So I’m trying to work up an elk load for my 308 with 165gr partition and Varget. Did my initial testing today and it looks like I found a nice wide accuracy node from 43.5 to 44.1 with.3gr increments. All 3 loads printed sub MOA groups with POI shifting less than 1” left to right. 44.0 grain would give me around 2690fps. I was hoping for more like 2750ish but everything in that range was somewhat erratic. 45gr printed a ragged hole but the load below and above printed 1.5moa groups. Do I take stable and accurate load and sacrifice 50-60fps or should I play with the seating depth and try to get better velocity?
- Thread starter locash78
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I'd say 45gr, but how are your primers looking when popped out and analyzed? Straight primer walls or mushroom tops? What is your primer pocket growth? Anything beyond .2095-210 primer pocket diameter is pressuring too much. This is if you want to save brass.
What length barrel?
What was the 45gr MV?
What length barrel?
What was the 45gr MV?
Thanks for your response. Just popped t primer out of 45.3gr load. The primer pocket is identical to previously fired brass at .2080. Picture attached. The 3 shots fired of 45gr had nearly identical velocities with ES of 3fps measured with Labradar and the new Garmin with slight variations between the two, around 2748fps on average. CZ 550 26” Varmint barrel 1:12 twist. The 45gr seems would be a no brainer but it concerns me that the window is so narrow.
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That's some of the prettiest fired brass I've seen in regards to fired brass in general and pressure. 26" barrel hell yeah 2750fps is a solid velocity. You could push to pressure loading 1rnd each of 45.4-45.7-46 and might stretch the node after 45gr and also find where over pressure starts.
Edited to add: I am seeing some primer cratering and extractor shine on the 45.3 loads. The primer still looks great as well as primer pocket size reported.
Edited to add: I am seeing some primer cratering and extractor shine on the 45.3 loads. The primer still looks great as well as primer pocket size reported.
That shiny smiley face you’re seeing is caused by this shiny spot, kind of a burr in my ejector groove if you can see it. I find it even on mild loads but it gets more pronounced and shinier hotter the loads get
. The 45.3 group looked terrible over 1.5” so idk if it’s worth pursuing higher node. 45.3 produced velocities 2757-2776. It’s definitely getting little hot. I’m new to reloading and still little bit scared and not confident in my ability to correctly read pressure signs 
That shiny smiley face you’re seeing is caused by this shiny spot, kind of a burr in my ejector groove if you can see it. I find it even on mild loads but it gets more pronounced and shinier hotter the loads get
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Ok, you know your own equipment more than I do. Why is the jump .075? Magazine length restriction? The finickiest could be in the seating depth, not just powder charge.
I had a RPR 308 once that only liked 42gr IMR4064 with a 175SMK. Shot everything else like garbage, but 42gr stayed steady for me the life of the gun in my possession.
I had a RPR 308 once that only liked 42gr IMR4064 with a 175SMK. Shot everything else like garbage, but 42gr stayed steady for me the life of the gun in my possession.
Ok, you know your own equipment more than I do. Why is the jump .075? Magazine length restriction? The finickiest could be in the seating depth, not just powder charge.
I had a RPR 308 once that only liked 42gr IMR4064 with a 175SMK. Shot everything else like garbage, but 42gr stayed steady for me the life of the gun in my possession.
it’s halfway between my mag restriction and Nosler’ recommended COAL of 2.770. I thought it would be a good starting point. I didn’t go with Nosler’ length as that would give me over.100 jump. I might seat them little closer to the lands to see if it tightens up the 44.7 and 45.3 charges.
What is your DTL and how did you measure it?
I made a dummy round to find the lands and I use Hornady bullet comparator when seating bullets and calculating my jump
I'd seat to 2.8" and test.
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That was the COAL of the rounds tested
Whatever your magazine length is. Load them .003-.005 from touching the front. Test that length and reduce by .010 till you find precision. Good luck!
If your mag will allow seating to bullet touching the lands, that's where I start. I have chambers cut with that in mind.
At bullet kissing the lands (-0.001"), I increase charge until I find pressure signs. Then I back off the charge until I no longer see pressure signs, I call this max charge. Then I do seating depths with my newly observed max charge. Before the component shortage era, I would do that by shooting 10 rounds each seating 0.001" deeper at a time. Now I go 0.005" at a whack. I usually find a seating depth that is very noticeably more accurate. Then I try in closer increments above and below that depth, stopping short of repeating the +- depths I already shot. If I have a choice, I choose as close to the lands as possible to allow for future chasing of eroded chamber if I choose to. (I never have but that's still my philosophy) Once I find that optimum seating depth, I go back to some charge testing. Then some seating. Then some charge. I usually shoot 200-300 rounds to get a rifle dialed in.
Accuracy is foremost but I want that accuracy as fast as I can get it.
At bullet kissing the lands (-0.001"), I increase charge until I find pressure signs. Then I back off the charge until I no longer see pressure signs, I call this max charge. Then I do seating depths with my newly observed max charge. Before the component shortage era, I would do that by shooting 10 rounds each seating 0.001" deeper at a time. Now I go 0.005" at a whack. I usually find a seating depth that is very noticeably more accurate. Then I try in closer increments above and below that depth, stopping short of repeating the +- depths I already shot. If I have a choice, I choose as close to the lands as possible to allow for future chasing of eroded chamber if I choose to. (I never have but that's still my philosophy) Once I find that optimum seating depth, I go back to some charge testing. Then some seating. Then some charge. I usually shoot 200-300 rounds to get a rifle dialed in.
Accuracy is foremost but I want that accuracy as fast as I can get it.
Thanks, I appreciate your help!
You've had some good load advice, so I won't duplicate. I just want to put that 2,690 vs 2,750 into perspective:
It is 300 vs 325 yards for the same impact velocity and energy. Is it worth the added time, money and effort to see (no guarantee) if you can improve when you've got a wide node? That's up to you.
On the other hand: 1.5 MOA of your "opening up" loads will get the job done on elk at .308 limits all day.
I agree. Do you think I should load on the higher end of the node since the shot would be most likely taken in colder temperatures then testing temperature?
I would definitely stick with happy combustion.
I would also stick to the middle of the node, maybe .1 above center. Why introduce an assumption? You don’t know that cold weather moves the node. It’s logical, but you haven’t tested it. In the absence of testing cold ammo and rifle, I’d stick with what I know. That said, I’d throw them both in the deep freeze and check it out.
The whole point is to stay in the predictable / consistent zone, especially with a hunting load where the whole trip comes down to 1 shot 1 kill.
My goal is accuracy and precision but fast accuracy and precision.
If the A&P is the same at 2700 fps as it is at 3200 fps, I'm shooting the 3200 fps.
If I find a seating depth that produces good A&P at -0.1" and another seating depth that duplicates that A&P at -0.001", I'm shooting that -0.001".
As I said above, it usually takes me 200 rounds or so to really tune a load to a rifle. Then I'm good for a couple thousand rounds. With a hunting rifle, you are likely to never reach even 1000 rounds down the tube. You owe it to the animal to be as exacting as you can.
If the A&P is the same at 2700 fps as it is at 3200 fps, I'm shooting the 3200 fps.
If I find a seating depth that produces good A&P at -0.1" and another seating depth that duplicates that A&P at -0.001", I'm shooting that -0.001".
As I said above, it usually takes me 200 rounds or so to really tune a load to a rifle. Then I'm good for a couple thousand rounds. With a hunting rifle, you are likely to never reach even 1000 rounds down the tube. You owe it to the animal to be as exacting as you can.
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