20 Practical AR Project [Archive]

Recko555

06-22-2009, 03:24 AM

I have been waiting to start this thread since I joined the forums, but wanted to have more of it to show before I did and now I do.

First off, specs of the gun I am building. It is going to be a 20 Practical in an AR platform. This is my first project rifle.

The barrel is going to be a 24" Pac-Nor 1:10 twist coming from WOA. I was going to order just the barrel from WOA, but then decided to let them do the whole complete upper. (I was going to buy all the parts from them anyway and thought it would be just as easy). The only thing is there is a LONG wait time. I was told 16-20 weeks. I placed the order for the upper on April 20, I am about half way.

The lower started out as a stripped lower from Rock River Arms (purchased that from a local dealer). I then quickly proceeded to order the rest of the parts necessary to complete the lower half from WOA.
A2 Butt stock Assembly
Lower Parts Kit
Trigger (I was going to go with a tuned 2 stage Rock River, but couldn't get one anywhere. So I went big and bought a Geissele trigger.)

As for sights, I am going to use a 10 MOA extend scope rail that goes underneath an Armalite 1 piece rings that is going to be holding a Sightron III.

Recko555

06-22-2009, 03:48 AM

I ordered the lower parts kit, A2 butt stock assembly, and trigger about a month ago and received the lower parts kit and A2 stock last Thursday. About 2 hours later, I had it together. It was super straight forward and easy to do even though it was my first time putting an AR lower together.

I should of took some assembly pictures, but totally forgot to (I think I was too excited). All I have are beginning and final assembly pictures. I also took some close ups of the color fill I did on the safety.

(Figured out Posting)

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/th_strippedlower-1.jpg (http://s835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/?action=view&current=strippedlower-1.jpg)

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/Lower001.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/Lower003.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/Lower002.jpg

rbeckwith

06-22-2009, 08:22 PM

There was a great article about building and shooting the AR in 20 Practical...you could probably find it in their archive if you were interested in reading it.

Recko555

06-22-2009, 10:34 PM

There was a great article about building and shooting the AR in 20 Practical...you could probably find it in their archive if you were interested in reading it.

Who's article? I know there are a couple on 6mmbr. Let me know.

trappst

06-23-2009, 02:51 AM

Recko555

06-23-2009, 09:58 PM

New guy here but have had a 20 Practical AR for a little while now. Mine has a 18" Shilen 1:9 twist barrel with a rifle length gas system.

So far, I've shot 35g Bergers with H4198 and 50g Bergers with BL-C(2). The 35's don't create enough port pressure but the 50's do just fine. I have rounds loaded with the 35's and H4895.....just gotta find time to shoot!

I've really been wanting to try some Vhit N133 but I'm having hard time finding it locally.

It's a fun little round. I just need to find that powder/bullet combo that my gas system will like.

Did you put the upper together yourself or did you have someone put it together for you? When you say gas system, do you mean a piston system (piston pushes on rod and rod pushes on bolt)?

For reloading, do you use a 223 seating die or do you use a 204 seating die?
How long do you seat the bullets? Mag length?
Sorry for all the questions (probably will have more later though).

trappst

06-23-2009, 10:48 PM

A good friend of mine put the rifle together for me.....I don't have the tools and I'm more of a Savage guy. Anyway, I had Shilen make the barrel for my bolt and I sent them a dummy round to ensure the throat was correct.

Gas system - meaning the gas tube, gas block, etc. Mine is a rifle length system meaning there is very little barrel after the gas port due to the 18" barrel length. check out ar15.com for a full explanation of the AR gas system. I'm by no means an expert!

I use Redding 223 rem competition dies to reload the 20 Practical. I already had them so it was a no brainer. The sizing die works fine with the appropriate bushing but I did add a carbide expander kit from Sinclair. By doing that, I'm able to iron out any neck issues (dents, etc.) in one pass. I was doing it in another step.........body die takes care of any shoulder bump when needed.

