FNAR 10 subsonic
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I usually always do research before I buy something like this. But this was an exception because the sale was too good to pass up. So it was a no brainer to buy it now then do research later. Someone on this forum and my roommate have already offered me $100 more than I paid for it.The FNAR is built by FN to be a reliable & accurate LONGER range .308 semi-auto, based on the older Browning BAR HUNTING RIFLE ACTION.
It has nothing in common with an AR-10 design aside from the .308 caliber.
You can't switch calibers or "uppers", since there is no switchable "upper" on the gun.
It IS accurate at longer distances, with a good scope.
It's reliable, it's also heavy & a nuisance to break down for cleaning. Unless you hunt from a stand, you won't enjoy hunting with it much.
FN intends it for police & long range shooters, 500-800 yards or so, with good glass. It has no iron sights, as you probably noted, and whoever told you it's an AR10 was an idiot, IF it's an FNAR.
If what you have LOOKS like an AR in profile, has an upper & lower receiver section, and uses an AR mechanism internally, then it's not an FNAR.
I've never dealt with subsonics in the .308, but there's nothing wrong with a 1/12 twist for general use in the 168-grain range for the caliber.
You can't change the twist rate in the barrel, unless you go to a larger caliber. Not cost effective & probably not particularly compatible with the gas system & action as the FNAR is set up at the factory.
Your best bet to get what you want is sell the gun unfired, if it is an FNAR, take the loss if any, pay more attention to what you're doing BEFORE you buy next time, and get an actual .308 AR-10 from whoever.
Also, suppressors will still not make your gun "Hollywood quiet" even with subsonics, you may end up with more gunk in your AR action, and the suppressor will require cleaning & maintenance. You'll also lose distance & power with subsonics. You may want to re-think that, too.
Denis
There also no question I have an FNAR. The only thing I was confused about thanks for the guy behind the counter, was it was considered a AR10 or AR style. I was confused about the terminology. Silencer, $200 tax stamp, got it. In Oregon it's up to the county sheriff to sign off on the stamp. Apparently the old county I used to live in, the sheriff wouldn't sign off on any permits. They would just sit in a stack not refused but not allowed. Good thing I don't live there anymore.
I does seem a little on the heavy side. But according to my owners manual it weighs in at 8.25 lbs. Most bolt rifles that claim to be lightweight are in the 7 lb range. Plus I don't plan to put bi pods on it so I'm not too worried about the weight.
Eou,
Sell if you can make anything off it, you did get a good price.
Re the weight, once you load that box & stick glass on the gun, you won't dismiss the issue lightly.
And again on the suppressor, it won't make the gun as quiet as you probably expect it to.
All else being equal, which it never is, an autoloader with a suppressor generally isn't as quiet as a boltgun, which is another factor.
A few weeks ago when I was doing some sound level testing at a local suppressor maker's lab here in Utah I was told more noise comes out the ejection port than the muzzle with one of their suppressors in place.
Firing a boltgun with my suppressor on it was quieter than my autopistol was with the same suppressor.
Not trying to talk you out of one, just saying if you're going to spend the money, understand what you are & are not getting.
Kinda like when you buy AR-10s....
Denis
Sell if you can make anything off it, you did get a good price.
Re the weight, once you load that box & stick glass on the gun, you won't dismiss the issue lightly.
And again on the suppressor, it won't make the gun as quiet as you probably expect it to.
All else being equal, which it never is, an autoloader with a suppressor generally isn't as quiet as a boltgun, which is another factor.
A few weeks ago when I was doing some sound level testing at a local suppressor maker's lab here in Utah I was told more noise comes out the ejection port than the muzzle with one of their suppressors in place.
Firing a boltgun with my suppressor on it was quieter than my autopistol was with the same suppressor.
Not trying to talk you out of one, just saying if you're going to spend the money, understand what you are & are not getting.
Kinda like when you buy AR-10s....
Denis
Bill_Rights
Member
FNAR waste gas vent and 1:12 twist for subsonic
Regarding the earlier question of where is the gas vent on the FNAR's bolt-cycling system, and regarding this comment:
Having disassembled my FNAR and played with it a bit, it seems that the barrel gas vented off to cycle the short stroke piston just stays in the op cylinder and vents back into the barrel, after the bore pressure subsides and the action spring moves the piston back forward. If I am wrong, then the used operating gas gets vented right at the op cylinder, which is far forward under the fore-stock. (This mode of venting would require two one-way check valves on the op cylinder, which I have never heard of anywhere, and are not evident to the eye.) In any case, the used op gas does not get vented to the ejection port or anywhere near the receiver. Therefore, if the reason "more noise comes out the ejection port" on some AR-style rifles is because that's where the op gas gets vented, then you won't see this on an FNAR.
