7mm 700 Sendaro and 180 Hybrids

[aramarine6]

I had a compulsive buy over the weekend at my local Cabelas that had a 700 Sendaro on sale. I had been in the market for a 7 Rem mag for some time and jumped on the opportunity. This is going to be my second long range build and was planning on shooting the 180s. I really don't have an interest in the 162-168 grainers. Two questions I have are, what is the correct twist rate of the 7mm Sendaro? and will the 180 Hybrids stabilize in that twist rate? I know that Remington's website says the twist is 1-9.25 however I have read on multiple occasions that its actually a 1-9.5? Berger says optimal twist for the 180s is 1-9. Anyone that has answers is greatly appreciated.

 

[tbrice23]

If it is a 7mm Remington magnum SendEro ,
Mine is1:9.25 twist.

 

[MudRunner2005]

I had a compulsive buy over the weekend at my local Cabelas that had a 700 Sendaro on sale. I had been in the market for a 7 Rem mag for some time and jumped on the opportunity. This is going to be my second long range build and was planning on shooting the 180s. I really don't have an interest in the 162-168 grainers. Two questions I have are, what is the correct twist rate of the 7mm Sendaro? and will the 180 Hybrids stabilize in that twist rate? I know that Remington's website says the twist is 1-9.25 however I have read on multiple occasions that its actually a 1-9.5? Berger says optimal twist for the 180s is 1-9. Anyone that has answers is greatly appreciated.

The correct twist is 9.25. You should be able to stabilize them. My old Sendero SF 7mm STW has a 9.25 twist, and it stabilizes the 180 Hybrids.

 

[7mmShooter]

With a little elevation you can get full stability out of the 180 Hybrids no problem. I'm at about 1500' here and the 180 hybrids are fully stable down to about 40 degrees.
http://www.bergerbullets.com/twist-rate-calculator/ here's the link to Berger's Stability Calculator, input your environmental conditions, velocity, and twist rate, and it will tell you how stable they will be.

 

[aramarine6]

Thanks guys! Really put my mind at ease. I'm looking forward to working up a load. I've never owned a 7mm before. From other threads I've read it seems like h1000 and Retumbo are the powders of choice.

 

[MudRunner2005]

Thanks guys! Really put my mind at ease. I'm looking forward to working up a load. I've never owned a 7mm before. From other threads I've read it seems like h1000 and Retumbo are the powders of choice.

IMR 7828 SSC (about the same as Reloder 25) and 7977 (about the same as H1000) are also worth looking into. Those are what I use.

 

[WAMBO]

With a 26.625" Proof Research 1-9" twist barrel chambered in 7mm Rem Mag I'm getting sub .5moa accuracy at 300 yds using the 180 Hybrid over 69.7 grs of Retumbo at 2948 fps, 68.2 grs of H1000 was also good with the same accuracy but netted 50 fps less velocity.
This is a new build with less than 100 rounds fired.
As always work up to these loads as they are safe in my rifle and are near maximum.

 

[aramarine6]

That's encouraging to see that both powders are capable of 2900+ fps. My goal with this build was to find an accuracy node somewhere around 2900 without trashing my brass.

 

[jweigel]

I just did powder work up in my 7RM Sendero shooting N570 but using 180 VLD....NOT HYBRIDS. Morning was 55 degrees, calm and lots of smoke haze from Alberta fires.

70 to 72 gr all shot sub .5 MOA at 200 yrds. Speed was 2900 to slightly over 3000. The best was 72 grains with a spread of 8 fps. and av speed of 3020.

73 and 74 grains opened to .75 MOA+ and increased to right at 3100.

75 gr I had a slight bolt lift and a nice shiner with speed at 3127....I quit there.

Will shot more around 72 grains but very nice groups so far...for me anyway.

Factory Sendero 7RM, Nosler Brass, F215.

jjw
ND

 

[aramarine6]

Those speeds are smoking for a 7 rem mag and 180s!

 

[roninflag]

i shot 180 bergers out of my sendero no problem kick was more than the 168's so i have been shooting those and 140's.

 

[jweigel]

I have since shot twice using N570 and the 180 VLDs. Yesterday was 70 degrees out and I did get ejector marks at 72 grains on up. Hard bolt lift at 72.5. But the 71, 71.5 and 72 all had MOE under .5. 71.5 was .433. average speed was:

70.0 - 2970
71.0 - 3017
72.0 - 3025

I was also shooting my 7STW with the same bullets and powder. My go to Retumbo load with this bullet was 78 gr running 3080 as corrected with Strelok out to 1000 yards. I shot a 3 round group to see how relative the speed was this day and it was 3044. Three shot group average 3044 shot a few weeks back (50 degrees out).

WOW.....that is crazy speed out of 7RM. I would love to use 72 grains as it has really low ES and great MOA but getting ejector marks (70 degrees out) I will drop back to 70 to give me a little room.

So as not have have a 7RM shooting as fast as my 7STW with 180 VLD....I was able to get good MOA and a very tight ES with 80 grains running 3114.

Will stay with this for now.

jjw
ND

 

[moombaskier]

With a Remington chamber I recommend seating your bullets 0.010-0.015" from the lands and start with H1000.