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ripper51

DPMS Oracle Accurizing

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Brand new (May 2016) DPMS Oracle received. BUIS installed. Range report. After Mechanical zero set and boresighted it was apparent something wasn't coming together. 25yd shots high and 11o'clock. Corrected using all sights front (elevation) rear (windage). Rear sight bottomed out at 200. Tried again at 100 and 200 yds. 11o'clock 5 ring.  Checked for play in upper and lower-none & tight. Checked barrel- screwed in and torqued 65lbs. Still hitting 11 at 5 ring. Sent back to DPMS. They checked, waved their magic wands and said "Yup, 11o'clock and 5 ring. at 100yds". Shipped it back to me. Took it down, replaced handguards with free float tube. Now its consistent at 11 o'clock 7 ring. Talked with DPMS about shipping up back to have some look at receiver facing and how there could been this much ,

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31 minutes ago, ripper51 said:

 BUIS installed.

What kind?

Pics of this rifle configuration, as it is now, are going to help tremendously.

Edited by 98Z5V

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32 minutes ago, ripper51 said:

Took it down, replaced handguards with free float tube.

What kind?

Gotta work through the details here, in order to try to help, or figure out what's going on. 

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DPMS Free Float Tube, Magpul front and rear sites. What's going on? Kind of apparent to me.Either the barrel was screwed in wrong, cross threaded (not likely- doesn't show when the barrel is unscrewed), or the receiver is slightly twisted- probably the better approach.

And when does it matter what brand or type of free float tube or Back Up Iron sights are used, if installed correctly? I had this problem awhile back with a DPMS LR-308 that shot consistently at 2 oclock 12-15 inches out at 200yds. and an equivalent distance at any other yardage. That one turned out to be receiver barrel threads that had been cut wrong by DPMS. 

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 Still using the Railed Gas Block or did you use a upper Rail for the front sight on the FF HG ?  ( if it had one )

 Do you have or can you use another complete Upper to try out , a shooting buddy 's or something .

 You can also use a laser to see how the sights line up with the Upper's Rail .

IMG_1509.thumb.JPG.707b35c895a75c07d102950c56087704.JPG

Edited by survivalshop

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15 hours ago, ripper51 said:

And when does it matter what brand or type of free float tube or Back Up Iron sights are used, if installed correctly?

Right on - I'll leave you to it, then.  :thumbup:

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Used the original railed gas block for front sight mounting. Used top rail for rear sight mounting.  And for 98Z5V- have no idea who you are or what you do other than post. I do know my limitations though. I have tried 5 different free float tubes. First 3 were from DPMS who installed them, Did not like them because they were basically unvented heat traps. Tried a Daniel Defense modloc ff tube. Felt weird and seemed to put the COG too far forward. Put the Rock River CMP-legal FF tube that looks like the original A1/A2 handguards and it balances and holds right. Magpul front and rear sights are well Magpul front and rear sights. You mount them, zero using a bore laser and the open bore (you know this trick- look down the bore from the breech at a black dot 25yds away with upper in a viseblock). And I am curious- what difference do the various fft or detachable iron sights make if they are installed correctly? I'm looking for a way to inspect the method used to tap the receiver for the barrel as I suspect that as the culprit.

Wish I could post pics but camera won't be back from Nikon for a week.

No rush here, just looking for ideas.  Survivalshop, that is a good idea on lasers. I have enough that I can do bore, sights in 2 ways and barrel alignment. Using a buddy's upper- I'm in El Paso. Don't know anyone close by really that has a DPMS Oracle in 308. Lots of 223 though.

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  The use of the Laser will tell you if the Gas Block or sight is off , if the sights sight plane is dead nuts in line with the Uppers Rail ( measured aligning marks at the front & back of the Rail ) then that tells you it could be the Barrel thats off , be it mounting of Rifling or some other weird stuff . 

   If you are using Magpul Plastic/Polymer sights , they are not made to mount on a Railed Gas Block & they tell you so in the instructions , if they are the Pro's , not an issue . I have never trusted Railed Gas Blocks to be precisely aligned with the Upper Receiver or that they are level with the Uppers Rail . If you had a Railed HG , did you try the Front sight on the HG's Rail ?

