Plunging In

[unforgiven]

I don't see a lot of soft 5.56 and have shot and seen Remmington in .308 with soft points. :confused:

[techmike]

I had a similar accuracy issue with my AR - it turned out to be the flash hider, and the crush washer. Took off the flash hider, and cleaned off the deposits on the crown, test fired a-ok. Installed a new flash hider without the crush washer and it has been fine since.

[Dusty44]

My A2 (?) flash hider was clocked slightly too far at the factory.  I bought 2 new washers when I bought the free float tube and had the gunsmith who installed the FF tube re-install the flash hider --straight-- & with a new washer. (The other washer is for a new high-dollar precision barrel,  if that seems necessary).  If the next range visit has bad results I will try removing just the washer.  And see about cleaning up the crown.  Like soak in Hoppes and then soak in my gun oil and see what will wipe off?

The last few minutes at the range,  reported above,  the last 5-shot clip:  it all seemed to come together.  Really,  the last 6 rounds.  The last clip and the final shot of the preceding clip.  It would have taken new targets and another full Green.Range.Hot.Range.Green.Range cycle to place and recover targets and shoot more test clips and I did not have time.

All ammo this last range trip was factory Bitterroot Valley.  Started with 69 gr;  ended with 75 gr. Last target was all 75 gr.

[Dusty44]

All the loaded 223 & 5.56 ammo I have seen or bought is HPBT or FMJ.  I have seen some plastic tip spitzer BT advertised online.

I bought a box of 100 bullets for reloading:  Sierra Gameking,  65 gr,  SBT,  #1395.  Soft lead tip;  red warning on the label:  7" - 10" BBL.S. ONLY

My barrel is 1 - 9 inch twist;  If I get another barrel,  it will be 1 - 7 inch.

[Microgunner]

Don't cha just love it when a plan comes together?

[Dusty44]

Took the DPMS Oracle 5.56 with all the new hardware to the range,  Tuesday the 19th of June.

Fired 10 rounds of each of 6 different bullet weights.

55 gr Tul Ammo  Aluminum cased Hollow Point bullets *

62 gr Herter Hollow Pointed bullets

64 gr HPBT Bitterroot Valley

69 gr HPBT Bitterroot Valley

75 gr HPBT Bitterroot Valley

77 gr HPBT Black Hills Match

*  The Tul Ammo was probably steel case with a beautiful 1-molecule-thick brass finish and the Herters was the aluminum cases.  Unless it wasn't?  All this ammo ran magnificently.

Target distance:  100 yards;  temperature high 90's to maybe 102 F;  wind 5 - 15 gusting to 20 from the right side (firing line faces 090;  wind was nearly 180).  At 100 yards and nearly 3000 FPS,  the wind should not be significant;  an inch or less in the 1/10 second it had to affect the bullet.  Started with 4 targets on backing board,  reduced to 2 targets at a time later.  Always a fresh target available when needed.

On the pics below the blue marker number indicates which mag in each pair.  There was only one (20 round MagPul) mag used.  5 rounds were loaded,  mag inserted in rifle and the string fired.  Mag released,  rifle laid on its side and partly on a sandbag so the barrel would be slightly angled down and sometimes the rifle was tilted so the scope was low relative to the rest of the rifle.  Mag reloaded with 5 more rounds,  etc.  Usually by the time 2 or three (or 4 at most) of these 5-shot strings had been fired the range was called 'Green' for posting and checking targets and there was a significant delay before shooting was allowed again.  When the range is Green,  bolts must be open.  I slip my yellow plastic flag into the chamber,  also.  The rifle never had an opportunity to get very hot.  The DPMS design barrel nut and slotted FF tube help cooling,  too.  That nut is a good heat sink all by itself.

These targets have one-inch wide rings and one-inch square grid overlay.  The red stick-on target dots are one-inch diameter.

Target 001 shows a decent group for the first mag;  then it all goes to hell for mag #2.

Target 003 mag #1 really shows two tight groups.  DIIK?  Then mag #2 drops back to the usual spread.  Targets not shown have spreads slightly larger,  pretty much the size of the full diameter of the 9 ring;  as displayed on Target 004A.

