Caribou Gear Tarp

Load Development in a Time of Scarcity

Backofbeyond

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Kind of like “Love in the Time of Cholera” but totally different.

I’m about to start load development on my .300 PRC, and the scarcity of components has me a little spooked. The last time I did a full work-up any and all components we’re easy off the shelf items.

I’ve got 100 brand new ADG brass, ~500 Mag rifle primers, soon will have about (100) 215 gr Berger VLD, and 2 lbs of H1000. My concern is if I do what worked for me last time (multiple ladders with different powders/bullets/primers) changing one variable at a time I’ll be out of freedom seeds and freedoms dust before I can even smell Spring Bear season.

So here’s my plan, please pick it apart.

Step 1. Find the lands (bullet in a case with a drop of Loctite) then seat .015 off the lands on a 10 shot, single round per charge, ladder test. Using a buddy’s chronograph I’ll find my velocity nodes to drill down on. (Round count 12 - 2 sighters)

Step 2: Shoot a 3 round per charge ladder test + and - 1 grain around the upper velocity node. (Round count 24 - 28 depending on the size of the node.)

Step 3: Shoot a 3 shot seating depth test from at the lands to .030 off, every .005. (Round Count 18)

Fingers crossed, I hope to have a fairly well developed load in ~54 - 58 rounds, leaving me 40 - 45 for practice and 2 rounds for my bear tag.

Am I pushing it? Seeing anything I can cut out? The round and the rifle are way above my shooting abilities, so I’m looking forward to honing my skills - at least once components are available.
 

kiwi hunter

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You'll most likely shoot most of your animals at under 200, don't get hung up on quarter inch groups, half an lunch will be more than adequate.go hunting
 

grizzly63

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Is the rifle broke in? You don't know if it will even like this bullet and powder. You'll find more primers, just dont shoot the barrel out trying to figure out what it likes. Good plan and I hope it works for you. Might find the magic pill right off the bat.
 

Backofbeyond

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Is the rifle broke in? You don't know if it will even like this bullet and powder. You'll find more primers, just dont shoot the barrel out trying to figure out what it likes. Good plan and I hope it works for you. Might find the magic pill right off the bat.

I have 3 boxes of Hornady Match through it. Last 15 shots velocity generally stabilized, even if the ES and SD were less than spectacular.

I’m assuming it’s “broke in” but really, who knows.

I’ve also got some Hornady ELDX 212 gr in reserve, but I’ve read lots of glowing reviews about the Berger 215 with H1000 in .300 PRC. So that where I’ll start.
 

BucksnDucks

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Sounds like a solid plan. For me the days of trying out several powders and multiple projectiles combinations are over.
I've got a new rifle for this season. I'll do some initial sighting and break in with powder and bullets I have an excess of, then try to find the combo that works with what I have on hand that I plan to hunt with.
I will do the same as you described, test charge and velocity. Then using that info pick the charge and test some seating depth variables.
I got lucky with my last rifle and found a sweet spot quickly.
 

VikingsGuy

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I find velocity node approach an efficient process but think you can slim yours down a bit further. I don't think you need to go +/-1 grain on each side of node, as the nodes are usually narrower than that. Also, for a hunting round, if you get a decent node you probably don't need to mess with seating depth. From another post here is my process:

"I make one load each of powder increments of 0.3gr (0.5gr for magnums) from max book load down 10 increments. I then start on the light end and shoot each over a chrono while watching for pressure signs as I go up. I then look at the resulting velocity plot to find one or two promising "flat spots" - suggesting loads that are somewhat load insensitive ("velocity nodes"). At these nodes I go by 0.1gr increments 2 loads above, 2 loads below and midpoint - I make 3x of each of these (15 rounds) and shoot over chrono looking for both low ES/sd velocity numbers and also low MOA on paper at 100y. If a node looks iffy, I drop it. If a node looks promising I pick the best load(s) and make 5x to confirm over velocity and paper.

When I first tried I wasn't sure if I trusted my loading process and did the velocity ladder 3x at each load, but after a few time through I was very comfortable that there was little noise in my loading process and that I could comfortably rely on the single bullet approach.

This process lets me get from no info to really solid round in 25-50 shots depending on whether I test one or two nodes and if either or both are worth confirming with 5x. If using for target rifle I would then play with seating depth to ekke out final improvements."
 