 That Laser I used was on a New Colt Carbine that was shooting so far right , the rear sight was buried to the left & still shot 8" right , by using the Laser , I found that the Taper Pinned A2 Front Sight Tower was off to one side , removing the Tapered Pins & aligning the Sight tower so it was dead on aligned with the Uppers Rail ( shown in the Photo ) , the rear sight could be adj. to center hit all ammo used in it , though its was still left in the rear Sight adj. , you could still do a little adj. with it .

 If the front Sight is low on that Gas Block Rail , you will have issues doing any adj. on it & if that Gas Block is off to one side or the other , even a couple of hairs , you will have issues sighting the rifle .

 All this still doesn't mean you could have a goofy shooting Barrel , I've seen those also . The Upper Receivers can be Tweaked out of alignment by not using proper Fixtures to install the barrel or not having them set up properly . DPMS Rifles , like most production rifles are built by factory line personal , like any factory , no longer are firearms made or assembled by GunSmiths .They make too many . Ordinary factory workers on an assembly line assemble them & DPMS doesn't make their own Barrels , so hard to say who makes them , 

Edited by survivalshop

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New Colt M4 Carbine- yep have one of those, had the problem until I unscrewed the barrel which was loose at the time. Rifle had never been fired before me. And it was shooting waaaay right. Disassembled, re-assembled, torqued according to specs, mechanically zero'd sights, used in the bore laser boresight, shifted sights elevation and windage by 2 clicks each left and up. At 25yds, shot cloverleaf, 100yds, cloverleaf, 200yds cloverleaf, 300yds all in the x ring. Yup, barrel loose and A2 sight tower cocked. 

I like the idea of the lasers to true things up. I used the Magpul Pro's but also have this mistrust of railed blocks. I moved the sight to the HG and voila what a change. Still out there but at least its now the 6 ring at 11. The experience with the Colt M4 has made me leery of assembly by factory. And no this ain't my first rodeo<grin>. I'll use the lasers to measure angles and parallels, then get back to y'all.

Oh yeah, had to re-register since it kept asking me to reset my password.

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OK, railed gas block was off by an RCH. Still delivering enough gas but not TDC. After uninstalling and reinstalling FFT and barrel, I thought about iron sights and mounted a scope instead. Now, we're cooking. Thanks to survivalshop for laser leveling idea. Now looking into iron sights that can be used on this rifle successfully. Open to ideas.

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 Is there a rail on the Hand Guard ?    Most of us just mount the front BUIS on the Rail & they co witness with the rear Sight , in most conditions. Pretty much thats how they are designed . There are Front sights that are made for the railed Gas Blocks because of the height differences in most of them & the Upper Receivers Rail .

  Yankee hill makes one http://www.brownells.com/rifle-parts/sights/front-sights/gas-block-front-flip-sight-prod21358.aspx

  There are also plenty of Gas Blocks with flip up sights on them & you can also install a A2 type Tower sight that clamps on also .Check Brownells http://www.brownells.com/rifle-parts/sights/front-sights/gas-block-front-flip-sight-prod21358.aspx

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There is a rail along top of receiver, but not on handguard. FFT is the Rock River CMP tube. Now DPMS makes a set of sights that look like they are made for the Oracle ( eyes rolling) .Between Brownells and Midway I can see a lot of combos. No, not going to try the A2 Tower front sight. Had an earlier DPMS 308 Classic. It had an A2 tower and the A3 detachable handle with sights. Looked good but really had some issues.

Have tried a scope mounted in the A3 rail area but with an A2 tower the tower was in the way of the scope. Super high mounts moved it up, but I may as well just mounted the scope on top of an A3 detachable handle. But thanks for idea. Now that I have the method of laser leveling and equalizing, I may try the A2 Tower and make sure it is aligned with everything

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 I have an AR 15 with a A2 Front sight & can't see the sight through the scope at all . Rings are Xtra high Burris extreme Tactical , I have to have them that height for proper sighting, but their height doesn't matter , you should not see the tower through the scope any way . 
  If your concerned about it , its why they have the fold down types , I don't have any BUIS on my Scoped AR's . The rifle below had an A2 Upper Receiver on it for over thirty years , I wanted a scope to see how good the Barrel would shoot , will probably go back to the Original Upper at some point .Shoots real good with the A2 set up . I'm just getting to old .:laffs:

DSCN2758.thumb.JPG.6f3b370758af972582907eda21f98a6e.JPG

Edited by survivalshop

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I have run a couple different scope with the sight towers in place setups and never had an issue, I can see it on my PM400 with the 1-6x on 1x but by the time it hits 2x the sight disappears.

