Good-looking gun and good timing! I went out to the range today as well despite the fact we hit 100 degrees Fahrenheit today. Would likely explain why I was the only guy out there for most of the day and the only one on the 100 yard line.
I had my barrel replaced by POF after I determined the headspace on my old barrel was out of specification and too large. That barrel shot really well though and when you hand load, and can set the appropriate head space, you're good. Rifle is a Revolution DI and it's the standard 16" barrel.
New barrel comes in and my initial look through it with a bore scope was positive. I began breaking the barrel in and honestly, nothing was super tight. Mostly 2-3 MOA. Took out the bore scope again and noticed the gas port was not in between lands and there was now quite a bit of tool chatter present that I didn't notice before. But I kept at it, cleaning, shooting a few, cleaning, shooting more, etc...until I was up around 50-60 shots. Still not grouping great like the old barrel.
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Today I went out with the rifle to test a few things. First, a new suppressor, the Radical Defense CS3, against its big brother, the LS3. Second, a new Tubbs buffer spring (thanks for the tip!) and different buffer weights. I brought along an H, H1 and H2. My goal was to eliminate my brass being torn up, shaving material off the base. I did clean it prior to going and the gas port is spotless, even before cleaning. No buildup of copper whatsoever.
I ended up putting 70 rounds exactly down the barrel, hot as dog's balls outside, mirage from hell, and wind as strong as a god's fart. And no great groups. My brass WAS better, the gun was functioning really well and ejecting brass at 4 o'clock once the gas was dialed in. Ok so maybe it's a 2MOA gun on a good day. Fine. I mean I'm using off-the-shelf PMC so maybe hand loads will improve the situation, right?
On a whim, I decided to swap to the H1 buffer just to see if it would clean up my brass a touch more. Stock is H, and I wanted to see if the Tubb flat wire spring would have an effect on its own.
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Well, that did the trick. Group on the left was I dunno, was 11 or 12 shots. I'd basically used up all my ammo loaded into mags by then and I wanted to see what the barrel would do when good and hot. I had a partial box of ammo left. I loaded one round to see if the bolt would lock back and it did. So no gas adjustment. I put five more rounds in the mag and they all pretty much went through the same hole, group on the right. First shot is the one to the bottom left of that group. The rest were all shot at once, like one every second or two. I was shocked to say the least. Not saying I can do that every time I go out but I now have high hopes for the barrel and will develop loads from here. The X-Tac Match uses the Sierra 168 HPBT which I believe is a secant ogive and thus jump sensitive. I've never had great luck with that style bullet in a gas gun. I use Sierra 169's in my bolt gun so I'm hoping I can develop a good load for the POF using the same bullet as it has a tangent ogive.
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The brass does look far, far better than it has in the past. I'm tempted to try the H2 but I can't argue with the results especially given the environmental conditions today. The fifth piece of brass from the left has a raised portion but not nearly as bad as in the past. The others are all smooth despite having visible marks. And yes, it does this to ANY ammo, factory loads of various types and all my hand loads, none of which are spicy. The fact this thing is sub-7 pounds and can shoot like this is pretty amazing. I do have a Geissle trigger, a Riflespeed gas system and Magpul furniture. Rest of it is all POF off the shelf. The suppressor was a Radical Defense LS3 but I saw no difference in group size between it and a CS3 I brought along (shorter version). It's strange that not all the brass gets nicked. Some doesn't. I did chrono a bunch of the PMC and the standard deviation was 14.2 over nine shots in the last group I metered. Velocity ranged from high 2400's to low 2500's, bout a 50fps spread. The long string I did had a SD of 16.7 and a spread of 66.9 over 53 shots. Not horrible but not great.
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Anyway, I'm just happy to have her back, functioning, with the hope of decent accuracy. I know it's common around here to dog on POF but I have to say, of the two I own, they're both exceptional rifles. Yes, the first barrel had a chamber issue but I shot that for years with great results. And I have to admit, I was a bit disappointed with how poorly the new one did out of the box, poor being relative, and I chalked it up to needing to be broken in. But the barrel was free, new bolt, they took apart the rifle, installed the new barrel, tested it WITH the Riflespeed gas block even, and sent it all back quite quickly. And it did absolutely function perfectly out of the box albeit still tearing up brass. I had a few extra things done (aka ODG cerakote) while there too. The chamber was initially tight but that's gone away. Thinking about the brass, I'm now under the belief that the E2 extraction/gas slots in the chamber are what cause this so there's no real way to tune it out but just lessen it a bit.
