Really wanting to get into a 6.5 Grendel and thinking about an ACR over an AR.  What would be the best route to go, buy a factory SBR and convert it or build one?  If I go the build route where would be the best places the get parts, upper, lower etc?

Thanks

I wouldn’t recommend doing it yourself with little to no knowledge on the platform.   The Acr isn’t an ar15 so there’s a completely different learning curve and mistakes are expensive.

During testing, any time I’ve ever done a conversion and did something wrong I ended up paying hundreds of dollars in repairs that I do myself. Sometimes those parts are backordered too so there’s no replacement parts immediately available.

ETA I reread your post and it sounded like you were going to do the conversion yourself.  If you are going to do a grendel build I wouldn’t worry about the rifle version you get.  Most everything will be swapped out once you’re done anyways.  I’d try to find the color and possibly the stock you’d like to go with.   It’s almost impossible to find an Acr in small pieces.

Appreciate the input  Not wanting to do the conversion myself, just buy the bolt head and barrel.  Looks like an upper is about impossible to find by itself .  I'm in no hurry for it, may start buying the specific pieces I would need to swap out anyway and keep an eye out for an upper or just buy the whole gun if it comes down to it

Who would be a go to supplier for a Grendel barrel?  Would like it dimpled to cut weight.

You can use any AR barrel that you like, but it must be converted on a mill. You mentioned dimpling, so Marvin Pitts (Nefarious Arms) can convert the barrel, fit a new (proprietary) gas system, dimple, and parkerize/cerakote it however you like.

Dana (Bigdog2003_99 / Templar Precision) can do the barrel conversion with all new Bushmaster parts.

Both are well respected.

Complete lowers can be found and even bought new from Nexus Tactical. The Upper is the serialized  receiver on the ACR, but Bushmaster never sold them as standalone units. So finding bare uppers is next to impossible.  Your best bet is to buy a complete rifle and sell off the complete barrel assembly (if you don't want it at all) or cannibalize the gas parts for your Grendel build and just sell off the 556 barrel.

Thanks for the info.  I would want to go with the Nexus lower.  Still not 100% certain what route I want to go.

You'll need to take care when selecting your bolt and barrel. The "Type 2" bolt face depth (.136) has basically at this point become the standard, while the "Why Are My Lugs Shearing" bolt face depth (.125) is still being sold out there. The old Argonauts x39/Grendel bolt was "correct", but I think now you're going to have to get a spare bolt machined. :( ArgoMike is who knows where, although maybe Dana has more info?

Wish Bushie would just sell a .136 deep X39 bolt and let us sort out the rest. </3

I just open up factory bolts and have them increase the depth to .136.  Mine has about 500 rounds on it with zero issues so far, that includes some full auto as well.