Extreme spread question 300 win mag

[muleman69]

Shot a group today that was .237 but my e.s. was at 20. Should my spread be in the single didgets and if so were do I go from here?

 

[Willie]

At what distance? ES seems become a bit more relevant as range increases. The target will tell you what will work. ES doesn't mean much unless it's stable for 10-20 shots over a reliable chronograph and repeatable for that load. JMO

 

[dkhunt14]

It's all about when the bullet leaves the muzzle. I have had loads where the ES was 2 or 3 and it would shoot in the zeros at 100. When shot at 1000 yards it went all vertical. Other loads would shoot with 10 to 15 ES and would shoot small groups at 1000 with no vertical. You need to test at distance you want to shoot and let the target tell you what it wants.

It is also harder to get the bigger cartridges to shoot very small Extreme spreads. It seems to be much easier with a Dasher then a magnum. Matt

 

[Zero333]

10 shot string with ES of 20 or less is good enough for me. Above 20 ES needs a little work.

 

[muleman69]

At what distance? ES seems become a bit more relevant as range increases. The target will tell you what will work. ES doesn't mean much unless it's stable for 10-20 shots over a reliable chronograph and repeatable for that load. JMO

I shot this at 100,think I will mess with neck tension then move on out like you say

 

[FeMan]

I would listen to Matt’s advice and shoot the load as is at distance before refining it. You could possibly find it shoots best like it is. Once you have a baseline of groups at distance, then you should look at load refinement as needed. If you do have excessive vertical you can go from there. ES is a good place to start but may not be where the “solution” lies either.

 

[muleman69]

I would listen to Matt’s advice and shoot the load as is at distance before refining it. You could possibly find it shoots best like it is. Once you have a baseline of groups at distance, then you should look at load refinement as needed. If you do have excessive vertical you can go from there. ES is a good place to start but may not be where the “solution” lies either.

Okay I will go for distance and see what happens tsk

 

[FatBoy]

I ran my first aftermarket CM barrel in my first 300WM. Probability that either matters is low, but in had a hell of a time finding a load that had SDs under 30 and even MOA accuracy with anything except A191, which was a solid. 5 moa shooter 300 and under , where I was testing. I switched off H1000 and RL22 to Retumbo and moved to a Berger OTM and it was like the skies parted and the sun shown down. Instantly dropped to single digit ES and groups well under half MOA to 600 and under moa at 1k, off a bipod in the dirt with a can.

I have only had one other rifle give me fits to find a load before. Guess one every 10 years or so isn't that bad.

 

[muleman69]

I ran my first aftermarket CM barrel in my first 300WM. Probability that either matters is low, but in had a hell of a time finding a load that had SDs under 30 and even MOA accuracy with anything except A191, which was a solid. 5 moa shooter 300 and under , where I was testing. I switched off H1000 and RL22 to Retumbo and moved to a Berger OTM and it was like the skies parted and the sun shown down. Instantly dropped to single digit ES and groups well under half MOA to 600 and under moa at 1k, off a bipod in the dirt with a can.

I have only had one other rifle give me fits to find a load before. Guess one every 10 years or so isn't that bad.

Mind me asking what your load was with Retumbo and which Bergers

 

[FatBoy]

Mind me asking what your load was with Retumbo and which Bergers

With Winchester Brass and Remington 9 1/2M primer . 230OTMS. 030" off with. 004" neck tension . I'd start around 72gr. I run 73.8. I don't consider this hot, but I'm not in the deep South or Texas on a hot , humid day. Be careful. I run a body die cut down so I can size to the belt and I run .005" HS to help with pressure. There are MANY here that will argue the merit of this, and they may have good points.

 

[muleman69]

With Winchester Brass and Remington 9 1/2M primer . 230OTMS. 030" off with. 004" neck tension . I'd start around 72gr. I run 73.8. I don't consider this hot, but I'm not in the deep South or Texas on a hot , humid day. Be careful. I run a body die cut down so I can size to the belt and I run .005" HS to help with pressure. There are MANY here that will argue the merit of this, and they may have good points.

Thank you

 

[FatBoy]

Thank you

Sure . Just be careful and work up by the book (default statement...) I have an A191 chamber for the M248 Mod0 190gr rounds (fed GMM and 190Black Hills) If you have a match chamber this may be too hot.

Hoping to try some ADG and Petterson 300WM brass this spring. Winchester has worked well, but if there's a better mousetrap .....

 

[muleman69]

Sure . Just be careful and work up by the book (default statement...) I have an A191 chamber for the M248 Mod0 190gr rounds (fed GMM and 190Black Hills) If you have a match chamber this may be too hot.

Hoping to try some ADG and Petterson 300WM brass this spring. Winchester has worked well, but if there's a better mousetrap .....

Okay,good info