I ran with book max of 29.3gr, being I am running a Howa mini. Speed was there in the 18.5” barrel but it lacked accuracy. I did a little research and Internet lore claimed 28.5gr was the sweet spot. Loaded up 5 and let them rip. Albeit 50y, this is the type of accuracy I’m chasing.
What is the COAL with 29.6? I know you’re running a bolt gun and all, but that much powder has to be coming up the neck of the case pretty far… I am getting crunchy at @27.5gr of most extruded powders with 2.260 COAL…
Those velocities seem low for a 120gr bullet with that much 8208 in an 18.5”.
In a gas gun and an 18” barrel with 123s I am seeing 2500fps at 28.3gr. It is with 123 ELDMs so there will be some difference but that feels like a lot.
28.3 seems awefuly hot when I look at my load data for 8208 and 123. The brass from bullets hitting much over 2400 seemed to be showing some hard signs of over pressure
It’s almost max in Lyman’s and over max in a number of others. Definitely a hot load and not one I would go up right up to. (CCI450, 8208xbr 28.3, 123ELDMs, 2.255”)
I know others have more easily matched this velocity with 2520 and leverevolution which I might try soon because while it will show no pressure signs the vast majority of the time ( I have shot over 5k of this) every once in a while it will leave swipes on every other piece of brass (hornady). 8208 behaves a little erratic at high charges.
But yea this is higher than my other Hornady, Sierra, and hodgedon data.
The only other source that gives anything this high is the Grendel reloading handbook. But I take that with a grain of salt since it really compiles data rather than tests loads.
Let me be very clear though, i don’t recommend anyone push up to that load. I just know it works in MY rifle.
I just had a thread about why I had trouble getting a predictable result with a ladder charge test with 8208 123 in a 6.5
I maxed out under your load and have no interest in going that high, if I can get 2400 ish fps with this setup out of a 20 inch barrel I’ll be happy with its place in my gun collection.
Your post just caught my attention for being a full grain above what i shot
It’s all about use case. I wouldn’t push velocity to the edge if I wasn’t shooting an 18” Grendel to 1K yards several times a month. But for me leaving 100fps on the table matters.
Forgive me for all of the questions, crimping or no?
Nice setup.
I’m looking to learn 500 yards and reading wind, so I don’t need the extra 100
Thank you so much for all this info so far
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u/Trollygag 8d ago
You need more than just 5 rounds to compare.
5 shot group variance is >50% group to group just from probability and getting one that is double or half the size happens regularly.
Same for SD numbers.