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08-17-2020, 02:59 AM
(This post was last modified: 08-17-2020, 03:00 AM by Pig_Popper.)
The objective was to get 2850 fps - DIDN'T ACHIEVE THE OBJECTIVE.
***Note there is NO load data available for this combo of bullet, powder, and primer - I essentially worked off of 6mm PPC data and extrapolated the hell out of things to derive starting loads.
I am familiar with 90 grain loads and velocities in 6.8 SPC and 6.5 Grendel - so using those as a ceiling I aimed for a slightly less velocity out of the smaller 6mm ARC case.
At this point I intend to refine the load and await published data to see if I am close to safe loadings.
Velocity Readings:
26.0 grains - 2546 / 2540 / 2575 FPS
26.5 grains - 2574 / 2573 / 2555 FPS
270. grains - 2650 / 2633 / 2604 FPS
27.5 grains - 2669 / 2684 / 2665 FPS
28.0 grains - 2734 / 2730 / 2709 FPS
28.5 grains - 2793 / error / 2795 FPS
29.0 grains - 2801 / 2814 / 2796 FPS
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Looking at 28.5 & 29.0 grains there Really was no change in velocity, I’d be careful with those charge weights. You are right in the ballpark of your objective if TAC doesn’t do it for you, what will you try next
Trashy
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You’re probably correct in reading the signs of diminishing returns on loads above 28.5 grains . I may forego further exploration of fine tuned loads and just go with 28.5.
Next up is probably w748 .....
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I would try either H335 or 8208. Even though it's a smaller case (so you can tweak downwards on the actual # of grains), you ought to get up into the 2800's or even close to 2900, their book loads in the Grr top out at 3000+. For a powder that has the proper pressure curve you're still accelerating 90 grs of mass, so should be able to get to your goal.
For my 90 gr Tgk's I'm hoping for 2800 but not that that's a top end, it's a place where I think I will find a node.
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I don’t have any of those powders
I have about 40 lbs of WC 846 S which is a tad slower than W748, at this stage in the game I’ll take 2800 and sub MOA accuracy for chasing pigs.
Whenever real reload data comes to be IF I have additional head room I will explore it further.
Not bothering with CFe223 I’m sure some will start there so let’s see what they report.
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H322 is what all the 6mm Benchrest guys are using, I have 16 LBS of it. It is my favorite powder, burns very clean and gives me the best accuracy in my precision .223 loads. It is a fine powder that meters well. You could cram a lot of it into this round if your hunting velocity. I don't load for speed but for accuracy.
I'm telling you this stuff is great. It shoots sub MOA @ 100 in all my rifles, but it is pretty hot stuff for a small bore bottle neck round.
You got me thinking that I need to visit this and start doing some homework.
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Hmmmm. it's faster than powders I would have thought of... maybe for the lighter loads...?
where is that quickload guy when we need him?
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(08-18-2020, 06:17 PM)Dino11 Wrote: H322 is what all the 6mm Benchrest guys are using, I have 16 LBS of it. It is my favorite powder, burns very clean and gives me the best accuracy in my precision .223 loads. It is a fine powder that meters well. You could cram a lot of it into this round if your hunting velocity. I don't load for speed but for accuracy.
I'm telling you this stuff is great. It shoots sub MOA @ 100 in all my rifles, but it is pretty hot stuff for a small bore bottle neck round.
You got me thinking that I need to visit this and start doing some homework.
It's a brave new world for the ARC and you are needed to volunteer! The 6PPC Hodgdon web data for 85 grain Sierra has a H322 load although it's at the bottom of the velocity chart. Load some up and report back your findings! I'm also wondering about H355 as a test, it has done very well with the light bullets in my other (slow twist) PPC.
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Going to the range tomorrow with rounds loaded to 28.1 grains of 8208under 95 gr SST’s. If those don’t get to 2900 without pressure signs I’m going to try leverevolution but I read somewhere that folks were getting good results with Benchmark in the 6 mm ar, seems a bit fast for this application though. As good as h322 is I have some doubt it getting there velocity wise.
Trashy
