Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Site Notices
4/22/2019 5:32:20 PM
Posted: 10/8/2014 8:15:24 PM EDT
[Last Edit: 1/17/2015 7:36:42 PM EDT by Mark082]
Prose details on the build itself and the ammo I designed will follow.

SIG SB-15 Brace
Looped receiver plate
KAK Industries buffer tube
Billet lower
G.I. 20-round mag
Magpul K2 Grip
KNS non-rotate pin set
ALG Combat Trigger
Forged flat top upper
VLTOR charging handle
Palmetto State Armory flip-up rear sight
Yankee Hill Diamond handguard
Ergo rail covers
Magpul AFG2
10.5” heavy barrel, .223 Wylde chamber
Yankee Hill FSB, H&K flip-up front sight
Smith Enterprises Vortex FH
Streamlight TLR-4 light/laser

http://i27.photobucket.com/albums/c195/numero_6/000_Full_LHS_no_sling_zps44e9814b.jpg
8.2 lbs in home defense trim, loaded. 28.5" OAL, 26.5" to end of bbl threads.

http://i27.photobucket.com/albums/c195/numero_6/002_LHS_front_zps1d87095a.jpg
http://i27.photobucket.com/albums/c195/numero_6/003_LHS_front_sight_down_zps84a39890.jpg
http://i27.photobucket.com/albums/c195/numero_6/004_TLR-4_AFG2_detail_zps70d74a11.jpg
http://i27.photobucket.com/albums/c195/numero_6/005_hold_LHS_zps4015bd36.jpg
Link Posted: 10/8/2014 8:21:13 PM EDT
Looks nice. I have a similar set-up.
Link Posted: 10/8/2014 8:35:32 PM EDT
I like the two tone look, hate quad rails though.
Link Posted: 10/8/2014 9:00:50 PM EDT
I agree on the quad rail. CDNN has a great deal on LWRC rails which are the ones that I chose to go with on my build.
Link Posted: 10/8/2014 9:14:25 PM EDT
the KNS non-rotate pin set was a waste the rest seems fine
Link Posted: 10/8/2014 9:19:52 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By angelbeast6:
I agree on the quad rail. CDNN has a great deal on LWRC rails which are the ones that I chose to go with on my build.
View Quote


$90-100 are fantastic prices for a quality quad rail handguard. I had a LWRC midlength a while back, but decided it was too heavy and opted for a modular handguard.

My currently pistol build is getting a Samson EVO 7" for a 8" 300BO.
Link Posted: 10/8/2014 9:25:09 PM EDT
Think I'm covered on AR-based PDW's for now



.45 DI SBR work in progress
Link Posted: 10/8/2014 9:29:07 PM EDT
Discussion ForumsJump to Quoted PostQuote History
View Quote


Where'd you get that rail? Lower right pic.
Link Posted: 10/8/2014 9:37:15 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:
Think I'm covered on AR-based PDW's for now

http://i241.photobucket.com/albums/ff206/devtucker/2013-03-04_17-36-46_163.jpg
View Quote


I am curious of the forward charging handle of the SBR with the Nordic CRS.
Link Posted: 10/8/2014 9:38:09 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By sparky923:


Where'd you get that rail? Lower right pic.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By sparky923:


Where'd you get that rail? Lower right pic.


That's an ARMS Swan Sleeve for an AR10.
Link Posted: 10/8/2014 9:42:19 PM EDT
[Last Edit: 10/8/2014 9:43:34 PM EDT by RDTCU]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By SilentDeath12886:


I am curious of the forward charging handle of the SBR with the Nordic CRS.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By SilentDeath12886:
Originally Posted By RDTCU:
Think I'm covered on AR-based PDW's for now

http://i241.photobucket.com/albums/ff206/devtucker/2013-03-04_17-36-46_163.jpg


I am curious of the forward charging handle of the SBR with the Nordic CRS.


Built my own bufferless upper with a non-reciprocating charging handle.

Original pistol configuration:


More recently:
Link Posted: 10/8/2014 9:57:45 PM EDT
Spend the extra $200 if you can. You lose the whole "compact" thing when the brace is on there.



CHRIS
Link Posted: 10/9/2014 12:34:38 AM EDT
10.5" seems kinda long for a "PDW."

