AR Positional POI Shift Test
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I meant HOW its torqued on. I don't see any external screws or something with the photos I've seen.
These shipped with the megalithic uppers and could be purchased separately for a while.
I’d assume the ICON uppers will use something similar.
The MML, Semi monolithic, upper has a hole underneath to verify that the barrel is fully seated.
I can get you a picture this evening if you’d like.
For my upper with URX4 I see 0.5mil shift going from bipod to barricade.
I'm working on it brother, I'll get to it
The JP and the RD are competing for a spot in my home. Help me decide
I'll do my best..lol
I would do a Seekins before both and save the extra money for a Bartlien cut by cradock to replace the barrel when you shoot it out
Wonder how the poi poa shift compares.
You have the fat handguard with non integrated arca too for better or worse
I will try to test my RD15 from a tripod for the group. I find found that even an ATX chassis for an R700 from a tripod had a .3 mil shift low at 100yds compared to front bipod and rear bag.
I shot a positional test with 6br in a ATX chassis about 3 months ago just to compare against ARs. Long bipod, near bipod and then off of a bag on a barricade. Essentially no change to POI. The group off the bag showed potential to possibly be a little bit lower but it was less than .1mrad
My unscientific poi shift test results with the SPRecce. 16" WOA, Vltor MUR1a, MI NF 13.5" rail. About .1 mil difference but I can't say thats not totally me, I need to work on it for sure.
Interesting. I had a .3 Mrad shift down with a 223ai Stiller in an ATX chassis regardless of whether I clipped into arca or ran a bag on the chassis.
I haven't put the RD15 on paper yet but my dial was spot on for a 450yd 1/3 IPSC steel target and a thermal clip on last month. Or at least within .1 mil.
I tested my LWRC mlok version yesterday. Saw about .2 mil shift (low) going to a bag after zeroing with a bipod.
Thanks
Little late to this thread but I’ve done this testing before. For me personally, I have a higher POI from bipod and rear bag than off a single bag, like many people here.
However I’ve determined my issue to be dropping pressure on rear bag during the shot, causing rifle to tip up. I came to this conclusion after adding a bag rider to my setups significantly reduced the shifts.
With a bag rider I get approximately .1 mil shift with almost all my rifles:
Bolt gun in MPA
AI AT-x
LRI-20 x2
Mega MML
URX4
Without a bag rider, I get a .3mil shift with below:
LRI-20
Mega MML
BCM rail
I currently have 2 LRI-20s and the one with the bag rider has significantly less shift.
I also tend to shoot significantly more accurately (precisely) off a bag and barricade than prone which leads me to believe my issue is my prone skills. I tend to zero off a bag due to the number of bag shots vs prone shots at matches.
I will be shooting Gas Gun in pro series again this year and will take note of my results. May even test this out today.
However I’ve determined my issue to be dropping pressure on rear bag during the shot, causing rifle to tip up. I came to this conclusion after adding a bag rider to my setups significantly reduced the shifts.
With a bag rider I get approximately .1 mil shift with almost all my rifles:
Bolt gun in MPA
AI AT-x
LRI-20 x2
Mega MML
URX4
Without a bag rider, I get a .3mil shift with below:
LRI-20
Mega MML
BCM rail
I currently have 2 LRI-20s and the one with the bag rider has significantly less shift.
I also tend to shoot significantly more accurately (precisely) off a bag and barricade than prone which leads me to believe my issue is my prone skills. I tend to zero off a bag due to the number of bag shots vs prone shots at matches.
I will be shooting Gas Gun in pro series again this year and will take note of my results. May even test this out today.
That's super interesting - my first thought is that I would try swapping the LRI20 uppers and lowers to isolate if there's anything different about upper receiver to barrel fit.
All my shifts have been recorded using a pint size GC with git lite fill and a magpul CTR.
I have noticed that with an angled stock you have to be better with the rear bag than with a straight stock/bag rider. Probably never quite equal the straight stock on raw accuracy/precision…I mean, that’s why the bench rest guys use straight (or straight-ish) stocks.
Advantage with the angled stock is that you can change elevation with the rear bag waaaay quicker. At least that’s my experience, but I’m no high-speed sort of dude.
4 pages later and someone has finally acknowledged that positions change impact, I'm glad we finally made it there. Kudos to you for doing the testing to prove this to yourself and documenting it.
The mechanics of a rifle firing have been documented for a long time; the rifle starts recoiling before the bullet is out. An unsupported rear stock can OF COURSE change the POI. A modification in the support of the rifle can OF COURSE change the POI.
Who knows how much of this entire thread and the subsequent 'data' is real or shooter-induced. Everyone went down the rabbit hole and forgot to come up for air.
EDIT: My mistake. The effect of NPOA / support was litigated to death in another thread with most of the same participants
One more point.
Shoot rifle A prone and off a barricade. See 0.4mil shift.
Shoot rifle B prone and off barricade (same shooter and technique as before, for the sake of argument also assume the stock is the same). See 0.1 mil shift.
Tell me that it's still support/NPOA and not at all affected by the actual rifle.
Shoot rifle A prone and off a barricade. See 0.4mil shift.
Shoot rifle B prone and off barricade (same shooter and technique as before, for the sake of argument also assume the stock is the same). See 0.1 mil shift.
