What powders for .270, 7MM.08, and 7MM Mag

Walkalong

Walkalong

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So, I've never loaded any of these, but have nephews/great nephews who hunt with them and have asked me if I can reload them. They are all using bullet weights in the 140 range, Hornady 140 Gr Interlocks in the .270 , 139 Gr Interlocks in the .08, not sure what bullet in the 7 Mag. (One uses .308 as well, but I have that covered).

Looking for what (hopefully one) powder I'll need. I have nothing slower than H-4350. & N-160, which might work. Dunno other than looking at data for them.

What does the THR brain trust use for these calibers?
 
Responses should be interesting here. Just based on the expansion ratio (case capacity divided by bore diameter), your .308 powders should be pretty good for the 7mm-08, but the the .270 and 7mm mag would be very different. A quick look at Hodgdon indicates that IMR 4350 is gives above average velocity for all three cartridges with 140 gr bullets.

On the other hand, if your powders for .308 would work well for 7mm-08, then maybe pick the best powder for .270 and 7mm mag and add that to your shelf.
 
I used H4350 with a 140NBT in 270. It was before I had a chronograph. So I don't have velocity data. But it was very consistent as far as field conditions went. I shot more crows with that rifle between 3 and 4 yards than anything.
Since you have h4350 I would try to find h1000 or h4831 for the 7mag.
 
I have rifles in all three of those cartridges. I use H4831 in the 270, RL22 or RL25 in the 7mm Rem Mag. The 7/08 I have used H4350, H414, H4895 among others. If I was you, I'd use the H4350 for the 7/08 and try to find something slower for the other two. The H4350 would also work for the 270 if needed. There is some data for the H4350 in the 7mm Mag but it isn't close to ideal.
 
My Mod 70 7RM--H4831, 154gr Hornady Interlock,
Sako Finnbear .270 Win--H4831, 150gr Hornady Interlock, occasionaly, Nosler 160gr Partition,
No help with 7-08, but, looking at manuals, H or IMR 4350 sure seems it would fill the bill.
 
IMR 4064 was always my go to for .280 Rem., 7MM Rem Mag and it is my favorite for 30-06 Garand. Most bullet weights were in the 150 to 168 grain though. Hate to send you on a powder hunt.
 
Ive used RL-22 in both .270 and 7mm RM with excellent results. I bought it for loading ammo for my 6.5x55, which also worked very well.

For whatever reason, there is no RL-22 data for 7mm08 or 308 on the Alliant site, but there is for .243, .260 and 7x57. (Go figure o_O) If data for RL-22 is out there for the 7mm08, , RL-22 (or RL-19) could be a great one-powder choice for them all.

Stay safe.
 
Riomouse911 said:
Ive used RL-22 in both .270 and 7mm RM with excellent results. I bought it for loading ammo for my 6.5x55, which also worked very well.

For whatever reason, there is no RL-22 data for 7mm08 or 308 on the Alliant site, but there is for .243, .260 and 7x57. (Go figure o_O) If data for RL-22 is out there for the 7mm08, , RL-22 (or RL-19) could be a great one-powder choice for them all.

Stay safe.
Click to expand...
That isn't surprising based on the expansion ratios for these cartridges (i.e., the case capacity divided by the area of the bore). Cartridges with higher expansion ratios typically use slower burning powders. Here are the expansion ratios for the cartridges under discussion and a couple extra for reference (approximate values since it can vary if you use a slightly different case capacity):

.308 win - 750 grains/square inch
7mm-08 - 820
.30-06 - 920
.260 rem - 980
6.5x55 - 1040
.270 win - 1100
.243 win - 1160
7mm RM - 1320

The expansion ratio for 7mm-08 is much lower than rounds that typically use RL 22, such as 7mm RM, .243 win on this list or .300WM and .25-06 which I load.

Looking at expansion ratio won't tell you the best powder to use, but it will give you an idea of a set of powders that will likely work. Two cartridges with similar expansion ratios will almost certainly have several powders that work well for both. Looking at Hodgdon data for this thread, I was surprised to see CFE 223 producing very good velocity in .308 and 7mm-08. But then I checked the expansion ratio of .223 rem and it's 760, right there next to .308 and 7mm-08.
 
I've done a bit of loading for a 270 and used IMR 4831 for that. I wouldn't hesitate to use 4831 in the 7mm Rem Mag, but it's probably on the slow side for the 7mm-08. If you're going for one powder to load all of those, as others have suggested, I'd try your H4350 and see how you get along. Ideally, I'd want something a bit slower for the 7RM (and even the 270), and maybe something faster for the 7mm-08, but 4350 could work just fine as a compromise for all of them. You'll just have to test it.
 
wombat13 said:
That isn't surprising based on the expansion ratios for these cartridges (i.e., the case capacity divided by the area of the bore). Cartridges with higher expansion ratios typically use slower burning powders. Here are the expansion ratios for the cartridges under discussion and a couple extra for reference (approximate values since it can vary if you use a slightly different case capacity):

.308 win - 750 grains/square inch
7mm-08 - 820
.30-06 - 920
.260 rem - 980
6.5x55 - 1040
.270 win - 1100
.243 win - 1160
7mm RM - 1320

The expansion ratio for 7mm-08 is much lower than rounds that typically use RL 22, such as 7mm RM, .243 win on this list or .300WM and .25-06 which I load.

Looking at expansion ratio won't tell you the best powder to use, but it will give you an idea of a set of powders that will likely work. Two cartridges with similar expansion ratios will almost certainly have several powders that work well for both. Looking at Hodgdon data for this thread, I was surprised to see CFE 223 producing very good velocity in .308 and 7mm-08. But then I checked the expansion ratio of .223 rem and it's 760, right there next to .308 and 7mm-08.
Click to expand...
I do the same for guessing at which powder to use. CFE223 is either giving good velocity. Or it's not recommended.
 
