Hello I have a Howa 223 with a 1 in 12 twist.
I have rem cases, cci small rifle primers, ADI Benchmark 1 powder and Sierra 52 grain hpbt projectiles.

Does anyone have any info for how much grains for min and max ?
Or do you have a load using this powder and projectile that works for you ?

I read somewhere that the min and max is 21 to 23 grains but then on another site said 23.5 to 26.5 grains so I'm not sure.
On the ADI website it has 50grain hornady sp start is 22 and max is 24.5 grains of benchmark.
But then a 53grain sierra hp is 21 and 23 grains max.

I have tried 21.8 to 22.8 grains and best group was 1 1/4 inch at 100 yards which was disappointing

Also does anyone have any info for the same load but with 55grain hornady v-max ?

Thanks

Sorry, never met anyone who used BM1 before - I use BM1 and others use AR2206H, which doesn't help you, I know.

Lots to be said here. You are justified in your disappointment, for sure.

But lets take it one step at a time.

First the nomenclature *( ID ) of a rifle/cartridge is often too incomplete. There is lots of confusion about the thousands of different cases/calibers. Just saying .223 isn't sufficient since there can be 5 or 6 different ones.

Second the HOWA reputedly has a mixed reputation among owners. Some good, some bad. The bad ones are really bad. Hundreds of dollars were spent re-crowning barrels, glass bedding, changing triggers and more to no avail. Others *( The majority ) had very good success. That gun combination should shoot 1/2 MOA.

It is truly a wooly booger of a task to perform the forensics. There are so many aspects to consider.

I ran your recipe through internal ballistics software and I want to say that quite typically changing any criteria, bullet weight, bullet type, bullet construction, powder load reflects back in significant differences in velocity and pressure. So what you are seeing from one data set to another isn't a mystery. It is typical. It gets very involved and takes a lot of explaining, far too voluminous to post here.

I found this video on U Tube which shows factory ammo giving groups a lot better than your MOA's.

https://www.youtube.com/watch?v=Pm_oDYzEtFc

Sorry I don't have the magic answer. But keep plugging. Something good will happen with persistence and determination.