For those loading 300 Blackout

[Dolomite_supafly]

I found this and not sure how long it will be publically posted.

 

http://sierrabullets.files.wordpress.com/2013/07/300-aac-blackout.pdf

 

It is the first time I have seen Sierra load data for the 300 Blackout It is different than Sierra's 300 Whisper load data. I will say that the Whisper load data has more options and works for a 300 Blackout but may not cycle all AR's. The Whisper data works with my AR but it will cycle with a lot more powders than most Blackout AR's too.

 

The load data provided by Sierra for the Blackout was tested in an AR. Unfortunately it doesn't have subsonic load data.

 

Make sure to save yourself a copy because this is some great information.

 

BTW, the PDF above is linked from here:

http://sierrabullets.wordpress.com/2013/07/17/300-aac-blackout-medium-length-gas-tube/

Edited September 7, 2013 by Dolomite_supafly

[Lumber_Jack]

When they say "medium length gas tub" are they meaning carbine?

[173rdABN]

It's longer than carbine and shorter than standard/full length

[Lumber_Jack]

Yeah sorry for the confusion, I understand what a mid-length gas system is, I've just never seen anything over carbine length in 300 BLK.

I can't imagine a true mid length gas system on a .300 BLK would function very well

[Dolomite_supafly]

It's longer than carbine and shorter than standard/full length

 

There is no such animal for the 300 Blackout. Midlength is NOT medium length.

 

Carbine is considered the medium length gas tube. Pistol is the short length, rifle is the long length and carbine is medium length.

[Dustbuster]

Dolomite u are a gentleman and a black rifle scholar thanks!!!!

[173rdABN]

Didn't know his level of knowledge. Figured he meant mid length so I tried to make it easy to understand.

Thanks for the proper terms and correcting it.

[Luke E.]

I found this and not sure how long it will be publically posted.

 

http://sierrabullets.files.wordpress.com/2013/07/300-aac-blackout.pdf

 

It is the first time I have seen Sierra load data for the 300 Blackout It is different than Sierra's 300 Whisper load data. I will say that the Whisper load data has more options and works for a 300 Blackout but may not cycle all AR's. The Whisper data works with my AR but it will cycle with a lot more powders than most Blackout AR's too.

 

The load data provided by Sierra for the Blackout was tested in an AR. Unfortunately it doesn't have subsonic load data.

 

Make sure to save yourself a copy because this is some great information.

 

BTW, the PDF above is linked from here:

http://sierrabullets.wordpress.com/2013/07/17/300-aac-blackout-medium-length-gas-tube/

 

 

 Thanks much for posting this!

[Guest 6.8 AR]

There is no such animal for the 300 Blackout. Midlength is NOT medium length.

 

Carbine is considered the medium length gas tube. Pistol is the short length, rifle is the long length and carbine is medium length.

You know that someone will find one, now. :D Probably Cheaper than Dirt, or that other place in Texas that sells junk.

[Dolomite_supafly]

Actually a length somewhere between carbine and pistol would be better than all the carbine lengths out there. Carbine lengths have so many issues with subsonic ammo, with and without a suppressor. Pistol length is the best for subsonic ammo but can be over gassed with supersonic ammo and 16" barrels unless you meter it.

[TNRat]

I don't recall having seen an upper for sale lately with a carbine length tube. All have had pistol length tubes, no matter the barrel length.

 

Thanks for the pdf.

[Lumber_Jack]

The vast majority are carbine length gas systems. You have to actually search to find a pistol length gas system with a .750" gas pad. They are out there but they are rare.

 

The originator of the 300 Blackout called for a carbine length gas system. It was when people started wanting to SBR them that they began making them with a pistol length gas system.

 

When I built mine, about a year and a half ago, I had to custom order a barrel to get it with a .750" gas pad with a pistol length gas system.

 

 

Yep, I do think CMMG makes a 16" pistol gas now.  I also noticed that all the Noveske barrels on Rainier Arms are pistol gas regardless of length

[Luke E.]

Yep, I do think CMMG makes a 16" pistol gas now.  I also noticed that all the Noveske barrels on Rainier Arms are pistol gas regardless of length

 

 CMMG does make a 16" barrel with pistol gas, I have one on my rifle. The hiccup is that it has a .936 gas pad rather than the .750 and that makes it hard to get an adjustable gas block under a free float rail or tube. I bought a Wilson combat adjustable block and a quad rail that is narrow like the DD rails but I did spend a little time doing some "strategic" Dremel work to make it fit. It was either that, buy a custom barrel or have the gas pad turned down on this CMMG so I decided to try this way first.

