Can I get some help checking my work on a proposed low flash SBR 223/5.56 load?

[adamjma]

So, let's get a few things out of the way first:

1) I'm in Canada, so suppressors are out. Period. Please don't be that guy who says "get a suppressor". Yes, this is a sore point for us perennially abused Canadian gun owners.
2) I have a decent flash hider, Surefire Warcomp. Admittedly a 3 prong would likely be better, but I have what I have.
3) This is going on a 10.5" NON-SEMIAUTOMATIC SBR which is going to be the all round use case for defence from threats I can't run or hide from (i.e., not for sniping). Again, Canada. Yes we have dumb laws.

Working assumptions:

1) It seems reasonable to me that complete burning of the propellant in a rifle cartridge is necessary to reduce flash. This implies a faster burning powder, all else equal.
2) A good all-round projectile for the 0.224" bore is a 77 TMK, which seems to work nicely.
3) Because the barrel is short, I am giving up velocity. Trade off accepted, but I don't want to lose more than I have to.
4) I assume many fast powder loads don't work in gas guns. This is not a gas gun, so hopefully it won't be an issue.

I don't have Quickload (I may yet purchase, but for a single exercise like this I didn't feel it was worth the expenditure) but I did download Gordons Reloading Tool (GRT) to do some analysis to see what might be interesting to try.

I played around with various powders, using a 2020 powder burn speed chart from the internet to guide me towards progressively faster powders. After quite a bit of trial and error I came up with the following proposed load (particular to powders I can actually find easily locally):

19.8 grains Vihtavuori N120 over a Sierra 77 grain TMK, loaded to SAAMI length (GRT does not appear to have a 5.56 cartridge in the available cartridges).

N120 is recommended for lower to mid-weight bullets in 223 Remington, so I'm not doing anything insane like filling the case with pistol powder. It is not suggested for heavier bullets, but in this case seems to work.

According to GRT, I should get 2323 fps muzzle velocity out of that load. This seems not terrible, and I am also showing 100% of propellant burned per the attached analysis:

So, can someone with more experience in this please help me out and walk through my rambling and tell me if I am at all on the right track? If someone would kindly check my math in Quickload, especially the pressure values, I would be very thankful.

 

[straightshooter1]

So, let's get a few things out of the way first:

1) I'm in Canada, so suppressors are out. Period. Please don't be that guy who says "get a suppressor". Yes, this is a sore point for us perennially abused Canadian gun owners.
2) I have a decent flash hider, Surefire Warcomp. Admittedly a 3 prong would likely be better, but I have what I have.
3) This is going on a 10.5" NON-SEMIAUTOMATIC SBR which is going to be the all round use case for defence from threats I can't run or hide from (i.e., not for sniping). Again, Canada. Yes we have dumb laws.

Working assumptions:

1) It seems reasonable to me that complete burning of the propellant in a rifle cartridge is necessary to reduce flash. This implies a faster burning powder, all else equal.
2) A good all-round projectile for the 0.224" bore is a 77 TMK, which seems to work nicely.
3) Because the barrel is short, I am giving up velocity. Trade off accepted, but I don't want to lose more than I have to.
4) I assume many fast powder loads don't work in gas guns. This is not a gas gun, so hopefully it won't be an issue.

I don't have Quickload (I may yet purchase, but for a single exercise like this I didn't feel it was worth the expenditure) but I did download Gordons Reloading Tool (GRT) to do some analysis to see what might be interesting to try.

I played around with various powders, using a 2020 powder burn speed chart from the internet to guide me towards progressively faster powders. After quite a bit of trial and error I came up with the following proposed load (particular to powders I can actually find easily locally):

19.8 grains Vihtavuori N120 over a Sierra 77 grain TMK, loaded to SAAMI length (GRT does not appear to have a 5.56 cartridge in the available cartridges).

N120 is recommended for lower to mid-weight bullets in 223 Remington, so I'm not doing anything insane like filling the case with pistol powder. It is not suggested for heavier bullets, but in this case seems to work.

