7mm RM 150 E-Tip ladder test

davkrat

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I've got a 150 E-Tip load worked up for my brother's 7mm Rem Mag using H4831. His rifle is a 700 BDL he bought in Germany and it has a 22" barrel. Gorgeous European style stock and iron sights I assume geared twards shooting driven game as they do in Europe. I plan to work up a load in my 26" barrel 7Mag and hope that Retumbo might get me an extra hundred fps or so of pressure that I doubt his shorter barrel could get.

As I said in the past the 7mm Rem Mag data is all over the place in manuals. One book for the same weight bullet will list a max charge that is equal to the starting charge of another it seems. Hope to shoot a couple ladders this weekend using the 150 E-Tip and H4831 and Retumbo.

H4831: 60.5-65.0 grains
Retumbo: 68.0-73.0 grains

Just looking for second opinions those are in the ballpark. I averaged the min and max of several book loads in the 150-160 grain range. I don't have access to Quickload.
 
I have 7 years experience with the 7mm rm using 150 grn etip, I used to use partition points but ran out and tried the etip. A huge improvement.
I have a savage 111/ 7mm rm that loves 67.0 grn IMR7828 cci mag primer, 3/4" @100 meters, 2995 to 3010fps. Full length sized 10thou off the lands OAL 3.465" no crimp. They just fit snug in the mag with no feeding problems.
I love the Etip. 1 shot drops with no bullet break ups, 5 deer and 1 moose over 7 years.
 
Thanks. That's at 80% between the min and mag for Nosler 150 gr. data. Looks like they got a little more speed with IMR 7828 than H4831. I don't have any on hand but I will stick with the 61-65 gr. that Nosler shows for H4831. A little inthe dark on Retumbo. The Hodgdon data is all over the place. There are larger powder charges for 170 grain bullets than 150 grains on their website. I'm going to see how their 162 gr Nosler Partition info works with the 150 ETips. For the .308 I've found the data for the next heavier weight bullet pretty much lines up with the ETips.

I'm surprised you had luck with them that close to the lands. Seems everyone reports best performance with a significant jump. I loaded mine at 3.280" which is .100" off the lands. Nosler suggests 3.260" which is an even greater jump. In my .308 I'm at .120" off the lands at maximum magazine length.

Got them all loaded up just need to find some time to sneak off to my 300-400 yard range and shoot the things. We've had great results on deer with the ETips out of the .308. Getting them to shoot accurately is another issue. In my brother's 7 basically the first load I tested shot a one hole group at 100 yards. I'm really looking forward to see how the 7mm expand with the increased BC and velocity at longer ranges.
 
Got out and shot the first ladder test with H4831. Set up at 285 yards, 78 degrees and 4,465 ft. elevation, baro = 25.4

Ran all the way through the ladder test and never experienced any pressure signs. As I said previously the various data I found online is all over the place for 7mm Rem Mag. I think I can safely try up to the higher load data on Hodgdon's website for 150 grain bullets.

Looks like I hit a node at loads #7-#10. If I could squeeze another 100-200fps of speed I would be happy even though the ballistic calculations at 2950 fps are suitable for hunting in California. I was hoping to get up around 3100 fps. A few grains more H4831 might get me there. Also plan to run a Retumbo ladder next.

1. 150 Etip 60.5 H4831 2676
1. 150 Etip 60.5 H4831 2706
1. 150 Etip 60.5 H4831 2701
2. 150 Etip 61.0 H4831 2756
3. 150 Etip 61.5 H4831 2780
4. 150 Etip 62.0 H4831 2809
5. 150 Etip 62.5 H4831 2821
6. 150 Etip 63.0 H4831 2873
7. 150 Etip 63.5 H4831 2921
8. 150 Etip 64.0 H4831 2933
9. 150 Etip 64.5 H4831 2992
10. 150 Etip 65.0 H4831 2933

 
I tried Retumbo in my 7mm RM and it didn't like it. It does love 7828 SSC behind the Berger 168 VLD's and H1000 behind the 160 NAB's. All with a Fed 215 primer, of course.
 
Just got back from shooting the rest of the ladder with H4831 and Retumbo. Think my chrono is on the fritz. The H4831 load from 64.5 up did not seem to increase velocity at all.

Retumbo might get me another 100 fps but it didn't seem to be as accurate as the node around 64.5 gr of H4831. The funny thing is my 26" barrel got 2975-3000 fps burning 2-3 grains more powder than my brothers 22" barrel. Two grains more powder and 4" more barrel to get the same speed???

Used Hodgdon's data for 150 grain Barnes TTSX. Plan to do some 3 shot groups around 64.5-66.0. Probably have to redo the Retumbo ladder all together.

150 Etip 60.5 H4831 2676
150 Etip 60.5 H4831 2706
150 Etip 60.5 H4831 2701
150 Etip 61.0 H4831 2756
150 Etip 61.5 H4831 2780
150 Etip 62.0 H4831 2809
150 Etip 62.5 H4831 2821
150 Etip 63.0 H4831 2873
150 Etip 63.5 H4831 2921
150 Etip 64.0 H4831 2933
150 Etip 64.5 H4831 2992
150 Etip 65.0 H4831 2933
150 Etip 65.5 H4831 2951
150 Etip 66.0 H4831 2982
150 Etip 66.5 H4831 3039
150 Etip 67.0 H4831 2991
150 Etip 67.5 H4831 2987


150 Etip 68.0 Retumbo 2914
150 Etip 68.5 Retumbo 2931
150 Etip 69.0 Retumbo 2965
150 Etip 69.5 Retumbo 3065
150 Etip 70.0 Retumbo 2951
150 Etip 70.5 Retumbo 3059
150 Etip 71.0 Retumbo 3090
150 Etip 71.5 Retumbo err
150 Etip 72.0 Retumbo err
150 Etip 72.5 Retumbo err (slight ejector mark)
 
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