Seems most factory PD dubs are 7-8."
Link Posted: 10/9/2014 9:56:04 AM EDT
[Last Edit: 1/17/2015 7:38:32 PM EDT by Mark082]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Rick_A:
10.5" seems kinda long for a "PDW."

Seems most factory PD dubs are 7-8."
View Quote


Yep, you're probably right.

More thoughts to follow, especially on ammo, as soon as I get 'em written up...
Link Posted: 10/9/2014 11:03:44 AM EDT
[Last Edit: 1/17/2015 7:42:55 PM EDT by Mark082]
Thought you guys would like to see how I added the GG&G universal loop to
the SB-15. Probably never need it for my application (house gun). More to see if
it could be done than anything else:

http://i27.photobucket.com/albums/c195/numero_6/001_GGG_zpsa95e88de.jpg
Loop must be located low enough so the screws don't hit the tube!
I chose the position shown, 1.5" from the back of the butt to
the centerline of the back mounting screw. This rubber cuts like
butter with a utility knife or X-acto, go slow. I finished up with
a Dremel.


http://i27.photobucket.com/albums/c195/numero_6/002_GGG_zps74098174.jpg
Measure FIVE times, cut once.


http://i27.photobucket.com/albums/c195/numero_6/003_GGG_zps97adee9f.jpg
I think I used 1.5" #8 dark plated screws from the hardware store.
Each screw goes all the way through the open area and just starts in on
the far end. I also used rubber contact cement on the loop before
this step. Tighten screws only far enough to press loop into the rubber
a little.


http://i27.photobucket.com/albums/c195/numero_6/004_GGG_zps8edeb8f8.jpg
Contemplated many solutions for a retainer/stiffener: threaded dowel,
threaded aluminum piece, etc. Then it hit me - good ol' JB-Weld.
Love that stuff. Just kept glommin' it in until it went under and over the screws.


In use, the loop has proven plenty solid. As you know, the
SB-15 tends to rotate on the tube. IMHOP you really must glue it on.
I used a little two-element epoxy. This mod does not interfere in
any way with the brace function of the SB-15 and it gives me a way to
carry my firearm comfortably to the range.
Link Posted: 10/9/2014 12:31:09 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By katrina24:
the KNS non-rotate pin set was a waste the rest seems fine
View Quote


My reasoning on the pin set --

Even though I was careful to "sneak up" on the pin hole diameters by
drilling first then hand-reaming they still came out just a tad looser
than I would prefer. It's hardened steel (albeit very smooth) against
aluminum, so I figured what the heck, it couldn't hurt.

I keep the wrench in the grip.
Link Posted: 10/9/2014 12:33:43 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Mark082:


My reasoning on the pin set --

Even though I was careful to "sneak up" on the pin hole diameters by
drilling first then hand-reaming they still came out just a tad looser
than I would prefer. It's hardened steel (albeit very smooth) against
aluminum, so I figured what the heck, it couldn't hurt.

I keep the wrench in the grip.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Mark082:
Originally Posted By katrina24:
the KNS non-rotate pin set was a waste the rest seems fine


My reasoning on the pin set --

Even though I was careful to "sneak up" on the pin hole diameters by
drilling first then hand-reaming they still came out just a tad looser
than I would prefer. It's hardened steel (albeit very smooth) against
aluminum, so I figured what the heck, it couldn't hurt.

I keep the wrench in the grip.


Any reason you reamed them by hand instead of using the drill press / jig?
Link Posted: 10/9/2014 12:42:09 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By 10mmillie:
I like the two tone look, hate quad rails though.
View Quote


At first, I left the lower alone because I was too busy
using it and trying out different ideas. Now the appearance is
growing on me too. The lower came bead-blasted so it
isn't too shiny. May leave it as-is.

The quad rail was what I had, and I wanted some weight to
start with anyway. I find the grip shown to be very natural.

But I think the next upper I build will be in completely the opposite
direction - how LIGHT can I make it. .625" BBL, Magpul guard,
add rails only where I need 'em, etc.
Link Posted: 10/9/2014 1:26:43 PM EDT
Discussion ForumsJump to Quoted PostQuote History
My reasoning on the pin set --

Even though I was careful to "sneak up" on the pin hole diameters by
drilling first then hand-reaming they still came out just a tad looser
than I would prefer. It's hardened steel (albeit very smooth) against
aluminum, so I figured what the heck, it couldn't hurt.

