BM8208 and the 223

[mitchellchandler_au]

Hi all,
So the situation is I have a Tikka with the 1:8 twist barrel. I also have a quantity of 8208 from another project and a heap of 80gn noslers for my F standard rifle. I was toying with the idea of trying 8208 with the 80gn to use it up. Does anyone have any experience with 8208 in the 223 with the heavier projectile?
Thanks,

[DenisA]

Following. Soon to start testing myself.

[scott/r]

Hi all,
So the situation is I have a Tikka with the 1:8 twist barrel. I also have a quantity of 8208 from another project and a heap of 80gn noslers for my F standard rifle. I was toying with the idea of trying 8208 with the 80gn to use it up. Does anyone have any experience with 8208 in the 223 with the heavier projectile?
Thanks,

Mitchell, I have have tried 8208 in a 223, but it was in a 26" 1:9 twist barrel with 70 & 75 grn Bergers. I personally found it a bit hit and miss, so to speak. I found 2206h was a lot better for both projectiles for consistent grouping. In saying that, 8208 was a bit better through the chrony 2206h, with a lot smaller es and sd measurements. They seemed a lot more consistent on loading bench as well, probably because of the smaller granuals of powder.
At the end of the day, there's only one way to find out if it'll work in your rifle, get out there and give it a go. If the worst thing to come out of it is that you get an extra couple of hours on a range, then you are already ahead.
Scott.

[mitchellchandler_au]

Some prelim testing is showing groups around 1" with a sd of 12 and average velocity of 2560fps, that's with 21 grains of 8208. The load doesn't seem very hot so i might try 22 grains. All else failing will give 2208 a go. I decided to junk the ADI cases i was using. Neck thickness running around 0.004" over 10 cases. I have some new lapua sitting around so i might try these as well.

[DenisA]

Some prelim testing is showing groups around 1" with a sd of 12 and average velocity of 2560fps, that's with 21 grains of 8208. The load doesn't seem very hot so i might try 22 grains. All else failing will give 2208 a go. I decided to junk the ADI cases i was using. Neck thickness running around 0.004" over 10 cases. I have some new lapua sitting around so i might try these as well.

Hi Mitchell, what type of chronny are you using?

Also, is that 1” at 100y?

[mitchellchandler_au]

Hi denis,
I was using a labradar. Yep 1 inch at 100 yards

[AlexE]

Some prelim testing is showing groups around 1" with a sd of 12 and average velocity of 2560fps, that's with 21 grains of 8208. The load doesn't seem very hot so i might try 22 grains. All else failing will give 2208 a go. I decided to junk the ADI cases i was using. Neck thickness running around 0.004" over 10 cases. I have some new lapua sitting around so i might try these as well.

How long is your barrel? 8208 will have no trouble driving a 80gr projectile close to 3000fps in a 30 inch barrel. I'd suggest you could be low by more than one whole grain

[DenisA]

Something I've learned in my current .223 journey is that one of the characteristics of the .223 Rem that needs to be approached with CAUTION is comparing powder charges in different rifles with different chambers. There can be a huge amount of variation especially between factory rifles and target rifles. Being such a small cartridge, if someones trying to run a comparatively big 80.5gn bullet in a standard SAAMI spec chamber then chamber pressure will skyrocket quickly especially using fast powders like BM8208.

Obviously, given that the .223 cases are the same size and the 80.5gn bullets for example are the same size, the shorter the Cartridge Over All Length, the more bullet is sitting inside the case, essentially the smaller the powder chamber is. A smaller combustion chamber for the same load equals higher pressure spike.

The specs I've found in the Berger manual work on a 24" barrel, COAL base to meplat of 2.260" (very short COAL). With an 80.5gn bullet the starting load is 19.0 gn and max load is 21.3gn BM8208, MV at approximately 2718 fps. Entering those specs into Quickload, the max load suggests that chamber pressure will be in the vicinity of 55,000 PSI. If someone tried to push that to 3000 fps, it would take approximately 23gn BM8208 with dangerously high chamber pressure of approximately 70,000 psi. The shooter may find out too late.

Like many other target .223's, the chamber I'm running in my sons 30" barrel is throated long. The COAL of 2.565" is a .010" jump. Using Quickload, at those specs, 21.3gn BM8208 results in approximately 2690 fps and only 43,000 psi. To get that chamber pressure up to ball park equivelant chamber pressure of the max load 55,000 psi would take approx 23gn BM8208 with a MV of 2900 fps.

