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FOGeologist

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Everything posted by FOGeologist

  1. Santa Claus : It's Lee Majors! The Six Million Dollar Man! Lee Majors : Santa, is there a back way outta this place? Santa Claus : Of course there is Lee, but this is one Santa who's going out the front door. Lee Majors : Look, it don't matter a hill of beans what happens to me but the world couldn't afford it if anything happened to you. Now stay put. Santa Claus : Oh that's very nice of you, Lee. And Lee... You've been a real good boy this year! Mrs. Claus : Yes you sure have!
  2. Thanks for all your help and guidance this year with my Ship of Theseus project. You guys have been great. Waiting for warmer weather to see if I can put out a nice load for that rifle.
  3. Have you had to use shims to time a handguard? You have to add them such that it holds off the nut rotating into torque value until one of the threaded holes is lined up (within maybe 2 degrees either way, they build a little slop in the handguard so you can have some room to rotate it enough to make a finely-adjusted alignment with the upper rail). It requires some patience to get it to where you have an opportunity to get the nut aligned. If you add too many shims, you may have to tighten the nut a LOT to get to the next hole. Too few and it will crank past the aligned position before you reach tension. My next handguard will be the clamp-on style. You can torque the nut to a nice 40 lbs and then clamp the guard on, using the groove in the nut to put the guard on at the desired angle - no "timing" needed. Not a fan of "reefing" on aluminum as it seems to put some stress on the whole assembly. I couldn't imaging cranking one to (what is the upper spec?) 80 foot-lbs? Holy CRAP!
  4. I've heard of that research that someone did - I'll probably pull the handguard and use shims to tighten the barrel enough to bring the value up over 40 or so.
  5. I think the relatively dark range and kooky optics of a pair of $7 shooting glasses they forced me to wear conspired to make the target hella-blurry. Plus the rushed feeling I was getting was not helpful to get me an opportunity to settle down, shoot effectively and take breaks to allow the barrel to cool was not helpful, either. Barrel has about 160 rounds through it. Clearly the brass shows much less damage from the feed ramp than the last shooting session, where the rifle was shooting better. No extraction or other issues after I brought the adjustable plug out 6 clicks from its previous location, seemingly a large adjustment, IMO. I'll develop some loads for the rifle to see if I can wear it in a bit better, but I'm thinking a 1.6 MOA barrel with FGMM may be about as good as it is going to get in the first place.
  6. Update: In another thread I described how I found out my PSA adjustable gas block was hitting the inside of my too-narrow Guntec free-float handguard. I sawed off the top 3" of the handguard around the gas block and now the barrel flexes without striking anything. Took the rifle out to Liberty Firearms Institute's indoor 100 yard rifle range and shot a box of Federal Power- Shock 180 grain, and a box of Federal Gold Medal 168 grain Sierra Matchking out of it. Here's the result. I did have to open the gas block up another 6 clicks to get the gun to run consistently. Curious. Results from the Power Shock 180 grain; I shot 4 x 5-round groups, achieving a 2.188 MOA average. Then, I shot a 5 x 4 round group, averaging 1.526 MOA: So, not so great, especially for a rifle shot indoors. Possible issues: set up took a while, and I was on the clock... the Range Officer was bearing down on me and forced me to wear safety glasses, and I could not see the crosshairs very well on this low-power (9x) scope indoors. I felt rushed and was banging out the last two groups in short time. The barrel was too hot to touch all the way through the shooting session. For a skinny barrel like a Faxon Big Gunner, with no wind (inside shooting) there was little chance to cool the barrel. It might be impossible to get better groups than this with this rifle in this configuration. I probably need a 14x or better scope. I probably should dump the barrel and get something more rigid, and get a better handguard that I can torque effectively without worrying about timing issues; this barrel is probably right at 30 foot-lbs and may not be lashed down tightly enough to prevent whip.
  7. Oh, God. Another thread that I'd need a degree in psychology to understand.
  8. All thanks to jtallen83! He suggested to another poster to check flex on his barrel. I had read his advice before but never considered that my gas block could hit the handguard. Boy, was I wrong! My goofy PSA adjustable gas block is lopsided, and I couldn’t tell because the handguard was blocking me from seeing it. I thought the unthinkable - “Could my gas block be hitting the inside of my Guntech handguard?” Yep. Easily. After my eyes were rolling like the digits on an old style gas pump, I chopped off the top front 3” from that thing and went to town sanding and touching up the handguard. No amount of barrel whip will cause it to strike anything now. Gotta get back out to the range to see if this brought the accuracy up.
