Best powder for LR 300 win mag

[C Harrison]

Also, Norma 217 is very good. Nearly identical to RL 25 just more consistent, so I have heard. Slightly temp sensitive but the most accurate in my rifle. 1100 yards needed a 1.25 MOA elevation correction between 85 degrees and 55 degrees.

 

[Deleted member 46119]

Imr7828ssc and MRP are both available and will both work well. Very well.

What he said. 7828 is a goto powder for me with the long skinny powder (aka belted) magnums.

IIWM I'd switch to 215 or 215M or CCI 250 or Win Mag Rifle primers. No disrespect to Remmy of Wolf or Tulla I just use the others first.

 

[Greyfox]

I'm scratching my head after reading this thread. I'm another one using H1000 in my 300 win but I'm finding my load to be more temp sensitive than any other load I've ever used in any caliber/cartridge (except for ball powders) including any that have used RL15, 19, 22 or 25.

At 25 degrees they're 2600'sec. At 75 degrees they're 2700'sec. No joke and they're doing it consistently. Load is 71.5 h1000 under 210ablr lit by the 210match.

That is a head scratcher. While I had switched a while back to Retumbo because of increased velocity, I did a lot of work with H1000 and found it to be very temperature stable. This is probably long shot. Your loads seems light. My load that produces 2750FPS in a 24" Milspect runs 75.5 gr with a Fed215 magnum primer. No pressure signs. Bullets are 210 Bergers and ABLR's, both giving the same results. A few of my buddies run the same load range with similar results. ES is generally 10-12FPS and temperature stability is good. Is it possible that your lot of powder is off, or, the light load of 71.5gr combined with the standard rifle, Fed 210 is creating a temp/pressure effect? Just some thoughts.

 

[DocB]

What he said. 7828 is a goto powder for me with the long skinny powder (aka belted) magnums.

jf, I'm going to be working up loads with 7828 and was thinking about using the SSC version. Will there be any significant differences between 7828SSC and the 'normal' long grain 7828?

Thank,

DocB

 

[Deleted member 46119]

jf, I'm going to be working up loads with 7828 and was thinking about using the SSC version. Will there be any significant differences between 7828SSC and the 'normal' long grain 7828?

Thank,

DocB

No and yes.

Books and QL say the data for 7828 can be used for SSC. Not the other way around.

In reality, SSC can produce slower loads if the same charge would fit for regular 7828. It was too much difference and remained consistent from lot to lot of both powders.

I can only point to unused case capacity taking some of the push.

 

[DocB]

No and yes.

Books and QL say the data for 7828 can be used for SSC. Not the other way around.

In reality, SSC can produce slower loads if the same charge would fit for regular 7828. It was too much difference and remained consistent from lot to lot of both powders.

I can only point to unused case capacity taking some of the push.

Fred, so if I'm tracking correctly, if using the same charge weight, regular 7828 may be faster than SSC because it will fill the case more to a 'compressed' load state, creating more pressure than SSC which would leave 'empty' space in the case with the same amount of powder.

Thanks, DocB

 

[Deleted member 46119]

Fred, so if I'm tracking correctly, if using the same charge weight, regular 7828 may be faster than SSC because it will fill the case more to a 'compressed' load state, creating more pressure than SSC which would leave 'empty' space in the case with the same amount of powder.

Thanks, DocB

That's how it seemed to work in the real world.

BTW: My best results in the most of my belted case designs are with 7828 reg or SSC depending on charge. My buddy likes R19 better in his DTA.

 

[mountainman56]

Imr7828ssc and MRP are both available and will both work well. Very well.

Gotta agree with that. Sent a lot of bullets down range lately with both these powders with the nod going to MRP. Lightweight 300 Win mag shooting 3/4" groups at 300 yards with 200 grain lrx.

 

[DocB]

That's how it seemed to work in the real world.

BTW: My best results in the most of my belted case designs are with 7828 reg or SSC depending on charge. My buddy likes R19 better in his DTA.

Thanks Fred, I'll be using this in my 300WM with both 215 Bergers and 208 Amaxs in Winchester brass. I'll do test loads with both long cut 7828 and SSC.

Appreciate the info!

DocB

 

[Saracen]

I'm scratching my head after reading this thread. I'm another one using H1000 in my 300 win but I'm finding my load to be more temp sensitive than any other load I've ever used in any caliber/cartridge (except for ball powders) including any that have used RL15, 19, 22 or 25.

At 25 degrees they're 2600'sec. At 75 degrees they're 2700'sec. No joke and they're doing it consistently. Load is 71.5 h1000 under 210ablr lit by the 210match.

 

[Saracen]

Personally, I'd try a 215 magnum primer.

 

[jrsolocam]

Fred, so if I'm tracking correctly, if using the same charge weight, regular 7828 may be faster than SSC because it will fill the case more to a 'compressed' load state, creating more pressure than SSC which would leave 'empty' space in the case with the same amount of powder.

Thanks, DocB

But cant you get more ssc in the case????

 

[jrsolocam]

Gotta agree with that. Sent a lot of bullets down range lately with both these powders with the nod going to MRP. Lightweight 300 Win mag shooting 3/4" groups at 300 yards with 200 grain lrx.

MRP is so under rated. Great powder in the "medium magnums". Used in Weatherby FL's I think.

 

[cape cove]

MRP is so under rated. Great powder in the "medium magnums". Used in Weatherby FL's I think.

Agree. I believe the only reason for it's lack of use is it becomes so hard to obtain from time to time. As you stated great in medium mags and calibers such as 25/06. 6.5/06 280 rem etc. Just a great stable powder