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Jerry R
25 August 2017, 12:10
I am putting together a 308 DMR. Not called that because I ever was, or ever could be, called a Designated Marksman, but because of the desired results I hope to achieve in the quality, and accuracy of the build.

Parts are starting to trickle in, and I will update this thread with photos of parts, and of the assembly as it progresses.

The parts that have been ordered:

Ascend Armory Match Billet Receiver Set – 7075
Rainier Arms AR10 Switch Keymod Rail .308 – 17”
Rainier Arms Ultramatch Mod2 .308 Barrel .800 Gas Block TiN Extension Fluted – 18”
Rainier Arms Adjustable Bas Block Solid Bleed Off .800 Black
I asked Rainier to pin the gas block for me – I do not have a jig for that.
SI UDC Ultimate Dust Cover for .308
Rainier Arms .308 NiB BCG DPMS SR-25 Pattern
Geissele Super Charging Handle
CMC AR-15/AR10 Lantac E-CT1 Single Stage Upgrade Trigger – Curved
Ascend Armory Titanium 50 Degree Short Throw Ambi-Safety
LUTH-AR .308 Rifle Length Buffer Tube Kit (includes Rifle Length Spring and Rifle Buffer)
MagPul PRS Gen3 Stock
BCM Gunfighter Grip Mod-1
AAC Blackout 51T Flash Hider / Suppressor Mount (for use with the 762-SD)
BoBro Precision Optic Mount – 30mm 20MOA

For initial accuracy testing I will pull the Leupold 8.5x25 x 50 AO Target scope off the .243 Prairie Dog rifle (Remington 40XB KS). This scope was sent to Premier Reticle in 1999 for conversion to a 25 to 50 variable. They did an awesome job, but I’m not sure I am a fan of that much magnification. In both trips to Montana, the mirage was VERY noticeable and the high end of the scope was rarely used. However, I will be shooting off a very stable bench at 100 yards, and I think the scope will help my poor old eyes wring out the last drop of accuracy that I can squeeze from the build. This may, or may not, be the final optic solution for this build. I hope to go back to Montana at least once more.

I selected the CMC Curved Trigger because currently I do not have a flat trigger. I may get one in the future and drop it into one of the guns with a “mil-spec” just to see if I like it. But I wanted to build this DMR with a fire-control setup I am very comfortable with, and that means a curved trigger.

I selected the Ascend Armory Receiver Set because of certain unique features and controls. It is an ambidextrous lower receiver, and they have stated they will upgrade the lower (for free) with their ambi-mag release when it is available. The matched set also looks good. [BD]

The barrel was selected because I have other Rainier Ultramatch barrels and I am extremely pleased with their accuracy off the bench. If a rifle is accurate off the bench, it will be accurate in the field – in the hands of a rifleman (apologies to the many ladies that are excellent shooters). The barrel has a “.308 Rainier Match Chamber”. Quote from the Rainier web site:
The Rainier Match Chamber is a modified .308 WIN-7.62 NATO chamber to produce ultimate reliability and accuracy shooting both the 7.62 NATO & .308 WIN rounds. It is (extremely) unlikely that I will ever hump a DMR in the boonies with a spotter and kit, but as Townsend Whelen once said, “Only accurate rifles are interesting.”

I thought about putting another BattleComp 51.30 on this build, but I have a never used AAC 308 mount in the parts box. SilencerCo shipped it with the 762-SD and I did not know it was a package deal, so I bought a mount when I bought the can. My loss then, my gain now.

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4070&d=1503687738

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4071&d=1503687752

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4072&d=1503687764

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4085&d=1503778745

FortTom
25 August 2017, 13:10
Jerry,

This is going to be interesting. Any guesstimate on when it will be completed? Have an ulterior motive for wanting to see the end results, especially the accuracy aspect.

FT[:D]

Jerry R
25 August 2017, 13:17
Any guesstimate on when it will be completed?

FT, all the parts have shipped and should be in next week. I hope to complete the assembly that weekend. I am going to GriffonSec's the last week of September/first week of October. Benching will be done then with chrono, GMM, and ball.

RobertTheTexan
25 August 2017, 13:27
Looks to be an excellent build Jerry. Looking forward to see the completed weapon.


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Joelski
25 August 2017, 13:55
Very interesting!

FortTom
25 August 2017, 14:19
I understand the "mature vision" thing, but damn, that's going to be a lot of scope[:D]

FT

Jester Gunwerkz
25 August 2017, 17:02
Subscribed.

