300WM Load Development Methods | Berger Bullets

[dmossu]

Hi everyone! I am fairly new to reloading and was hoping to get some advice from some of you that have been doing it for awhile! I am getting ready to start load development for my 300WM with Berger 205’s, CCI250 primers, H1000, and Norma Brass and was hoping to get some tips on where to start. For load development, I can only shoot out to 150 yards – but I do have access to a range out to 500 yards, but it is a hike from my house and prefer to get the majority of it done at 100 yards and fine tune at the longer distances.

With that being said, how does everyone start load development? I was thinking of starting about 2-3gr lower than Berger’s max load data and performing a pressure test in .5gr increments at .010 off all while looking for similar vertical points of impact. If I get a few consecutive similar points, to select the middle of them and perform seating depth testing at 10, 20, 30, and 40 off. Once I find the seating depth node, go back and fine tune the powder charge. My question with this being, how reliable are the vertical impacts on the pressure test if my rifle hates to shoot this bullet at 10 off (don’t know if it does, just wondering)? What does everyone usually do here? What do you do if during the pressure test none of the vertical points of impact are really that close?

Has anyone ever tried the Berger recommended load development method of starting with the minimum charge listed in the manual and seat the bullets at 10, 50, 90, and 130 off? I feel like the minimum charge is way too low and the jumps of seating depth are way too large. I know for the 205's for example the minimum load is 70.9 and the maximum load is 77.9 - so if I do seating depth at 70.9 and say it likes .050, and I bump the powder charge up to 76 gr, would that not dramatically change the pressure and likely change that seating depth node? So, it all seems counterintuitive lol.

I appreciate any feedback/advice!

 

[Pickettpuncher]

If you have a chrony, look up the satterlee method. Without a chrony, I’d suggest running a pressure test and start working down from that. I’d still run a pressure test to confirm you’re ok but you can look around the net and see where others are having success

 

[wind gypsy]

No way in I'd waste components on a charge of 70.9 grains of h1000 behind a 205.

I have a berger manual and it is the worst i've seen as far as reloading manuals go for min/max powder charges. Many cartridges are overly conservative (300wm being one of them) and some were outrageously hot (300 NM for example). My berger manual also doesn't list which case they use which makes a huge difference in 300wm.

Personally, if I were using Norma or Lapua 300wm brass I wouldn't start below 74.0 grains of h1000 with a 205 berger unless i had reason to believe a particular barrel built pressure faster than normal.

 

[Jimbee]

I did the Berger recommended seating depth test. I loaded 30 rounds, 6 for each depth. I shot 3 for each depth and it definitely looked like the mid 2 depths were more accurate. The following day I added 3 shots to each group, then they all looked the same. This was for 200.20x in 300wsm. I don't put much stock in seating depth anymore. I'm of the opinion that a bullet powder combo shoots well or it doesn't. I'm also not an expert reloader or shooter and have become a fan of the "painless load development." Keeping it simple and realistic expectations have served me well.

 

[dmossu]

No way in I'd waste components on a charge of 70.9 grains of h1000 behind a 205.

I have a berger manual and it is the worst i've seen as far as reloading manuals go for min/max powder charges. Many cartridges are overly conservative (300wm being one of them) and some were outrageously hot (300 NM for example). My berger manual also doesn't list which case they use which makes a huge difference in 300wm.

Personally, if I were using Norma or Lapua 300wm brass I wouldn't start below 74.0 grains of h1000 with a 205 berger unless i had reason to believe a particular barrel built pressure faster than normal.

Yeah I ended up loading 75, 75.5, 76, 76.5, and 77 for my OCW test at .025

 

[7LRM]

do you have IMR 7828 or H4831 SSC, H1000 won't give you good velocity, I tried H1000 for my 300 WM an then try both 4831 sec and IMR 7828 and see a better group and speed too.
good luck and happy reloading.

 

[dmossu]

do you have IMR 7828 or H4831 SSC, H1000 won't give you good velocity, I tried H1000 for my 300 WM an then try both 4831 sec and IMR 7828 and see a better group and speed too.
good luck and happy reloading.

I do have a pound of H4831SC - are you really getting more velocity with the 4831? The Berger book says H1000 will produce higher velocities

 

[PRC_GUY]

I do have a pound of H4831SC - are you really getting more velocity with the 4831? The Berger book says H1000 will produce higher velocities

The H1000 is too slow and you have to load a compress load and still do not have the velocity of the H4831 ssc ,
I shoot 180 gr bullets, the H1000 never reaches 3000 fps, both IMR 7828 or H4831 ssc can shoot 32xx FPS
Good luck .

 

[Harvey_NW]

For me it depends on limitations, if limited by mag length I do a seating depth test in tight increments and then switch to powder. If I have plenty of room I'll typically start with the bottom edge of the bearing surface at the neck shoulder junction, shoot a powder ladder or Satterlee test up to pressure, and then test seating depth in .010" jumps north and south of that point and also shoot a small OCW at the velocity plateau, if one shows up. I think the Berger jumps are too aggressive for an across the board recommendation, I find it more conservative to pick a window you'd like to be and test tighter increments within.

I don't put much stock in seating depth anymore. I'm of the opinion that a bullet powder combo shoots well or it doesn't. I'm also not an expert reloader or shooter and have become a fan of the "painless load development." Keeping it simple and realistic expectations have served me well.

