Rhovee
Well-Known Member
- Joined
- Jun 29, 2017
- Messages
- 1,595
I recently had Alex Wheeler build me a 300 NM Improved. I have done quite a bit of playing around with it and hope that i am able to save some heart ache with someone looking for information. Lets start off with the good stuff:
Bat HR Action
26" Fluted Broughton #5
Manners EH1 stock
Trigger tech trigger
NF NXS 5.5-22x50
I first started fire forming brass with 85 grains H1000 jammed .020". I started to do a seating depth test while fire forming and quickly found that .030 off with 215 Bergers was very good. The brass was still fully forming. Speed was 3000 FPS and very accurate.
My first issue that i ran into was dies. The die was made from the reamer print and was not sizing the brass hardly at all. O at the web and .005 at the shoulder. I still tried to get the gun to shoot but it did not work. DO NOT try and do load development without a proper sizing die.
IMR 8133 is a new slow burning powder that sounded promising. I bought 8 LBS and gave it a whirl. I was getting pretty good accuracy (1.25" @ 300), but carbon fouling was TERRIBLE. I had such carbon build up that my lands were .007" SHORTER. This was after 60 rounds between cleaning. I cleaned very good and lost 80 FPS from old load.
I finally had to apologize to H1000 for ever leaving her. I quickly found multiple good accuracy groups with 215 Bergers and H1000. I did a (2) shot ladder with H1000 today and they were all 1/2 moa or less. It looks like it wants to shoot around 3125@ 88 Grains.
I know that N570 is a great powder for this caliber. I do not have any, and H1000 is easy to get, burns cooler on throats, and is about the most temp stable powder around.
Bat HR Action
26" Fluted Broughton #5
Manners EH1 stock
Trigger tech trigger
NF NXS 5.5-22x50
I first started fire forming brass with 85 grains H1000 jammed .020". I started to do a seating depth test while fire forming and quickly found that .030 off with 215 Bergers was very good. The brass was still fully forming. Speed was 3000 FPS and very accurate.
My first issue that i ran into was dies. The die was made from the reamer print and was not sizing the brass hardly at all. O at the web and .005 at the shoulder. I still tried to get the gun to shoot but it did not work. DO NOT try and do load development without a proper sizing die.
IMR 8133 is a new slow burning powder that sounded promising. I bought 8 LBS and gave it a whirl. I was getting pretty good accuracy (1.25" @ 300), but carbon fouling was TERRIBLE. I had such carbon build up that my lands were .007" SHORTER. This was after 60 rounds between cleaning. I cleaned very good and lost 80 FPS from old load.
I finally had to apologize to H1000 for ever leaving her. I quickly found multiple good accuracy groups with 215 Bergers and H1000. I did a (2) shot ladder with H1000 today and they were all 1/2 moa or less. It looks like it wants to shoot around 3125@ 88 Grains.
I know that N570 is a great powder for this caliber. I do not have any, and H1000 is easy to get, burns cooler on throats, and is about the most temp stable powder around.
