Best Powder for 7mm Rem

[Autorotate19]

I did a search and couldn't find what I was looking for so I figured Id ask. What powder is going to give the fastest velocity in the 7mm rem mag with 168gr bullet out of a 26" barrel? Right now Im shooting the bergers with retumbo and Iv got a really compressed load shooting around 2,950fps. Iv got quite a bit of powder crunching as it is so I'm not going to keep adding to it. What other powders will I get better velocity with that are still not to temp sensitive. Where I hunt it can go from 70 degrees to below 20 in a day so its kinda important. Thanks

 

[steadyrest1]

H - 1000 will give you what you want for temp stability and vel.I'm curious as to what rifle your using that requires seating of the 168 gr bullets deep enough to be compressing powder.Also what 168 bullets are you using?

 

[Autorotate19]

A weatherby accumark and berger vld.

 

[Shortmagman]

From my experience with the 7mm Rem Mag. I would agree that H1000 gives me the best accuracy, velocity, and temp stability. I have gotten great accuracy, velocity etc out of RL-22, but it does not offer the same temp stability as H1000.

 

[ForneyRider]

I tried R25 with mediocre results in accuracy and velocity department for the 168 SMK. I use R22 for 120gr to 162gr with excellent results. My next batch for the 168 will use R22. IMR 4350 has been great with 7mm Mag, but haven't tried with 168gr.

 

[4xforfun]

H1000 has given me the most cosistently accurate loads with very good speed in many, many 7mm's using many different bullets (including 168 and 180 Berger and JLK) . RL 25 has given me off the charts speed with both the 168 and 180 VLD's in the only 2 guns I have tried them in. Accuracy has been good....not great, but good.

 

[Autorotate19]

I saw in another post that kirby suggested 4831sc. Anyone else use it.

 

[Pdvdh]

You're already using the best powder available, based on your description of 'desired' performance. You won't exceed Retumbo MVs at maximum Retumbo powder charges with the maximum load of H1000.

Best of the West reportedly settled on Retumbo and 168 Berger VLDs. I settled on Retumbo before I learned Retumbo was the go-to powder for this cartridge and bulllet load by Best of the West.

Let me know if you better Retumbo velocity with H1000. I'd be quite surprised. I'm also surprised that you're compacting Retumbo with your bullet seating depth. I load 74.6 grains Retumbo under the 168 VLD with my 7mm Rem Mag with a 24 3/8" barrel. Federal 210M primers. Muzzle velocity is 3045-3050 fps. Cartridge overall length is about 3.455", with the bullet jammed about 0.010" into the lands. I load single-shot style. If I need a magazine full of cartridges, I load 160 accubonds.

Seems like you should be getting more than 2950 fps MV out of a 26" barrel that's got the Weatherby free bore.

 

[Autorotate19]

It doesn't have as much free bore as the weatherby mags. Im 69thousands off the lands loaded at mag length. I guess ill stick with it. I'm loaded to 3.36" oal. I was just curious if there was something out there better. O well its still going fast enough to expand to at long range.

 

[Autorotate19]

Okay i have another question, how do you know if your load is too compressed. I have yet to get pressure signs with up to 75grs. Iv heard the bullets will actually push out of the case?

 

[retiredcpo]

I tried several differant powder/bullet combos
In the end I got 4831sc to shoot sub moa out to 500 yards
at 100 all 5 shoots are touching.
also got the 160 gr accubond to shoot the same with rl22
only problem now is I only have 170 bergers left and cant find any more anywhere.
Im not sure about the Vel on these loads but the way its shooting Ill keep it
Going to the desert on friday to stretch it out to 100 yards
retiredcpo

 

[Pdvdh]

I know that if the bullet won't maintain its seating depth or if the bullet tip is damaged during seating due to the force required to seat it to depth, that in my mind one has reached the point of overcompressed. Yes, bullets can spring forward some if there's not enough neck tension to keep them in place. How much is too much? If compaction causes inconsistent burn rates, reflected in higher ES/SD, or poor accuracy, then I suppose that could be considered too much. Other than these factors, I know of no written standard for too much powder compaction. I know some reloaders frown on overly compacted powder charges and will switch to a slightly faster powder to avoid heavily compacted powder charges.

Are you using a magnum primer or a standard primer? If you're using a standard primer, you might try a magnum. In my rifle the difference between a CCI 250 and a Federal 210 amounted to ~40-50 fps with the same powder charge. In other words, if you're lacking space for powder, a magnum primer can boost pressure and velocity over a standard primer. I ended up going with the Federal 210M with lower MV because they provided lower/better ES/SDs than the CCI 250s.


Here's some Retumbo versus MV data from my rifle. Add 8 fps for actual MVs. These were the chrono'd values at the location of the skyscreens

Retumbo - MV with CCI 250
73.0 . . . . 3061
73.5 . . . . 3069
74.0 . . . . 3086
74.5 . . . . 3105
75.0 . . . . 3119
75.5 . . . . 3134
76.0 . . . . 3152

 

[Autorotate19]

Im already using magnum primers. Thanks

 

[Pdvdh]

Well if you try and find a powder that yields higher MV than Retumbo with the 168 VLDs from your rifle, please update this thread. I'd certainly like to know so I can give it a go also.