BoilerUp
25 August 2017, 19:51
Sounds like a great build.

I like the BCM Gunfighter grips for carbines, but don't care for them much for bench rest shooting. I prefer the Ergos for that.

Jerry R
29 August 2017, 08:09
Most of the remaining parts are scheduled to be delivered tomorrow, and another round of photos will begin.

But before that, I wanted to say Thank You to the team at Rainier Arms, and specially to UWone77. The insight, advice, and assistance (that is not seen in this thread) has made this build possible. I have cobbled together a lot of AR-15's, but this is my first non-factory AR10. Subtle nuances such as differences between receiver types, what fits with which type, and on and on ... generates the need for lots of research, or VERY knowledgeable friends that are willing to take the time to help.

So ...

Thank You !!

Joelski
29 August 2017, 08:45
Can you publish the knowledge you've amassed? It would sure help those of us that are hung up on the whole Armalite vs. DPMS pattern thing.

Jerry R
29 August 2017, 09:02
I wished that I had amassed some knowledge. [BD] There are so many variables in that arena. Basically what I did was look at a given set of parts and tried to determine if they would work together. Luckily they do. With all the manufacturers out there, it comes down to a piece-by-piece check. Unless a part (forend / barrel / receiver / etc.) specifically states which pattern they are, you have to either ping the manufacturer, or find someone using the same parts. I am not sure if a set of blueprints with specs and tolerances for each receiver type would help. You would still have to research the adjuncts.

That was the reason for the Thank You to UWone77 and the folks at Rainier. They (VERY) patiently listened to my concerns and responded quickly to my questions. So, the sum and substance of my knowledge was phone calls and emails. The parts shown in post #1 work together - that's what I found out.

But, having said that; I wish someone like UW or some of the 'smiths at Rainier - or the very good manufacturers that are members here - would start an AR10 "Spec" thread.

I think that would be a great 'sticky' for this forum.

GOST
29 August 2017, 12:57
Look forward to seeing the finished product.

Jerry R
29 August 2017, 13:09
The Ascend Armory 50 Degree Safety/Selector came in ...

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4122&d=1504037302

gatordev
29 August 2017, 13:31
Can you publish the knowledge you've amassed? It would sure help those of us that are hung up on the whole Armalite vs. DPMS pattern thing.

Technically it's "...the whole Armalite vs. DPMS vs. KAC pattern thing." I think a lot of times the KAC pattern is what causes a lot of the confusion, since it's sort of a hybrid of the other two patterns.

Joelski
29 August 2017, 13:39
Technically it's "...the whole Armalite vs. DPMS vs. KAC pattern thing." I think a lot of times the KAC pattern is what causes a lot of the confusion, since it's sort of a hybrid of the other two patterns.

I would rather have Aero or CMT's interpretation of the DPMS vs. Armalite thing. If I had KAC style cash to spend, it would be a line-built SR25, no question.

BTW: Did anybody cash in on yesterday's Aero email deal of a complete AR 10 receiver set in FDE for $299?

gatordev
29 August 2017, 14:15
I would rather have Aero or CMT's interpretation of the DPMS vs. Armalite thing. If I had KAC style cash to spend, it would be a line-built SR25, no question.


I can understand that and totally understand budgetary restraints. But Mega puts out a good product, and they follow the KAC standard (with a sprinkle of AR-15 in there), so there's still options. Or you could go with LMT, but then you have to buy a NF 2.5-10x24 to keep up with your internet friends. Or so I've heard.

UWone77
29 August 2017, 14:20
I can understand that and totally understand budgetary restraints. But Mega puts out a good product, and they follow the KAC standard (with a sprinkle of AR-15 in there), so there's still options. Or you could go with LMT, but then you have to buy a NF 2.5-10x24 to keep up with your internet friends. Or so I've heard.

Heh, you get a guy to buy a 416 upper and the next thing you know you, I keep getting some passive aggressive shade thrown my way [:D]

gatordev
29 August 2017, 18:13
Heh, you get a guy to buy a 416 upper and the next thing you know you, I keep getting some passive aggressive shade thrown my way [:D]

Hey, I can't be responsible for convincing you that a combat-proven optic is way better than you make it out to be. If only the 416 functioned!

