M*CARBO Brotherhood

Mossberg 500/835 Trigger Assembly Tool Issue

Good morning M*CARBO Brotherhood!

Just wanted to make you all aware of an issue I’ve had with the Mossberg 500/835 Trigger Spring Assembly tool.

I’ve already purchased two and they have both broken. I have a Mossberg 590A1 and it actually has two trigger springs (in addition to the trigger return spring). There’s a smaller diameter spring that slides over the hammer plunger and the larger spring that is replaced by the M*CARBO spring. I’ve tried twice to use the installation tool. Because of the extra spring, it’s very hard to get the springs to compress enough to get the pin installed. I’ve gone through two installation tools and beat up the trigger housing. I finally had to get a hex key to push the pin and my wife tapped it all the way in. The spring was preventing the pin from seating properly in the hole. Anyway, if anyone has a 590A1 with dual springs, you will most likely run into this problem.

I own a ton of M*Carbo products which I’m extremely happy with so I don’t want you all to think I’m bashing the company. They make very good quality stuff. I think it’s hard to test a product on all of the different versions it applies to.

Mr. Nelson - As a suggestion, you might want to update your video to include the two trigger springs included with the Mossberg 590A1. I’m assuming you keep the secondary spring.

Thanks for taking the time to listen to my issue!

Best regards,


Can I make my Mossberg 500 an inch or 2 longer?


Is THAT what you call it? :rofl:


I was going to ask about the butt bigger but that didn’t sound right.