For initial testing, I seated bullets .020" off the lands although at the lands still fits the mags even with the 50g Berger.

Here she is: (currently wearing a different scope)

http://img.photobucket.com/albums/v284/trappst/th_20PTAR004.jpg (http://smg.photobucket.com/albums/v284/trappst/?action=view&current=20PTAR004.jpg)

Recko555

06-24-2009, 02:16 AM

That is a nice looking rifle. What scope is in the picture and what did you switch too?

trappst

06-24-2009, 03:49 PM

scope in pic is a Nikon Buckmaster 4.5-14 she's now wearing an older Burrs FFII 3.5-10x50 with a lighted recticle. I'm hoping to do some night coyote calling this coming winter and wanted the lighted reticle if needed.

charles in Va.

07-04-2009, 03:12 PM

I believe you will love that AR ! I got on the 20 bandwagon early and have mine in the 20 TAC (driver). Insight Shooting Systems in Colo. built my upper. I just put a fantastic scope on it and went out and shot a .243 ,five shot group ! The scope is a Vortex Viper 6.5 x 20. I had a Leupold 6.5 x 20 VX 111 and the Vortex is far superior to it ! Both have 30mm tubes and side parallex adj. Go to Camera Land (in New York) to their sports optics dept. to buy one. The price is cheap compared to the quality !
Anyway, Have a great time building yours and you'll love smacking P.D.s and yotes with the 39 gr. Sierra. Personally, I would have gone with either a 12 or even 11 twist; not sure why you opted for the 10 so I'm not being critical of your choice. I can shoot 40s with the 12 and am building another upper with 11 twist for 45s. In a PD town, the AR in 20 rules ! Charles

savage204

07-04-2009, 07:20 PM

Hi first post,would like to build a 20 practical ar would WOA :confused:be white oak armanment thanks for the help.:D

Recko555

07-05-2009, 03:57 AM

Hi first post,would like to build a 20 practical ar would WOA :confused:be white oak armanment thanks for the help.:D

Yes you are correct. WOA = White Oak Armament

savage204

07-05-2009, 04:06 AM

Thank you for your help:):):)

Recko555

07-07-2009, 12:12 AM

Small update on the project.

I picked up some powder, bullets, primers (luckily), and received the extended scope rail.
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/IMG_2015.jpg

larryinIA

07-07-2009, 02:08 AM

When will the rifle be done? We gotta get out and shoot!

Dennis_in_VA

07-07-2009, 08:11 PM

Hey Recko, where did you get the scope rail?

You say it has 10 MOA?

Can you post pictures of both sides and bottom of the rail?

I want to see how it mounts.

I am building a 20 Practical AR myself.

Pictures to follow as soon as I get things to take pictures of.

Thanks,
Dennis

Recko555

07-08-2009, 12:45 AM

The rifle should be done around the beginning to middle of August. It sure does seem like a long time from now.

Dennis,
I got the extended scope rail from WOA (http://www.whiteoakarmament.com/) for $85. It is in their downloadedable pdf catalog (download link is on the main page).
Yes, they offer two types of extended scope rail, 10MOA and 20MOA (even though the catalog only says they have a 15 MOA). Which means that the scope rail has 10 or 20 mintues of angle machine/built into the rail. This helps if your scope doesn't have enough adjustment to hit the Pdog that is WAY out there. (Pretty much there is a slant on the scope rail)
Here are the pictures you requested.

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/ExtendedScopeRail003.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/ExtendedScopeRail002.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/ExtendedScopeRail001.jpg

Yotecallr

07-08-2009, 02:25 AM

So where in Iowa did you find primers?

Recko555

07-08-2009, 03:08 AM

A buddy's friend had some extras. He didn't even gouge me either.

Dennis_in_VA

07-08-2009, 03:16 AM

Thanks for the pictures.

Is that thing made of steel?

I had thought about getting one from EGW (20 MOA) but I bought a GGG scout rail (0 MOA) that Robert Whitley recommends.
I still might get a 20 MOA rail after I get some trigger time.

