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Ridgeline Defense RD-15 LPR

dms416 said:
Sure. I got the calipers out last night, and the recess for the rear lug in the lower receiver is about 2.5-3 thou smaller than the rear lug on the Ridgeline upper. Still have a few lowers to check on the off chance, but the ones I had in my bench/shop area were as mentioned above.

Like it's DAMN close...like I could probably thermo fit and persuade (i.e. force with rubber mallet) it into place, but knowing how both of these are notoriously tight, I might just hold tight (no pun intended) and source a lower that's not ridiculously tight as fuck already.
Click to expand...
Upper receiver lug widths are 0.496" (-0.003")
Lower receiver takedown pin lug pocket width is 0.500" (+0.005")

Dimensions are before finish. MIL-A-8625, Type III, Class 2 anodize thickness is 0.002” ± 0.0002”. Roughly, 50% of that thickness is "penetration", 50% is "growth".
So taking into account anodizing thickness, max lug and min pocket can both be 0.498" (not taking into account anodizing thickness tolerance)
 
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msgriff said:
Upper receiver lug widths are 0.496" (-0.003")
Lower receiver takedown pin pocket width is 0.500" (+0.005")

Dimensions are before finish. MIL-A-8625, Type III, Class 2 anodize thickness is 0.002” ± 0.0002”. Roughly, 50% of that thickness is "penetration", 50% is "growth".
So taking into account anodizing thickness, max lug and min pocket can both be 0.498" (not taking into account anodizing thickness tolerance)
Click to expand...
Basically my measurements show a flip-flop
Ridgeline upper rear lug is 0.5020
Hodge Mod 1 and 2 pocket is 0.4990 and 0.4985 respectively
 
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dms416 said:
Basically my measurements show a flip-flop
Ridgeline upper rear lug is 0.500
Hodge Mod 1 and 2 pocket is 0.498 and 0.497ish respectively
Click to expand...
Sounds like each manufacturer decided to tighten up play from opposite ends. It might be one of those upper/lower combinations that's problematic.
 
Don’t mind the weeds
 

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msgriff said:
Sounds like each manufacturer decided to tighten up play from opposite ends. It might be one of those upper/lower combinations that's problematic.
Click to expand...
Yep, that's my thought as well....each understands the fit aspect, and I think I just have a combo that isn't going to play well with respective tolerances on each end... not really surprised to be honest.

Only person I can be annoyed is myself...thought I would do the "easy button" and just get the upper rather than yet another receiver and the hassle involved in this forsaken state.
 
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dms416 said:
Only person I can be annoyed is myself...thought I would do the "easy button" and just get the upper rather than yet another receiver and the hassle involved in this forsaken state.
Click to expand...
I just wanted to avoid the ambi mag release lol, I wasn't trying to cheap out. Thank you for posting the measurements.
 
Had my RDR for about a month now I guess and here are my findings running a 4-16 ATACR and a YHM Turbo K RB on a Q plan B mount. The gun has only been fired suppressed and has about 500 rounds on it. All groups shot prone off a bipod and rear bag.

Test target it came with was .73 MOA. I've only shot 77gr IMI through it. I zero every gun I own with it because I keep a ton of it on hand. First outing groups hovering in the .75 MOA range with best being .67

I don't follow Proofs process. I do all the same love it or hate it. I shoot rounds through it typically 40 -100 the first outing. I then run a boresnake through it a few times. Done.

2nd outing groups tightened up delivering a best of .55 MOA and hovering in the .6 range. Got data every 100 yds out to 1000 and micro dope. No issues.

3rd outing groups consistently in the .5 MOA range and I have not grouped it again since but will after a few more sessions.

Velocity avg with 77gr IMI has been 2690 FPS

Cold bore shot measured shooting a 3/4 inch paster at 100yds first round of the day has been consistently center and 0.1 mil high.

