Long time pistol owner, picked up the first couple of ARs this year.
I know these AR platforms are supposed to be modular and interchangeable but is it common for certain upper/lower combos to work better together?
I started with the bottom rifle. Originally Ballistic advantage lower and barrel, parts bin upper and other parts purchased from my gunsmith. He began doing builds to undercut lower shops when they got down to having only 1200 dollar rifles left.
Worked well.
Added lower #2, an Anderson lower I got a deal on a few months later.
Put the Anderson lower on my Gunsmith budget build upper to test while waiting to buy the test of the second rifle and it functioned perfectly.
A little bit down the line, purchased a complete upper built from an Aeroprecision upper with BCA SS 223 Wylde barrel online from a site called pro2tactical.
Ran my new complete upper on the Anderson lower. Function tested fine and never malfunctioned at the range. Thought good to go until I noticed once you download AR mags from 30 you start to get feeding issues whether you use the charging handle or hit the bolt release. Bolt would ride over the round before it could be chambered and scratch it up. Never a problem cycling the gun when firing, only when trying to chamber a round from a down-loaded magazine.
Couldn’t see anything visually wrong with the new upper so on a whim I swapped the Anderson lower to the first rifle. Put the ballistic advantage lower on the new upper.
I now have what seem to be two functional rifles that will chamber every round in a magazine using the charging handle or bolt catch down to the last one, resolving the only function problem I had.
Time to leave well enough alone? How bothered should I be I can’t swap uppers and lowers without an issue? My best guess is swapping the two lowers got me a better fit which made just enough difference to resolve the feed issues that may have been caused by receiver wiggle??!
I know these AR platforms are supposed to be modular and interchangeable but is it common for certain upper/lower combos to work better together?
I started with the bottom rifle. Originally Ballistic advantage lower and barrel, parts bin upper and other parts purchased from my gunsmith. He began doing builds to undercut lower shops when they got down to having only 1200 dollar rifles left.
Worked well.
Added lower #2, an Anderson lower I got a deal on a few months later.
Put the Anderson lower on my Gunsmith budget build upper to test while waiting to buy the test of the second rifle and it functioned perfectly.
A little bit down the line, purchased a complete upper built from an Aeroprecision upper with BCA SS 223 Wylde barrel online from a site called pro2tactical.
Ran my new complete upper on the Anderson lower. Function tested fine and never malfunctioned at the range. Thought good to go until I noticed once you download AR mags from 30 you start to get feeding issues whether you use the charging handle or hit the bolt release. Bolt would ride over the round before it could be chambered and scratch it up. Never a problem cycling the gun when firing, only when trying to chamber a round from a down-loaded magazine.
Couldn’t see anything visually wrong with the new upper so on a whim I swapped the Anderson lower to the first rifle. Put the ballistic advantage lower on the new upper.
I now have what seem to be two functional rifles that will chamber every round in a magazine using the charging handle or bolt catch down to the last one, resolving the only function problem I had.
Time to leave well enough alone? How bothered should I be I can’t swap uppers and lowers without an issue? My best guess is swapping the two lowers got me a better fit which made just enough difference to resolve the feed issues that may have been caused by receiver wiggle??!
Attachments
Last edited:
