PDA

View Full Version : Building a 300 upper - opinions/suggestions needed



voodoo_man
28 December 2014, 17:13
Ok so I have the following parts:

PWS DI BCG
PWS 10.5" 300BLK barrel w/ .30cal Triad
CMT stripper upper

I need the following:

Rail (dunno length, thinking 10-12 inches?)
Charging Handle
Dust cover for upper
Forward Assist for upper
Gas block
Gas Tube


Considerations:

All parts need to be super awesome / new / cool / non-standard
$$ = no fucks given


Suggestions / opinions appreciated, do not mind used parts but would prefer new parts. This will probably go on a dedicated 300blk lower and will more than likely be suppressed by a 762 can of some sort (probably saker)

Also let me know what your 300blk build let you wanting and what you would have done different if you could.

Pix to come

alamo5000
28 December 2014, 17:25
Which CMT Upper?

I say go with a SLR 10" rail and a strike industries dust cover....

voodoo_man
28 December 2014, 17:30
Pws di bcg
http://i.imgur.com/9p6ifC9.jpg

Cmt upper

http://i.imgur.com/IVHmXI4.jpg

jymbeux
28 December 2014, 17:38
Here is an idea I've had: fortis switch rail and an adjustable gas block. The switch rail would make it easier to adjust the settings on the gas block (settings for super/subsonic loads). A friend of mine has adjustable gas blocks on two separate 300blk uppers and dialing in the gas blocks makes them shoot super smooth. I cannot recommend a specific adjustable gas block but I'm sure somebody here would have input on a specific make/model.

Computalotapus
28 December 2014, 17:57
I am really digging the SLR Rifleworks Solo Ultra Lite series rails. Very slim profile and picatinny section only at the end of the rail, can get it in M-LOK or KeyMod. BCM Mod3/4 CH of if you are going to suppress it maybe a PRI Gas Buster CH? And I like the tear drop waffled FA that UW gave me for my NTD build. And if you are wanting an adjustable gas block then you gotta go with Syrac Ordance adjustable GB.

schambers
28 December 2014, 18:47
If you check out my thread in the custom build section (http://www.weaponevolution.com/forum/showthread.php?6734-Handguard-clearance-w-Noveske-10.2-quot) you can see some 10.5" barrels with different rail configurations.

I ordered a 10" URX4 and once that comes in, I'll throw some pics up

akersc
28 December 2014, 18:48
Ok so I have the following parts:

PWS DI BCG
PWS 10.5" 300BLK barrel w/ .30cal Triad
CMT stripper upper

I need the following:

Rail (dunno length, thinking 10-12 inches?)
Charging Handle
Dust cover for upper
Forward Assist for upper
Gas block
Gas Tube


Considerations:

All parts need to be super awesome / new / cool / non-standard
$$ = no fucks given


Suggestions / opinions appreciated, do not mind used parts but would prefer new parts. This will probably go on a dedicated 300blk lower and will more than likely be suppressed by a 762 can of some sort (probably saker)

Also let me know what your 300blk build let you wanting and what you would have done different if you could.

Pix to come

You should check out LEO armory for the dust cover, he makes laser fricken engraved ones (that's what the packaging says) he's also a really nice guy. I'm in the process of putting together my spreadsheet for my SBR build, I'm really excited about this one.


Sent from my iPhone using Tapatalk

alamo5000
28 December 2014, 19:00
Is your upper going on a pistol or an SBR? Is it going to be suppressed?

If I won the lotto I would have some awesome builds going and lots and lots of ammo :)

10.5" 300 BO with a 10" rail suppressed SBR... yowsers.... a guy can dream can't he?

BoilerUp
28 December 2014, 19:02
Seekins MCSR V2 rail in 10" if you'll shoot it w/o a can or 12" or even 15" to cover the can, depending on how long the can is. Something like this (pictured is an older rail...source of pic is Seekins):

http://i687.photobucket.com/albums/vv237/bigmoney890/seekins-home-banner.png

SINNER
28 December 2014, 19:52
I have found that both of my Syrac blocks get very difficult to adjust if you leave them set for 4-500 rounds. You must run the adjustment screw through it's range or remove and clean every so often. I have had much better luck with the Seekins adjustable block with the brass set screw. The Syrac are easier to adjust when new.

WHSmithIV
28 December 2014, 20:37
Is your upper going on a pistol or an SBR? Is it going to be suppressed?

If I won the lotto I would have some awesome builds going and lots and lots of ammo :)

10.5" 300 BO with a 10" rail suppressed SBR... yowsers.... a guy can dream can't he?