300stw

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i load 1 at every grain from 10 percent below book max to a couple over book max, using max length of the chosen bullet that fits magazine first, lands second,
i shoot at 300 yardss if ive allready got a good sightin done, i find the maximum powder chrg, then load 2ea of each every half grain chg lower then the max for 3 grains and continuine shooting at 300 yards, if a pair of shots touch or a node shows i load a handful at that charge weight, and see what they do,,,,then re evaluate, if im shooting a 7stw, i dont keep going lower on the charges into 7mm rem mag velocity, theres no point for me, if it dont shoot in the upper velocity expectations, i find another bullet or another powder, if its finicky i rebarrel or sell the gun and buy another,,,, just my routine, no better or worse then anyone else's,,,
 

Wind Gypsy

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Mar 12, 2017
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Here’s what I’d do:

Do the ladder referenced in step 1 to see what velocities look like.

Assuming a 26” barrel and you didn’t see pressure at the charges necessary, load up 3 sets of 3 each in .5 grain intervals with the middle charge being around whatever gets you roughly 2970 FPS. Jumping about 0.040” to 0.050”.

If accuracy is acceptable, pick a charge that seems best based on the limited info you’ve collected and load up 10 rounds to confirm.

Your velocity will likely change on your second firing of brass and I would bet your barrel is not fully stabilized now at 60 rounds either.
 

Backofbeyond

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Here’s what I’d do:

Do the ladder referenced in step 1 to see what velocities look like.

Assuming a 26” barrel and you didn’t see pressure at the charges necessary, load up 3 sets of 3 each in .5 grain intervals with the middle charge being around whatever gets you roughly 2970 FPS. Jumping about 0.040” to 0.050”.

If accuracy is acceptable, pick a charge that seems best based on the limited info you’ve collected and load up 10 rounds to confirm.

Your velocity will likely change on your second firing of brass and I would bet your barrel is not fully stabilized now at 60 rounds either.
Why that velocity? Is that what you’re getting with H1000 and Berger 215b Yes, it’s a 26” barrel, but Hodgdon is showing a velocity of 2870 fps from a max load of 79.2 grains.
 

BenInMT

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I would completely scrap #3. If you’re going to look for meaningful difference in depth you need to look WAY bigger in jump. In my experience the 215 hybrid in 300 PRC like some freebore and I am right now jumping them a good ways. Don’t waste your valuable components making marginal adjustments. Adjust big or not at all.
 

Wind Gypsy

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Why that velocity? Is that what you’re getting with H1000 and Berger 215b Yes, it’s a 26” barrel, but Hodgdon is showing a velocity of 2870 fps from a max load of 79.2 grains.

Just picked that velocity because 2900-2950 is a common h1000/215 Berger win mag node and the PRC is a #@**@% hair bigger case with longer freebore so it should run a hair faster at same pressure. Nothing wrong with running it a little slower either. My 26” custom throated win mag wasn’t showing pressure @3k FPS with the same bullet/powder but I settled on lower 2900s just for consistency and a little safety margin.

I think you’ll find that the short bearing surface of the 215 requires it to be seated out a ways to be in the lands too. Nothin wrong with jumping those hybrids a bit. Seems they are less sensitive to the changing jump as throat erodes that way too.

@BenInMT beat me to it but I wouldn’t mess with that small of an incremental seating depth changes either. Give er 0.040”+ and call it good if it shoots well enough.

Tell us more about the rifle
 

std7mag

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While some say your barrel will settle down about the 100 round mark, it shouldn't take more than about 20 rounds to "break in".

I do a 10 shot ladder test going 0.3gr per round.
Watch for 3 closest vertically.
The chrono will help too.
Then seating depth.

While some have found best accuracy with a fairly good jump ( 0.060-0.090") most find best groupings with the VLD up close & personal to the lands.
Touching to 0.010".
Mine seem to do best 0.005" off the lands. That for multiple rifles & multiple calibers.
 

Backofbeyond

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Some good reading on Bullet Jump research:
Ok, my inner nerd is fascinated, even though I’m not sure I want to go down that rabbit hole to fully test it.

And to answer your earlier question it’s a Christensen Arms Ridgeline. Nothing custom, just off the shelf. So far I’ve been very impressed with the accuracy. I shot it again this last weekend to sight in with my new scope and shot ~1” group at 300 yards. Might have been luck, it was the smallest group yet, but plenty of 0.5 - 0.75 MOA groups when I shot it for the first time.

I will take your advice though, and set my seating depth around 0.040” off and do my initial load testing there. If it shoots, it shoots.
 

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