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For whatever reason, the Leupold VX2 3-9 sees them at all magnifications although only as a very faint shadowing at 9x. I have experience significant POI shifts at higher magnifications at 600yds, no wind, same loads. When I put on the ultra high extreme rings, it places the bottom of the bell even with the top of the "wings" and all goes well. This is with an A2 tower only. With fold aways, obviously no problem. Maybe as I get older my eyes are seeing stuff. 

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OK, lets resurrect this. 98Z5V- I probably owe you an apology as you were trying to methodically walk me thru it and I was rushing. Forward railed gas block is low profile so any iron front sight would sit low. A2 carry handle didn't help as it sits high. Putting "iron" rear sights on A3 rail still too high. Found a spacer for the forward gas block rail which evens it out with A3 rail. Then decided, the heck with it, and put scope on. That was a learning experience. No front "iron" sight, no rear "iron sight, just the scope. Had to set it forward quite a bit. Leupold VX2 3-9. And I also tried a UTG Bug Buster in 1-4x. Liked the bug buster and it held up well. Leupold did well but it doesn't have the easily adjust turret knobs the UTG Leapers has. I'm using medium Leupold forward leaning mounts for the Leupold. The Leapers UTG comes with mounts and is so short it doesn't need extension or forward leaning mounts. 

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Now the hunt begins. I don't want to spend the equivalent of another rifle, but want to look at options here . 

First option- different upper in complete 18-20 inch barrel vs buying barrel, extended rifle gas tube?

Second option- Scopes. Love the Leupold as the clarity is amazing. Like the UTG Leapers for the turrets. Suggestions?

Third option- man- releasing the bolt stop is a bear since I shoot right handed. I saw one extended bolt release but it looked like a strange contraption that merely extended the release to a lever system under the trigger housing. Any others out there?

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I also have several UTG scopes and like them for their ease of dealing with parallax and locking knobs, and they hold zero very well.  An alternative that you might want to consider are the new Monstrum FFP scopes.  I got two of these to try out (in 6-24x50) and have one on my 6.8 SPC and one on the 338 Federal.  I just zeroed them this past weekend and have the following observations:

1.  I originally was going to use a Burris PRPR mount but these scopes are too long, because of the offset of the parallax and horizontal controls) to fit.  Instead I am using a very cheap mount from Amazon which seems to be doing surprisingly well.

2.  The clarity and light transmission are very close to my Vortex PST (also 6-24x50) which is second focal plane.

3.  The FFP reticle is a bit challenging to get used to, but once you are used to it everything becomes very easy.

4.  So far, they are holding zero but only have about 30 rounds down range.  Next time out I want to test how they hold zero and then take off the scope (the cheap mounts are quick release), put it back on and see if it holds zero with the change.

5.  These are significantly heavier than the Vortex and are built like tanks so they should hold up, and with the etched reticle I should never have a problem with wires coming loose.

YRMV

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On 1/14/2018 at 11:40 PM, Mike Schwartz said:

Now the hunt begins. I don't want to spend the equivalent of another rifle, but want to look at options here . 

First option- different upper in complete 18-20 inch barrel vs buying barrel, extended rifle gas tube?

Second option- Scopes. Love the Leupold as the clarity is amazing. Like the UTG Leapers for the turrets. Suggestions?

Third option- man- releasing the bolt stop is a bear since I shoot right handed. I saw one extended bolt release but it looked like a strange contraption that merely extended the release to a lever system under the trigger housing. Any others out there?

Ok, you have a few things going on here so let’s address each.

1. You can buy an upper, or build/change your barrel ( not sure what an extended rifle gas tube is) but I don’t think you’re addressing your main problem. You are looking to hit the ten ring, with solid groupings, consistently correct? Not knowing you or how you targets are looking at the range (you have not posted any pictures) but how are your fundamentals? Are you consistent shooting with your set up now? Groups generally in the same spot? Tight or loose?  What FCG is in the rifle? I find that this is usually the first and most useful thing to change.

2. Scopes. The better the scope quality, higher magnification and mount quality will result in repeated shot impact points. Again grouping is more on your end but these keep it consistent. 

