Home Forums Hunting & Shooting AR and Tactical Rifles 24HC Black Rifle Challenge Thread

I really like the looks and adjustability of the PRS. I actually had to buy a .80" thick recoil pad for mine to get the LOP right. Fits me like a glove now. Most complain about the weight of that stock, but if your rifle has a heavy barrel, it really helps to balance things out. Personally, I would rather have a well balanced rifle than a barrel heavy pig. Just the way I see it...

Thank you sir. It is indeed an aero lower with mostly LMT lower parts kit, a strike industries extended Mag catch, JMT single stage trigger.
Uppers is also Aero with 15" Rainier Arms Forcerail, Strike Industries charging handle, Fathom Arms nitride bcg, ADM 20 moa mount and a leupold MK6 3-18.

You asked about the trigger specifically. It is made by John Madison Tactical out of WA. It is a drop in single stage cassette trigger that included Allen screws to eliminate cassette wobble and antiroll trigger pins for $100. Mine was bought on a whim and breaks at 3lb even with barely any creep. I'm probably the only guy who doesn't really like 2 stage triggers except on fighting rifles.

Here is an idea of what it groups like. 10 rds at 150yds prone off a bipod and my coat rolled up under the buttstock. That's a 1" sticker for reference.

Thanks mallardaddict. Looks great and shoots very well. You should shoot this event. Throw 2 10 shot groups downrange. Looks like you will fare very well, if you can keep both groups looking like the pic you posted. Thanks for answering my questions. Your build sounds great. Cool trigger too..

Was at the range today to work out some gas settings & buffers with a couple of new guns & another rifle, so I shot all 3 for groups.

All guns got the same load: 23.5 gr of AR-Comp under 75 gr Hornady OTM's, LC-16 Brass, BR4 primers.

I'll list the pics & guns in 3 separate posts as I'm not sure how many pics a single post can contain.

The guns are a KAC 18" barrel rifle, 2nd gun is a built rifle with with Viltor MUR upper, 18" WOA barrel, Areo lower; 3rd gun is a newly built gun with an American Defense upper, a Rise Armament 16" barrel with a SIG lower off an older SIG 400.

MM

The Range


The 1st Gun: KAC 18" barrel with SS 16x scope


Targets

The 2nd gun is a built gun with a Viltor MUR upper, Aero Lower, WOA 18" barrel gun with a NF SHV 3-10 scope. It has less than 100 rounds through it, so it may get a little better as it breaks in fully.

The gun


The Targets............obviously, I pulled a couple in the 2nd group


MM

The 3rd gun is a newly built gun that only has about 75 rounds through it.

It is an American Defense upper, with a SIG lower, a Rise Armament 16" barrel & the only scope I had around that was not mounted is an older BSA 1-6x but it seems to hold zero for range work in the past when used, but at best, a 6x scope, even a good one, is a bit of a handicap for this kind of group shooting.

Likely a different scope & a little more break-in & it may do a bit better.

The Gun


The Targets




MM

Awesome MM. I have a question: Which ones did you play around with buffers on???? I'm thinking my rifle set-up almost like this one needs a heavier buffer. I'm running a rifle length gas system, 18" barrel (1 in 7 twist), carbine (ACS) stock. My rifle seems to be working harder than it needs to be/maybe overgassed. I bought a Spikes ST-T2 buffer to throw in it to calm it down a bit. I'm hoping it settles down and still functions 100%... Good shooting too buddy...

The gun that was the most problematic & that I was working with the most was gun #3 with the 16" Rise barrel with a mid-length gas system.

The barrel has a larger than typical gas port by quite a bit, .091" vs a typical mid-length at around .080" so it was very much originally overgassed as I expected it would be.

I originally installed a fixed Viltor gas block as it was on hand & available, & I expected to be able to use a heavier buffer to get it near where I want it to be. As I originally tested it, I used an H buffer & a Sprinco Blue (enhanced spring) & ejection was forward at 1 o'clock & the brass was pretty heavily dented from hitting the rear of the ejection port & the very front of the deflector.

