Bought a Bontrager Air Rush and came with a single threaded cartridge 16 gram (pictured on the left). This cartridge has a small dimple in the top. I ordered some cheapo refills and saw the replacements don't have the hole (pictured on the right). Looks they're the BB gun kind and must be pierced when mounting.

Where could I find cheaper replacements for the threaded with the hole?

Or should I just move on and get one that uses non-threaded cartridges, punctures the seal and has a trigger?

Or how about a frame or mini pump? A lot cheaper in the long run...

the cartridges I use dont have a dimple on the seal.

The one on the left in the OP's picture is a used cartridge. The dimple is the hole made by the screwed on head. That solid front is the seal.

I have a Topeak Morph G, just need a Co2 to top off.

Yep. Look inside the screw on head and you'll see a small tube with an angled sharp end, like a large diameter hypodermic needle. That is what pierces the end of the CO2 cartridge to let the CO2 out. The "cheepo" cartridge is normal and should work fine (and look like the one on the left after it's used).

Got it.

Then the Bontrager Air Rush is crap. Tried to screw on another cartridge with the regulator screwed down, full open, nothing worked. Won't pierce the new cartridge.

Gonna look at the Ultraflate or the Lezyne.

Thanks

Hmmm. If you haven't already, maybe try screwing it down tighter? It takes some force to pierce the seal, nothing herculean, but a firm twist.

BTW, rather then CO2, I greatly prefer carrying a good mini-pump with hose, specifically the Lezyne Road Drive etc. or Topeak Race Rocket (the best, IMO). The only downside to pumps like these is it takes a minute or so and some effort to inflate the tire.

I use the Bontrager Air Rush, and haven't had any problems with it. And I'm sure there are others who also use it and have no problems with it.

You might want to check and make sure there isn't anything in the threads for either the cart or chuck.

Pierced the first cartridge, then wouldn't pierce the second, or any other cartridge. Tried several.

Had my 340 lb. wife put her muscle to it. No dice.

Still gonna rely on my Topeak Morph for now.

I carry a mini pump in my saddle bag just in case but much prefer inflating a tire in 15 seconds effortlessly with a CO2 cartridge. Especially after swapping tubes out in my clipless road shoes. But I really hate getting flats in the middle of a ride...