My build is this:

20 Practical upper from AR-X (24" PacNor super match 1-11" barrel) with billet receiver upgrade

Billet lower from APA with a RRA LPK and a Geissele trigger

Magpul PRS Gen II stock

Ergogrip Tactical Deluxe Suregrip

GGG GS-1 Scope Rail

Nightforce 5.5-22X50 NP-R1

Nightforce UL rings

Harris 9-13 swivel / notch leg w/ Pod Lock

I can't wait to get this thing rockin'.

I will have everything except the upper by the end of next week.

Recko555

07-08-2009, 12:03 PM

Sounds like a sweet rifle. When will the upper be completed?

Dennis_in_VA

07-09-2009, 05:21 AM

According to what I was told.... about 8 weeks.

The Lower should be in my hands by the end of next week.

Like I said.... I will post pic's as I progress with this project.

Forming the brass is simple childs play....

I will keep y'all posted.

Recko555

07-16-2009, 10:50 PM

Received the GA match trigger yesterday. Got it installed with some pictures. The trigger comes with tools and great instructions. +1 for Geissele!

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/GAMatchTrigger001.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/GAMatchTrigger003.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/GAMatchTrigger004.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/GAMatchTrigger006.jpg

Recko555

07-16-2009, 10:50 PM

Another picture.

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/GAMatchTrigger007.jpg

Yotecallr

07-17-2009, 02:23 AM

This should be one quality rifle when it's completed. You have good components.

Recko555

07-20-2009, 05:41 PM

Thanks yotecallr.

I received this over the weekend. It is made by Armalite, 1 piece 30mm scope rings.

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/1piecescoperings002.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/1piecescoperings003.jpg

Dennis_in_VA

07-22-2009, 11:12 PM

I finally got all of the parts together for my 20 Practical AR.

The Trigger is AWESOME. I have never had a 2 stage trigger before.

I can't wait until tomorrow to go put some lead down the barrel.

I had to borrow the scope off of my Rem 700 for the photo OP but it is what will end up on the 20.

http://i31.photobucket.com/albums/c385/Dennis_in_VA/VARMINTS%20STUFF/P7220814.jpg

http://i31.photobucket.com/albums/c385/Dennis_in_VA/VARMINTS%20STUFF/P7220816.jpg

http://i31.photobucket.com/albums/c385/Dennis_in_VA/VARMINTS%20STUFF/P7220811.jpg

http://i31.photobucket.com/albums/c385/Dennis_in_VA/VARMINTS%20STUFF/P7220804.jpg

Recko555

07-23-2009, 12:36 AM

Nice rifle. I was expecting you to have the upper so soon. I though it was like 5-6 weeks out still.
Where did you get the float tube?

Recko555

07-23-2009, 12:54 AM

I bought a bore guide that I thought had a solvent port, but when I received it, no port. So I went back and looked at what I ordered. Sure enough, I ordered one without a solvent port. Well I didn't want to return it and get the right one, so I had a friend mill out a solvent port on his mini CNC. The port could be a little wider, but he didn't have the exact size bit I was looking for. It came out really nice.

Before......
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/boreguide001.jpg

After......
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/boreguide002.jpg

Dennis_in_VA

07-23-2009, 01:55 AM

The Tube came with the Upper.

This is his vented version that is an upgrade, which I got FOC because he was out of the standard / non vented version.

That Geissele Trigger is the HEAT.

I got mine from Rainier because he includes the springs to convert the Trigger to either one of the three versions.

I got a Dewey Stainless Rod and a Sinclair Bore Guide / Link kit and I ordered a solvent port as well.
Come to find out that the Guide had a solvent port in it and the extra add on solvent port wont even fit this guide.

I will post up my findings ( velocity & targets) after I take this rifle out and shoot it.

I am going to test H335 + 39 gr Blitzkings + CCI BR4 / Rem 7 1/2 / Fed 205 Match.