[Lumber_Jack]

CMMG does make a 16" barrel with pistol gas, I have one on my rifle. The hiccup is that it has a .936 gas pad rather than the .750 and that makes it hard to get an adjustable gas block under a free float rail or tube. I bought a Wilson combat adjustable block and a quad rail that is narrow like the DD rails but I did spend a little time doing some "strategic" Dremel work to make it fit. It was either that, buy a custom barrel or have the gas pad turned down on this CMMG so I decided to try this way first.

Good info, I was unaware the gas pad was that size. Do you know why they are that way? Seems unnecessary.

[Luke E.]

Good info, I was unaware the gas pad was that size. Do you know why they are that way? Seems unnecessary.

 

 They are a heavy profile barrel and it steps down in size the further towards the muzzle you go so out where a carbine port would be the diameter is smaller than back where a pistol port would is. Now why no one offers one commercially that is turned down earlier I don't know but they could sell a bunch of them if they did. Dolomite had his custom made and he loves his so there's obviously nothing inherently with designing one with a .750 gas pad. He might could shed a bit more light on this since he has poured over all things Blackout to a much further degree than I have.

[Dolomite_supafly]

I have no clue why they make them with .936" gas pads. Make no sense to me to me why they did especially when you consider there is probably 100x as many items for a .750" gas pad than a .936".

[Lumber_Jack]

They are a heavy profile barrel and it steps down in size the further towards the muzzle you go so out where a carbine port would be the diameter is smaller than back where a pistol port would is. Now why no one offers one commercially that is turned down earlier I don't know but they could sell a bunch of them if they did. Dolomite had his custom made and he loves his so there's obviously nothing inherently with designing one with a .750 gas pad. He might could shed a bit more light on this since he has poured over all things Blackout to a much further degree than I have.

Yeah that seems odd. I think the Noveske 16" had a standard .750 pistol gas pad. But it's $455. I very well may order one as Dolomite did, it's a great value

[Luke E.]

I have no clue why they make them with .936" gas pads. Make no sense to me to me why they did especially when you consider there is probably 100x as many items for a .750" gas pad than a .936".

 

 I agree, it was a headache to have to do so much looking to find a barrel compatible with gas blocks or to look for gas blocks to work with the barrel. Someone could gain themselves a large share of the 16" Blackout barrel market with a decent quality barrel with pistol gas and .750 pad.

 

Yeah that seems odd. I think the Noveske 16" had a standard .750 pistol gas pad. But it's $455. I very well may order one as Dolomite did, it's a great value

 

 If I had it to do over again I probably would have had one made like Dolomite did but at the time I wanted it done and parts were still tough to find because of our idiot in chief.

[Dolomite_supafly]

I know there are cheaper barrels out there and who knows they might work as well as mine but I am tickled pink with my McGowen barrel. It was $225 at the time for a SS 16" barrel made on a blank and that included the price of the blank. Now I think he charges $240 shipped for a barrel. He will also do it to your specs.

 

Sucks that I am getting ready to chop 7" off the barrel for my SBR.

[Lumber_Jack]

I know there are cheaper barrels out there and who knows they might work as well as mine but I am tickled pink with my McGowen barrel. It was $225 at the time for a SS 16" barrel made on a blank and that included the price of the blank. Now I think he charges $240 shipped for a barrel. He will also do it to your specs.

Sucks that I am getting ready to chop 7" off the barrel for my SBR.

Do you think that's the best option? I've debated buying a 16" pistol gas from him and then cutting down after SBR paperwork comes back, but would it be more feasible to sell the barrel and buy a new shirt barrel?

[Dolomite_supafly]

I would buy a short barrel before ordering a barrel and later having it cut down. I am actually debating on buying a short barrel myself and setting the 16" aside for now rather than cut those 7" off.

 

BTW, Alpha has a few in stock. Here is a 14.5" with a .750" gas pad. I think they have seen the need for them.

 

In the past they have had short barrels in stock for $120 which is a deal.

[Luke E.]

I know there are cheaper barrels out there and who knows they might work as well as mine but I am tickled pink with my McGowen barrel. It was $225 at the time for a SS 16" barrel made on a blank and that included the price of the blank. Now I think he charges $240 shipped for a barrel. He will also do it to your specs.

Sucks that I am getting ready to chop 7" off the barrel for my SBR.

Unless I'm remembering wrong my CMMG barrel cost about $200 so it's definitely worth it to go your route for less than $50 more.

[Il Duce]

Dolo, do you have a link for the Alpha barrels? I searched Google and came up empty.

[2.ooohhh]

Dolo, do you have a link for the Alpha barrels? I searched Google and came up empty.

http://www.shop.ar15hardware.com/

[Il Duce]

Thank you