According to GRT, I should get 2323 fps muzzle velocity out of that load. This seems not terrible, and I am also showing 100% of propellant burned per the attached analysis:

View attachment 7380931

So, can someone with more experience in this please help me out and walk through my rambling and tell me if I am at all on the right track? If someone would kindly check my math in Quickload, especially the pressure values, I would be very thankful.

Running QuickLoad and the number are pretty much in line with what you're app is showing, except for a couple things. 1. Case volume of 30.1 gr of H2O is significantly higher that what QL has for a default volume (which is 28.8). So, you probably should measure your own cases (or maybe that's what you did???) as that 1.3 grs is a significant difference. 2. QL shows pressure at 61.964 psi with 30.1 gr of H2O and 68,635 psi with 28.8 H2O, so either one looks really HOT! Take a looks at the QL data:

Besides measuring your own cases for volume, you should chrono your loads and use the velocities you get to adjust the powder burn rate. Then the all numbers will be more accurate.

 

[adamjma]

Fantastic! Thanks so much for running this for me. I am new to this kind of software, so I erroneously assumed some things like case volume I should not have. I will now spend a lot more time checking the numbers that are being inputted to the calculations.

 

[db2000]

I wonder if a different flash hider might also help? Frankly, I'm not sure by how much.

Noveske KX5 Pig Flash Hider 5.56mm 1/2-28 Thread Nitride

You asked, Noveske listened. New slim design allows installation under the Noveske NSR handguard in addition to many other popular slim diameter rails....

www.midwayusa.com

 

[adamjma]

I wonder if a different flash hider might also help? Frankly, I'm not sure by how much.

Noveske KX5 Pig Flash Hider 5.56mm 1/2-28 Thread Nitride

You asked, Noveske listened. New slim design allows installation under the Noveske NSR handguard in addition to many other popular slim diameter rails....

www.midwayusa.com

Had one a while back. Thing absolutely spits fireballs!! Most definitely NOT a good choice for signature reduction but good for pushing the noise (and a massive fireball) downrange.

 

[rweaver00geo]

Shooters world Tactical powder is " flash suppressed " and Precision rifle powder " Due to its cleanliness of burn and incorporated flash suppressant, there is virtually no muzzle flash with Precision Rifle " Or so the website states. I haven't used the stuff so I do not have any personal experience with it.

 

[Broncovan]

Had one a while back. Thing absolutely spits fireballs!! Most definitely NOT a good choice for signature reduction but good for pushing the noise (and a massive fireball) downrange.

There's a reason they call it the "Flaming Pig"

 

[adamjma]

Shooters world Tactical powder is " flash suppressed " and Precision rifle powder " Due to its cleanliness of burn and incorporated flash suppressant, there is virtually no muzzle flash with Precision Rifle " Or so the website states. I haven't used the stuff so I do not have any personal experience with it.

Never heard of it, but I'll give it a look. Thanks!

 

[adamjma]

There's a reason they call it the "Flaming Pig"

Yes there is!

 

[MK20]

I have done this with a lever gun. If you make a load where the powder burns completely in the barrel AND where the pressure has dropped to almost ambient levels, your barrel is then accomplishing the same thing as a suppressor. This ballistic combo is very heavily reliant upon heavy bullet weight however.
My load in that gun is quieter than a suppressed 22.

 

[adamjma]

I have done this with a lever gun. If you make a load where the powder burns completely in the barrel AND where the pressure has dropped to almost ambient levels, your barrel is then accomplishing the same thing as a suppressor. This ballistic combo is very heavily reliant upon heavy bullet weight however.
My load in that gun is quieter than a suppressed 22.

Interesting. Thanks for that. I think I'll have to play around quite a bit to get muzzle pressure to be close to ambient. Might not be possible on such a short barrel.

 

[MK20]

if you are using 5.56 dont bother. It will have the same power as a .22 if you are using a small caliber.
with a lever gun i can basically have the bullet coming out of the barrel at around 700 fps with almost no noise. In a .44 mag this is very close ballistically to a 45 ACP. If you are using a .77 grain bullet out of a .223 you will only have enough energy to piss someone off.

 

[adamjma]

i If you are using a .77 grain bullet out of a .223 you will only have enough energy to piss someone off.

HA HA HA. Thanks.