Oleman

07-23-2009, 02:37 AM

My guess is you will do much better with 10X or N133.

Dennis_in_VA

07-23-2009, 05:47 AM

I don't have either of those powders.

I am running what I have.

Robert Whitley said that H335 was one of the powders to use, N133 was the other. http://www.6mmar.com/20_Practical.html Scroll down the page.

I really need some primers most of all.
I'm low on 7 1/2 and BR-4 ( got less than 200 each ).

Jay T.

07-23-2009, 11:17 PM

That is a very nice rifle. Nice choice in components. Well put together gun all the way around.

Jay T.

vmthtr in Green Bay

07-24-2009, 02:02 AM

I bought a bore guide that I thought had a solvent port, but when I received it, no port. So I went back and looked at what I ordered. Sure enough, I ordered one without a solvent port. Well I didn't want to return it and get the right one, so I had a friend mill out a solvent port on his mini CNC. The port could be a little wider, but he didn't have the exact size bit I was looking for. It came out really nice.
<SNIP>

After......
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/boreguide002.jpg

How are you gonna use that, won't it be in the action?

Mike

Dennis_in_VA

07-24-2009, 03:22 AM

The solvent port will be oriented so that it will be accessible thru the ejection port.

Recko555

07-24-2009, 03:26 AM

You take out the bolt carrier assembly and then instert the bore quide. The solvent port is located where the ejection port is.
http://www.tactical-life.com/online/wp-content/uploads/2009/03/221-resized-2.jpg

vmthtr in Green Bay

07-24-2009, 03:30 AM

Gotcha.

Mike

Dennis_in_VA

07-29-2009, 01:40 AM

Well I am posting pictures of the Load Data as promised.

I am going with H335 + 205M + 39 gr Blitzking for now.

That 3695 fps was an average of the three shots in that group.

The rifle will do it's part if I steer it correctly and feed it what it likes.

http://i31.photobucket.com/albums/c385/Dennis_in_VA/VARMINTS%20STUFF/P7280827.jpg

http://i31.photobucket.com/albums/c385/Dennis_in_VA/VARMINTS%20STUFF/P7280825.jpg

Silverfox

07-29-2009, 03:39 AM

WOW!!! That is one fine looking firearm!!! Those groups look fantastic too. I wonder if you tweak your loads a bit if they'll get better, but even if they don't you have one fine shooter there.

Dennis_in_VA

07-29-2009, 03:56 AM

I am seating the bullets out about as far as I can ( mag fed ) .

I guess I could seat .010" deeper to see what happens.

Maybe even try .2 gr on either side as well.

Gotta love science / statistics .

I am gunna run with what I got right now.

The loads are on the WARM side, so don't use my data w/o backing down 10% first.

I will post up some carnage later this week if I get to go Ground Hoggin' .

Dennis_in_VA

08-03-2009, 12:12 AM

Field Report....

Friday...
I took my rifle out to Roanoke Rifle to check my loads at 500 yards and check my drop chart.

I was busting Clays consistently at 500 yards.

I was shooting from a Bipod and a rear bag.

Saturday...
Took out the 20 Practical today for it's first hunt.

I double checked my dope and zero which was set at 200 yards.

I fired a three shot group at 200 yards that had all three shots making a nice little cloverleaf with all shots cutting each other.

I dialed in some elevation to check my drop chart and dialed back to my zero and fired three more shots at the center of my clover leaf.

Two of the shots went into the group just slightly enlarging it and the third shot got blown out by and undetected blast of wind down range.

The group was still under 3/4 MOA. The main cluster would have been hidden under a dime!

Some observations...

I had the GG&G 20 MOA rail on my rifle along with a Leupold 6.5-20 (1" tube) riding in a set of MarkIV rings I had laying around. Well the 20 MOA induced by the rail cause some binding of the windage adjustments so I removed the rail and reinstalled the scope. The binding disappeared after making the needed adjustments to put me back on target.

