Unable to develop load for rifle

[IDspud]

I have been struggling for a long, long time trying to develop a load for my 300 WinMag. Nothing seems to work.

Bergara HMR 1:10. Shoots sub MOA with factory ammo.


Peterson brass (new)
H1000
Berger 200 grn hybrid targets

I have tried 220 grain Bergers and different high quality brass. Large rifle, benchrest, and magnum primers. No difference.

My groups are wild. Wild as in sometimes 2-3 inches.


Loaded between 74 and 78 grains. Tried playing with seating depth at the two flat spots with low ES and SD at 75 and 77.5 grains.

I incrementally adjusted seating depth in at .010 increments. I found one load that shot 0.75" but .010 on each end caused almost 2" groups. I tried .005 in between and they were also 2-3 inches, while my original 0.75" group was now 1.1"


I am so confused. I am meticulous when it comes to tolerances in my loads. This isn't happening loading for my other rifle. I don't even know what to do at this point. I've blown through hundreds of rounds trying to figure out what's going on and everything seems super inconsistent.


Anyone have any advice? I feel like I've tried everything. I've spent a fortune on reloading supplies and still don't even have something that shoots as well as regular factory ammo.

 

[lennywd87]

I usually do a ladder test of 3-5 shot groups seated at .02 off jam in the lands, while looking for pressure signs and take my best group from that test. Then adjust seating from that charge weight and seating depth back in .006 increments to find the widest node with best groups (the two tightest groups in the same .018 seating range) using the same ladder style test and once found seat to the top of that node. That’s got me my best groups. I’ve heard the Berger’s really love a big jump to the lands though. I’ve had really good luck with nosler’s accuracy load data as well.

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[BBob]

So It'll shoot factory ammunition consistently less than MOA? You say you've tried everything but also said you've tried only two bullets? You say you've incrementally tested seating depth changes of .010" and .005" but what total depth/jumps have you actually tried? Maybe you need to test some various jump windows to see if one will work and go from there.

 

[35WhelenAI]

What factory ammo, what bullet?

Is velocity of your handloads similar to that of the factory loads?

Measure the overall length on the factory loads, how far is the factory bullet off the lands, pull a bullet and see how heavy the case is, see if you can gain information if there's anything wildly different.

Even though it's a 200 grain bullet, 1:10 twist may be marginal to get a long for caliber bullet stabilized, as a 200 Berger is relatively long for caliber in my estimation.

 

[IDspud]

I started loading with the smallest safe jump from the lands and tested seating farther in from there. All crap.

This time I started at max mag length and in from there. Spanned across 0.1 range.


Something seems really off. Everyone I've talked to that does this a lot (PRS shooters, precision rifle company etc) said they've never seen a huge group like that when using quality components. More like seating depth closed 1.5 into 1, 1 in to .75, .5, etc.

Has anyone here ever seen 2-3 inch groups suddenly close in to 0.5?? I realize the sweet spot could be a node in .003 increments, but suddenly 2-3" right on the fringes?

 

[Formidilosus]

Has anyone here ever seen 2-3 inch groups suddenly close in to 0.5?? I realize the sweet spot could be a node in .003 increments, but suddenly 2-3" right on the fringes?

No. It’s bs. Change bullets or powder. If a rifle does not shoot a bullet/powder combo acceptably, no amount of incremental tinkering will result in a stable load with that combo. You’re wasting time and money.

 

[IDspud]

Shitty. I bought 10 pounds of H1000 and 400 Berger bullets due to availability and probably not being able to find more.

Change from Bergers completely or just go down in bullet weight again? Ditch the H1000?


Has anyone had quality components like Bergers flat out not work at all like this? I was under the impression from competition shooters like Eric Cortina that you could tune just about anything as long as it wasn't a crap component.

 

[Formidilosus]

Shitty. I bought 10 pounds of H1000 and 400 Berger bullets due to availability and probably not being able to find more.

Change from Bergers completely or just go down in bullet weight again? Ditch the H1000?

Change bullets. The 185gr Juggernaut is worth a try, or a Hornady ELD-M.

