[btmmiller]

Greetings all,

I'm new to this forum and I'm sorry if this question has already been asked, but I'm looking for a means to convert an ACR to a 10.5' .300 aac blackout as well as 5.56 in a 1x7 twist. (Why bushmaster chose to go with a 1x9 I could never guess.) I've already emailed and called bushmaster several times and have failed to hear from them.

I'm assuming the ACR uses AR profile barrels. What is the best way to go about getting this done? If this were a DI rifle like the AR-15 this would be easy, but I'm not sure how to get a hold of the proprietary piston and barrel parts bushmaster uses.

Any suggestions you guys may have are much appreciated.

 

[DSM]

You have a few different options:

1. Cannibalize your stock barrel for the parts you need and install them on a different barrel
2. Find someone that is parting out their rifle and buy their barrel, or alternatively, buy another rifle for donor parts
3. Sit around and wait for BM to sell what you need

Talk to rsilvers here, 300BLK is his deal. Getting it to work in the ACR requires non-standard parts.

 

[Devil Doc]

The stock barrel is 1/8 twist.

 

[btmmiller]

You have a few different options:

1. Cannibalize your stock barrel for the parts you need and install them on a different barrel
2. Find someone that is parting out their rifle and buy their barrel, or alternatively, buy another rifle for donor parts
3. Sit around and wait for BM to sell what you need

Talk to rsilvers here, 300BLK is his deal. Getting it to work in the ACR requires non-standard parts.

Thanks DSM! I'll flip him a message and see what he has to say.

 

[bigdog2003_99]

The acr barrel, two or 3 people measured it and came out with 1/8, which explains why it doesn't mind 75gr rounds

 

[Devil Doc]

I posted a thread on here with xcr,lwrc, ACR which explains this in detail.

 

[btmmiller]

Really? According to bushmaster's site its a 1x9. Every one I've handled is stamped at 1x9 as well.

 

[mpow66m]

???????????????????

 

[phirenmojo]

i was thinking the same

 

[dirty.30]

Ya many of us are unsure why its stamped 1/9, but several members have measured it at 1/8, while I can't confirm this from personal measurements, I can confirm that it likes the Sierra 69gr bthp's I load up, and I've shot hornady 75s without any issues, whereas other guns with a 1/9 don't usually like anything heavier than 62, and the heavier it gets, the worse the accuracy is, generally speaking, with a slower twist barrel