(but seriously, I think the 416 issue is resolved with confirmation this weekend and it's been fun to see what all the hub-bub is about with this thing)

Joelski
29 August 2017, 19:58
I can understand that and totally understand budgetary restraints. But Mega puts out a good product, and they follow the KAC standard (with a sprinkle of AR-15 in there), so there's still options. Or you could go with LMT, but then you have to buy a NF 2.5-10x24 to keep up with your internet friends. Or so I've heard.

I'm liking the MWS, but if I get that, I'll have to rely on my awesome internet friends to hook me up with the NF glass. [:D]

UWone77
29 August 2017, 20:01
Hey, I can't be responsible for convincing you that a combat-proven optic is way better than you make it out to be. If only the 416 functioned!

(but seriously, I think the 416 issue is resolved with confirmation this weekend and it's been fun to see what all the hub-bub is about with this thing)

No question it's battle proven. I said it had unforgiving eye relief... and it still does ;)

It will probably end up on a future MK12ish build.

Jerry R
31 August 2017, 08:24
Shipment from Rainier arrived yesterday. Ascend Armory 308 Receiver set ...

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4136&d=1504192977

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4137&d=1504192987

GOST
31 August 2017, 09:31
That's a great looking reciever set, gonna be one sexy rifle.

Jerry R
1 September 2017, 07:41
Last of the "major" components. I will post pics of the "build in process" also.

Rainier Switch Keymod 17" Rail and the Rainier 18" Ultramatch 308 barrel polished and fluted. I asked Rainier to slip on the barrel nut and pin the adjustable gas block for me.

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4144&d=1504276735

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4145&d=1504276743

Jerry R
1 September 2017, 09:20
Rainier Arms .308 NiB BCG DPMS SR-25 Pattern

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4148&d=1504282744

Former11B
1 September 2017, 13:25
That adjustable gas block looks good. I want to get one also to mess with. I've only used WAR uppers in the past and I want to keep my build Rainier only

Joelski
2 September 2017, 10:08
Looking good, Jerry. It's rainy and cold here; a perfect day to spend time at the work bench.

JMJ
3 September 2017, 17:53
Shipment from Rainier arrived yesterday. Ascend Armory 308 Receiver set ...

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4136&d=1504192977

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4137&d=1504192987

Those are the slickest looking receivers I've ever seen! Anxious to see how awesome your rifle is when you complete it.

Mecha_Arms
4 September 2017, 13:52
Nice choice on that Ascend Armory receiver set. After fondling one at Triggrcon it was VERY difficult to leave without buying it.

Jerry R
17 September 2017, 10:47
Now that the wind has finally died down a little, and I have figured out where the heck I live ... I was able to finish the build today. Better pictures coming, but a quickie just to show the completion.

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4247&d=1505670406

SINNER
17 September 2017, 11:31
Looks fantastic!

Jester Gunwerkz
17 September 2017, 14:03
That's one fine looking stick, Jerry. Nicely done.

Jerry R
17 September 2017, 14:34
Thanks Guys - much appreciated! I will be at GriffonSec's the last weekend of September to zero and accuracy test it on the new bench.

JMJ
17 September 2017, 17:46
Man that's a gorgeous rifle!!!

Jerry R
18 September 2017, 12:03
All finished except for testing. Sorry about the background - does not fit on the light table [BD]

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4253&d=1505760732

Pyzik
19 September 2017, 06:39
Jerry, that rifle turned out great! Couldn't have gotten much better looking.

Jerry R
19 September 2017, 10:06
Thank you Sir. I am very pleased with not only the way the build turned out, but the help UW provided, and the excellent service at Rainier made this all come together. I hope it shoots as good as it looks.

FortTom
20 September 2017, 16:53
Very nice!

FT;)

mustangfreek
22 September 2017, 18:08
What everyone else has says, very clean and quality parts list, should be a shooter... Post up how it shoots.

Curious how much does it weigh .

Jerry R
2 October 2017, 18:40
Okay, was at GriffonSec's this past weekend and finally got to zero the build. "Crappy Cell Phone Pic" setup shown below. Five shot group off bench rest, not the Atlas bipod. CTC is right at 3/4" with Federal 168 GMM; CBC 168 Sniper shot to the same POI and same group size. A younger shooter might shave it some, but I was very pleased with the way it performed for me.

http://www.weaponevolution.com/forum/attachment.php?attachmentid=4333&d=1506994365

GriffonSec
3 October 2017, 13:12
Should be noted, group shown NOT group with suppressor! LOL

Wonderful shooter, lighter than it looks, especially against the Sig 716 Patrol rifle.