  9. You know something? I had read your response before, but never considered this could be happening to me. Then, I grabbed the skinny 18" Faxon Big Gunner barrel on my rifle and flexed it... and the lop-sided, weirdly-shaped PSA adjustable gas block hit the inside of the handguard on the left. I know I'll be replacing the Guntec handguard soon, so I decided to hack off the top 3" of it. Now no amount of flexing of the barrel will allow it to hit the inside of the handguard. We'll see if there is any beneficial effect come next shoot.
  10. Holy LORD, you are gonna fit in well around here. Us geriatrics love to shake our canes at every post!
  11. Welcome from Frederick, Co.
  12. You can use the Federal Fusion rounds; the 150 grainers would be good for the smaller whitetails and hogs, but you could go with the 180 grain bullets if you're hunting some of the larger Western counterparts. The open nose on these rounds is tiny - probably 1/16th or 3/32nds of an inch. They don't seem to interact on the feed ramps of my rifle, and they are certainly "hunting accurate" (3.5 MOA to 1.6 MOA in my minimal testing), so you should get good performance at a price.
  13. A suggestion on this: I have had two barrels on my AR-308, a 16" bull barrel from DPMS, which seemed capable of producing sub MOA groups with some ammo, and an 18" Faxon Big Gunner, which seems to be a little worse performing. Use a shim, if your barrel's sloppy in the upper. Refer to the JP Rifles thermofit video on YouTube to see how it can be fitted. Consider a heavy profile barrel; it will be like handling a tank turret, but if your goal is accuracy above all, then the thicker profile seems to prevent whip from wrecking your accuracy. I would also stick with 18" (preferably 20" +) to retain as much velocity as possible. Get a numbered drill bit and identify the gas port diameter, if it doesn't match 98's list, drill it out.
  14. Range Report: “Ship of Theseus” Aero Precision M5 Build On 6 October, I took my rifle to Baker’s Draw Shooting Area in the Pawnee Grasslands. The rifle range there is only 100 yards, which, for my purposes, was just fine. My goal was to take my newly-reconstituted now-rifle (was a carbine previously) and make sure my changes (new upper and lower, revised buffer, tube, spring, stock, gas tube, and bolt stop) were working appropriately, and to tune my PSA adjustable gas block to the new system. My plan was to bring a box of Federal Fusion 150 grain hunting ammo and a box of Federal 180 grain hunting ammo to the field to check for function. My old setup had been smearing brass on the ejectors and tearing up rims, due to improper timing. I had used a short gas tube, an inappropriate spring, and far too light a buffer. The rifle was trying to extract the cases early from the chamber before the pressures diminished and the brass had an opportunity to shrink. I drove an hour north to this wilderness range, and set up my target at the 50 yard line for initial shots - changing receivers and remounting my Leupold Freedom 3 - 9 x 40 scope concerned me enough to check initial shooting at a close distance. My zeroing regime is to aim at center point of the largest clean target, fire one round, then re-aim the rifle at the same exact aiming point. Without moving the rifle, I then adjust the windage and elevation until the crosshairs are directly centered over the bullet hole. This means the scope is now aligned at point of impact. At that point I can move the target to 100 yards and I should be centered up, and perhaps an inch low. Adjustments are minor from there. I started with the 150 grain Fusion and an open gas block, dialing inward on the 7/64th set screw one turn per shot, looking for “failure to lock back” on an empty mag (one shot in the mag). Goal here is to tune the rifle to use the amount of gas required to operate the action, without a lot of recoil slamming the rifle and operator. “Completely Open” on that adjustable gas block is 5 turns +1 click (the system’s click adjustment is 5 clicks per full turn). To find the correct operating gas amount, I dialed in one full turn for each of the first five shots, until the rifle couldn’t lock back the bolt, then I’d turn backwards 3 clicks, then I’d try again. The “function point” is 1 turns + 1 clicks out from “Fully Closed.” From there, I had not one, any, NO failures to feed, function, or eject. No brass damage, no blown primers, no cratering, no hammered case heads, no cartridges being ejected into the next county (like shooting an HK91). This was all due to YOU GUYS and your excellent recommendations. Accuracy on the 150 grain Federal Fusion wasn’t anything to write home about. Best group was about 2.5". Most were near