^^ Ditto this. why would you look at using a 12" rail with a 10.5" barrel? Ideally you want to be able to change your muzzle device without taking off the handguard to do so. I suppose if you were going to mount a suppressor permanently to the barrel it might make sense to go with a longer handguard than the barrel length. i can't imagine anybody wanting to weld a suppressor to a barrel though. I've been playing around with some designs for a suppressed 300 Blackout SBR using a 9.5" barrel. It's something I will build someday in the future.

din
28 December 2014, 21:34
V7 should have all the cool guy stuff you're looking for. vertexops.com stocks V7 and a mess of other neat stuff.

DutyUse
29 December 2014, 00:07
I have found that both of my Syrac blocks get very difficult to adjust if you leave them set for 4-500 rounds. You must run the adjustment screw through it's range or remove and clean every so often. I have had much better luck with the Seekins adjustable block with the brass set screw. The Syrac are easier to adjust when new.

Not what I needed to read 3 days before mine is due to arrive ;P

Having seen some of your quality builds in the past I know this little blaster is going to be a beast. *sub'd*

SwissyJim
29 December 2014, 00:55
I'm digging my SLR Sentry adj gas block... and the Seekins MCSRv2 rail. I went 8.2" barrel and the 10" rail covers 1/4 of the suppressor (Specwar762). I'm liking it so much that I'm getting another rail only 12" so more is covered, giving me more real estate on the rail for gripping, lights, BUIS, etc.



https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xpa1/v/t1.0-9/q84/s261x260/10891620_780652822005530_6155455290795857816_n.jpg ?oh=7c69092b158c6f4cc9a86e947742d58e&oe=55413F4D&__gda__=1425777227_cc056e4b430237dca0b8906f3a9518e 5 (https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xpa1/t31.0-8/10633456_780652822005530_6155455290795857816_o.jpg )

And yeah - big scope does not reside on this. I put it on while doing some load testing which made it easier.

I just gave away a dust cover that had 300BLK laser etched, but BDL Custom Covers had/has a killer cover that I now use. Cerakoted lettering inside and out,
https://dl.dropboxusercontent.com/u/165145882/shooting/BDL.jpg

And I went ahead and used the Gas Vent for the forward assist - I have yet to get 'gas face' and I shoot 90% suppressed now. May not be needed, but I like it. My Tavor gives me bad 'gas face' and not fond of it.

DutyUse
29 December 2014, 01:31
I'm digging my SLR Sentry adj gas block... and the Seekins MCSRv2 rail. I went 8.2" barrel and the 10" rail covers 1/4 of the suppressor (Specwar762). I'm liking it so much that I'm getting another rail only 12" so more is covered, giving me more real estate on the rail for gripping, lights, BUIS, etc.



https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xpa1/v/t1.0-9/q84/s261x260/10891620_780652822005530_6155455290795857816_n.jpg ?oh=7c69092b158c6f4cc9a86e947742d58e&oe=55413F4D&__gda__=1425777227_cc056e4b430237dca0b8906f3a9518e 5 (https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xpa1/t31.0-8/10633456_780652822005530_6155455290795857816_o.jpg )

And yeah - big scope does not reside on this. I put it on while doing some load testing which made it easier.

I just gave away a dust cover that had 300BLK laser etched, but BDL Custom Covers had/has a killer cover that I now use. Cerakoted lettering inside and out,
https://dl.dropboxusercontent.com/u/165145882/shooting/BDL.jpg

And I went ahead and used the Gas Vent for the forward assist - I have yet to get 'gas face' and I shoot 90% suppressed now. May not be needed, but I like it. My Tavor gives me bad 'gas face' and not fond of it.

Wow what an awesome, well executed build Jim! I think a double stamp 300blk is just about the perfect home defense weapon.
Question though. Even though you have the adj GB, how often do you actually change it?

Reason I ask is because I got a Syrac ADJ for my 10.5 build but just a regular BCM GB for my 11.5. Just wondering if you use yours enough to justify the cost upgrading my second build.

Thanks in advance

voodoo_man
29 December 2014, 02:41
Isnt the whole point of 300blk so that you dont need an adjustable gas block?

schambers
29 December 2014, 05:40
You do not need an adjustable gas block if you have a pistol length gas system.

voodoo_man
29 December 2014, 06:11
You should not need an adjustable gas block if you have a pistol length gas system. With a carbine length you might.

Thats what I though.

schambers
29 December 2014, 06:14
Forgot to mention this in my last post. I'll be running a colt H2 buffer and Springco white spring.