SAAMI spec max chamber pressure for a .223 Rem IS 55,000 psi. Adhering to that limit with a factory chamber might be very difficult when trying to run heavy bullets and fast powders. How much does that go up again in Summer conditions?

Another variable that's seems fairly volatile is the brand of brass. Some brands seem to have reasonably less powder chamber volume than others which would also factor heavily into the equation.

All I'm saying is be careful developing small cartridges, heavy bullets and fast powders, get the details and understand the chamber specs of the "advice givers" rifle.

I'm sure you guys know this already but I thought it might be pertinent to anyone none the wiser interested in this thread.

[AlexE]

Something I've learned in my current .223 journey is that one of the characteristics of the .223 Rem that needs to be approached with CAUTION is comparing powder charges in different rifles with different chambers. There can be a huge amount of variation especially between factory rifles and target rifles. Being such a small cartridge, if someones trying to run a comparatively big 80.5gn bullet in a standard SAAMI spec chamber then chamber pressure will skyrocket quickly especially using fast powders like BM8208.

Obviously, given that the .223 cases are the same size and the 80.5gn bullets for example are the same size, the shorter the Cartridge Over All Length, the more bullet is sitting inside the case, essentially the smaller the powder chamber is. A smaller combustion chamber for the same load equals higher pressure spike.

The specs I've found in the Berger manual work on a 24" barrel, COAL base to meplat of 2.260" (very short COAL). With an 80.5gn bullet the starting load is 19.0 gn and max load is 21.3gn BM8208, MV at approximately 2718 fps. Entering those specs into Quickload, the max load suggests that chamber pressure will be in the vicinity of 55,000 PSI. If someone tried to push that to 3000 fps, it would take approximately 23gn BM8208 with dangerously high chamber pressure of approximately 70,000 psi. The shooter may find out too late.

Like many other target .223's, the chamber I'm running in my sons 30" barrel is throated long. The COAL of 2.565" is a .010" jump. Using Quickload, at those specs, 21.3gn BM8208 results in approximately 2690 fps and only 43,000 psi. To get that chamber pressure up to ball park equivelant chamber pressure of the max load 55,000 psi would take approx 23gn BM8208 with a MV of 2900 fps.

SAAMI spec max chamber pressure for a .223 Rem IS 55,000 psi. Adhering to that limit with a factory chamber might be very difficult when trying to run heavy bullets and fast powders. How much does that go up again in Summer conditions?

Another variable that's seems fairly volatile is the brand of brass. Some brands seem to have reasonably less powder chamber volume than others which would also factor heavily into the equation.

All I'm saying is be careful developing small cartridges, heavy bullets and fast powders, get the details and understand the chamber specs of the "advice givers" rifle.

I'm sure you guys know this already but I thought it might be pertinent to anyone none the wiser interested in this thread.

Sage advice. I should have qualified my post with something akin to your post. I did do some "what ifs" in quickload the same as you. Based on the information provided he's either running a fairly short barrel, or an oal much longer than SAAMI spec

If the OP would like to share some particulars such as oal, case capacity and barrel length, one or more of us can probably provide some much better advice

[Brad Y]

8208 is a brilliant powder. With varmint bullets. I always had better luck with 2206h in the tikka 8 twist factory barrel.
Over 3700 with 40's in a 12 twist Krieger with 8208

[DenisA]

I started loading some test rounds on the weekend. First time using BM8208. The tiny kernels weigh 0.01gn each as compared to AR2206H at approx 0.015gn and ar2208 at 0.02gn.

Just have to wait now until 2021 when the ranges open again to actually test.

[mitchellchandler_au]

Got a bit of testing done before the Asian pox closed me down. I decided on sticking to AR2208 and lapua cases. I used 24.8gn with the nosler 80gn. Groups were around 0.75" with a SD of 10fps and velocity of 2880fps. I got 25.0gn to try next but wont be doing that till the pox pisses off.

[Jacoll]

Hi, I've had good results with 8208 in a 31" target rifle using both nosler 80 and 80.5 fullbores. ADI brass has been excellent, had a problem using win sr primers so changed to rem 7 1/2 all good. I am getting around 3000 FPS with an es of 20 and .5 moa . It really depends on your barrel length and chamber, my coal is 2.525. I bought a copy of quickload and it has helped me no end.
Work up slowly and check for pressure signs. Happy to run some figures in qload if you wish. Regards Richard