PDA

View Full Version : Rainer arms LR-308 build



Jmcrips
18 December 2014, 22:50
Howdy. I just finished my lr308 build using a ton of Rainer arms parts and I figured I'd publish my results.
The guns foundation is a Rainer 308 dpms profile matched upper and lower set. I put a fortis 15 inch switch rail on it and inside is a Rainer arms ultra match 20" barrel, and a Rainer bcg from revolver. On the back is a magpul PRS and I have a Bushnell HDMR H59 SCOP on top. I figure I'll give a review of the parts, how I built it and where its at. The only thing I really need to get for it is a geseliee dmr trigger and start working up some hand loads.
I've built 2 ar15's and this was my first 308 I've built so I'm hoping my experiences will help newcomers like me!
I built my self two (ar15,lr-308) "reaction rod" type tools from 1 inch bar stock, and cut out a bolt face on my CNC plasma cutter and tig welded it onto the top after powder coating and creating a sleeve for the 308 tool I had two tools that would allow the barrels to be installed without stressing the upper. On the instructions for the rail it says I need a dpms barrel wrench, instead of buying said wrench I measured the size of what I needed, cut it on the CNC and welded it to a 26" long pipe, on the other side of the pipe I welded in a bung to run my 1/2" torque wrench. I created my own barrel wrench that allowed for torquing of the barrel along the length of the barrel.
So off to building the gun. I ordered the parts in sections, I'm kind of stingy so I wait until I see bargains, like I got my PRS stock used for cheap, waited until the barrel was on discount, etc, etc. With this said here are a few things I learned.
The Rainer upper and lower doesn't come with takedown or pivot pin and should be ordered separately. In my opinion this is slightly aggravating, I would think common sense would dictate that if your selling a matched set, pins would be included. So in a huge rush I ended up ordering pins from dsg arms that didn't fit, so I had to contact Rainer and get the pins, it was kind of a pain. I'd prefer that the set included the pins and had the price of them included so I don't have to look for these that fit the set. To throw salt on the wound the pivot pin seemed to be .005 inch larger then the hole and required tolerances to be fit to get it to work. Minor problem, but still I think its a bit strange.
This ar10/sr25 seemed to need some shooting to get it cycling right. It took about 125 rounds to get it working great. For the first 25 rounds it was a short stroking son of a gun, don't be alarmed, its a mechanical device and after about 50 rounds it started loosening up.
The bcg from revolver was a beautiful system, but it was very hard to operate the bolt. I ended up having to take it apart and investigate, upon tearing it apart I noticed that the gas ring gaps were all aligned. Going back to engine building on a piston of a engine your gaps on the rings need to be separated, so I did that on the gas rings, I separated them 1/3 apart from another and that made all the difference, it started working great! So if your having trouble with yours and the bolt is very gritty feeling moving it in the bcg I recommend pulling it apart and checking the rings.
Gas tube. These Rainer barrels run rifle length systems, for some reason the gas tube I got from Rainer was 1/4 inch longer then it needed to be and wouldn't allow the bcg to go into battery. Kind of a strange problem and fixed it with a new tube. I'll be sending that back to Rainer hoping they don't have that problem with other tubes.

OK now the good stuff. This barrel is a thing of beauty and a joy to behold. Today at 100 yards running cheap 147 grain lake city ammo from the lumber store it was extremely accurate. I'll throw up a pic of sighting it in, it doesn't show any groups to say since I was sighting it in and didn't have time to shoot a new paper due to the sun going to bed early in December. But I'll get one soon.

The manufacturing quality of this upper and lower is amazing. Yes the pivot pan may be tight, that's my only gripe and it really isn't a problem.

Fortis shift rail. This rail is awesome. I was skeptical at first because its so light, but after putting it on and shooting I have no reason to worry, they have accomplished something rare. Fortis has built something light, strong, looks good and is cheap.

In closing I have to say building this has been a extremely rewarding experience. It is extremely ergonomic, feels great and shoots like a laser.
I hope my light review can be of help to people and if you have any questions please ask.
Oh yes my front cap needs more belt sander to fit right. http://tapatalk.imageshack.com/v2/14/12/18/69882d7de016b24f9bc5254989bf1f57.jpghttp://tapatalk.imageshack.com/v2/14/12/18/1332c99a57568af445c7fc8c853017ad.jpghttp://tapatalk.imageshack.com/v2/14/12/18/f6db593f02b71abe2c3e054f693cf553.jpg

Jmcrips
18 December 2014, 22:58
http://tapatalk.imageshack.com/v2/14/12/18/2e7acf7bb2a1ce5afd3a8c2bd62da793.jpg. Another pic of my diy/CNC plasma/tiged up reaction rod. Cheap and worked great.
http://tapatalk.imageshack.com/v2/14/12/18/0bf594aea78708891fd32627ec0e5017.jpg making the PVC sleeve for the upper reaction rod so I didn't tear it all up by having it all floppy. http://tapatalk.imageshack.com/v2/14/12/18/d606b0abf207536d9557f8f89dc63fd2.jpg one more pic from the side.

WHSmithIV
18 December 2014, 23:23
Nice rifle. A .308 is in my future too. It'll be down the road away though.

toolboxluis00200
19 December 2014, 05:30
very nice

maybe one day i can build a .308

JHoward
19 December 2014, 05:42
The gas rings being aligned would explain the short stroking as well.

Gaspipeshooter
19 December 2014, 08:29
I'll give you $20 for one of your home made "reaction rods"...[:D]

On a more serious note, that is very cool that you have the resources to build tools like that! Nice build!

Jmcrips
22 December 2014, 12:01
@gaspipeshooter! Funny thing is I'm looking at redesigning them and selling them on my eBay store. But I've got to make them so I can get a better weld on the star part. But yea, 20$ sounds doable, I'm hoping to sell them for around that price. :) shipping might move the cost up a bit, but around 20 yea!

Jmcrips
22 December 2014, 12:02
Thanks for the kind words guys! I'll be getting a better trigger other then the left over alg I had and stuffed into it and I'll start working hand loads and I'll post more up.

WHSmithIV
22 December 2014, 12:43
@gaspipeshooter! Funny thing is I'm looking at redesigning them and selling them on my eBay store. But I've got to make them so I can get a better weld on the star part. But yea, 20$ sounds doable, I'm hoping to sell them for around that price. :) shipping might move the cost up a bit, but around 20 yea!

Heck - I'd want one for that price!

Do you have any idea what the complete weight of the rifle is just out of curiosity?

Jmcrips
22 December 2014, 13:09
Its looking doable, just have to make sure the steel I'm going to use will be cost effective and strong enough for a 65 ftlbs load. The two I built we're made of scrap metal so I have zero cost in them...lol

Jmcrips
22 December 2014, 14:33
Oh I haven't weighed it yet, hopefully soon!