Based on what you have or likely have what I'd want to test with.

If you already have n160 I'd be testing it in 270 and 7mm mag. The 7-08 would be better served by the faster powders you have like 4064, varget or rl15. If you want to buy something h1000 in the 7 mag would be gooder....
 
Bfh_auto said:
I do the same for guessing at which powder to use. CFE223 is either giving good velocity. Or it's not recommended.
Click to expand...
I use this method when deciding which cartridges to buy. My first rifle that I loaded for was .300WM and I stocked up on a variety of powders. I also load for .30-06. So now I'm reluctant to buy any rifles for cartridges with expansion ratios much lower than .30-06. I've already got $1,000s in powders in the slower than average burn rate. I don't want to have to stock up on faster burning powders and these days it's tough to find powders.

My last two rifle purchases have been .25-06 (which uses identical powders to .300WM) and .280ai which is about halfway between .30-06 and .300WM.
 
Of those 3 I only load .270. In .270 I load 130's, 140's and 150's
For the 140 Nosler BT I've loaded, H4831 is the ticket.
For the 130 BT I love RL16
For the 150 BT I like RL26 but still looking and going to try some IMR 7828SSC that I found recently.
 
I load for 7mm-08, .280 Rem and 7mm RM.

If you are set on the “1 powder for everything” you will be compromising.

I used similar powder for 7mm-08 139 gr bullets and .280 Rem 150 grain bullets.

7-08 liked H414 slightly better than RL19.
.280 liked RL19 slightly more than H414.
IMR 4350 was tested in both those and were serviceable. I believe it came out 3rd best in both based solely on accuracy.

Without referencing a manual, I think 4350 would work in the 7mag with lighter bullets. I shoot 160s in mine with RL22. But you need to reference that manual.

PS: You probably won’t find H414 but W760 is the same powder and has been readily available.
 
Years ago, I loaded for a 7mm-08 with 140 gr bullets, and had my best results with Varget. The previous owner had favored IMR-4064.
I have loaded for a couple .270 Winchesters over the years and have had good results with Ramshot Hunter, Alliant 4000-MR, IMR-4831 and H-414. I like the 130 gr bullets and doubtless could find decent loads with a bunch of other powders. I have only loaded the Remington 7 mm Magnum a liitle bit, but imagine it would use similar powders that my .270 WSM likes, including the nearly unobtainable H-1000, Retumbo, Reloder 22, 23, and 26, along with more readily available Accurate MagPro and Ramshot Magnum.
 
I have been using RL23 and H4831sc in my 270 with great results. My current load is RL23 and a 140gr Accubond at around 3000fps.
 
Walkalong said:
So, I've never loaded any of these, but have nephews/great nephews who hunt with them and have asked me if I can reload them. They are all using bullet weights in the 140 range, Hornady 140 Gr Interlocks in the .270 , 139 Gr Interlocks in the .08, not sure what bullet in the 7 Mag. (One uses .308 as well, but I have that covered).

Looking for what (hopefully one) powder I'll need. I have nothing slower than H-4350. & N-160, which might work. Dunno other than looking at data for them.

What does the THR brain trust use for these calibers?
Click to expand...

N160 data here. Looks like a better option for the 7MM mag and 270
Vice the 7-08

https://www.vihtavuori.com/powder/n160-rifle-powder/
 
I’ve never tried H1000 but hear great things. I’m convinced that those who like IMR4064, Varget, and H380 in the 7-08 don’t own chronographs.

My 7-08 gags on H380, Max’s out 2gr below Lyman #48. Varget and IMR 4064 max out 200fps below RL17. 100fps below max of IMR4350 which is volume restrictive. (Only 46.5gr will fit under a 139-140gr bullet. Only 45.0 under a 150, but it’s a splendid powder for the 7-08.
#2 behind the RL17 is H4350. Realistically they’re very similar. RL17 gives the accuracy of IMR4350 but velocity of H4350.
John Barsness says you can use up to 50.0gr of H4350 under a 139gr Hornady btspt . My gun wants 48.0 H4350 or 47.0gr RL17 for 3,000fps (20”bbl!!!). Accuracy about 1.25moa-three shots. But it’s a “killing fool”! A “Lucky” rifle that punches above its weight.

I use the same powders in the .270 for 3,000fps with 130grbullet. Usually 55.0gr of H4350 or IMR4350. However I’m working through a pound of MagPro and getting great results. 3,200fps from my 24” MkX and 3,100 from my 22” REM M700. Accuracy is excellent.

I’m in the early stages working with the 7mm RemMag.
I’ve gotten acceptable accuracy with some WC860 military pulled down from .50BMG. It’s the same as the discontinued Hodgons H870. (Lots of variability between lot#’s). 77.0gr with a PPU 174grSpt gives 2,900fps and 1.5” for 3-shots.
68.0gr of MagPro gives 3,000fps with a Speer FB Hotcore 160gr. Accuracy approaches 3-shot MOA. Probably my elk load next time I get draw for a permit.
Just last Thursday I shot some 139gr Hornadys I loaded over 64.0gr of H4831. It delivered 3,150fps and two sub 1” 3-shot groups. This is the best the rifle has shot to date. I’m satisfied with it! It’s a pre-bankruptcy Remington M700 CDS 26”bbl -synthetic I got on close-out at Walmart for $378.00
Much cheaper than a new barrel in 280AI for a Mauser or Remington action, installed.

But, I knew going in that it would only beat my 7mm08 by 175-250fps...
the 7mag lives up to the hype. But the 7mm8 is an over achiever! The . 270 is still the standard for a light, flat shooting “deer” rifle, but I prefer the near twin 7mm08.
 
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