I keep the wrench in the grip.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
My reasoning on the pin set --

Even though I was careful to "sneak up" on the pin hole diameters by
drilling first then hand-reaming they still came out just a tad looser
than I would prefer. It's hardened steel (albeit very smooth) against
aluminum, so I figured what the heck, it couldn't hurt.

I keep the wrench in the grip.


Any reason you reamed them by hand instead of using the drill press / jig?


The drill press I used appeared to have more run-out than I liked, so I felt
much better doing it by hand. I carefully reamed through before milling the inside
so I knew the holes would be aligned. If you have a high-quality drill press you can
certainly use a chucking reamer in it.

Even when you use a good drill press, bits tend to bore a couple thousandths
over their nominal size. More with bigger bits if your press is like mine.
Especially true with the safety hole! If you just
use a 3/8" (.375") drill right off, it'll work, but you won't like the way your safety
wobbles. I used the 3/8" bit through the jig to make a dimple, then drilled
thru with a "U" bit (.368") before using a .375" hand reamer. The safety fits and
works like factory.

Link Posted: 10/9/2014 1:31:17 PM EDT
I don't use jigs and I do all my work on my Bridgeport mill...

Be glad you don't have the old style 80% where you had to tap the buffer tower, I paid about $60 for that tap, and I would hate to have to ream and tap it without a mill.
Link Posted: 10/9/2014 2:11:42 PM EDT
the around the house thing is part of why i build my 7.5, but im sure it would just light walls on fire.... its nice and short though. and it fits in a vehicle i can pivot from side window to side window in my fiero even... the ramcharger might as well be a pill box tho
Link Posted: 10/10/2014 12:41:02 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:
I don't use jigs and I do all my work on my Bridgeport mill...

Be glad you don't have the old style 80% where you had to tap the buffer tower, I paid about $60 for that tap, and I would hate to have to ream and tap it without a mill.
View Quote


You're way aheada me! Sorry about the machining 101 tutorial. I finished mine on
a friend's mill - an old but still solid Bridgeport BTW, beautiful piece of equipment.

I'm amazed you found a tap that big for $60. Can't even imagine having to do
that operation without the right equipment. That area of the lower is the only
part of the whole weapon that's always bothered me - just not enough meat.

I wonder about the possibility of getting a forging with an internal fault that just happens
to be in that tower area. Solution: pay more and get a good billet lower!
Link Posted: 10/10/2014 12:52:58 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Mark082:
I wonder about the possibility of getting a forging with an internal fault that just happens
to be in that tower area. Solution: pay more and get a good billet lower!
View Quote


Much less likely to happen in a forging compared to one of the crappy cast 80% lowers that still pop up from time to time.
Link Posted: 10/10/2014 1:34:10 PM EDT
[Last Edit: 1/17/2015 7:49:14 PM EDT by Mark082]
Further comments on my pix above, split over six posts since newbies get
2000 chars per post to start.

Twenty years ago or so after building my first AR, I considered
building up a compact semi-auto AR-based personal defense weapon. It
seemed to me that sort of AR would be ideal for home defense. It
would be relatively lightweight, handy, and suited for the job of
moving around inside and through doors. It seemed like it would
be easier to shoot well than a handgun, especially for someone
who has plenty of shooting experience but minimal formal combat
training.

Another consideration was the fact that we are seeing more and
more home invasions by perps wearing body armor of the Threat
Level IIa or II variety. The bad guys know homeowners are more likely
to be armed and willing to defend themselves, and they're raising the
stakes. I didn't think of the requirement to penetrate body armor back
then, but times have changed...

This was all assuming the right 5.56 ammo. I had thoughts about that,
too. But the pistol buffers seemed awkward and I backburnered the
idea.

In the meantime, semiauto versions of PDWs like the PS90 began
appearing but, good grief, are they expensive! And in most cases it
would have meant a new caliber or specialized cartridge (or both).
It also meant different, more expensive, tougher to get spare parts.
That meant changes I really didn't want to mess with in my my nice,
steady AR-15 logistics chain.