No noticeable POI shift from various positions but i have not shot a ton of groupings but rather I've done positional work out to 1030 yds on various types and sizes of steel. Some of the fun highlights were 2nd round impact on mini IPSC at 1030 off a barricade and Shooting a know your limits target down to half MOA size at 650 yds. I have shot grouping at 100yds off a barricade with a game changer and no shift in POI.

Great rifle that addressed a lot of my complaints with other gas guns and so far I'm really enjoying it. Super fun to be able to get consistent impacts out to 1k with a lil 16inch 5.56.
 
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@Rudy Gonsior 2 questions.

1. Has RD considering doing a 12.5" upper in this lineup?

2. Aside from the thermal fitting (seen in RD's recent video), what makes the RD upper reciever different than Seekins, Colbalt, or Aero?

The way y'all show heating the reciever extension to mate the barrel was really cool!
 
PBWalsh said:
@Rudy Gonsior 2 questions.

1. Has RD considering doing a 12.5" upper in this lineup?

2. Aside from the thermal fitting (seen in RD's recent video), what makes the RD upper reciever different than Seekins, Colbalt, or Aero?

The way y'all show heating the reciever extension to mate the barrel was really cool!
Click to expand...
1.) There is a 11.5/12.5 CQBR (basically a compact LPR) on the drawing board currently. Not sure which length just yet but I do have some prototype 11.5 barrels from the RDM4 project that have shown some great results.

2.) Regarding the difference in design, I’d wager it’s fairly similar from big picture perspective. The semi-monolithic rail concept isn’t exactly something we pioneered it’s just that it didn’t seemed to be being paired with some of the other concepts we wanted to see as shooters.

The big difference I will point out is the effort that we put into pair and fitting upper receivers, barrels and gas systems. We could batch test parts and simply pay somebody minimum wage to assemble and ship rifles, and I’d suspect a good chunk of the rifles would be fine, kinda like grandmas old fashion fried donuts, it’s just a good recipe. Problem being though is that for certain end users, especially in a professional capacity, your time should not/cannot be spent troubleshooting or second guessing a rifle out of the box. You’d be surprised how many little things that get caught during 100% CQ that are showstoppers for producing functional rifles.

That said we currently have something like a 98% first-time pass rate for during accuracy/function testing. Turns out even when following the recipe, it’s still not a perfect thing. “Trust…but verify” is the name of the game. There are certain aspects of a rifle that just can’t be measured outside of live fire.

And that’s the difference between us and the others. Most companies in this industry have a “guarantee”, The guarantee that most companies have nowadays is a just a promise that it should be good and if it doesn’t buff just send it back. This is the cheapest way to deal with performance issues because in reality most of the time it is probably good …and/or they are banking on you not being able to tell the difference. The requirement on the other hand is what we’re offering with every LPR. We are not just promising you it will perform, we are showing you that it did in fact perform to at or above the standard we promise. This is the single biggest difference I see.
 
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@Rudy Gonsior

1. I appreciate the response. Looking forward to a hopeful 12.5 upper! Makes me consider holding off building one for now. Big fan of that barrel length and 77SMK class bullets. Its just so well rounded giving up only 50-75 yards of comprable data to a 16" barrel.

2. Thats what I figured. RDs QC seems like it goes to the "nth" degree and makes the upper stand apart.

Thanks again!
 
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Paris_Bulks said:
That’s great news. Any thoughts on if 6 ARC will be offered? Or a 14.5” 556 LPR that can be updated with a new bolt and 14.5 proof barrel on my end?
Click to expand...
If (big if here) a 6 ARC can be made to an acceptable MRBS/F then maybe within the year but it’s a tall order.

A 14.5 (Proof barrel) LPR is drawn up but it’s back burner project. I suppose you could cut a 16” LPR if you’re feeling crafty. I wouldn’t go changing the bolt though.
 
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Cut a 16” back 🤔

Maybe I missed it, but mid-length gas, intermediate or a custom length of your own ? Thinking mid-length with the A5 system unless you have a special weight buffer??
 
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