Has anyone had quality components like Bergers flat out not work at all like this? I was under the impression from competition shooters like Eric Cortina that you could tune just about anything as long as it wasn't a crap component.

No. Good guns with very good barrels generally shoot most everything ok. But you absolutely can have combos that won’t shoot.

 

[SDHNTR]

The gun just plain doesn’t like your powder and/or bullet combo. You need to change it. Seating depth will not meaningfully change your groups.

 

[SDHNTR]

Wrong. Some guns just flat won’t shoot certain bullets, even with acceptable twist. Same with powder. Change the bullet first. Then change to powder.

 

[Wrench]

Before you bail...

Hows the neck tension? Is it a saami chamber or custom? What dies? What's the biggest jump you've tried? Velocity?

I have a rifle that will shoot very sub moa but the lrab shot 2" plus groups. I had to talk to the ballisticians to get advice. I ended up way deep and a factory crimp and dropped to sub moa again.

 

[sndmn11]

Shitty. I bought 10 pounds of H1000 and 400 Berger bullets due to availability and probably not being able to find more.

Change from Bergers completely or just go down in bullet weight again? Ditch the H1000?

I'd ditch the powder, you can probably sell it for well over what you paid, and there's a dozen suitable replacements.

 

[Wrench]

The good news is h1k is real easy to unload. If you end up with h4831 as a winner, I can trade some out.

 

[SDHNTR]

Wrong. Some guns just flat won’t shoot certain bullets, even with acceptable twist.

Wrong. Some guns just flat won’t shoot certain bullets, even with acceptable twist. Same with powder. Change the bullet first. Then change to powder.

Sorry, wrong quote. I meant to respond to IDSpud comment about quality components.

 

[swavescatter]

Following. Just getting into reloading and have a Bergara B14 300 WM.

I've tried a couple 200+ grain cartridges (ELDX and Terminal Ascent) and it just won't shoot them. Another user here posted the same issue. Tight groups with lighter bullets. I think these rifles just might not like heavier bullets. Bergara provides the ammo they used to guarantee MOA and one bullet was the 185 Juggernaut.

I bought some 178 ELDX to try for my first foray...

 

[rifletuner]

If it were my rifle, I would not persevere which what you are describing. You might see some improvement with tweaking loads, but it is never going to turn into a great shooter.

A bad rifle is only a barrel change away from shooting well. If you dont like the idea of a barrel swap, sell the rifle to someone you dont like and go again with a new rifle.

 

[ndayton]

Literally did load testing yesterday with h4831 and H1000 results as follows.
H1000 143eldx 1.2 moa
H4831 143eldx 1.1 moa
H4831 156 EOL 1.2 moa
H1000 156 EOL 2.6 moa

This was testing different charge weights with a magneto speed, so group size wasn't the goal, but you can see H1000 and the 156 EOL did not play well compared to the others, so I am not going to waste a bunch of time and components testing it.
Like others, have said try a different powder or bullet.

 

[brn2hnt]

I would ditch the H1000 for sure.


Mainly because I’m in Idaho as well and will take it all for you


On the factory loads though, are they a similar bullet weight/ogive design to the bergers you’re trying to shoot?


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[Don Qui Puncher]

Shitty. I bought 10 pounds of H1000 and 400 Berger bullets due to availability and probably not being able to find more.

Change from Bergers completely or just go down in bullet weight again? Ditch the H1000?


Has anyone had quality components like Bergers flat out not work at all like this? I was under the impression from competition shooters like Eric Cortina that you could tune just about anything as long as it wasn't a crap component.

I had the exact same thing happen with a fierce win mag I tried every Berger from 200-215 and couldn’t get any of them to shoot I pulled the gun apart and swapped scope several times. I wasted an insane amount of time and components trying to get it to shoot, neck tension seating depth charge weight powder and primers, finally I tried the 212 and 208 Hornadys and they shot excellent. I couldn’t get that barrel to shoot bergers for the life of me.

 

[Couescrazy33]

Scheels has 200 and 220gr eldx available for you to try