I have the option to get a Manfrotto 3021bn for $50.  It comes with the ball mount.  I tried doing some research to see if this would be a good tripod to shoot my Remington 700 and Ar15 off of.  I wasn't able to find anything.  Any input would be appreciated.  Mostly concerned about it being able to handle the weight.

Thanks

Hard to tell as your ballhead will probably be the limiting factor. Even without the ballhead, it will be a bit shaky when extended. I think they were only designed for a little over 10 pounds static load.

If you want strong/cheap, look at a used Induro 114/214/314 on ebay or whatever. Most of them are rated to 30lbs and far more solid than the lighter manfrottos that you will find at a similar price.

These are rock solid tripods that were originally designed for photography. I have the  original Bogen 3021 B Pro (before Manfrotto bought them out) and It will hold a camera steady for 5 minutes in the middle of a thunderstorm. My ball head is capable of holding 70 lbs

This photo was taken using that tripod in the middle of the storm. I think it was about a 12 minute exposure and the wind was blowing like crazy. It held the camera rock solid all that time.