Looking at cost options for an AR9 build and I have 3 options. The options below are using existing parts and lowers etc.

Option 1 - AR9 EPC dedicated lower glock mag and parts

$550

Option 2 - EndoMags and 2 standard lowers

$560

Option 3 - AR9 EPC dedicated lower glock mags and parts

$860

Option 1 gives me 1 EPC 9 lower for AR9 and one standard lower to share between 556 and 22 uppers.

Option 2 gives me 2 standard lowers and can swap 22/9 or 556/22 out as needed. Allows for any combo with buffer swaps.

Option 3 give 3 full dedicated setups for 9 22 and 556. AR9 would be dedicated and can’t be swapped cause of EPC9 lower.

What is the best option?

I’d go Brandon!

Lol not one of the options. But might be the front runner right now!

With Endo's you can get by with just one lower receiver.

Living in CT your going to be limited to 10 rounds anyhow..

I personally like an option that i can use a standard lower.

This way if i get tired of a 9mm or I find out i don't use it enough i still can reuse that lower for another build etc..

Than it comes down to be which way is the best way to go.. Conversion piece using glock mags or the endomags.. You will be in the same ball park for mag cost...

The glock mag might be advantage due to using it in a pistol or another rifle like the ruger pcc if you think its something you get into ..

When i did mine only reason i went with the stern sig/mp conversion is my wife carries the p320c and i carry a mp so it was a win win for me.. I had a ton of mags already.

I don't own a glock.. or this would have been the route i would have went.. I wanted a ruger pcc but couldn't find one due to the panic buying.

Also I am just finding out this morning my Bear Creek upper I already own is not compatible with the endomags. So it sounds like I need to go with the dedicated lower at this point.

Also can either get the Aero lower with no bolt hold open (my upper doesn’t have it) or go with the spikes that has LRBHO for a little cost more.

And why is that?