7SAUM and 195 EOL Bergers

[Endyo]

I've exhausted every search forum I can.

Anyone using this caliber and bullet combination? Any actual user input on the new Bergers, expected velocity?

I've all but decided on the 7SAUM as a future rifle build and need to spec a reamer.

I'm open to other caliber suggestions. I can tolerate recoil I am shooting F-Open so strings would be 20+ rounds X3 on the day.

 

[Sheldon N]

There's a lot of broad commentary on the Long Range Hunting forum about both the 195 Hybrid and the 7 SAUM. I would say a rough estimate of what you could expect would be around 2900fps from normal barrel lengths, maybe a little faster if you're running a 30" F-Open tube. Powder choice based on case capacity/pressure probably favors H1000, maybe H4831 if your gun shot more accurately with the faster powder (at the expense of a little velocity loss).

If you can get it to be accurate with low SD and good vertical at 1000, and can manage the recoil, you would get a wind drift improvement of around 10-15% over the standard 284 Win/180 Hybrid loads.

You going to build it on a long action or can you single feed a short action with the 195 seated properly above the case neck/shoulder junction? Those 195's are long buggers! Don't forget the faster twist rate you'll need to keep them stable.

 

[Endyo]

Thanks for your post Sheldon!

I was leaning towards a long action likely a Barnard.

I've read some reports of velocities as high as 2975fps. I'm not sure if that's obtainable while still maintaining accuracy.

I've also read falconpilot's post on these forums on the 195s. His was for a .284 Shehane. I think he settled on a .290 throat.

 

[kev77]

Thanks for your post Sheldon!

I was leaning towards a long action likely a Barnard.

I've read some reports of velocities as high as 2975fps. I'm not sure if that's obtainable while still maintaining accuracy.

I've also read falconpilot's post on these forums on the 195s. His was for a .284 Shehane. I think he settled on a .290 throat.

Why not just point 180 bergers 720 bc. And shot them at 2990 -3050. ????

 

[Endyo]

Is that B.C. estimate a little high on the pointed 180 hybrid?

Pointing adds 3-5% improvement (Bryan Litz's numbers), sometimes more if the meplat is wide. Most 7mm projectiles have a fairly narrow meplat.

 

[Endyo]

JBM caculations I've done show 195s (2975FPS) are going to shoot 1/2MOA (5 inches) inside of the 180s (3050FPS) at top speed at 1,000 yards with a 10MPH crosswind.

Compared to a straight .284 shooting 180 hybrids at 2850fps the 195s in a SAUM will be shooting 1MOA or 10 inches inside of the 284win.

 

[Keith Glasscock]

If you read Litz's writings closely, his testing suggests that the 180 hybrid has a much higher percentage increase in BC from pointing. IIRC, he was stating something like 8-9%. My testing mirrors his, as rudimentary as mine is...

 

[Endyo]

The 180s are such great bullets. I wonder if that's why the 195s seem to be slow to catch on.

Here's an interesting thought. Do the 195s point well?

Even if they don't a 3% increase from pointing would net a BC of 778 vs the 720 of pointed 180s.

 

[MTlager]

A friend of mine is getting 2925 in his 7 Saum with a 28 inch 9 twist barrel and 7828sc. With 180vld over 3000. The 195 was a real good elk hammer!!
Lonnie

 

[Endyo]

I just spoke with an experienced F-class SAUM shooter over the phone. His node for the 180 Hybrids was @ 2880-2920 FPS. Any faster and accuracy degraded.

Close to what a Shehane can provide.

He did not have experience with 195 EOLs