Target 004A shows mag #1 aimed at the golf ball,  mag #2 aimed at the red dot target.  The spread was doing fine with both strings until the last two shots of mag #2.  Both of these bullets went where they were supposed to.  It is a little difficult to see:  one hole at 7 o'clock in the red disk and the other at 2 o'clock.  Then the next and the rest of the mags continued the big spreads.

The Nikon scope is in Burris Tactical scope mounts.  These are tip-off mounts.  I use a 1/4 inch drive ratchet handle and a 1/2 inch deep-socket (the deep socket is like a short extension;  knuckle saver)  and torque the bejezus out of the nuts.  All those little screws in the top of the rings have been torqued round-&-round and criss-cross until they are all as tight as my fingers and that supplied little 'L' wrench can make them.  Instructions that came with the mounts said to lightly finger-tight the nuts on the rail grip and be sure the mounts were facing the right way with the mounts both against the risers in the rail;  then tighten the top rings and finally be sure the mounts are firmly forward and torque the nuts.  I have removed and replaced the scope/mount assembly and the POA/POI stayed about the same (considering that the ammo used is constantly changing.  And no,  different ammo does not account for the big spreads on target).

I intend to try one more scope on this rifle to see if the second scope has problems.    This will be a new scope,  not one moved from another rifle.  There will be considerable time before it can be managed.  Once there is a new scope in place,  I will repeat this trial.

[techmike]

I know this is a new rifle, but have you checked that the barrel nut is tight?  Those groups resemble what my Garand used to produce when it had a very slightly loose gas cylinder.

[Dusty44]

I have done my best for the barrel nut.  I do not have the tools to do the proper tightening myself.  I bought the free float tube because I wanted to have it on the rifle and accelerated the purchase a lot so I could justify the cost of a gunsmith by having the new barrel nut installed (and hopefully properly tightened).  I requested the gunsmith personally  to tighten,  loosen and retighten the new nut.  He expressed reservations about the "thin aluminum."  He also said he usually torqued the nut to 35 foot-pounds.  Subsequently to having the tube installed,  I found a mention in a post on '308AR' that 50 foot-pounds may be optimum.  Something to request if there is a next time.  I am and was aware that the spec on these is 30 to 80 foot-pounds.  This nut is most likely properly tight and the barrel is properly seated.  It is still a possible until those holes in the targets get a lot more chummy?

I wonder if the glass inside the scope tube is loose.  I have two of these Nikon scopes and the other one is tight,  that rifle/scope (308 Win) makes excellent groups--  probably better than I am capable of supporting with my own abilities.  When I adjust the controls on that scope everything is very positive.  The scope now on the 5.56 AR seems always to need for the innards to drop into place--  like the Leopold that I dislike intensely and replaced on the relevant rifle.  I wonder if this Nikon on the 5.56 AR has always had a problem and perhaps that problem is getting progressively worse.  This possibility of internal glass moving seems consistent with the shooting result.  The rifle was laid down on its side after each 5-shot string for reloading the mag,  loose glass inside the scope tube could easily move around.  The few good groups might have had the glass shift during the next reload.  Perhaps even the spread of the rest shows the product of internal glass bouncing from recoil? 

Current plan is to try a new scope first,  because I can do it by myself.  If that does not fix the problem,  I will pay a different gunsmith to retighten the barrel nut and hope that will do the job.  Last possible,  if push comes to shove,  is a new premium Ranier heavier profile barrel.  And cross my fingers and burn a bunch of candles.

If a new scope does fix the problem,  the current Nikon will go back to the factory for evaluation.  Lifetime warranty,  then I will have an extra scope for back-up.  Or,  will feel the need to buy a new rifle to give it a home?  416 Rigby AR,  anyone?

[techmike]

Question, how did it shoot out of the box, with the original handguard and iron sights?

[Dusty44]

I cannot see for beans.  There is no point in me shooting without optics.  The rifle came with an integral rail and no iron sights.  Pics earlier in the thread show the rifle with the OEM handguard and the Nikon scope.  The targets in those pics are from the 'phase two' trials with the Nikon.

I do have the targets from the initial firing trials with the Pentax scope.  The spread of holes in the targets is similar.

[Dusty44]

Here we are in August.  New scope.  Cabela's did not have one in the store;  ordered it online on a Thursday;  it arrived direct from Vortex on the following Wednesday.