I had also bought one of those hard plastic brass catchers. It is a nice set up but the mouth of the cases get beat up some. I am going to have to stick a pencil or something in the mouth of the case to round it out so that I can size it. I am going to look at a different catcher.... one that will be easier on my brass.

The Groundhogs were not very cooperative / plentiful today. We only had 7 or 8 opportunities between the two of us and we had several rifles that we wanted to shoot today.
I hit a Groundhog at 465 yards but it made it to the Den ( he was a foot from the Den, so diving in was easily done) and there was no blood. I assume that the little 39 grain Blitzking would have not made an exit with a solid body hit.

I will be putting a Nightforce on this rifle as soon as my wallet allows me to.
(I know the posted picture of the rifle shows a Nightforce but it was borrowed from my other Groundhog rifle for the photo).
Having the NP-R1 Reticle sure helps out when you need to hold off for varying wind conditions and when spotting your shots and making corrections.

Overall I feel that this Rifle is a very capable 400 yard Groundhog Rifle with rapid follow up shot capability.

I will need some more kill shots to evaluate the performance level of the 39 grain Blitzking though.

I might even try out some Berger 40 grainers while I'm at it.

BTW, I am sorry for HIJACKING this thread.

Recko555

08-10-2009, 05:18 PM

Just a quick update.
Today is exactly 16 weeks since I ordered it. WOA said it would be between 16-20 weeks, which was before he ordered a different chamber print and had to have it modified. Time will tell.

Recko555

08-26-2009, 01:58 AM

Update..............
No upper yet. :(

Recko555

09-09-2009, 01:32 AM

I received the scope today. Can't wait to mount it on the upper (which I don't have yet).

Sightron SIII 6-24x50 Mil-dot

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/SIII001.jpg

Mil-dot
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/SIII003.jpg

Recko555

09-09-2009, 10:45 PM

Talked to WOA today about my upper. They told me they were just starting April orders. They said it shouldn't be more than 4 more weeks. :eek:

Recko555

09-22-2009, 10:42 PM

Just received email that my upper has shipped, will post pictures in a few days. Woo-hoo!

I also switched my Armalite 1 piece mount to a Larue mount. Will post pictures soon.

Recko555

09-24-2009, 11:16 PM

I received my upper today. What a thrill! Here are some pictures. Hopefully I can get the barrel broken in this weekend, so I can do some shooting soon.
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/20PracticalUpper002.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/20PracticalUpper003.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/20PracticalUpper006.jpg

http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/20PracticalUpper008.jpg
With the larue scope mount attached.

larryinIA

09-25-2009, 12:11 AM

It looks great! Make sure you let us know how it shoots. Make sure you break it in properly.

Give me a call, will see if we can manage to get to the range, and shoot up some lowly paper. I got a couple for you to try.

3 weeks til crow season opens! (still can't believe we have a stupid season on those garbage eatin sky carp)

Recko555

09-25-2009, 05:25 PM

Sounds good Larry. I am measuring OAL right now and I am still waiting for the scope to be delieveried again (long story, sent it back for cleaning). It should get here Monday.

Recko555

10-28-2009, 02:47 AM

Small update on my 20 Practical...
I have been trying H4198 and 39gr Sierra BKs and couldn't get it to group quite right and feed right in my AR. I switched to 40gr Bergers and H335 powder and had great grouping results and didn't have any feeding problems either (I think H4198 is too fast a burning powder for my application). I think if I put some H335 behind the 39gr BKs I would have similar results too. Here is the ladder test I did the other day.

All groups are five shot groups shot off a bipod and rear bag at 100 yards.