Then the Sig SB15 Pistol Brace appeared on the scene, and the
thoughts started percolating again. What could be done with the
standard AR platform to meet my PDW requirements? The result of
that percolation is presented here for your consideration.
Link Posted: 10/10/2014 1:35:01 PM EDT
[Last Edit: 1/17/2015 7:50:31 PM EDT by Mark082]
Part 2:

The basic weapon is 8.2 lbs, unloaded. This could be reduced
somewhat if desired by using a lightweight ("pencil")
barrel assembly and a plastic handguard like the Magpul instead
of the quad-rail. I built this first effort a little heavy on
purpose. Easy to build any sort of upper you like.

Everything I did here had a reason. May not have been the BEST
reason - but there was a reason. The idea was to design to the
task at hand, but no more. In keeping with that philosophy, I knew
I needed to come up with a suitable 5.56 variant for the ammo.

A quick aside. I realize .300 Blackout has been mentioned more
and more often for the PDW concept and, I believe, for good
reasons. For now the author is limiting himself to 5.56 because
that's his current self-imposed logistics chain.

Shooting military loads or full-patch hot reloads out of a short
barrel in the home defense application is unsatisfactory IMHOP for
several reasons:

1) The flash and blast in confined spaces is often disorienting,
not something you want to deal with under the circumstances, if
possible. In some instances you can permanently damage your
hearing. The idea here is presumeably to take down the bad guy
without wrecking yourself.

2) With the powders most often used in mil cartridges and by
reloaders in 16" and longer barrels, a good proportion of the
powder is wasted producing flash and blast as it burns outside a
shorter barrel.

3) The highest possible velocity and bullet energy may not
be the best goal, since the result may be overly-penetrative.
Link Posted: 10/10/2014 1:35:33 PM EDT
Concept implies something new.

We have 146 pages (at last count) already
Link Posted: 10/10/2014 1:35:39 PM EDT
[Last Edit: 1/17/2015 7:52:19 PM EDT by Mark082]
Part 3:

So the requirements for my 5.56 house gun load became:

1) Reduce the flash and blast enough to partially mitigate the
effects of firing 5.56 inside a home.

2) Within requirement #1, pick a projectile and move it fast
enough to reliably penetrate Threat Level II and IIa body
armor while retaining enough energy to stop the perp.

3) Within requirements #1 and #2, the load should not be
overly penetrative.

4) Finally, within all three requirements above, the load
must cycle the action with as close to 100% reliability as
practical.

4a) Had to add this in - ALL STANDARD PARTS, no shortened
buffer springs, lightweight oddball buffers, etc.

I began by doing a survey to get an idea of the ballistics I
needed to match. Looking at military cartridges that have
been developed for short barrels like the U.S. Mk 318 round
can be misleading since they have to dance around the Hague
Convention restrictions concerning expanding bullets. Ironically,
we as civilians can use bullet types our fighting men and women
can't.

The FN "Duty" SS190 5.7x28 cartridge that defeats body armor
has a steel core and has been deemed armor-piercing by BATF.

The SS197SR (sporting round) uses a Hornady 40gr V-Max
bullet at 2100 fps when fired from the P90's 10.5” bbl. There is
conflicting data on whether this cartridge will defeat Threat
Level II vests:

This from Wikipedia:
"The SS196 was classified by the ATF as not armor-piercing,
and in testing by FNH USA it did not penetrate a Level II
vest when fired from the Five-Seven." No mention of whether
the round will penetrate when fired from the P90's 10.5" barrel.

But then there is this link:
http://www.eliteammunition.net/multi_media_page.html
Scroll down to "5.7x28 ProtecTOR One Level II Vest 15% Gel
Test". They show the bullet penetrating the vest and then
an additional 9" into ballistic gelatine. I tend to believe
what I see with my own eyes.
Link Posted: 10/10/2014 1:36:13 PM EDT
Part 4:

There are many powders for .223/.556 out there. I did my
preliminary development with these three:

Accurate Arms 2230 - #83 out of 145 on my burn rate chart,
sort of a standard powder for .223/5.56. Not sure it's made
any more but it's what I have.

IMR 4198 - quite a bit faster at #71 on the chart, IMR's
fastest rifle-specific powder.

