LanceCriminal
24 March 2011, 14:47
****DISCLAIMER!!! This is not a bash of my rifle or of POF! This is my feedback on the rifle I currently own as well as some questions towards those that have constructive input or can speak on behalf of POF! ***
So here's the situation: I've had a P-415, 16 inch recon with P12SX rails. No FTF's or FTE's, or any failures of any soret here. This is one of the earlier variants of the rifle, so the upper is still the traditional A4 style flat top upper, not the current offering with threads to actually screw the Predator rails into the receiver. The rails are lightweight, but do add to sight and optic height as they clamp to the upper, albeit not as securely as I want IMHO (more on that later). The upper and lower have a bit of wobble (this is the lower's fault I'd say, as my BCM and Mk12 ASA uppers are both loose as well, but are super-tight on my LMT lower), which I didn't really expect from a $2K gun, but frankly I was a young Marine with money in the pocket and a mind bent on getting a piston AR.
After I put my GI style M4 together, and realized the massive weight difference, I began to rethink the POF's fate. I like the barrel, it is kind of heavy, yes, but it is very accurate and I can rapid fire the hell out of it without really warming up anything. But the rail system is nearly a deal breaker to me now. And this is where I have most of my questions. I have read/heard that the gigantic barrel nut on the POF rifles is there for more than the heat sink "advantage", and that it is necessary due to the forces imparted by the piston system and that a lesser barrel nut left room for bad joo-joo of sorts. Granted, that may have been a thread about a P-308 rifle, so I wanted to get some perspective from some of the guys here with experience, as I believe I have also seen current and former POF reps on these forums.
So the big question, if I replace the current monster heatsink/barrel nut in order to install another company's rails, are there structural issues due to the forces generated by the piston system that I will encounter? The gas block and piston/op rod holder is pretty huge, so I'm aware I'd need to find one of the rails that is definitely piston compatible, which may also mean getting a shorter rail leaving some of the piston system exposed somewhat. I'd also have to consider the barrel nut's inner diameter thanks to the big beefy barrel.
A second issue is the fact that the rifle is some intermediate gas length that appears to be neither "mid-length" nor rifle length. Thus converting it to D-I is pretty much out. So if I could actually do a different barrel nut, now I must consider the options in terms of dimensions and what would fit. Photos below with rough measurements:
http://img846.imageshack.us/img846/9959/dimensions.jpg
http://img848.imageshack.us/img848/7651/frontdimensions.jpg
To borrow the Adams Arms gas system length chart: http://adamsarms.net/images/gaslength1.pdf
If I add the 3/4 to an inch inside the receiver that includes the barrel extension, the gas system seems to be right around 11 1/8 " in length. As far as what rails would fit the system (if barrel nut is replaceable), the rails would probably need to be a 10 inch model, if it has clearance for the piston/op rod tube.
Now, if the swapping of the barrel nut is an absolute no-go, then my only option (or should I say the only way I'd keep it) would be to drill and tap the receiver, and use screws or bolts or somesuch to secure the rail. I am not at all satisfied with the current multiple set screw layout, as the rear set screw simply rests or pushes against the receiver. The little black spacer sits on top of the barrel nut and screws into the rail, but does not actually screw into the nut. The only screw that actually enters any part of the rest of the rifle is a set screw underneath that screws directly into the barrel nut.
http://img197.imageshack.us/img197/8702/dscn0301m.jpg
http://img19.imageshack.us/img19/2808/dscn0302x.jpg
http://img808.imageshack.us/img808/7562/dscn0303l.jpg
Unless the POF guys want to let me swap it for a newer generation upper with the more secure current rail (though I am not a fan of the higher rail) I would probably either keep the lower and hock the upper, or sell the entire rifle. I'd just as soon keep it though as I really don't feel like letting it go for any large sum below what I paid for it. Plus, it functioned flawlessly, other than the receiver wobble and rail system I really like the rest of it. Any ideas? ( aside from "shoulda gotten an X-Y-Z piston rifle instead", as they were not available when I got the rifle). I feel with the barrel and its accuracy I've seen thus far this rifle would be great for a 1-4 power scope or similar, and I really want to turn this rifle into a good recce rifle.