UWone77
3 October 2017, 13:35
Jerry, that handguard on the 18" barrel looks perfect.

You need to pop for some dedicated glass on this one!

Jerry R
3 October 2017, 14:12
Jerry, that handguard on the 18" barrel looks perfect.

You need to pop for some dedicated glass on this one!

Thank you Sir. And ... I did. I sold the Sig 716 Patrol Rifle sans scope, and put it on the Ascend. The 6.5x20 Leupold works great, and not a bad choice for a long range thumper.

BoilerUp
3 October 2017, 19:27
nice looking rifle

Tyrannosaur
4 October 2017, 07:38
Awesome build. Do you guys recommend the rifle length gas system or mid length for the 18" barrel?

Jerry R
4 October 2017, 07:55
Awesome build. Do you guys recommend the rifle length gas system or mid length for the 18" barrel?

Thank you Sir. This particular 18" is a mid-gas with a rifle buffer. A very soft shooter. I have not shot a rifle length gas system on a 308, but it is hard to imagine it having less felt recoil. Once I got the gas block adjusted, I have had zero issues. I had Rainier pin the gas block, and they shipped it completely closed for me to adjust. Made a real believer out of me on the Switch Rail !!

Joelski
4 October 2017, 17:59
Looking good!

BoilerUp
4 October 2017, 19:40
Awesome build. Do you guys recommend the rifle length gas system or mid length for the 18" barrel?

My 18" JP barrel is rifle length gas. It's great. Whatever barrel / gas system you chose, get an adjustable gas block so you can dial it in (I personally recommend SLR)

RobertTheTexan
4 October 2017, 19:40
Awesome build. Do you guys recommend the rifle length gas system or mid length for the 18" barrel?

I prefer rifle gas for a couple of reasons. The first being the benefits the longer tube gives in reducing dwell time, slowing the BCG down a little and the positive effect that has on recoil. So for my precision guns - the DMR and my SPR (5.56) I chose rifle length gas systems. I also run an A5 Buffer system on the SPR, and on the DMR I have a UBR 2.0 stock which is for all intents an A5 length buffer tube, although with the longer 308 BCG you have to run either a carbine buffer or a 308 carbine buffer, (not the A5 Buffer) which is shorter than the standard mil spec AR-15 carbine buffer, and in the UBR requires a spacer. I’m using a KAK Heavy Buffer with a Sprinco Red spring. I mention all these other parts because they are all variables that can have an effect on how your weapon cycles and affects felt recoil. Likely I could reduce recoil a little more using rifle length stock or a PRS, but weight and adjustability were two options important to me.
I too believe my DMR is a really nice shooter. I was so surprised and impressed by it that I immediately made plans to build a .308 SBR. I’ve cooled my jets on that project thankfully.

It’s hard to quantify “soft shooting” and “reduced recoil”, unless you shoot the guns, so I’m not going to say my DMR is smoother than anyone’s. I couldn’t know that until I shot both. But the “science” behind the direct impingement gas system says that the longer the gas system, the slower the BCG travels, the reduced gas port pressure, which are part of what you feel in your shoulder. Another reason I went with a gas system is because while we don’t have a mil standard on the 308, I felt the rifle gas was more the norm, more empirical data on what worked and what didn’t work, and since I may run a suppressor, I wanted to “normalize” where I could, and that was one area.

My comment on standardization isn’t to imply there are issues running mid gas systems on 308. I really didn’t do much research as I wanted gas from the get go.
It’s just more commonplace and I saw that as an advantage on achieving a first shot functional weapon.


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RobertTheTexan
4 October 2017, 22:15
I meant to add that I also have an adjustable gas block and if you’re planning on suppressing, you should probably get one. I use the SLR Sentry 7 on all my builds, for use with a .750 has journal, and SLR has treated me fantastic customer service wise. I say all my builds, I mean all my builds that will run a can. Even contacting me at almost 2100 to make sure I knew he was squaring me away the next day. I run my GB fully open on my .308. I don’t think I would use an adjustable however if I was running unsuppressed. It is one less moving part and also in my book another reason for rifle gas. But I know adjustable GB’s are popular these days.

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Joelski
13 September 2018, 20:31
Anybody have a .308 kreaction rod, or some such that I could borrow? I will completely cover any cost to get it to me and return it immediately. I'm just not relishing that one time $180 for one of my own. Really would appreciate it!