IMR 4759 - faster still at #66, IMR actually lists it in
the pistol column, and as a "reduced load propellant for
rifle cartridges". I'm extremely wary about using any
pistol-SPECIFIC powders in a rifle cartridge.

I began by trying to approximate the ballistics of the FN
SS197 cartridge (40gr V-Max, 2100fps, 392 ft-lbs).

It became obvious that a lot of the 2230 was burning outside
the barrel even with this reduced load...

20.6gr Accurate 2230 powder, 40gr V-max
Velocity: 2050fps
Bullet energy: 373 ft-lbs

...so I didn't even bother to keep going after this point.

To shorten the story, I eventually arrived at these two
loads, both are 2.25" OAL, Winchester silver primers, US
mil brass (LC and WCC):

17.5gr of IMR4198, 55gr V-Max bullet
Velocity: 2218 fps
Bullet energy: 601 ft-lbs

15.5gr IMR 4759, 55gr V-Max bullet
Velocity: 2283 fps
Bullet energy: 636 ft-lbs

No FTFs or FTEs now with either of these loads. AT FIRST
when the weapon was new, the SR4759 load failed to hold open on
the last shot about 50% of the time. However, after the first
100 rounds or so of testing, I could no longer reproduce the fault.

Between the 40gr and 55gr V-Max and 60gr Nosler Ballistic Tip,
the 55gr bullet had the highest bullet energy using the faster
powders.

Ejection was positive, although not as energetic as full-patch
loads. The cases did not appear to hit the deflector. Rather,
they came out at a slight angle to the rear and 6 - 7 feet out.
Link Posted: 10/10/2014 1:36:53 PM EDT
Part 5:

There are many powders for .223/.556 out there. I did my
preliminary development with these three:

Accurate Arms 2230 - #83 out of 145 on my burn rate chart,
sort of a standard powder for .223/5.56. Not sure it's made
any more but it's what I have.

IMR 4198 - quite a bit faster at #71 on the chart, IMR's
fastest rifle-specific powder.

IMR 4759 - faster still at #66, IMR actually lists it in
the pistol column, and as a "reduced load propellant for
rifle cartridges". I'm extremely wary about using any
pistol-SPECIFIC powders in a rifle cartridge.

I began by trying to approximate the ballistics of the FN
SS197 cartridge (40gr V-Max, 2100fps, 392 ft-lbs).

It became obvious that a lot of the 2230 was burning outside
the barrel even with this reduced load...

20.6gr Accurate 2230 powder, 40gr V-max
Velocity: 2050fps
Bullet energy: 373 ft-lbs

...so I didn't even bother to keep going after this point.

To shorten the story, I eventually arrived at these two
loads, both are 2.25" OAL, Winchester silver primers, US
mil brass (LC and WCC):

17.5gr of IMR4198, 55gr V-Max bullet
Velocity: 2218 fps
Bullet energy: 601 ft-lbs

15.5gr IMR 4759, 55gr V-Max bullet
Velocity: 2283 fps
Bullet energy: 636 ft-lbs

No FTFs or FTEs now with either of these loads. AT FIRST
when the weapon was new, the SR4759 load failed to hold open on
the last shot about 50% of the time. However, after the first
100 rounds or so of testing, I could no longer reproduce the fault.

Between the 40gr and 55gr V-Max and 60gr Nosler Ballistic Tip,
the 55gr bullet had the highest bullet energy using the faster
powders.

Ejection was positive, although not as energetic as full-patch
loads. The cases did not appear to hit the deflector. Rather,
they came out at a slight angle to the rear and 6 - 7 feet out.
Link Posted: 10/10/2014 1:37:43 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:


Built my own bufferless upper with a non-reciprocating charging handle.

Original pistol configuration:
http://i241.photobucket.com/albums/ff206/devtucker/AR%20Pistol/DSCN0363.jpg

More recently:
http://i241.photobucket.com/albums/ff206/devtucker/IMG_20130704_231500_079.jpg
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:
Originally Posted By SilentDeath12886:
Originally Posted By RDTCU:
Think I'm covered on AR-based PDW's for now

http://i241.photobucket.com/albums/ff206/devtucker/2013-03-04_17-36-46_163.jpg


I am curious of the forward charging handle of the SBR with the Nordic CRS.