Tell me that it's still support/NPOA and not at all affected by the actual rifle.
I definitely need to do more testing, but reading this thread got me curious. I shot my LMT MRP tonight from a bag and also from a bipod extended all the way out on the rail. I did get two nice tight groups, but with a bipod the group dropped .1 mil and shifted .1 mil left.
Barrel is a Bartlein conversion, it's now a very accurate rifle. I went with LMT partially because of the minimal POI shift, along with the ability to change barrels quickly and easily.
I'll test this more this weekend and follow up with some photos
Barrel is a Bartlein conversion, it's now a very accurate rifle. I went with LMT partially because of the minimal POI shift, along with the ability to change barrels quickly and easily.
I'll test this more this weekend and follow up with some photos
This reflects my personal testing as well at .4 and .2 shift.
Is it the rifle? Is it the shooter? Most likely, yes.
My 18" KAC LPR Mod 2 upper with 15" URX4 mlok, with Area419 arcalock rail, OCL OCM5 can, shows at 100y
.30 mil shift down from bipod far to bipod middle
.44 mil shift down from bipod far to bipod near
.41 mil shift down from bipod far to bag near
I zero off my bipod far so that's why I keep that as my reference point.
I will try my 18" Centurion MK12 barrel with 15" CMT HDM handguard with Area419 arca lock rail this weekend maybe.
.30 mil shift down from bipod far to bipod middle
.44 mil shift down from bipod far to bipod near
.41 mil shift down from bipod far to bag near
I zero off my bipod far so that's why I keep that as my reference point.
I will try my 18" Centurion MK12 barrel with 15" CMT HDM handguard with Area419 arca lock rail this weekend maybe.
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I tested the following for this yesterday:
DDM4V7
LPR
LMT MRP
Larue Stealth
Springfield ATC
Cobalt BAMF
SOLGW
DD5V3
Aero Enhanced
MCX Virtus
LWRC IC DI
and a normal BCM as a baseline
No major surprises. I’ll post the full write up here when I put the data together.
DDM4V7
LPR
LMT MRP
Larue Stealth
Springfield ATC
Cobalt BAMF
SOLGW
DD5V3
Aero Enhanced
MCX Virtus
LWRC IC DI
and a normal BCM as a baseline
No major surprises. I’ll post the full write up here when I put the data together.
First dot is prone. Second is prone with a heavy pre-load on the bipod. Third dot is standing off a single bag on a barricade.
100y, 5 shots each except I think the DD .308 a couple were 4. I have a number of concerns regarding the validity of these results that I'll express a bit more in a video later so for now here are the results for your own consideration.
I'm dyslexic as hell and rounded the conversions so if I'm way off anywhere let me know so I can fix it.
The BCM was an 18" barrel in a standard BCM upper with a Geissele Mk18 ARCA rail.
100y, 5 shots each except I think the DD .308 a couple were 4. I have a number of concerns regarding the validity of these results that I'll express a bit more in a video later so for now here are the results for your own consideration.
I'm dyslexic as hell and rounded the conversions so if I'm way off anywhere let me know so I can fix it.
The BCM was an 18" barrel in a standard BCM upper with a Geissele Mk18 ARCA rail.
I thought making composites to see how these would be expressed as 15 round groups would be interesting.
Was the Larue the original "Stealth" hand guard that can fit a conventional upper or the Stealth "2.0" proprietary billet upper+hand guard combo?
I've been really impressed with both of my LWRC DI's.
I bought them to be cheap ammo blasters but the 16" is very accurate, is Okay.. 1 MOA-ish.
I just had a custom Barrel nut Wrench made so I can swap barrels up to 1"
If anyone has ever used the LWRC Barrel nut Wrench you know that it is specifically contoured for the LWRC barrels only..
Thinking of swapping barrels in my 10.5" LWRC with a 11.5" 22 ARC
I also got the load development done for the JP SCI-20 so I'll finally be able to contribute to this thread.
For the POI shift I've got 3 rifles I want to test.
Larue OBR / 14.5" 6 ARC
JP SCI-20 / 22" Kreiger .223
Mega Monolithic / 20" Bartlein .223
For the POI shift I've got 3 rifles I want to test.
Larue OBR / 14.5" 6 ARC
JP SCI-20 / 22" Kreiger .223
Mega Monolithic / 20" Bartlein .223
Someone test the Vltor.
i might have to break down and do it myself on a good shooting day
i might have to break down and do it myself on a good shooting day
LWRC Barrel Nut Wrench $145, Custom work $50, shipping $25... Having the ability to run any Barrel in my LWRC's....Priceless
Have you heard anything on when they will? I emailed them a few weeks back and they said it was in the works but no ETA. Impatiently waiting on these or the new Icon monos for a 6arc build
I’ve called and emailed they are probably getting annoyed. They say working on it. Later this year. No firm date.
Gonna snag a ridgeline striped upper if they ever come out. For a 350 build
In case anyone else didn’t know about them
www.snipershide.com
Monolithic uppers coming from Icon Defense (former Mega Arms guys)
Came across an MSM video from Triggrcon with Killer Innovations/Icon Defense talking about their upcoming monolithic uppers. Mono upper info starts at 4:37
www.snipershide.com