This scope is a Vortex Viper:  3 - 9 x 40 MM,  1 inch tube.  The scope mounts previously in use did well on the previous scope and would have worked with a 50 MM objective lens scope but were too tall for me to be comfortable for this new scope.  I replaced the Burris scope mounts with Warne Quick-Detachable scope mounts that are half as tall.

The reticle is a Vortex BDC.  It looks a lot like a Mil-Dot reticle.  I wanted a Mil-Dot;  I think this reticle will be OK.  The glass is spectacularly clear.  I bore-sighted the scope in my usual manner.  Balanced the upper on the kitchen table with BCG removed on top of a couple 12-packs of bottled water so I could see that chimney cap 4 houses down,  80 to 100 yards away.  The double stack of water cases keeps the bore and the scope above the cross-bar of the window.  On the rifles & scopes that have done well,  which is all the 308's and the 7 MM,  this has resulted in a 2 to 4 inch diff between the POA and the first POI,  less rather than more.  If you have been reading all the way through this thread,  you understand my attitude as I write this and my clenched teeth.

The Burris scope mounts needed a 1/2 inch socket wrench;  the new Warne QD scope mounts have finger levers.  Never mind that they lock up tight enough with fingers to easily justify a pair of pliers when releasing the scope:  it will be easier to de-mount the scope while cleaning the rifle (to protect the scope). 

Pics below:  DPMS Panther-Oracle 5.56x45;  mods are 12 inch DPMS slotted Free-Float tube,  Battle Arms Ambi Safety Selector,  CAA grip,  RRA NM trigger,  Vortex Viper 3-9x40MM scope in Warne Quick-Detachable mounts.

Range trip for live-fire tests as soon as I can manage it;  will post results.

As usual,  click on the pics to make them bigger.

[imschur]

crossing my fingers for you buddy  :thumb:

[wobblinwheel]

You might want to remove the flash-suppressor and check the "crown" on the muzzle. Any irregularities there can scatter your groups all over the place. Some of these guns are just being made too fast these days.

[Dusty44]

The flash suppressor mounting and the crown will get a close inspection and check if this newest scope does not fix things.  I am still considering a Ranier barrel.

[Dusty44]

Visited the shooting range last Thursday,  August 9,  2012.  Could not remember the date when I was marking the targets and put the 10th on the paper.  LOL.  Temperature,  officially,  was 100 F.  The sensor under the front bumper of the car said 109 F.  No apparent wind.  At the same time of day for the two days since,  the official temperature has been down to mid-90's.

Could not find my factory ammo from the last shooting session.  It turned up a day later and I will eventually repeat the sequence reported on July 01.  I had a box of reloads that I used instead.

The reloads are mixed brass accumulated from the previous range trips.  I eliminated the steel cases with a magnet.  I full-length resized in a Hornady die & Lee Hand Press.  The Hornady die decapper has a belling die which was too much for the hand press.  I decapped with a Lee Loader.  Very nice to have several systems to back each other up.  The Lee Loader is cheap,  easy to have available,  and will do it all very well if needed.  Except the Lee Loader is neck-size only;  but usually that is enough.

I do not so far clean my cases.  The case lube and handling do enough but I intend to buy an ultra-sonic case cleaner.  Eventually.  My fired cases are caught in my range box or picked up from the carpeted range bench or the concrete floor and do not get visibly dirty.

I had 179 fired cases to reload.  Decapped;  cleaned the primer pockets with a Lee tool and reamed them with a Lyman tool for trimming military brass primer crimps;  full-length resized;  primed all with WSR primers.  Then picked cases from the pile at random and loaded with three different bullets and three different powders.  Took 10 of each loading to the range.  Originally I had intended to fire the reloads after doing the factory ammo sequence.  At the range I realized the factory ammo was not in my ammo box but the reloads were there.  It was another case of my Angels watching over.  My body was having a bad day and the heat was tough.  It was hot enough that when the rifle was sitting idle,  bolt open and when needed for safety the yellow plastic flag in the chamber,  the rifle did not cool but kept getting hotter.  I was glad for every inch of the free-float tube.  It was uncomfortably warm all the way at the end,  too hot for shooting even trying to hold it in the middle.  Note that there is a full overhead canopy and the benches and shooting gear are all fully in shade.  The 30 rounds I had available to shoot were more than enough and already too many trips down the range to service targets.  There was also some Ruger 10-22 shooting,  posted elsewhere in this forum.