With that cleared up, hopefully correctly, why eou, do you say 1:12 twist rate is not good for sub-sonic ammo? You mentioned that you read this somewhere during your research. Where? Can you post a link? So what would be better than 1:12, 1:9 or 1:15? Which direction does this go, and why?
Regarding the earlier question of where is the gas vent on the FNAR's bolt-cycling system, and regarding this comment:
Having disassembled my FNAR and played with it a bit, it seems that the barrel gas vented off to cycle the short stroke piston just stays in the op cylinder and vents back into the barrel, after the bore pressure subsides and the action spring moves the piston back forward. If I am wrong, then the used operating gas gets vented right at the op cylinder, which is far forward under the fore-stock. (This mode of venting would require two one-way check valves on the op cylinder, which I have never heard of anywhere, and are not evident to the eye.) In any case, the used op gas does not get vented to the ejection port or anywhere near the receiver. Therefore, if the reason "more noise comes out the ejection port" on some AR-style rifles is because that's where the op gas gets vented, then you won't see this on an FNAR.
With that cleared up, hopefully correctly, why eou, do you say 1:12 twist rate is not good for sub-sonic ammo? You mentioned that you read this somewhere during your research. Where? Can you post a link? So what would be better than 1:12, 1:9 or 1:15? Which direction does this go, and why?
Bill_Rights
Member
Gas exhaust noise on FNAR - suppressor worthwhile?
I realized I could show that the gas exhaust of the FNAR is either back into the barrel bore or into the interior of the fore-stock, by showing photos of the rifle itself. The point is, the action op gas is NOT exhausted into the receiver or anywhere close. Therefore, the gas exhaust should not be noisy and a suppressor is worthwhile, at least from the op gas point of view.
Here are the photos of an FNAR-LB (light barrel). The tape mark shows where the end of the fore-stock lays, when the stock has been removed. Some of the parts are labeled in one view.
SIDE VIEW - STOCK ON
SIDE VIEW - STOCK OFF
45° SIDE-BOTTOM VIEW
BOTTOM VIEW
Notably, the piston throw of the action is extremely short, less than 1/2". The piston impulse sends the inertial block back the full 3" or so needed to cycle the bolt for even the "short-action" .30 cal (.308 Win). The inertial block rides on the spring-loaded guide rod, but the push rods transmit the motion back to the receiver. The point is, there is no gas connection at all from the barrel-port manifold/cylinder zone back to the receiver. The only things connecting those two zones are the guide-rod and the two push rods (and the barrel, of course).
I realized I could show that the gas exhaust of the FNAR is either back into the barrel bore or into the interior of the fore-stock, by showing photos of the rifle itself. The point is, the action op gas is NOT exhausted into the receiver or anywhere close. Therefore, the gas exhaust should not be noisy and a suppressor is worthwhile, at least from the op gas point of view.
Here are the photos of an FNAR-LB (light barrel). The tape mark shows where the end of the fore-stock lays, when the stock has been removed. Some of the parts are labeled in one view.
SIDE VIEW - STOCK ON
SIDE VIEW - STOCK OFF
45° SIDE-BOTTOM VIEW
BOTTOM VIEW
Notably, the piston throw of the action is extremely short, less than 1/2". The piston impulse sends the inertial block back the full 3" or so needed to cycle the bolt for even the "short-action" .30 cal (.308 Win). The inertial block rides on the spring-loaded guide rod, but the push rods transmit the motion back to the receiver. The point is, there is no gas connection at all from the barrel-port manifold/cylinder zone back to the receiver. The only things connecting those two zones are the guide-rod and the two push rods (and the barrel, of course).
It's not gas venting through the ejection port, as such, it's the sound.
The comment was made to me as a general observation, and we were testing a Ruger .22 semi-auto pistol at the time.
To demonstrate, one of the guys hauled out a .22 boltgun, we screwed my suppressor on it & compared the sound signature from one shot through it to what we'd been getting with the pistol.
Despite the longer barrel, the sound level was lower, since the bolt wasn't reciprocating and the ejection port wasn't opening to allow part of the sound to travel out it.