Built my own bufferless upper with a non-reciprocating charging handle.

Original pistol configuration:
http://i241.photobucket.com/albums/ff206/devtucker/AR%20Pistol/DSCN0363.jpg

More recently:
http://i241.photobucket.com/albums/ff206/devtucker/IMG_20130704_231500_079.jpg


You have the ugliest feet.

Link Posted: 10/10/2014 1:40:42 PM EDT
[Last Edit: 10/10/2014 1:43:21 PM EDT by Mark082]
Sorry, repeat posted by accident...
Link Posted: 10/10/2014 1:42:24 PM EDT
>>1) Reduce the flash and blast enough to partially mitigate the
effects of firing a rifle inside a home.


You need a flash can.

Link Posted: 10/10/2014 1:43:41 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Stoop:
>>1) Reduce the flash and blast enough to partially mitigate the
effects of firing a rifle inside a home.


You need a flash can.

https://dl.dropboxusercontent.com/u/302245/300blk_sm.jpg
View Quote


How are you liking that light?
Link Posted: 10/10/2014 1:46:34 PM EDT
[Last Edit: 10/10/2014 1:48:30 PM EDT by Stoop]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:


How are you liking that light?
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:
Originally Posted By Stoop:
>>1) Reduce the flash and blast enough to partially mitigate the
effects of firing a rifle inside a home.


You need a flash can.

https://dl.dropboxusercontent.com/u/302245/300blk_sm.jpg


How are you liking that light?



I don't like the fact that is rechargeable or that up close it looks plasticky, but I like the size, light weight and that it doesn't need a tailcap and is easy to remove/replace Overall I like it - but at the discounted price I got it at - not at $99

ETA - might have to put it on a riser of some kind because sliding it backwards to come off the mount would interfere with any rail panels - hence you can see the rail behind it is bare.
Link Posted: 10/10/2014 1:47:44 PM EDT
[Last Edit: 1/17/2015 7:56:52 PM EDT by Mark082]
Part 6

Picked the 10.5" barrel for several reasons:

1) The 7.5" I tried at first was distasteful to shoot, even with
reduced loads - excessive flash and blast. Far too much powder wasted
outside the bore.

2) Extraction was violent with standard mil loads - at least on my
example - and tore up the case rims to the point it interfered with
reloading.

3) Shortest standard length that allowed use of a carbine gas system and
a standard-size gas block.

4) Shortest standard length that resulted in 26"+ OAL to the bbl threads,
using the SB15 configuration I wanted.

I picked the bottom-mount position for the TLR-4 because operation was
natural with the AFG2 (for me anyway).

Jury is still out on the charging handle. Definitely easier to operate
from the chest-ready position with the off-hand (no shredded palm syndrome)
but it jabs me sometimes when slung and gets caught on things. Since the
intent for the primary home defense application is to keep the weapon in
Condition 1 anyway, the utility of the bigger handle may be moot.

I went on the heavy side to start with, maybe a little too heavy. The
great thing about ARs is you can experiment until you get blue in the face
(or run outta moolah).

The Vortex just plain flat works. The real deal.

Last thought: Something like this but built lighter and firing downloaded
.300 Blackout 125gr ballistic tip just might be the ultimate house gun.

Oh well, yet another money sink...

Link Posted: 10/10/2014 1:57:08 PM EDT
[Last Edit: 1/17/2015 7:57:41 PM EDT by Mark082]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Stoop:
Concept implies something new.

We have 146 pages (at last count) already
View Quote


Roger that.

But the main thing here was to see if I could match the ammo to the intended purpose
without having to adopt yet another caliber. Eg: could I make the 5.56 behave like
a current PDW load?

Maybe not a new concept, but another project to mess with. It's what makes this
all so interesting.

I tried posting in the SB15 thread but goofed somehow and it ended up here.
Link Posted: 10/10/2014 2:06:47 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Stoop:
>>1) Reduce the flash and blast enough to partially mitigate the
effects of firing a rifle inside a home.


You need a flash can.

https://dl.dropboxusercontent.com/u/302245/300blk_sm.jpg
View Quote


I considered that, but since the main reason for the project was to see if I could
come up with a .556 load that behaves like a PDW load, I decided to go with the
Vortex instead. (See multi-part writeup).

