Press-on cap cart closure methods

Got sent a box of 300 polycarb carts with press-on caps. Struggling with finding a decent method for closing them up without an arbor press or specified piece of equipment. Living on an island and don’t have easy access to much in this realm. Rubber mallet is what the dude on the other end suggested, but finding a hammer is far more effective- but time consuming, difficult to evenly distribute and not always working. Lots of them floating up and popping off and unable to secure them after this occurs. A low-cost, easily accessible (hardware store or homemade) option for remedying this situation would be ideal, will not be using press-ons again in the future so not looking to heavily invest in them at this time. Any suggestions would be much appreciated! :grin:

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Could u post a pic of what they look like and what ur wanting to do, table top vice mite do sumthing lol

Plastic “c” clamp. The ones you squeeze to hold two pieces of wood together. Find em at harbor freight for a few buck. Has rubber pads on each side to and won’t mess up the mouth piece. Might push in the center contact on the cart and you’ll need to adjust a few that may not be working.

Even a brand name one is cheap. Easiest solution I’ve found with these.

If you are looking for an inexpensive screw top. has a good price on non branded ccell.

They aren’t jupiter or anything, but they are definitely of decent quality.


I use the same method as @Dred_pirate. Those press on ones suck. Especially for trying to remove the oil from carts that have bad center connections after pressing.

My solution for not damaging the center firing pin is using a magnetic piece from my yocan pen. I lightly screw on to the end and press with a hand clamp like dred showed. This way you don’t damage the firing pin when you press the caps on.


you can get a arbor press for like 100$ on amazon… Any other method is not really going to work well

The ones I was using have a “V” shaped groove in the rubber clamp spot. I put the threads there and it doesn’t push in the contact as easily. But, using the threads for that, or the small cap that comes with the palm batteries would work too.


I repurposed an old reloading press. Use 9mm dies. Works like a champ!

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do you have Photos? More info would be very helpful.