Improving ES in 300 WM is it just powder selection

hudel

Member
Joined
Jan 9, 2021
Messages
22
Location
Indiana
Been banging my head on the wall trying to improve the ES and SD on my 300 WM.
All brass prepared and trimmed properly,full length sized, mandrel sized necks, primed with federal LRM primers, all charges weighed on digital and 10-10 scale and were as perfect to the tenth of a grain as I could get them, bullets seated on lee die and all measured to ogive for OAL very consistent lengths. All cases water checked and all were with 1 grn of each between the highest and lowest capacity cases (the deviated shots for high or low extreme spread weren't in the cases with 1 grn off volume). All measured for concentricity and worst was .005 on bullet near tip, the concentricity again didnt seem to be the ones that were low or high on ES.
Tried h4350 with some barnes 180 ttsx and accuracy was horrible however just likely needed OAL adjusted, did the 10 shot method goin .2 at a time after working up safely of course and picked best node and the 5 and 10 shot ES and SD was bad tried a few other charges right in that charge area flat spot. ES was around 60 and SD around 20
Wanting more precision I also tried H414 (didn't wanna burn up the 4350) and some Hornady 168 match, same prep and load workup ES around 70 on a ten shot group after getting the best place on node and SD right around 20. These were accurate at 100 yards even without adjusting OAL

So my question is to really lower those numbers should i look back to my process or more to the powder?
 

Trnelson

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Joined
Feb 15, 2012
Messages
750
Location
Nebraska
IMO, your barking up the wrong tree with H4350 in a 300WM. H4350 is an excellent powder, just not for a 300WM. Case fill ratio is too low casing an erratic powder burn. Get your hands on H-1000, or IMR 7977. Either of those are going to be what you are looking for. Once you figure out the powder side of things swap primers with the best load to ware what yields the best SD.
 

hudel

Member
Joined
Jan 9, 2021
Messages
22
Location
Indiana
IMO, your barking up the wrong tree with H4350 in a 300WM. H4350 is an excellent powder, just not for a 300WM. Case fill ratio is too low casing an erratic powder burn. Get your hands on H-1000, or IMR 7977. Either of those are going to be what you are looking for. Once you figure out the powder side of things swap primers with the best load to ware what yields the best SD.
Thanks for the reply, I actually have a 12 round test on my bench loaded with h1000 waiting for time to shoot them and find a node. I just wanted to make sure that im not chasing a powder when there is something else in my process Im missing. How does 4831 do in 300 I have a couple pounds of that as well.
 

338 dude

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hudel

Member
Joined
Jan 9, 2021
Messages
22
Location
Indiana
If thats all the better you can do we will have to accept it. Hah my sarcasm doesnt read as well here. Thats certainly some fine shooting. The berger 185 classic hunter factory rounds shoot about that good in my gun at 100 if I do my part, I have 300 berger 185 classic hunter bullets setting on the bench, I'm saving them for the right powder combination, looks like h1000 may be it!!
 

Lynn Holifield

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Joined
Feb 9, 2019
Messages
177
Location
Mountain Home, AR
This 300 WM likes H1000 & RL-26. Also, I get better ES with heavier bullets. H1000 gives me slightly better ES. I get a few more FPS with RL-26.

I’m doing an edit because I forgot to mention the Peterson 300 WM Long brass that is being made. If I needed brass I would be trying it out. With it you should bump your shoulder the 1st shot. Could be filling your chamber might help ESs.
 

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Trnelson

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Joined
Feb 15, 2012
Messages
750
Location
Nebraska
Thanks for the reply, I actually have a 12 round test on my bench loaded with h1000 waiting for time to shoot them and find a node. I just wanted to make sure that im not chasing a powder when there is something else in my process Im missing. How does 4831 do in 300 I have a couple pounds of that as well.
H4831 / sc is another good choice, IMO. It won’t give you quite the velocity of H-1000, but it certainly can get the SD into the single digits where a guy likes to see it.
 