Jerry R
14 September 2018, 06:54
Anybody have a .308 kreaction rod, or some such that I could borrow? I will completely cover any cost to get it to me and return it immediately. I'm just not relishing that one time $180 for one of my own. Really would appreciate it!

I have a Geissele Reaction Rod marked "For the AR-10/SR25" If that is what you need, PM me your shipping details.

UWone77
14 September 2018, 07:17
So Jerry, how's the PRS Gen 3 treating you? I was thinking about doing a PRS Gen3, but didn't want to fork out the cash, so I used an old Gen 1 UBR for my recent 6.5. I'll probably upgrade after a few range trips.

Joelski
14 September 2018, 07:21
I have a Geissele Reaction Rod marked "For the AR-10/SR25" If that is what you need, PM me your shipping details.Jerry, you are a life saver!

RobertTheTexan
14 September 2018, 09:05
Anybody have a .308 kreaction rod, or some such that I could borrow? I will completely cover any cost to get it to me and return it immediately. I'm just not relishing that one time $180 for one of my own. Really would appreciate it!

Have you thought about something like
This? I have a set for both AR-15 and AR-10. and have lost count on how many barrel swaps & installs I’ve done with this.
I have a Magpul BEV block and honestly it feels more secure than when I use the BEV. My upper receiver blocks came with “anti-torque” plates, that are thick acrylic and slide over each end of the piece holding in the lugs of the receiver and on the picatinny rail. Doing at has removed any kind of twisting or torquing as you are cranking down on it. I mounted an URX4 rail once and the only way I could true it up was to crank it out to its max of 75 ft. lb’s and never once did I feel any twisting which obviously is a bad thing. I know it’s. It. Reaction rid, but I thought I’d mention it to you as an alternative. If you contact the guy he’ll give you a military discount. Or probably hurt I’ve you a discount if you ask for it. I’ve talked to him a couple of times. He comes from aerospace and still does some work in that space, but at his core, he’s use just a ordinary gun guy.

https://www.plastixrevolution.net/products/308-upper-receiver-vise-block-ar10-sr25-lr308

Hope this help.
RTX





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Joelski
14 September 2018, 09:14
Thanks Robert. I will consider that for the future, but Jerry has already sent me his reaction rod. The tracking just popped up as I was typing this. Tremendous help, from a tremendous group. Thanks fellas!

Joelski
14 September 2018, 09:22
Just waiting to pick up my builder set. Got a few bits to hit with some paint, so two days will be good to get set up for assembly.

Got a hell of a deal on the brownell nitride BCG and the raptor as well as the set.

http://i997.photobucket.com/albums/af93/Joelski144/ARs%20and%20Pistols/Gear/20180914_162107_zpsw8rqjjvt.jpg~original

ZhouJett
14 September 2018, 10:17
https://farm2.staticflickr.com/1868/44670238861_5efae3626c_b.jpg
https://farm2.staticflickr.com/1861/44670239431_ded63d5730_b.jpg
https://farm2.staticflickr.com/1841/30799514808_43eaa3a2d2_b.jpg
https://farm2.staticflickr.com/1873/44670242101_becd0b70f6_b.jpg

Joelski
14 September 2018, 14:25
Nice lookin' RA.

Jerry R
18 September 2018, 07:06
So Jerry, how's the PRS Gen 3 treating you? I was thinking about doing a PRS Gen3, but didn't want to fork out the cash, so I used an old Gen 1 UBR for my recent 6.5. I'll probably upgrade after a few range trips.

UW, I'm a benchrest shooter, and I really like the PRS Gen-3. I did not have any experience with previous generations though. I made minimal adjustments to the parts that can be adjusted, and it "feels" good off the bags and the bipod. It is a keeper - for me. Wish I could tell you how it is better than previous versions, but ............

Joelski
1 October 2018, 13:24
I thought about putting another BattleComp 51.30 on this build, but I have a never used AAC 308 mount in the parts box. SilencerCo shipped it with the 762-SD and I did not know it was a package deal, so I bought a mount when I bought the can. My loss then, my gain now.

So you built an entire DMR out of a suppressor mount....



MASTER!!! :NotWorthy: [:D]

Jerry R
1 October 2018, 13:29
So you built an entire DMR out of a suppressor mount....



MASTER!!! :NotWorthy: [:D]

ROFLMAO !