Target pics are below.  The new scope did well and validated my suspicions about the previous scopes.  Those scopes will go back for warranty review.

I used a Magpul 20-round clip intended for 5.56x45 cartridges.  I loaded 5 rounds at a time.

Target 1:  The loading was taken from an article in "Shooting Times."  Sierra MatchKing 69 gr  HPBT,  Ramshot TAC powder;  all loads done with a Hornady bullet seating die with the crimp backed out to not crimp. 

The boattails of all the bullets used slipped into the tops of the cases without any belling and seated properly and tightly.  I used a dial caliper to measure every round and did a little adjusting or removed and reseated the bullets for OAL plus or minus .003.  Powder charges are measured on a Lee beam scale so that powder weight is within,  generally,  two or three or so particles of powder. 

My loadings were the single charge weight in the magazine articles or 60-65% of the difference between minimum and maximum plus minimum.  That is,  for example,  if minimum with a given powder and bullet was 20.0 grains and maximum was 30.0 grains,  65% of the difference is 6.5 grains plus 20.0 grains giving a final loading weight of 26.5 grains.  This is a good conservative loading when working from formal published data.  It allows a slight margin for error in modern well-made guns in good condition.  My calculations are done with an inexpensive scientific electronic calculator (bubble pack at Wally World,  Target,  other places) to eliminate any brain glitches when doing the arithmetic.  The calculator will also do all the statistical gyrations for results or other data with no fuss,  no muss.

When I had 5 to 15 rounds loaded I used a second Lee Hand Press with a Lee Factory Crimp Die to crimp all cartridges after a final check for OAL with the caliper and some more adjusting for length.

Back to Target 1:  The first clip with the Sierra bullets was high.  I adjusted the vertical dial on the scope 'down' 10 clicks.  The second clip of 5 rounds did well.  The flier is me.  I did not change the scope settings beyond that for the rest of the day.

When shooting I was holding the rifle free of support,  on my hands and against my shoulder,  seated at the bench with my left wrist against sandbags and my right elbow on the bench.

Target 2:  The bullets are MidwayUSA Blems.  Origin unknown.  75 gr BT Poly Tips.  Dead ringers for Swift Scirocco's in a magazine article that had a loading I used.  OAL 2.270 with Varget powder.

I got two or three rounds to fire properly.  Then a misfire.  Dropped the clip,  waited 30 seconds and the round would not eject.  Several tries and then it just fell out unexpectedly.  No dimple in the primer.  Obviously failure to feed/seat properly and the bolt group not being in battery the hammer could not hit the firing pin properly so no big problem.  The bolt carrier is designed this way for safety.  Put the round back in the chamber by hand,  inserted clip.  Gun fired and double-fed jammed.  Finally got that clear and the remaining rounds fired.  Three holes in the target and all that struggling with the clip and double-feeds.  I have no idea.  Same problem with the second clip,  two holes in the target presumably from the first two cartridges that seemed to load and fire properly.  Then it was double-feeds and failures to eject.  I still have 40 rounds of this stuff.  I'm not going to buy a bolt or single-shot rifle just to see what the rest of these do.

Target 3:  After that struggle with the Poly Tips I took a break.  An entire cycle of range hot and safe.  Rifle placed securely,  bolt open,  yellow flag in chamber,  just backed off and rested and regrouped.  The rifle may have cooled a little but not enough to tell by touching it.  My body needed the break,  too.

Then there was the final two clips with Barnes Match Burners 69 gr HPBT.  Reloder 15.  Barnes website,  loading taken from TSX bullets of this weight.

After the chaos of Target 2,  I was expecting trouble.  It never happened.  Clips #5 and #6 went smooth as greased glass.  The spread of the holes in the target may be me or maybe I need a better loading for these bullets.  When I was loading,  I loaded the 50 casings that was my norm for that load session and then used up the left-over cases by loading these Barnes Bullets in them.  So I have ~70 rounds of this loading still to shoot.

Bottom line:  The newest scope seems to have fixed the accuracy problem.  I am thankful to whatever gods may be.

[techmike]

Looks good. Strange to have several scopes with the same issue...