bstomper

Well-Known Member
Joined
Sep 20, 2011
Messages
253
Location
Saskatchewan Canada
Been banging my head on the wall trying to improve the ES and SD on my 300 WM.
All brass prepared and trimmed properly,full length sized, mandrel sized necks, primed with federal LRM primers, all charges weighed on digital and 10-10 scale and were as perfect to the tenth of a grain as I could get them, bullets seated on lee die and all measured to ogive for OAL very consistent lengths. All cases water checked and all were with 1 grn of each between the highest and lowest capacity cases (the deviated shots for high or low extreme spread weren't in the cases with 1 grn off volume). All measured for concentricity and worst was .005 on bullet near tip, the concentricity again didnt seem to be the ones that were low or high on ES.
Tried h4350 with some barnes 180 ttsx and accuracy was horrible however just likely needed OAL adjusted, did the 10 shot method goin .2 at a time after working up safely of course and picked best node and the 5 and 10 shot ES and SD was bad tried a few other charges right in that charge area flat spot. ES was around 60 and SD around 20
Wanting more precision I also tried H414 (didn't wanna burn up the 4350) and some Hornady 168 match, same prep and load workup ES around 70 on a ten shot group after getting the best place on node and SD right around 20. These were accurate at 100 yards even without adjusting OAL

So my question is to really lower those numbers should i look back to my process or more to the powder?
I do the same case prep and load development as you do but I load a bigger range of charges for my initial test., 15-20 rounds instead of just 10. I followed this info in the video belo and it helped me a great deal. I don't worry about my groups until I have a low ES. If I can't get low ES I change bullets or powder or primer. I keep changing components untill I get what works in my gun.
 

Wildcat99

Active Member
Joined
Jan 11, 2021
Messages
33
Location
Montana
Been banging my head on the wall trying to improve the ES and SD on my 300 WM.
All brass prepared and trimmed properly,full length sized, mandrel sized necks, primed with federal LRM primers, all charges weighed on digital and 10-10 scale and were as perfect to the tenth of a grain as I could get them, bullets seated on lee die and all measured to ogive for OAL very consistent lengths. All cases water checked and all were with 1 grn of each between the highest and lowest capacity cases (the deviated shots for high or low extreme spread weren't in the cases with 1 grn off volume). All measured for concentricity and worst was .005 on bullet near tip, the concentricity again didnt seem to be the ones that were low or high on ES.
Tried h4350 with some barnes 180 ttsx and accuracy was horrible however just likely needed OAL adjusted, did the 10 shot method goin .2 at a time after working up safely of course and picked best node and the 5 and 10 shot ES and SD was bad tried a few other charges right in that charge area flat spot. ES was around 60 and SD around 20
Wanting more precision I also tried H414 (didn't wanna burn up the 4350) and some Hornady 168 match, same prep and load workup ES around 70 on a ten shot group after getting the best place on node and SD right around 20. These were accurate at 100 yards even without adjusting OAL

So my question is to really lower those numbers should i look back to my process or more to the powder?
What kind of seating depth are you playing with?
 

smokey3

Well-Known Member
Joined
Jan 20, 2016
Messages
204
Location
WV
Been banging my head on the wall trying to improve the ES and SD on my 300 WM.
All brass prepared and trimmed properly,full length sized, mandrel sized necks, primed with federal LRM primers, all charges weighed on digital and 10-10 scale and were as perfect to the tenth of a grain as I could get them, bullets seated on lee die and all measured to ogive for OAL very consistent lengths. All cases water checked and all were with 1 grn of each between the highest and lowest capacity cases (the deviated shots for high or low extreme spread weren't in the cases with 1 grn off volume). All measured for concentricity and worst was .005 on bullet near tip, the concentricity again didnt seem to be the ones that were low or high on ES.
Tried h4350 with some barnes 180 ttsx and accuracy was horrible however just likely needed OAL adjusted, did the 10 shot method goin .2 at a time after working up safely of course and picked best node and the 5 and 10 shot ES and SD was bad tried a few other charges right in that charge area flat spot. ES was around 60 and SD around 20
Wanting more precision I also tried H414 (didn't wanna burn up the 4350) and some Hornady 168 match, same prep and load workup ES around 70 on a ten shot group after getting the best place on node and SD right around 20. These were accurate at 100 yards even without adjusting OAL

So my question is to really lower those numbers should i look back to my process or more to the powder?
I have had good luck with H1000 and Federal 210M. The 215 magnum primers were erratic with ES and SD much greater. Different guns are going to react differently to components being used. I get less than .5 MOA with 180 AB's and 2" groups at 500 yards when I do my part. ES of 15 and SD average of 8.
 

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