Not being argumentative but I think it depends on the component combo, with a bullet known to be a little bit finicky like the Target VLD, seating depth can make a huge difference. Here's a seating test from .020"-.100" off the lands with a 180 VLD, 60 was around .4" and 100 was almost 2" group. Granted this was a minimum charge forming load, it shows how much impact it can have.

 

[Jimbee]

For me it depends on limitations, if limited by mag length I do a seating depth test in tight increments and then switch to powder. If I have plenty of room I'll typically start with the bottom edge of the bearing surface at the neck shoulder junction, shoot a powder ladder or Satterlee test up to pressure, and then test seating depth in .010" jumps north and south of that point and also shoot a small OCW at the velocity plateau, if one shows up. I think the Berger jumps are too aggressive for an across the board recommendation, I find it more conservative to pick a window you'd like to be and test tighter increments within.


Not being argumentative but I think it depends on the component combo, with a bullet known to be a little bit finicky like the Target VLD, seating depth can make a huge difference. Here's a seating test from .020"-.100" off the lands with a 180 VLD, 60 was around .4" and 100 was almost 2" group. Granted this was a minimum charge forming load, it shows how much impact it can have.
View attachment 437637

Again, I'm not an experienced reloader or shooter, but I had a seating depth test that looked much like yours, seeming to indicate accuracy discrepancies with seating depths until I increased the group size and they evened out. I'll see if I can find pictures. Would you be willing to add 3+ more shots to each group for the sake of science? I appreciate the discussion.

 

[wind gypsy]

Again, I'm not an experienced reloader or shooter, but I had a seating depth test that looked much like yours, seeming to indicate accuracy discrepancies with seating depths until I increased the group size and they evened out. I'll see if I can find pictures. Would you be willing to add 3+ more shots to each group for the sake of science? I appreciate the discussion.

I've had similar issues where something seems clear and then when validation time comes it frequently doesn't repeat. I have had times where I'm confident a seating depth makes a notable difference but anymore I hate dealing with combos that are that finicky.

 

[dmossu]

I've had similar issues where something seems clear and then when validation time comes it frequently doesn't repeat. I have had times where I'm confident a seating depth makes a notable difference but anymore I hate dealing with combos that are that finicky.

I had this issue with the Berger 215's in this rifle - hence why I am switching to the 205's. I could get decent groups one day and the next day it shoots a 1.5inch group @ 100 yards.

 

[Harvey_NW]

Again, I'm not an experienced reloader or shooter, but I had a seating depth test that looked much like yours, seeming to indicate accuracy discrepancies with seating depths until I increased the group size and they evened out. I'll see if I can find pictures. Would you be willing to add 3+ more shots to each group for the sake of science? I appreciate the discussion.

Likewise, I'm no pro but I'm working on 3 different rifles right now and I'm starting to see a pattern. In the initial testing I won't shoot any more than 3 shots because I feel like it's a waste of components. 3 shots touching tells you it's got potential, 2 shots and a flier tells you that's probably not a good spot. But that test showed no major POI shift from 30-100, but 60, 70, and 80 had no more than a 1" spread, to me that indicates an accuracy window. Now I'll do the same thing with powder and shoot a ladder to find pressure and see what velocities look like, and load an OCW test at a velocity plateau below pressure. Typically this will show the same results, groups will have consistent POI and 2 or 3 will be very tight and indicate a powder node. From there I'll load the higher charge of the tight groups to 5 shot zero and true calculator. So far it's been very consistent for me.

 

[Jimbee]

Likewise, I'm no pro but I'm working on 3 different rifles right now and I'm starting to see a pattern. In the initial testing I won't shoot any more than 3 shots because I feel like it's a waste of components. 3 shots touching tells you it's got potential, 2 shots and a flier tells you that's probably not a good spot. But that test showed no major POI shift from 30-100, but 60, 70, and 80 had no more than a 1" spread, to me that indicates an accuracy window. Now I'll do the same thing with powder and shoot a ladder to find pressure and see what velocities look like, and load an OCW test at a velocity plateau below pressure. Typically this will show the same results, groups will have consistent POI and 2 or 3 will be very tight and indicate a powder node. From there I'll load the higher charge of the tight groups to 5 shot zero and true calculator. So far it's been very consistent for me.

 

[Jimbee]

I attached a shoddy picture. I had a couple groups out of 5 that looked really good, but weren't repeatable.

 

[wind gypsy]

In regards to H1000 for a 205 berger - The 205 has a longer bearing surface than the 215 hybrid and is only 10 grains lighter so should be able to build plenty of pressure with h1000 IMO especially if using a bigger case like norma.

Looking at old notes, with a 26" barrel and 200.20x I saw around 3000 FPS avg with 79.5 grains h1000 and norma case and didn't have notable pressure. I had significant pressure signs with the same combo and RL26 @ around 3100 FPS so I'd say i'd probably cap it around 3050 FPS with RL26 in that rifle. That is with a lighter bullet that has a bearing surface length of only 0.413" vs the 205s 0.493".

I'd maybe lean towards RL23 or RL26 first but H1000 would be one of my top choices right out of the gate too.

 

[wind gypsy]

do you have IMR 7828 or H4831 SSC, H1000 won't give you good velocity, I tried H1000 for my 300 WM an then try both 4831 sec and IMR 7828 and see a better group and speed too.
good luck and happy reloading.

With what bullets?

 

[PRC_GUY]

I shoot Hammer 180 grain