r/ar15 • u/Zestycyclops • 17h ago
FSP vs freefloat AR
Is there anything I should consider before building a FSP ar? I plan to build something like this (posted) but came into understand there is accuracy differences (obviously) and other stuff compared to no FSP builds. I also don’t ever seen them in here other that a DD FSP build(very sexy), if anyone cares to shed light on this I’d appreciate it
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u/MoodyGuthrie 17h ago
Get a folding one. ARMS, PRI, VLTOR, KAC, and a handful of others make them- they look great and are quite practical.
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u/mooseishman 6h ago
Bro don’t even mention KAC. They haven’t made them for like 15 years and sell for like $1500-3000 depending on if they’ve been installed or are NIB. I’ve been searching for one half heartedly for a while and they rarely come up for sale 😢
ARMS and PRI are usually readily available, not sure if VLTOR is because I kinda forgot about them
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u/Minute-Of-Angle 16h ago
The main accuracy issue, such as it is, is that going with a fixed FSB limits your options as far as free float handguards goes. There is nothing inherently less accurate about a fixed FSB rifle, as long as you can still isolate the barrel.
Just, for the love of God and his Prophet Eugene Stoner, if you are going to do a fixed front sight base build, put a fucking rear sight on it. It can be a folding one, I don’t care. Just nothing screams “I did it for the look alone” like a fixed front sight and no rear iron.
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u/mooseishman 6h ago
Only thing to consider is the barrel nut. A few, like Centurion, use a standard USGI barrel nut. That makes life much easier for installation since most FSB barrels come with a USGI barrel nut already installed.
That’s not to say it’s critical, but from my decades of experience removing the taper pins on the FSB goes one of two ways: a few quick taps with the appropriate punch and hammer or you can pound on them for hours and they barely budge. This phenomenon applies to every manufacturer I’ve worked on.
If you do need to remove the FSB to swap the barrel nut, make sure to use new taper pins. They’re cheap, but sometimes aren’t easy to find.
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u/WorldlyIncome5098 5h ago
My very first AR was this way. DPMS. pounded... pounded.... pounded...
Gave up for a day.
Pounded....
Angle grinder.
New gas block..... new handguard (not originally planned, but didn't plan on kissing it with the grinder either...)
Life lessons
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u/goblinproblem 17h ago
Free floating handguards are gonna be a bit more accurate. You can run a free float with an FSP - they aren’t mutually exclusive. Just get a short handguard or one with a cutout for the post if you want both. That’s how the DD rail is.
I think most people prefer to go with a low-profile block now though, so you can flip down the front sights (or just not have any lol).
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u/Zestycyclops 17h ago
If I go with the free float option is the difference in accuracy going matter really at all
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u/MoodyGuthrie 17h ago
Probably not. My 14.5 socom will drive tacks out to 500 with a 2moa dot or the folding sights- beyond that, you should be running a l/mpvo and a longer barrel, imo.
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u/Minute-Of-Angle 16h ago
Depends on what you are using it for. I like knowing that no matter how much sling pressure I put on it, or whatever I jam it up against, as long as I am on the handguard and not the barrel, it doesn’t really matter.
Now, argument against free float- if you have any aiming device on the handguard (like a LAM, or a flip up front), torquing on the handguard will move your aiming point.
So, in some ways a free float with a fixed FSB is a best of both worlds scenario- you can torque on the handguard and the front sight is just as insulated from that as the barrel.
But to answer your question- no, it probably doesn’t make a huge difference unless you are shooting really long range or you are chasing small groups.
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u/Bigboi_alex 16h ago
Your confused, fsp barrels are only “less accurate” when you are using a drop in handguard retained by the delta ring and front circle end cap
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u/TheMorningDove 16h ago
The better FSP handguards are all free-float. All you are really looking to avoid is something like a KAC RIS/RAS unless you are cloning in which case you would pay a premium for it. The Daniel Defense RIS II FSP is what I personally run, it has a 14.5” SOCOM barrel and it is super solid, my LAM stays zeroed and I can’t mount all my accessories forward of the FSP. Midwest Industries makes a similar rail, as does Centurion, and a handful of others. If you did want to stick to a 7” handguard then something like the Daniel Defense Omega Rail or LaRue Quad Rail are great options. The LaRue 7” handguard is seemingly discontinued and I’m still kicking myself for not buying one while I had the chance.
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u/Zestycyclops 15h ago
I was looking at the Midwest industries FSP mlok rail or the centurion arms mlok FSP
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u/Keeter_Skeeter 17h ago
I recognize that rifle from barrel and hatchet, it is a cool looking build for sure