25.0 grains H335 w/40gr Berger - Upper right shot was third shot out of cleaned barrel. Looks like I need to shoot 3 foulers, hehe. .650" group.
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/BergerShooting10-26-09002.jpg

25.5 grains H335 w/40gr Berger - Don't know what happened here. Definitely think it was me. .696" group
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/BergerShooting10-26-09.jpg

26.0 grains H335 w/40gr Berger - Good group. .323" group
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/BergerShooting10-26-09003.jpg

26.5 grains H335 w/40gr Berger...I called the high and low shot on this target. .498" group
http://i835.photobucket.com/albums/zz275/Recko555/20%20Practical%20AR/BergerShooting10-26-09004.jpg

I am happy with the results especially when I don't think of myself as a great shot, but an okay shooter (trying to practice a lot more to get better). All the different charge weights had a similar point of impact. I know the gun can shoot, I just have to do my part.

minengr

10-30-2009, 03:50 PM

John builds a nice upper. I've got one, it was his first, in .17 Remington and it shoots lights out.

sshcoyote

10-31-2009, 06:40 AM

Interesting stuff on the AR projects here. I also have an AR by ISSI here in Pueblo, CO. It's a 223AI with a 1"9 Hart 26" upper. I was trying to maximize the ranging potential for this rig on coyotes, so i tried the 65 JLK Low Drag with a BC of .4. Of course this bullet was too long for my magazine so i got ahold of a couple of the old DPMS VLD magazines that allows for about .25" more length, by single stacking and sliding the base of the case back into the magazine guide ridge. Works great with a little spring work and adjusting the feed lips on the magazines. I ran the ballistics of the 20 cal. 40's (3800)against the 65 JLK @ 3050 mv and here's what i came up with--

bullet drop/wind/vel/energy (250 zero)

20/40's---22/65

300-2.5/8/2673/634--3.5/7/2364/807
400-11/15/2351/491--15/13/2156/671
500-26/26/2052/374--35/22/1958/553
600-50/39/1777/280--63/33/1772/453

well...? Wind just barely favors the big 22 with energy way up there, elevation and velocity is big in favor of the 20.

Be interesting to see what the 55 Berger would do out of the 20 Practical using the DPMS VLD magazine (if needed-i don't know). I wonder what kinduv velocities you'd get with it?

Recko555

11-01-2009, 01:39 AM

Steve,
I am interested in the magazines you are talking about and the modifications. Where can I find more information on this?
I wouldn't mind trying the 55 Bergers, but have no clue on what speeds I would be getting or what powder charge to start with.
I have never heard of that type of bullet before. It has one great BC, that is for sure.

sshcoyote

11-01-2009, 08:48 AM

Recko, the problem is that the guy that used to make the VLD magazines for DPMS is dead, and nobody's picked it up since then. They r available here and there on the Internet,etc. but u just have to get lucky finding 1. I have an extra, but it also requires a special bolt stop, that i may be able to lend to u after i get mine back from my buddy. I will post some pics today sometime after i sleep (graveyard shift, u know).

U know if u could run those at 3400 out of that AR u could very likely have one of the best 0-500 yd. AR-15 varmint cartridges going. I'll run the #'s.

Alright here it is, once again at SAP sea level, 225 zero--

300-2.8/6.5/2627/843
400-12/12/2396/700
500-27.8/19.7/2175/578
600-51/30/1967/472

Lord--look at the windage and velocity figures @ 500 and 600.

sshcoyote

11-01-2009, 11:32 PM

Alright here it is. Should be self-explanatory--
http://i157.photobucket.com/albums/t49/sscoyote1/DPMSVLDmagazine.jpg

and here's the 65 Low Drag relative to the 60 V-Max--
http://i157.photobucket.com/albums/t49/sscoyote1/IMG_0751.jpg

Now the 55 gr. Berger 20 cal is only .04" shorter than this JLK @ .91" long so as far as i can see u may actually need the VLD magazine to be able to get it to work...but u're shooting a 55 gr. bullet at a bunch more velocity than i can shoot this 65 and the BC's r very close, so...? Sounds like a great AR experiment, ehh?-- assuming u have the correct twist for this bullet and throating. But u know what--i bet nobody's done it yet.? Oh crap--probably shoulda' kept my mouth shut! Ha.