to four inches. I was careful about my shooting, taking some time to cool the barrel between shots and groups, and winds weren’t too severe - about 6 mph, and 100% from the rear. After knocking out 4 x 5-round groups, I switched to the 180 grain ammo… and was rewarded with markedly better performance. I fired four groups of five and averaged around 2” per group. I think it’s possible to get this rifle down to about 1.3 MOA, with an occasional lucky group below an inch, if I am careful about my handloads. Future Plans: I’ll probably buy a Krieger barrel with their version of an M110 profile in 20”; this could probably shoot a bit under 1 MOA with 168 to 175 grain bullets. I have already bought some bullets in those sizes and some AA2520 to build some loads in this range, which always seems to have an accuracy node between 165 grains and 200 grains for this caliber. I also have Varget, and will do some work ups based on both. I just want to see if the Faxon can make use of the extra effort of handloads. I'll drag out my chrono, too, to determine if I'm doing anything well in my reloading den. I will probably lose the Leupold VX Freedom as it’s magnification is a touch low at 9x. I will probably replace it with an Athlon or an Arken, which has better magnification and a more functional build. Yes, this will bring the weight up substantially, but 300 yard sightings should be less difficult. Weight has gone up in this rifle to 9.6 lbs, an increase of 0.8 lbs. My goal is to keep the rifle below 12 lbs with the new sighting gear and a better front handguard.
  15. You know that this was the handguard on the original DPMS low-PSA receiver I had, right? That was appropriate for the old setup. I’ll pick up a corresponding high handguard here in a bit.
  16. “Ship of Theseus” is a lesson in philosophy - “When does something lose its original nature?” It was said that Theseus’ ship, after many long years lying in display after his famous journey, had to have a great many parts replaced due to aging. At some point the docents replaced so many parts that no one for certain could state what part of Theseus' ship was original. So what remained, his real ship or a replica? I suspect it was an allegorical thought exercise by the ancient Greeks - some sort of kernel for an argument. Because, as we know, Greeks are fond of arguing. 😏
  17. Milestone! Ready to assemble Done. Not attaching muzzle device for initial firings. Removed (probably Chinese fakes) Magpul BUIS; the DPMS High profile of the M5 upper doesn't match the Guntech KeyMod poopy-pants handguard. I'll have to buy some kind of handguard that has a matching profile. Draw of the action is clearly tougher with the longer rifle based spring; It's an Aero spring, and I may replace it with a Sprinco Red if I have any functioning weirdness. Been watching the Johnny's Reloading Bench YouTube videos as he made a .308 AR in April 2019; BOY did he go on an adventure! He did eventually end up with a super-accurate AR 308, but had to go Krieger to get it to happen. I might go and shoot this thing tomorrow to see if I can get it to do anything right.
  18. Thanks MaineMan2 and 98C5V, it's making better sense to me now. I wonder why the AR15 doesn't have the nasty timing problem AR10s seem to have? I built a pistol a while back that was a bit of a shoulder-bruiser, until I put an Odin Works tunable GB on it. I guess the four lengths are pretty well standardized due to military specifications?
  19. Story's not done yet. Been waiting for my gauges... the guy told me they still aren't available and I canceled the order. I've put a couple hundred rounds through that barrel before I disassembled it and hadn't blown up yet, and my fired cases don't seem to need much, if any, resize, so the chamber can't be all that big. So tonight I'm going to re-assemble, and maybe head out to the range tomorrow to see if I can get the rifle operational with some factory 180-grain Federal, you know, tune the gas block, check ejection patterns, that sort of affair.
  20. What is the issue with the gas tube going to the middle of the cutout? What does that provide you with? The gas is getting released deeper into the key, but how would that influence the timing or pressures with these rifles, anyway? FWIW, I bought a tube that allowed this configuration in my build, on advice given in the gas tube length thread.
  21. Kind of a point, here. There is a LOT of the lead from "non-completely jacketed bullets" of the cheaper FMJ-variety, invariably that vaporized lead is left on the insides of cases. Which means you get to deal with its vapor every time you unass the cleaned brass from the tumbler.
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