I was using this to illustrate that a semi-auto (if all else is equal) will most likely be louder than a bolt-action.
The same principle with the old Vietnam Hush Puppy S&W suppressed tunnel pistol with a locked slide. No ejection port sound, quieter than a conventional version of the same pistol with a suppressor mounted.
I don't think the gas venting system on the FNAR would make much difference in this area.
Denis
The comment was made to me as a general observation, and we were testing a Ruger .22 semi-auto pistol at the time.
To demonstrate, one of the guys hauled out a .22 boltgun, we screwed my suppressor on it & compared the sound signature from one shot through it to what we'd been getting with the pistol.
Despite the longer barrel, the sound level was lower, since the bolt wasn't reciprocating and the ejection port wasn't opening to allow part of the sound to travel out it.
I was using this to illustrate that a semi-auto (if all else is equal) will most likely be louder than a bolt-action.
The same principle with the old Vietnam Hush Puppy S&W suppressed tunnel pistol with a locked slide. No ejection port sound, quieter than a conventional version of the same pistol with a suppressor mounted.
I don't think the gas venting system on the FNAR would make much difference in this area.
Denis
Nope.
The primary purpose for testing was to establish the sound reduction in several loads with the suppressor on that particular pistol. Fired without suppressor as a baseline, repeated with suppressor.
That's the way it'd normally be fired, without trying to hold the bolt closed on it.
The bit about a certain percentage of sound coming out the ejection port came up somewhere during the process, one of the guys hauled out a threaded Marlin boltgun, we fired it with the suppressor, it was quieter than the pistol.
Didn't take it any farther than that with either gun.
Denis
The primary purpose for testing was to establish the sound reduction in several loads with the suppressor on that particular pistol. Fired without suppressor as a baseline, repeated with suppressor.
That's the way it'd normally be fired, without trying to hold the bolt closed on it.
The bit about a certain percentage of sound coming out the ejection port came up somewhere during the process, one of the guys hauled out a threaded Marlin boltgun, we fired it with the suppressor, it was quieter than the pistol.
Didn't take it any farther than that with either gun.
Denis
Bill_Rights
Member
DPris said:
However, I have to agree: Because there is so much mechanical movement going on in a semi-auto action, a semi-auto rifle will always be noisier than a bolt rifle (until you manually operate the bolt, which may wake the dead).
Very possibly the Ruger .22 semi-auto pistol uses a "blow-back" style of cycling the action. I have a Beretta NEOS .22 LR semi-auto that works that way. As I understand it (which I don't, entirely), the blow-back action uses the recoiling cartridge casing itself to push back the slide. Inevitably, the front end of the casing clears the breach while hot chamber gases are still at high pressure, thus making a mess of soot and gunk all in the bolt-face/chamber-face area. And also making an undue amount of escaping gas noise, compared with a piped gas or piston system. So your statement
is wrong, in regard to the "all else being equal" part.
However, I have to agree: Because there is so much mechanical movement going on in a semi-auto action, a semi-auto rifle will always be noisier than a bolt rifle (until you manually operate the bolt, which may wake the dead
).Bill,
I realize it was an apples to oranges thing in one respect, but I was just attempting to illustrate the idea of sound coming out the chamber on a semi-auto, which most people are not aware of.
The FNAR with suppressor will be at least fractionally louder than a boltgun with suppressor, and the gas venting system can't change that entirely.
Denis
I realize it was an apples to oranges thing in one respect, but I was just attempting to illustrate the idea of sound coming out the chamber on a semi-auto, which most people are not aware of.
The FNAR with suppressor will be at least fractionally louder than a boltgun with suppressor, and the gas venting system can't change that entirely.
Denis
Bill_Rights
Member
It's cool. I am in basic agreement with you.
But THR is a teaching forum, and I want us to put out accurate, balanced information. So I added a few aspects to what you were saying. I've got no axe to grind, semi-auto vs. bolt or any other. I like them all. Been debating about getting a suppressor for a .17 HMR squirrel gun, myself. I learn a lot from THR, and you are a good, knowledgable poster. Please keep it up!
But THR is a teaching forum, and I want us to put out accurate, balanced information. So I added a few aspects to what you were saying. I've got no axe to grind, semi-auto vs. bolt or any other. I like them all. Been debating about getting a suppressor for a .17 HMR squirrel gun, myself. I learn a lot from THR, and you are a good, knowledgable poster. Please keep it up!
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