Thread: Hodgdon /ADI BM8208 data

Greetings all,
I have been scratching my head over some chronographed loads in my .223 using BM8208. I did some comparisons recently in my .308 using BM8208 and AR2206H and others. Velocities were very close to that predicted once charge and barrel lengths were allowed for. More recently I have been sorting out some loads using the 60 grain VMax in my .223. The AR2206H load was very close to predicted, 3,140 fps actual v 3,124 fps predicted but the BM8208 was way of with only 2,940 fps actual v 3,107 fps predicted. Looking at some other data predicted 3,011 fps for the same load.
So the question is has anyone found significant differences in the speed of BM8208 or does the Hodgdon /ADI data just have a glitch?
The .308 and .223 loads used different lots of BM8208 so I should reshoot the load with my powder but would appreciate your thoughts and observations.
Thanks and regards Grandpamac.

Started load development using IMR 8208 XBR but never finished, got sidetracked. This was a few years ago but I don't recall any great differences to the Hodgdon loading data. As I said it was a while back though.
Will follow your outcome with interest.

Maybe a "slow batch"? I've got a can of AR2209 here that is closer to 2213 than it is to normal 2209. Might be useful to post up the batch number.

Cheers

there is merit it mixing/blending whats left of your old batch with your new batch and puting it back in correct tins....... any difference between batch's will then be less by degrees.....
Ive always done this....SO FAR it hasnt bitten me in the bum...but then again I have no time for chronicgraphs so its a bit of a moot point for me. as long as my old school pressure signs are consistant Im happy... accuracy over velocity.

@grandpamac do you have access to GRT or quickload and crunch the numbers with one of them?
Is your 8208 from older batches. Early on in it's introduction there was talk on US reloading forums that it had swings from batch to batch.
I have found it pretty consistent over maybe 3 years and 10 kilos.
I have been substituting 2206H for practice ammo and the difference in charge weights has remained around 1/2 grain (0.3 to 0.5 depending on bullet profile)

Greetings @johnd and all,
After a bit more digging I have reached the conclusion that some of the Hodgdon /ADI data for BM8208 has been developed using a fast batch. Other of their data falls into the around 0.5 grain difference from AR2206H mentioned above. I have settled on a load of 24.5 grains of BM8208 with the 60 grain VMax in the heavy S&B cases. I have yet to chronograph this but it shoots well at 200 metres and for 300 yard F Class it should be fine. The 12 inch twist on my VSSF rifle precludes heavier projectiles. Most .223 loads to date have used AR2201, AR2206, IMR4895 and most recently AR2206H. Of these the best suited was probably AR2206 which is just a little slower than BM8208 from my chronographing in the .308. Will report velocities when tested.
Regards Grandpamac.

Greeting again,
Having an inside morning so I graphed the two sets of data I have been working with, the Hodgdon /ADI and Data from Handloader developed by Brian Pearce. I find the graphs make it much easier to understand the difference in the data sets and where my chronographed results fit in. I worked at least part time as a draughtsman for around 50 years which may explain this. Anyway my results are very close to the Handloader data in spite of my 4 inch longer barrel and heavy cases. Hornady data is slower still likely due to a shorter barrel.
Regarding pressure an article by John Barsness I read stated that velocity was a better indicator of pressure than anything else available to a Handloader. This makes sense to me so I work up to velocities rather than powder charges. The Hodgdon /ADI data shows pretty low pressure barely over 50,000 PSI so pressure is likely held down a bit to suit the semi auto rifles. My selected load of 24.5 grains of BM8208 with the 60 grain VMax should produce the same velocity as the Hodgdon /ADI max so pressure should be similar and I will go with that for the present.
Regards Grandpamac.

I don't rely on velocity alone and use all info available to sense/predict pressure.
Chrony obviously compared against loading charts. QL analysis and of course physical signs.
I don't stress too much if actual velocities don't closely match the loading table - there are too many variables that can cause that.
Different rifles can give different results or even earlier than expected pressure signs.
There are documented stories of guys with matching F class rifles - same action/barrel/loads/similar round counts, getting different velocities.

