up. A weeks worth
of 'junk food' add up to as much or more.

Yes you will hear "..I use a thick piece of spaghetti " or
" I use an almost straight brass rod, etc., that
are just as good..."

Read the various suppressor books and see results
of bad alignment in its many manifestations.

Please take it for what it's worth.

Best

Use a carbon arrow. Most are +/- .001 straightness.