Also, the flash can won't do much for the blast, right? That's my concern in closed
spaces.

Doesn't mean I won't try one at some point!
Link Posted: 10/10/2014 4:55:58 PM EDT
With the flash can the blast is also directed forward rather than out to the side so if your partner is beside you less cutting gas hitting them.

By the way mine is in 300 Blackout and I intend to experiment as you suggested with various subsonic rounds for HD. My barrel is 8.5 inch.
Link Posted: 10/10/2014 7:12:20 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Stoop:
With the flash can the blast is also directed forward rather than out to the side so if your partner is beside you less cutting gas hitting them.

By the way mine is in 300 Blackout and I intend to experiment as you suggested with various subsonic rounds for HD. My barrel is 8.5 inch.
View Quote


I'll be HIGHLY interested to hear what happens. Is your shorty hard on the case rim? If not you may be half there already.

That 125gr Nosler Ballistic Tip would be one bullet to try. I have no experience yet with .300 AAC but I see it has an actual
diameter of .308 so all sorts of bullets are out there. I wonder if anyone makes a 100gr .308 ballistic tip?

The challenge would be to see if you can get over that 1600fps beginning expansion velocity and still stay away from
pressure signs, while lowering blast and flash.

4198 will also work, but not quite as well in my 10.5", so probably a lot less well in an 8.5". But like everything else
technical, you just don't know until you try.

It's a bummer, but I think IMR is discontinuing 4759 yet again as of next year.
I say "yet again" because I think they've yanked it at least twice already and brought it back when enough people squawked.
Link Posted: 10/10/2014 7:18:17 PM EDT
Not bad.

Personally I'd go with lighter weight components and suppressor.

And move the weapon light to 12:00.
Link Posted: 10/10/2014 11:58:33 PM EDT
[Last Edit: 10/11/2014 12:01:09 AM EDT by RDTCU]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Mark082:


I'll be HIGHLY interested to hear what happens. Is your shorty hard on the case rim? If not you may be half there already.

That 125gr Nosler Ballistic Tip would be one bullet to try. I have no experience yet with .300 AAC but I see it has an actual
diameter of .308 so all sorts of bullets are out there. I wonder if anyone makes a 100gr .308 ballistic tip?

The challenge would be to see if you can get over that 1600fps beginning expansion velocity and still stay away from
pressure signs, while lowering blast and flash.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Mark082:
Originally Posted By Stoop:
With the flash can the blast is also directed forward rather than out to the side so if your partner is beside you less cutting gas hitting them.

By the way mine is in 300 Blackout and I intend to experiment as you suggested with various subsonic rounds for HD. My barrel is 8.5 inch.


I'll be HIGHLY interested to hear what happens. Is your shorty hard on the case rim? If not you may be half there already.

That 125gr Nosler Ballistic Tip would be one bullet to try. I have no experience yet with .300 AAC but I see it has an actual
diameter of .308 so all sorts of bullets are out there. I wonder if anyone makes a 100gr .308 ballistic tip?

The challenge would be to see if you can get over that 1600fps beginning expansion velocity and still stay away from
pressure signs, while lowering blast and flash.


That question has already been answered with the Barnes 110gr TSX load that expands down to 1300fps, Leaves at over 2300 from a 16" barrel, but doesn't give up much down in the 8-9" barrel range.

Link Posted: 10/27/2014 1:14:22 PM EDT
[Last Edit: 10/27/2014 1:14:36 PM EDT by jhereg]
Here's my solution. 7.5" 5.56 w/ a STD brake on it and a LAW folding adapter.

Link Posted: 10/27/2014 1:17:35 PM EDT
i do wish the law wasent so expensive.....
Link Posted: 10/27/2014 3:24:21 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By zetabird:
i do wish the law wasent so expensive.....
View Quote


So do I. The price and the PITA to disassemble it is why I only have one.
Link Posted: 10/27/2014 4:17:06 PM EDT
for now ill stick to takeing the upper and lower apart... i just need a nicer aluminum lower, not the poly omni i had in the safe.... if i wouldnt have found my fnx45 this weekend i was gonna buy one
Link Posted: 11/29/2014 12:44:21 AM EDT
Top Top