I might also add that 2 of my cartridges didn't have (one still doesn't) any manufacturer's reloading tables. Only info was network postings which you have to be very careful with.
Due to an optical chronograph giving an incorrect reading due to the sky conditions I actually went into severe overload. Found this out later on the next outing when I set the chronograph up under the shade of some pines. The optical chronograph had overstated the velocity by 100 feet per second. There was no swipe marks but the primer pockets had expanded as had the base measurement. Fortunately that was in a very strong action (Barnard) with very good gas venting should things have let go.
After that I went and treated my self to a magnetospeed.

Greetings @zimmer,
I still look very hard at chronograph reading that do not match predicted velocity and also tend to stop adding powder too soon which beats the alternative. My chronograph is a 35P that I run with a 4 foot screen spacing. Velocities are read twice and the machine alerts me if the two readings do not match to a reasonable level. I see that Oehler still offers much the same screens 30 years later in their latest offering. I also do not chronograph in bright sunlight conditions for the reason you noted. One of the advantages of having a home range. I also steer clear of load data from the intrepid years. There was some fire cracker hot data out there in load manuals until quite recently. I guess the more that you learn about handloading the less intrepid you are. Some old saying about old and bold springs to mind.
Regards Grandpamac.

Hi @grandpamac there is a huge following in the states for the 77gr TMK pushed by 8208. One long time shooter and loader claimed better velocities with 8208 than 4895. I have tried both with that projectile and have found very slight difference in velocity in favour of 2206h. To be honest, I’m not convinced my chronograph readings are 100%. Varying light levels as well as small data sets makes it hard to draw solid conclusions….
I recall @Mathias found higher pressure for similar velocity in the 6x45 with 8208 vs 2206h

Originally Posted by Hunter_Nick

Hi @grandpamac there is a huge following in the states for the 77gr TMK pushed by 8208. One long time shooter and loader claimed better velocities with 8208 than 4895. I have tried both with that projectile and have found very slight difference in velocity in favour of 2206h. To be honest, I’m not convinced my chronograph readings are 100%. Varying light levels as well as small data sets makes it hard to draw solid conclusions….
I recall @Mathias found higher pressure for similar velocity in the 6x45 with 8208 vs 2206h

Almost right Nick. It was IMR 8208 & H335 I found with equal loads, the 8208 was showing higher pressure signs & almost identical speed in the 6x45.

I am using the 8208 in my 20" 1:12 223 with 52gr Targex for 3245fps. I was expecting a bit more speed than that, but accuracy is superb, so not hunting down anymore fps.

Sent from my SM-S906E using Tapatalk

Originally Posted by Mathias

Almost right Nick. It was IMR 8208 & H335 I found with equal loads, the 8208 was showing higher pressure signs & almost identical speed in the 6x45.

I am using the 8208 in my 20" 1:12 223 with 52gr Targex for 3245fps. I was expecting a bit more speed than that, but accuracy is superb, so not hunting down anymore fps.

Sent from my SM-S906E using Tapatalk

Sounds about right for the 52grn .223. BM2 tops out at about 3275.

I'm using 8208 with 55gr Speer Gold Dots and 69gr TMK's. I've also used/am using it in 6.5 Grendel, 6mm-204 Ruger, 284 Winchester, and 308.

My data almost never lines up perfectly with Hodgdon/ADI (not just for 8208 either) but so what? Lot to lot variations happen all the time and there's plenty of other variables that will be different between your rifle and Hodgdon's test rig.

I would focus on what on what the speed you're getting in your rifle suggests you should do, rather than spend too long scratching your head over a small disparity.

Greetings @Pommy,
Thanks for your responce and suggestions. I have pretty well decided on 24.5 grains of BM8208 for the 60 grain projectiles. The load shot well at 200 metres and the rifle now has a rough zero for the next 300 yard shoot. The head scratching and trying to find out why things are, in the handloading field is due to me having the time, interest and inclination. It all started about 5 years ago when I became fully retired and decided to sort out a decent load for my pet 6.5x55, a cartridge which has more than its share of conflicting load data. I found this highly enjoyable and the cartridge of interest has moved on resting on the .223 currently. Others are waiting their turn. Currently in my 75th year and a non drinking person that does not get out that much this chasing of handloading knowledge keeps my brain active and me interested. Each to their own I guess.
Regards Grandpamac.