I finally started down the path of having a .308 rifle.
I won't make any claims about what it will be able to do just yet, but I'll explain what my intent is.
A few months back, a member started a thread to get insight into the board's options for rifle and sidearm pairings. In my response, I mentioned that I didn't have a good rifle for standard military engagement ranges of 300+ yards. Yes, my 5.56 could do it, but that round is so weak, it should really be kept in the sub-300 world. My Blackout is even less effective at that range due to the barrel length and heavier bullet inside an even shorter case than the 5.56. Neither of those guns is intended for range. They are for "hi, how are you, get out of my house/off my land" ranges.
I have no current expectation of ever needing to reach a target beyond these ranges in order to save my life... but neither did the civilians in Ukraine until about a year ago.
So I plan to rectify this. Any comments about fantasy and paranoia can be directed to the round file, not this thread. Thanks.
Intent:
The purpose for this rifle will be a medium to long range heavy hitter that is maneuverable and not overly cumbersome to carry.
Think somewhere between an AR-15 and a DMR. It will eventually get a variable optic scope, but is NOT intended for long range precision. No bipod. Potentially suppressed.
The same silencer I use for my .300 is rated for .308 full-auto and more. I have no expectations that it will actually suppress the round much, but it will likely find its way onto the gun from time to time for flash suppression and to alter the recoil impulse. When Texas finally gets the greenlight for "Made in Texas" silencers, I'll see about getting a more suitable one.
Concern:
What I've come to realize, however, is that my chosen platform (an AR-patterned .308) is not as standardized as its little brother, the AR-15.
I'm looking for insights from folks who've done these types of builds on AR-308s, and would like to know what you learned, what you wish you'd known beforehand, and any tips for assembly or part choosing that I should be aware of.
The foundation of this rifle will be the Palmetto State Armory "PA10" stripped lower receiver. I'm especially interested to hear from anyone who's used this exact receiver in their own build, as there seems to be some strong recommendations to stick with other PSA parts when using this one.
I will likely pair it with a PSA upper to ensure fitment of the two halves, but beyond that, I don't really have a solid plan for moving forward.
This pairing follows the DPMS style, and not the Armalite style, so that may play a role in parts compatibility.
Caliber:
I think I've settled on a caliber. I know the AR-10/308 platform can work with many calibers, like the AR-15, but I think .308 Winchester is what I'm going with.
I looked into the differences in a .308 vs a 7.62NATO chamber, and it looks like the .308 is built for higher pressures and modern chambers can handle the NATO variant without much risk. The reverse isn't necessarily true due to thinner walled cases and greater expansion of the .308 in a NATO chamber, but also likely low risk.
Unless there is a compelling reason for going with a different caliber, .308 WIN is my top choice at the moment.
Barrel:
I am leaning toward an 18" barrel. This seems to be a decent compromise between maneuverability and maintaining a long enough barrel to nearly fully burn the powder of this round.
I have a medium contour profile on my 5.56, and would likely stick with that for the .308, understanding that the weight will be noticeably different.
Any suggestions or concerns about this or other barrel lengths?
Receiver parts kits:
For the lower, I have learned that most of the parts are identical to an AR-15 lower parts kit, except for the takedown pins, the bolt catch, and the magazine release. If this sounds wrong, speak up.
I have no information on upper parts kits. Are they standard?
Bolt carrier group:
These seem to range quite a bit in length and bulk.
The PA10 receivers are supposed to be closely mimicking the DPMS pattern. Is there a good way to know what BCGs will fit without having the two parts in hand and trying them?
Buffer system:
Based on the BCG and chosen receiver extension, the buffer system can also vary greatly. I've seen some systems which utilize a normal carbine length spring and carbine buffer. I've seen some that use a short buffer and carbine spring. And then there's the rifle length springs with carbine buffers. Lots of options, not sure what each combination offers.
What else should I be thinking about while planning out this build?
I'm giving myself the rest of the year to complete it, so I plan to spread out the cost and go with good quality components.
