300 Blackout Bolt Gun Loads

Suputin

Suputin

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Finally decided to develop some loads for my 300 Blackout Rem 700. Its only been a year since I built this rifle. :roll eyes:

All the following loads were built with 200gr bullets.

N320 6.3gr
Avg Vely: 997 fps

AA#5 7.0gr
Avg Vely: 978 fps

HS6 8.0gr
Avg Vely: 1135 fps

Blue Dot 9.0gr
Avg Vely: 1232 fps

W296 9.7gr
Avg Vely: 1136 fps

Next step is to see how accurate these loads are.
 
You Dont state what bullet cast/ jacketed
what twist
What is/was the standard deavation when you did your velocity test

Lots of powder will work in a bolt gun where they will not work in a gas gun(semi auto)

Not a expert but the only powder you list that i have seen used in a gas gun is 296 (that in top loading can give short primer pocket life)

Hodgdon just put some new data on there web site

the most accurate load will be one with a lower standard deavation
 
Not saying it is the best powder but I have heard good thing about Accurate 1680 and the 300 Blackout

there is also other good powders that will not work in a semi that great in a bolt gun

also look for 300 Whisper data
 
Accurate 1680 is used in semi-auto's. It would be un-necessarily loud in a bolt gun.

I did some more testing today.

HS6 7.0gr 200gr bullet: 981 fps

BlueDot 7.0gr 200gr bullet: 965 fps

Just for fun tried a case full of Trailboss under a 150gr bullet. 6.0gr Trailboss: 791 fps and stupidly quiet.


I also did some accuracy testing on the loads from the other day (post #1)

For some reason that I can't work out, AA#5 consistently threw the first shot of the group way right and high. It did this with both bullets that I tried. The strange thing is this powder actually shows potential as it produced a couple of pretty tight groups .... if we ignore the first wild flyer. In one group it placed three rounds into a 0.35MOA cloverleaf .... however the first round of that group was nearly 4" right and high which is a bit annoying.

The N320 performed much more consistently and did not throw flyers. Groups with the 208 AMAX were the most consistent hovering around 1.75 MOA. I had one group that put 4 rounds into 0.77 MOA which was pretty impressive.

N320 groups with the Lapua 200gr subsonic bullet showed excellent vertical dispersion but tended to be quite wide. There was a fair bit of wind and shooting conditions were not ideal so this bullet bears some more testing to see if it can produce decent accuracy.
 
awesome work, I'd like to see how these perform.
I'm growing increasingly frustrated with searching out loads for bolt guns. Most are all gas, so it's the same powders over and over - ones I can't find.
 
Right now I am in the 1.5 - 2 MOA region but I am certain that can be improved with a bit of tweaking. I just needed a place to start from and some options for powders. Right now I have at least three potential powders that seem worthwhile and a couple of others that are OK for quiet plinking loads.

These are neat little rifles and I need to use mine more often. It was something I really wanted to build for a long time and then got caught up with other stuff and didn't do much with it so far.
 
Once I finish some more testing I'm going to start a thread like this for use in semi auto's.
So far I have my load with 110gr V-max pushed with 19.4gr of H110 doing pretty close to 1 MOA at 100yds and have found 15gr of Lil'gun is the minimum charge to cycle 155gr A-max projectiles and 12gr of AA-1680 is minimum that will cycle a 208gr A-max.
I've only done function testing so far with the heavier ones.

Testing done with my PWS Mk109 9.75 inch barrel piston operated AR.

Love the 300BLK cartridge. Just hate losing brass from the semi :( gotta remember the brass catcher every time I head out ;)

One of these days I'm gonna find a rifle I can rebarrel into a 300BLK bolt gun :)
 
One of these days I'm gonna find a rifle I can rebarrel into a 300BLK bolt gun
Click to expand...

A Rem 700 in 17 Fireball is the best choice. The Fireball being one of the parent cases for the BLK means the ejection system is designed for the shorter case and thus works better than anything in the 223 class of cases. A quick google of "Remington 700 17 Fireball Canada" turned up several options. The 17 is not that popular a cartridge so these rifles are not difficult to find on sale.

PS Order a barrel blank now so you will have it available by the time you decided to buy the rifle. My last blanks took a year to get.
 