3. Familiarity with the platform eliminates this. There are fully ambidextrous lowers out there, I like MEGA MATEN personally, but you get used to it with repetition. If you are shooting for groups this isn’t even a factor. More of a defense/drills issue which will resolve itself through repeated use.

 

Can you state your specific goals you are looking to achieve? How about a general budget? Maybe what you dislike the most also as there is a lot of people here with varying tastes who have tried a wide variety of options on these

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On 6/19/2017 at 9:12 PM, ripper51 said:

Brand new (May 2016) DPMS Oracle received. BUIS installed. Range report. After Mechanical zero set and boresighted it was apparent something wasn't coming together. 25yd shots high and 11o'clock. Corrected using all sights front (elevation) rear (windage). Rear sight bottomed out at 200. Tried again at 100 and 200 yds. 11o'clock 5 ring.  Checked for play in upper and lower-none & tight. Checked barrel- screwed in and torqued 65lbs. Still hitting 11 at 5 ring. Sent back to DPMS. They checked, waved their magic wands and said "Yup, 11o'clock and 5 ring. at 100yds". Shipped it back to me. Took it down, replaced handguards with free float tube. Now its consistent at 11 o'clock 7 ring. Talked with DPMS about shipping up back to have some look at receiver facing and how there could been this much ,

So you installed the BUIS yourself, since the Oracle didn't come with sights?  The most effective thing you can do after a proper installation of a scope on the upper is to put in a good aftermarket fire control system .  A Giesiele (ignor my spelling) or a drop in Timney, I put a drop in that was a group special a couple of years ago along with their charging handle. Forgot the iron sights with the original Oracle gas block. 

Edited by mrmackc

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Edgecrusher- I shoot NRA High Power Rifle, normally with an iron sight M1A in 308. Last time I looked I think I was ranked Expert but anywho my groups are generally x ring or x ring to 10 ring to 9 ring. With the Oracle, it has a 16 inch barrel and collapsing stock, and I believe it is considered a carbine just like my Colt Ar-15 with a 16inch barrel and collapsing stock. Tight groups. - So fundamentals- check. What I want to know has to do with my unfamiliarity with DPMS uppers and lowers. I know I can't mix 556 and 762 uppers and lowers. Can I indeed take an 18inch barrel upper and slap it on an Oracle lower?(762x51). As I said, I don't want to buy a new rifle.

mrmackc- Yeah, frustrated myself for awhile trying to figure out what was more screwed up- me not realizing the gas block rail was lower, or DPMS for putting out a rifle with no sights and a lower gas block ral. I won. Scope is on now and yup need the Timney drop in.

BTW, talk about feeling particularly stupid when it dawned on me- duh, yeah lower rail, iron sights not going to work- duh. 

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17 minutes ago, edgecrusher said:

Well you’re  the expert. You’ll figure it out then.

And I just want to take the opportunity to thank you for the tremendous help, advice and assistance you've provided in this matter. Your expertise and ability to zero in on the problem with a succinct solution is most appreciated.

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2 minutes ago, Mike Schwartz said:

And I just want to take the opportunity to thank you for the tremendous help, advice and assistance you've provided in this matter. Your expertise and ability to zero in on the problem with a succinct solution is most appreciated.

I know I was trying to zero in on the problem, and provide a succinct solution, right away - but you were pretty evasive with your answers, and instead, acted like I was attacking you.  At that point, you literally blew me off, and submitted a smartass reply.  Okay, have at it then.

Had you answered the questions I posed upon you, I could have told you right away what your primary issue was.  Had you provided the pics of the rifle I requested - it would have been immediately "solved" by numerous very smart people here.

Nah, you didn't want that, though.  What you ended up doing is what you wanted in the first place.

Hope you get it shooting, hope you figure it out, and hope you have a great time.

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Yessir, you are entirely correct. Nope not the expert just the student. Didn't have a way to take much less send readable pictures then and only recently have acquired that. It was frustrating to say the least. The Oracle is shooting. The earlier LR308 I had that had the original problems, still has those problems, but it is now DPMS' problem. The earlier LR308 was one of those fancy grade with Carry handle and A2 gas block. It had a 20inch barrel on it. This Oracle has a 16inch barrel. Makes my problems smaller?<GRIN?>

In all seriousness though, the simple answers I was looking for could be given without providing you all more info. My fault. 

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