Albroswift

My BAR 338 Win Mag Kevin Knight did his signature "slim-line brake" comp and played around with a couple other things for me must have been 15+ years ago. Working up some new loads, powder and bullets have come a long way, cut my groups in half yesterday. Delivers a lot of hurt down range on an unsuspecting critter. The VX-II 3x9 was a good scope at the time but after using my Viper HST on the 308 its got to go. Maybe after this season.

Ok, .082 drill fit, .086 didn't fit. Close enough. Tube AR15 length as you predicted, 98Z No divots in bottom of barrel for gas block. Before I pulled it apart, put a 6.8 oz buffer in it and loaded some rounds with a powder that has a little more chamber pressure but also a little faster burning. Started low worked up. Got higher velocities gun cycled flawlessly. Very nice groups. SD for 10 round strings approaching single digits when i got to the sweet spot. Tried some more of my hunting loads, back to the same problem. So long story short, longer tube, maybe an adjustable block, and Alliant AR-Comp powder and I think I should be there...

Thanks. I'll get the BAR off the bench and ready for hunting this weekend and then back to the Anderson.

18" barrel, M4-72 brake. Not the severe duty one.

Thanks, 98, plan on tearing it down soon and taking measurements you describe, I think I have a pin set around somewhere and know I have an index drill set. What hole size am I looking for?

Thanks, jtallen, for posting that. Trying to get all this clear in my head. Looks like for the Armalite sizes I would be correct in referring to my 308 gas system as Carbine or Mid, but not if I was talking DPMS or AR 15's

Good info, thanks. I had come across a couple of those threads earlier. I'm all over the dwell timing and pressure curves, been messing with different loads on auto loaders for some time now, but first for DI, other then my SP2A2, which functions flawlessly with 55 TO 78 Grain pills and several different powders. Don't think I found a powder that didn't work, more just tailoring loads for accuracy, fouling, and ease of dumping powder quickly in a skinny neck with that shooter. In fact, the more I think about it, this Anderson has to be the worst "out of the box" weapon I've ever laid hands on. And that's saying something! PS Where can I get actual tube lengths, example a Armalite 308 mid length = x, a carbine length = Y, Rifle length = z?

So 308 mid and carbine same?

What is the difference between mid and carbine length?

Great! Thanks for the info. 98, not sure if you're kidding, wouldn't be here if I didn't!

OK then... Thanks. My length would be the current tube length + the difference between the current end location and the center of the cut...Easy enough

All other 308s with the mid length/ 12.06" gas tube.

Yea, plan on it. Have a couple other projects to get off the bench before I pull this back apart. So nobody makes their own tubes? Doesn't look that difficult. Spoke with Anderson today they claim barrel drilling, set screw recess, gas block, tube same as all other 308 barrels

Don't really need bleedoff, the size fits inside my floating handguard and its got good reviews. The anderson block in it now is within a very few thousandths of hitting the guard, this one is smaller in all dims.

Haven't checked mine yet, but Anderson claims to use a 12.06 in their 308 builds. I like the looks of this adjustable block works as a standard adjustable or bleedoff type. Looks like the adjustment is accessible from the front. https://suparms.com/collections/adjustable-gas-blocks-direct-impingement/products/750-adjustable-low-pro-solid-gas-block-melonite-finish

What about this tube? https://www.cheaperthandirt.com/product/lbe-unlimited-ar-10-mid-length-gas-tube-stainless-steel-argt308-765857617589.do

Blue Angels and burgers if I had a 600M range in my back yard I'd be living the dream

Used the Aero Precision bolt catch, photos back a few posts next to the ar15 catch I dremmeled. Beefy looking part, stoned less then 50% of the thickness of the coating off each side for a fit any gunsmith would be proud of. No doubt the Anderson will be a shooter eventually, probably won't pull it apart until I have the new tube in hand. Still like the idea of an adjustable block...

I went through the thread, that receiver took a beating! Glad I caught mine after a couple of slams, don't feel so bad now. Dont see any of that damage around the relief cut, and my ears look pristine by comparison. Anderson's ar308 so far: Ar15 recoil tube and spring Ar 15 bolt catch Ar15 gas tube Get the feeling that they never test run their builds. Loaded some 180 gr rounds with a different pressure curve, similar to the curve that the 150 gr bullets have that ran flawlessly last weekend. Besides the tube length problem, think I was way over the top on gas pressure with the hunting rounds. Also just got a 6.8gr buffer. So while waiting for the correct tube have a few things to try next session. Shot pistols and revolvers this weekend, picked up a SW E series 1911 few weeks ago that shoots like a dream right out of the box, point of aim, crisp trigger, shoots match and seconds flawlessly. Awsome prints off hand at 50 yards, rivals my Hamilton Bowen built 44 revolver Finally someone gets it...

Measuring from the end of tube to the approximate center of the cut 0.180. Any reason not to get a rifle tube and cut it?

Measured the tube, 12.75 from the front of the gas block. Meased the key, tube to common point, .365 engagement into the key. Measued the key depth, 0.925 but there seems to be a step or ridge at 0.817, probably where the final reaming stopped. So safely I would think the tube could engage the key 0.800, which equates to 0.435 longer by math, or 0.347 by wd40 tube measurement

Took a few measurements Put a wd40 tube in the gas tube and closed the bolt. .347 protruding Tried a couple times, similar measurements

Came from Anderson with whatever length their assembly dude put in, but they only sell carbines I think. Questions: How much longer should it be? Do I need to gauge the gas tube depth in the key? How far into the key should it go? I didn't take my chrony with me today, didn't have a lot of time and was primarily checking function, but the larger then normal group and the hot weather make me think my hunting loads could have been very slightly over pressured. I don't see any indication of that, no flattened primers or flow but that load was developed in 40-50 deg weather. Wouldn't explain the winchester ammo but maybe hot chamber, and I didn't have much of that to test.

One other thing of note (maybe) The jambs were not so crammed together tight as before, and the live round being chambered showed no where near as much bend/damage as before like the bolt was (maybe?) moving a little slower.