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Hey guys. Has anyone had any experience loading
22-250 AI? I've recently purchased one and have the brass and dies. Was told load development had been started with ADI Benchmark 2. I have bottles of this but cant find any data in load book or website about using that powder and how much to use. I know I've used that powder in 22-250 before. Just wondering if anyone has any experience or advice on this. I'm running 50gr Hornady Vmax
@nznoddy
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For Ackley cartridges, you can use the load data from the original as your start point. FYI "ADI Benchmark 2" = "Hodgdon Benchmark".
You can head to the Hodgdon/ADI websites and look what they say about using BM/BM2 in a 22-250... 33.5gr to 36gr for a 50gr Sierra SP... The VMax will be similar. You've got more case capacity over a straight 22-250 so I'd start around 35gr and go up.
Thank you I will start with that and work my way up.Quote:
Originally Posted by Pommy
What you will find is that a given weight of powder will produce LESS velocity in an AI case compared to the standard, because of the increased case capacity in the AI. So expect to be above the listed max powder charge to get the same velocity. With the right powder the 22 250 can really fly - according to a bloke I used to know who had both versions.
Greetings Curtis27,
There are some simple ways to calculate what should be possible but you need to know the net volume of the parent and improved cases. Obviously the improved case needs to be fire formed. You can measure the case volumes by filling each type of case with either ball powder to the base of the neck. Weigh the result and calculate the increase in percent Divide the percent increase by 4 and this is the possible increase in velocity over the ADI listed maximums all else being equal. You can work up to this carefully using the chronograph to tell you when to stop.
This velocity will be less than claimed by many but it will be at factory pressures. I can do a worked example for you if you like.
Regards Grandpamac.
Greetings again Curtis27,
Nosler has data for the 22-250 AI in its online data but the only ADI powder listed is Varget (AR2208). They also list net case capacities for each projectile. The increase in case capacity is about 10% which should allow a 2.5% increase in velocity, roughly the difference in their loads. If your rifle had a new barrel it may have a faster twist than the standard 1 in 14. Worth measuring as this may allow a wider choice of projectile weights.
Grandpamac.
Thank you very much for that @grandpamac. So with that calculation, I run 35.5gr Benchmark 2 in my standard 22-250, the Ackley improved being 10% more case capacity, divided by 4, giving 2.5%, would I increase the powder charge by 2.5% to hope for roughly the same speed as my standard 22-250?Quote:
Originally Posted by grandpamac
I know every rifle is different and I will work my way up to that but is that the idea?
Greetings Curtis27,
Unfortunately its not that simple. The 2.5% increase refers to possible velocity. As Moa Hunter said in his post above it takes more powder just to equal the standard velocity. If you look at the Nosler data for each cartridge with AR2208 an additional 4 grains of powder was needed to get the extra velocity and almost 3 of those grains just brought the velocity back up to the velocity of the standard cartridge. Nosler got good results with AR2208 and this is likely a better powder for the AI but by all means start with your BM 2 at 35.5 grains and work up but I suspect you may not get much more velocity than standard. You are looking for a little over 3,900 feet per second assuming your barrel is the standard 24 inches. As you said above the AI can shine with the right powders. I suspect it shines most with the heavier projectiles if your barrel twist allows.
I suspect that you may not have a chronograph and to my mind they are an essential tool for any hand loader let alone a wildcat hand loader as you have recently become. If you don't have one see if you can team up with someone who has. I am sure that there is someone in Dunedin that knows more about the .22 - 250 AI than either of us. It's just a matter of finding them. One last thing. If something sounds to be too good to be true with load data then it almost certainly is. Same as any other endeavor.
Regards Grandpamac