That combination should be able to run supers and subs, suppressed and unsuppressed with no problems

SINNER
29 December 2014, 06:53
There is no doubt an improvement with adjustable gas block if you are switching from subs to supers and taking a can on and off. It will run fine with a standard block but you can definitely reduce the blowback. Being a lefty it is quite clear there is a difference.

SINNER
29 December 2014, 07:03
Not what I needed to read 3 days before mine is due to arrive ;P

Having seen some of your quality builds in the past I know this little blaster is going to be a beast. *sub'd*

They are a top quality block don't get me wrong. The seekins is harder to adjust because you need to access it from the front and side. I am still using a Syrac block on a new build because it's under the rail too far. Just be aware backing the screw out and cleaning it every 4-500 rounds will save you some headaches. a touch of nickel based anti-seize certainly helped on the threads.

DutyUse
29 December 2014, 09:41
They are a top quality block don't get me wrong. The seekins is harder to adjust because you need to access it from the front and side. I am still using a Syrac block on a new build because it's under the rail too far. Just be aware backing the screw out and cleaning it every 4-500 rounds will save you some headaches. a touch of nickel based anti-seize certainly helped on the threads.

Cool. Thanks for the pro tip :D

SwissyJim
29 December 2014, 11:47
Thanks... I'm pretty happy with the build myself. Only my 2nd AR build, but I could not be happier. Runs like a champ and is SUPER fun to shoot. Pretty near 'Hollywood Quiet' with the Specwar762 and my reloads. [:D]

As far as the adj gas block, to be honest - once I got it dialed in and set where I want it, I have not changed it since. In the process of testing the initial build, and some reloads, I was changing it quite a lot. But, I have it set in a position that allows my suppressed sub loads to work perfectly (BHO on last round), and the occasional super load runs as well unsuppressed. Honestly, sicne I got the Specwar, I'd say 90% of the shooting I do with this is suppressed sub loads.

Not only that, but there is less gas going thru than I think there would be with a non-adj block and therefore the recoil is less. With the recent addition of the JP captured buffer spring, the recoil is damn near non-existant. By far, my most fun gun to shoot.

If you're thinking home defense,look at the Lehigh Defense 194g projectiles... about the only subsonic bullet that will expand at sub speeds. Not cheap at $1.50 per bullet, but I tested them in gel and they do in fact expand (quite nasty I might add) as low as 900fps. They claim as low as 700fps but I only did as low as 900.

And for cheaper 'plinking' sub loads, SPS sells Nosler 190g Custom Competition 'blems' pretty cheaply - 1/2 the price of 208Amax's. And they give First Responder discounts.

SwissyJim
29 December 2014, 11:51
There is no doubt an improvement with adjustable gas block if you are switching from subs to supers and taking a can on and off. It will run fine with a standard block but you can definitely reduce the blowback. Being a lefty it is quite clear there is a difference.

Thats what I found... even with the pistol gas, a standard block was still overgassed. With the adj block I was able to dial it down even more, while keeping the function of both sub and super loads, suppressed and un-suppressed. To me, it was worth the extra $ for that reason -first guy I let shoot it at the range thought it was a .22 due to the almost non-existent recoil. I kinda laughed, as the suppressor was a tad bigger than a .22 version [BD]

tact
29 December 2014, 17:27
My 300 build is currently in parts as I wait for BDL to get up and running again for some paint.

I went with a Fortis upper microslicked inside, Battle Arms lower, Danger Close 9" 1/7 w/5R rifling, KAC rail, MVB Arc stock, St. Croix titanium BCG, 2A titanium GB, melonite gas tube, CMC flat 4# duty trigger........and a Saker762. I will most likely switch out the rail for a longer one as I've ordered another Saker so I am not worried about taking it on and off.

I don't buy the need for an adjustable GB either.

There's a dust cover on Article 15 Clothing you might like, VDM.

I am curious why you don't just buy the PWS Mk109 instead?

DutyUse
29 December 2014, 20:09
My 300 build is currently in parts as I wait for BDL to get up and running again for some paint.

I went with a Fortis upper microslicked inside, Battle Arms lower, Danger Close 9" 1/7 w/5R rifling, KAC rail, MVB Arc stock, St. Croix titanium BCG, 2A titanium GB, melonite gas tube, CMC flat 4# duty trigger........and a Saker762. I will most likely switch out the rail for a longer one as I've ordered another Saker so I am not worried about taking it on and off.

I don't buy the need for an adjustable GB either.

There's a dust cover on Article 15 Clothing you might like, VDM.

I am curious why you don't just buy the PWS Mk109 instead?