All suggestions are welcome.
I won't make any claims about what it will be able to do just yet, but I'll explain what my intent is.
A few months back, a member started a thread to get insight into the board's options for rifle and sidearm pairings. In my response, I mentioned that I didn't have a good rifle for standard military engagement ranges of 300+ yards. Yes, my 5.56 could do it, but that round is so weak, it should really be kept in the sub-300 world. My Blackout is even less effective at that range due to the barrel length and heavier bullet inside an even shorter case than the 5.56. Neither of those guns is intended for range. They are for "hi, how are you, get out of my house/off my land" ranges.
I have no current expectation of ever needing to reach a target beyond these ranges in order to save my life... but neither did the civilians in Ukraine until about a year ago.
So I plan to rectify this. Any comments about fantasy and paranoia can be directed to the round file, not this thread. Thanks.
Intent:
The purpose for this rifle will be a medium to long range heavy hitter that is maneuverable and not overly cumbersome to carry.
Think somewhere between an AR-15 and a DMR. It will eventually get a variable optic scope, but is NOT intended for long range precision. No bipod. Potentially suppressed.
The same silencer I use for my .300 is rated for .308 full-auto and more. I have no expectations that it will actually suppress the round much, but it will likely find its way onto the gun from time to time for flash suppression and to alter the recoil impulse. When Texas finally gets the greenlight for "Made in Texas" silencers, I'll see about getting a more suitable one.
Concern:
What I've come to realize, however, is that my chosen platform (an AR-patterned .308) is not as standardized as its little brother, the AR-15.
I'm looking for insights from folks who've done these types of builds on AR-308s, and would like to know what you learned, what you wish you'd known beforehand, and any tips for assembly or part choosing that I should be aware of.
The foundation of this rifle will be the Palmetto State Armory "PA10" stripped lower receiver. I'm especially interested to hear from anyone who's used this exact receiver in their own build, as there seems to be some strong recommendations to stick with other PSA parts when using this one.
I will likely pair it with a PSA upper to ensure fitment of the two halves, but beyond that, I don't really have a solid plan for moving forward.
This pairing follows the DPMS style, and not the Armalite style, so that may play a role in parts compatibility.
Caliber:
I think I've settled on a caliber. I know the AR-10/308 platform can work with many calibers, like the AR-15, but I think .308 Winchester is what I'm going with.
I looked into the differences in a .308 vs a 7.62NATO chamber, and it looks like the .308 is built for higher pressures and modern chambers can handle the NATO variant without much risk. The reverse isn't necessarily true due to thinner walled cases and greater expansion of the .308 in a NATO chamber, but also likely low risk.
Unless there is a compelling reason for going with a different caliber, .308 WIN is my top choice at the moment.
Barrel:
I am leaning toward an 18" barrel. This seems to be a decent compromise between maneuverability and maintaining a long enough barrel to nearly fully burn the powder of this round.
I have a medium contour profile on my 5.56, and would likely stick with that for the .308, understanding that the weight will be noticeably different.
Any suggestions or concerns about this or other barrel lengths?
Receiver parts kits:
For the lower, I have learned that most of the parts are identical to an AR-15 lower parts kit, except for the takedown pins, the bolt catch, and the magazine release. If this sounds wrong, speak up.
I have no information on upper parts kits. Are they standard?
Bolt carrier group:
These seem to range quite a bit in length and bulk.
The PA10 receivers are supposed to be closely mimicking the DPMS pattern. Is there a good way to know what BCGs will fit without having the two parts in hand and trying them?
Buffer system:
Based on the BCG and chosen receiver extension, the buffer system can also vary greatly. I've seen some systems which utilize a normal carbine length spring and carbine buffer. I've seen some that use a short buffer and carbine spring. And then there's the rifle length springs with carbine buffers. Lots of options, not sure what each combination offers.
What else should I be thinking about while planning out this build?
I'm giving myself the rest of the year to complete it, so I plan to spread out the cost and go with good quality components.
All suggestions are welcome.
)