So here's the situation: I've had a P-415, 16 inch recon with P12SX rails. No FTF's or FTE's, or any failures of any soret here. This is one of the earlier variants of the rifle, so the upper is still the traditional A4 style flat top upper, not the current offering with threads to actually screw the Predator rails into the receiver. The rails are lightweight, but do add to sight and optic height as they clamp to the upper, albeit not as securely as I want IMHO (more on that later). The upper and lower have a bit of wobble (this is the lower's fault I'd say, as my BCM and Mk12 ASA uppers are both loose as well, but are super-tight on my LMT lower), which I didn't really expect from a $2K gun, but frankly I was a young Marine with money in the pocket and a mind bent on getting a piston AR.
After I put my GI style M4 together, and realized the massive weight difference, I began to rethink the POF's fate. I like the barrel, it is kind of heavy, yes, but it is very accurate and I can rapid fire the hell out of it without really warming up anything. But the rail system is nearly a deal breaker to me now. And this is where I have most of my questions. I have read/heard that the gigantic barrel nut on the POF rifles is there for more than the heat sink "advantage", and that it is necessary due to the forces imparted by the piston system and that a lesser barrel nut left room for bad joo-joo of sorts. Granted, that may have been a thread about a P-308 rifle, so I wanted to get some perspective from some of the guys here with experience, as I believe I have also seen current and former POF reps on these forums.
So the big question, if I replace the current monster heatsink/barrel nut in order to install another company's rails, are there structural issues due to the forces generated by the piston system that I will encounter? The gas block and piston/op rod holder is pretty huge, so I'm aware I'd need to find one of the rails that is definitely piston compatible, which may also mean getting a shorter rail leaving some of the piston system exposed somewhat. I'd also have to consider the barrel nut's inner diameter thanks to the big beefy barrel.
A second issue is the fact that the rifle is some intermediate gas length that appears to be neither "mid-length" nor rifle length. Thus converting it to D-I is pretty much out. So if I could actually do a different barrel nut, now I must consider the options in terms of dimensions and what would fit. Photos below with rough measurements:
http://img846.imageshack.us/img846/9959/dimensions.jpg
http://img848.imageshack.us/img848/7651/frontdimensions.jpg
To borrow the Adams Arms gas system length chart: http://adamsarms.net/images/gaslength1.pdf
If I add the 3/4 to an inch inside the receiver that includes the barrel extension, the gas system seems to be right around 11 1/8 " in length. As far as what rails would fit the system (if barrel nut is replaceable), the rails would probably need to be a 10 inch model, if it has clearance for the piston/op rod tube.
Now, if the swapping of the barrel nut is an absolute no-go, then my only option (or should I say the only way I'd keep it) would be to drill and tap the receiver, and use screws or bolts or somesuch to secure the rail. I am not at all satisfied with the current multiple set screw layout, as the rear set screw simply rests or pushes against the receiver. The little black spacer sits on top of the barrel nut and screws into the rail, but does not actually screw into the nut. The only screw that actually enters any part of the rest of the rifle is a set screw underneath that screws directly into the barrel nut.
http://img197.imageshack.us/img197/8702/dscn0301m.jpg
http://img19.imageshack.us/img19/2808/dscn0302x.jpg
http://img808.imageshack.us/img808/7562/dscn0303l.jpg
Unless the POF guys want to let me swap it for a newer generation upper with the more secure current rail (though I am not a fan of the higher rail) I would probably either keep the lower and hock the upper, or sell the entire rifle. I'd just as soon keep it though as I really don't feel like letting it go for any large sum below what I paid for it. Plus, it functioned flawlessly, other than the receiver wobble and rail system I really like the rest of it. Any ideas? ( aside from "shoulda gotten an X-Y-Z piston rifle instead", as they were not available when I got the rifle). I feel with the barrel and its accuracy I've seen thus far this rifle would be great for a 1-4 power scope or similar, and I really want to turn this rifle into a good recce rifle.