Going to an H3 buffer did very little to help so I removed the fixed gas block & installed an adjustable gas block & re-tested with the H buffer & Blue spring & with the gas adjusted properly, all was good. I also tested with an H2 buffer & liked it better so that's how I've left it. Ejection is 3:00 to 4:30 depending on ammo, no dings & it seems to just be touching the very rear of the deflector & no failures to lock back with any ammo.

It's a pretty light & short barrel, in a fairly light gun, but the recoil & sharpness of the gun is now greatly improved.

It's generally my practice to use an adjustable gas block for flexibility, & in this case, that practice was just further validated.

Gun #2, the 18", also a mid-length gas barrel (but with a .083" port) was done from the git-go with an adjustable gas block & the Spikes ST-T2 buffer / standard weight Sprinco White spring & with some fine tuning to the gas block, it's been perfect. The ST-T2 is between an H & an H2 buffer in weight.

My own view of the world is to not go too heavy on the spring as getting carried away with spring weight leads to more likelihood of bolt bounce on the return bolt closure.

Maybe Blue or Yondering or WE700 or Rost might offer their insights................but an adjustable gas block just makes life much, much easier in the end.

The KAC 18" rifle gas gun has a non-adjustable gas block from KAC but it has run perfectly from day one with (from them) a carbine buffer & whatever spring they are using.............KAC knows WTF they are doing. I actually have 2 more of their guns that are 16" CL barreled guns with their proprietary intermediate gas systems & they all run perfectly with a carbine buffer & the stock spring......................I've seen no reason to change the way that any of them came from the factory. If I ever decide to change anything, it would be to put on an adjustable gas block, but so far, there has been no need.

MM

Yes, definitely.

In my experience, you really don't need a heavy buffer or spring if you can tune the gas. All of those are methods to get to the same point.

Thanks guys. I'm going to give the ST-T2 buffer a chance first. I'll also check prices on an adjustable gas block while I'm at the AR shop today too....

Prices should be $30 and up for an adjustable gas block. Something simple and side adjustable like the Seekins is my preference, for ~$60.

Thanks Yondering. I'll see if they have the Seekins... $60.00 doesn't seem like a bad deal.

I'm using SLR's adjustable gas blocks & they are superb; have not used Seekins, but usually anything that Seekins does is very good.

SLR's are not cheap, but they work.

MM

I looked at the Seekins, compared one to an Odin gunworks adjustable gas block. The Odin looked a little more robust. I did not have an SLR to compare it to. I wish there was more of a selection there. It seems like this would be the way to go on a system that is not matched or paired up right with parts and gas port sizes. I probably don't need to go that route with mine, as it's worked flawlessly, but seems to recoil more than necessary. I'll throw this ST-T2 buffer in and see if that helps. I should know right away after shooting it if the heavier buffer does the trick. If not, I'll definitely be looking at one of those cool adjustable gas blocks...

I would advise against using any solid buffer like rhe T2. Bolt bounce would be my concern.

What do you mean "solid" related to the T2 buffer?

Maybe I mis read the info on the T2 buffer

"The Spike's Tactical ST-T2 Heavy Buffer is one of the softest shooting, smoothest and quietest buffers on the market not to mention it looks awesome. It doesn't have any weights to move around or fluids to leak out, it's 100% maintenance free!"

I know when I was trying the 9mm buffers of old, they were solid and induced lots of bolt bounce. If the T2 doesn't have any weights to move around, how does it counteract bolt bounce? Or is this just bad info on the T2?

That whole series of buffers from Spike's use tungsten powder (that does move) instead of solid weights.

I've used one & can't really tell much difference compared to a buffer with solid weights, & they surely have no real magic IMO, but slight bolt bounce is a hard thing to detect & can also be caused by an overly strong recoil spring as well.

MM

Yeah, thats just a poor product description. As MontanaMan stated, tungsten powder is used and seems to work just fine.

WE700,

What page has your last compilation of standings?

MM