[Dusty44]

After a few days,  there are some general things that might be mentioned:

Scopes do get fried sometimes.  I read a sad story yesterday in a magazine about a hunter on African Safari.  All that money,  all that time and effort,  in Africa time was pressed by late-arriving luggage.  Basically,  he grabbed the scoped rifle out of the shipping container and jumped on a jeep to go out to the hunting area.  Prime Trophy game animal,  pulled the trigger and the bullet hit the rocks a hundred feet off target.  Fried scope from shipping & handling.  No back-up scope on that trip.  Lessons about being prepared.  Lessons about the delicacy of even the best and most expensive scopes.  In this thread it is easy to relate!!

Targets #2 and #3,  above,  Post of August 11,  show the effects of not having a fast enough twist to properly stabilize long bullets. 

Target #2,  heavy BT bullets with a long ogive and long poly tips,  jammed into the powder in the case and still sticking out to the absolute limit (and beyond by a few thousandths) of the design of the  magazine and action to handle them,  I could see the puff of dirt/dust when they hit the berm behind the target,  but as is apparent some were not stabilized well enough to even hit the paper.  The spread between POA and POI for the ones that did leave holes in the target is pathetic. 

The same is true of Target #3 with the Barnes bullets except the Barnes bullets are not so seriously extended in length and they did work in the 1 - 9 twist,  sort of.

There are two cures.  One is to stay with shorter bullets.  The Sierra's did well and I will load more of them for this rifle.  Barnes bullets that are lighter & shorter should do well,  also.  The second cure is to acquire a barrel with a faster twist,  necessarily a 1 - 7 twist.

Loading lighter and shorter bullets is easy.  Also the cheapest way.  But when we have the affliction .  .  .    .

I have begun researching a 1 - 7 twist barrel.  Decisions,  choices,  decisions . .  .  this itch goes on forever!

Replace the barrel?  Buy?---  or build?---  a new upper with a faster twist barrel?  Buy a complete rifle (and modify it to my preferred configuration)?  DIIK.  It will not be long,  but let's all call this thread a wrap and perhaps make whatever I do next with this rifle a new topic?  Thank You to all readers for hanging in with my verbosity!!

[Dusty44]

Postscript:

Look under 'Rifles,'  "Collecting Parts"  for the next phase of this saga.

My target pics are posted so that real results can be seen.  I am not a very good shooter,  hopefully somewhere within 'passable shooting.'  But,  other than those superlative results of top-end competition shooters,  rifles in the best machine rests,  and Hollywood Special Effects,  there are no shooting results on the internet.  Not that I have been able to find.  Post your targets.  Don't be embarrassed:  your actual results are just like everybody else's.  We all need some comparisons.  Some reality.

My posted pics,  from my cell phone camera or a digital camera, use the MS-7 Picture Editor and Paint.net (free download from the internet).  In the Picture Editor,  first I crop,  then do the automatic lighting adjust,  then resize some.  I work with copies of copies of copies so I can go back if needed.  I keep all this in a working folder.  I delete enough to keep it all manageable.  I use short titles to keep me on track.  I use Paint.net to resize more and to put text on the pics.  The finished pic is 'Attached' to the post.  Try it!! Post pics of your guns and target results!

[techmike]

This has been a great thread to watch unfold - thanks for sharing. I am pretty new to the black rifle, I traded a Garand for my first AR about 2 years ago. By far the biggest improvement in repeatable accuracy for me was ammunition. I initially purchased 800 rounds of Tula factory ammo. Teflon coated, steel-cased 55gr stuff. It was cheap and worked just fine during my learning curve with a new rifle. Then a friend and I split 1000 rnds of commercial reloads - 62 gr bullets, and wow. What a difference. The two targets were fired on the same day, all conditions the same, just different ammunition. The one flyer on target#2 was all me, tried holding the rifle differently.

[Dusty44]

I do not know where the rest of this thread may be. 

Here are some promised pics of targets.  These are from the last trips to the range and compare different ammo and a comparison between the modified factory upper and the upper I built.  I would like to think that the Ranier barrel does better,  but it is in doubt.  All shooting is hand-held with the butt against my shoulder.  There are sandbags and sometimes my wrist rested on them and sometimes the rifle rested on them.  This would vary from one target to another.  Shooting at a given target was done in the same manner.

Some days the sand in the bags was too hard,  sometimes it was fine.  Depended on the humidity,  apparently,  and if the sandbags had been rained on.

These are standard targets with 1 inch grid and rings.  The orange disks are stick-on 1 inch diameter.