Wow that sounds like one HELL of a build. Have you started acquiring parts yet?

voodoo_man
29 December 2014, 20:58
I would buy a complete gun but ive got these parts comin in for less than retail so I couldnt say no.

tact
30 December 2014, 17:08
Wow that sounds like one HELL of a build. Have you started acquiring parts yet?

Yes....all here except the BCG and rail which should arrive any day.

tact
30 December 2014, 17:09
I would buy a complete gun but ive got these parts comin in for less than retail so I couldnt say no.

I was basically in the same situation and really wanted the mk109 but will end up with this build for now.

voodoo_man
18 February 2015, 15:04
...so I ran into a little snag while doing research on parts for this build.

I got a Fortis Switch rail which I posted pictures of several times, but its a little too long...

http://i.imgur.com/daWH7Fh.jpg

As you can see I need like 4-5 inches of muzzle device (which is eventually going to be a suppressor but that'll be a while until the stamp comes back), so I need something to put there in the mean time.

Suggestions?

GaSwamper
18 February 2015, 15:28
...so I ran into a little snag while doing research on parts for this build.

I got a Fortis Switch rail which I posted pictures of several times, but its a little too long...

http://i.imgur.com/daWH7Fh.jpg

As you can see I need like 4-5 inches of muzzle device (which is eventually going to be a suppressor but that'll be a while until the stamp comes back), so I need something to put there in the mean time.

Suggestions?

How long is a Pig?

voodoo_man
18 February 2015, 15:46
How long is a Pig?

good question, wonder if the new v2 pig will work

voodoo_man
18 February 2015, 15:51
just checked KX5 (300blk) is 3.25 inch OAL, I measured it and I need 5 inch to clear the end of the rail.

I know this might sound stupid (and poserish) but maybe a faux suppressor until I get the real thing in?

GaSwamper
18 February 2015, 16:36
just checked KX5 (300blk) is 3.25 inch OAL, I measured it and I need 5 inch to clear the end of the rail.

I know this might sound stupid (and poserish) but maybe a faux suppressor until I get the real thing in?

I thought the same thing but didn't want you to laugh at me. 5'' is a lot of ground to cover, this may be the easiest temp fix.

UWone77
18 February 2015, 16:38
just checked KX5 (300blk) is 3.25 inch OAL, I measured it and I need 5 inch to clear the end of the rail.

I know this might sound stupid (and poserish) but maybe a faux suppressor until I get the real thing in?

Depends... how much is a fake can going to cost?

Dstrbdmedic167
18 February 2015, 16:45
Something like this may work as a temp fix http://www.brownells.com/rifle-parts/muzzle-devices/flash-hiders/slipover-xm177-flash-suppressor-sku231000309-45252-101673.aspx

voodoo_man
18 February 2015, 16:53
Something like this may work as a temp fix http://www.brownells.com/rifle-parts/muzzle-devices/flash-hiders/slipover-xm177-flash-suppressor-sku231000309-45252-101673.aspx

that might work! except I need one in 300blk

Dstrbdmedic167
18 February 2015, 16:57
that might work! except I need one in 300blk

My bad here's another I found but i know nthing about the site etc etc but worth a shot... http://www.northerngunparts.com/ar-15-m-16-512inchflashiderwithholes-1.aspx

voodoo_man
18 February 2015, 17:35
http://www.northerngunparts.com/slipover-flash-hider-1.aspx

Might work...

GaSwamper
18 February 2015, 17:47
http://www.northerngunparts.com/slipover-flash-hider-1.aspx

Might work...

This is a over barrel MD though. Says only 1'' past end of the barrel though right?

BoilerUp
18 February 2015, 20:15
Fake suppressor: http://www.ftfindustries.com/product/AR-FS300.html

voodoo_man
19 February 2015, 03:19
I gata do some research

six8
13 March 2015, 16:31
Any updates? I've started to order parts for my .300 build

usmcvet
10 July 2015, 19:32
just checked KX5 (300blk) is 3.25 inch OAL, I measured it and I need 5 inch to clear the end of the rail.

I know this might sound stupid (and poserish) but maybe a faux suppressor until I get the real thing in?

This is a cool option and functional too. Not sure if it is long enough for what you're doing. You'd also need a SF comp or FH. http://www.thetruthaboutguns.com/2015/01/foghorn/surefire-introduce-muzzle-brake-looks-like-silencer-attaches-silencer-mount/

voodoo_man
10 July 2015, 20:06
I sort of stalled out and figured id sell the parts before I get too deep on this.

300blk isnt for me right now.