Suputin said:
A Rem 700 in 17 Fireball is the best choice. The Fireball being one of the parent cases for the BLK means the ejection system is designed for the shorter case and thus works better than anything in the 223 class of cases. A quick google of "Remington 700 17 Fireball Canada" turned up several options. The 17 is not that popular a cartridge so these rifles are not difficult to find on sale.

PS Order a barrel blank now so you will have it available by the time you decided to buy the rifle. My last blanks took a year to get.
Click to expand...

You'll be building it for me so I'll just give you money when I'm ready and leave the rest to you. ;)
I'll take one of your special quiet barrels please :xes

:cheers:
 
Suputin said:
A Rem 700 in 17 Fireball is the best choice. The Fireball being one of the parent cases for the BLK means the ejection system is designed for the shorter case and thus works better than anything in the 223 class of cases. A quick google of "Remington 700 17 Fireball Canada" turned up several options. The 17 is not that popular a cartridge so these rifles are not difficult to find on sale.

PS Order a barrel blank now so you will have it available by the time you decided to buy the rifle. My last blanks took a year to get.
Click to expand...


Got the 17 Fireball Rem 700 :)
Too bad the one I got only has 38 rounds down the pipe, I'll have to multiply that number before yanking it to sell for the 300BLK project.
 
Suputin said:
I ran into the same problem. Bought a Savage Precision Carbine to convert to 30 BR but the rifle shoots so well as a 308 I can't bring myself to tear it apart. Now I need another donor rifle for the 30 BR.
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Aren't you glad I talked you into buying the .17FB Rem 700? ;) From time to time, I accidently grab a .223 bolt from one of my other 700's and you can tell right away that the wrong bolt was chosen. The ejection is so much more positive on the .17/.221 FB versions.

Having said that, IMHO there's no better action for a .300 Blackout than a Howa 1500/Weatherby Vanguard. They absolutely rock and I've never had even the slightest issue with mine. Feeds from the internal mag far better than the Remington, especially with lighter bullet weights and round nose bullets in general. I tried a feeding experiment one time where I loaded up a mag of 110gr. RN and 220gr. RN, each alternating in the same mag. I thought this would be problematic but it wasn't. Fed no different than if the magazine was loaded with identical rounds.
 
Yes, I think the 17 FB based rifle is the best donor to start with and I have recommended such to others.

I do have some feeing issues with mine but they are inconsistent and seem to be worse when slowly running the bolt forward. I have the 223 internals for the Rem mag system and will try that next to see if it makes any improvement.
 
Suputin said:
Yes, I think the 17 FB based rifle is the best donor to start with and I have recommended such to others.

I do have some feeing issues with mine but they are inconsistent and seem to be worse when slowly running the bolt forward. I have the 223 internals for the Rem mag system and will try that next to see if it makes any improvement.
Click to expand...

It made a definite improvement in my set up. Well worth the switch. I've never seen a mag and follower from a .300 Blackout SPS and compared it to either the FB or .223 set up to see if there's commonality there.
 
Pulled apart my rifle today and discovered that I had already installed the 223 mag parts. The pics below show the difference in the cartridges between 17 FB, 223 Rem and 300 Blackout as well as the difference in the magazine parts. As you can see it is not possible to run 300 BLK in the OEM 17 Fireball magazine. Luckily the three bits required: Mag Box, Spring, Follower are all inexpensive and easily available through Brownells.

IMG_2963.jpg



Magazine: 17 FB on the left, 223 Rem on the right

IMG_2964.jpg


IMG_2966.jpg
 
I'll be back to playing with mine this month.................got a few rounds loaded up and ready to try out 4 new powders

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Suputin said:
Finally decided to develop some loads for my 300 Blackout Rem 700. Its only been a year since I built this rifle. :roll eyes:

All the following loads were built with 200gr bullets.

N320 6.3gr
Avg Vely: 997 fps

AA#5 7.0gr
Avg Vely: 978 fps

HS6 8.0gr
Avg Vely: 1135 fps

Blue Dot 9.0gr
Avg Vely: 1232 fps

W296 9.7gr
Avg Vely: 1136 fps

Next step is to see how accurate these loads are.
Click to expand...

What OAL are you using?
 
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