Hi there. Whats the best powder to use for this cartridge? I loaded 20 up for my boss. His wife drew a tag. Cow elk tag. So we're wantin to know whats the best powder choices, and he bought 139 gr interlocks last year for deer. They should work for a cow. I got my books but just seeing what you all using. Thanks again.

Win 760 works well for me with 139/140 gr and heavier bullets and I have one 7-08 that shoots 140 Sierra's into little tiny groups with 4320. I would start with the 760. Hope that helps

That is right in the middle of the medium burn rate range and there are many good options. Personally, I like superformance. I get good speed and as a ball powder it goes through a meter well. For loading 20 rounds, this is probably not a factor. If you reload at all, then you probably already have something suitable on your bench.

Or you can look at it as a reason to buy something new too...

For me it depends on the bullet. I get sub .5moa accuracy with amax's and varget. If I want speed I use big game but the groups open up to a little over an inch or. H4350 with any 140gr bullet has yet to break the 1" mark, its my go to powder.

I chanced onto IMR 4064 with 139 grain flat based Hornady Interlocks and found pure magic, but I don't know what velocity they run at. I am sure there are a bunch of different propellants that will work, and some will work in one and not in another, but that is the mystery of ballistics.

140 gr bullets and Varget are like peanut butter and jelly....made for each other. The 139's would be great with it as well. The 7-08 isn't finicky at all IME.

I have had very good results with 4451 and H4350.

I'm with Luckyducker on this one. The Hornady 139 gr bullets and IMR 4064 are perfect together.

Steve......

i have loaded for this cartage for about 28-30 years.. for 139 and 140,s its hard to beat IMR4064 and IMR4166, my best groups came from RL-15.. WLR, Fed210 are very good primers for this also, I have also shot very good groups with S&B primers

Shooting 140gr TSX, I have had good luck with H4350. 3/4 moa from my rifle, velocity about 2800 FPS. I am loading 47.5gr in WW cases over CCI large rifle primers.
I went through several powders to get there.

Look at at the 120 gr TTSX with 44-45 gr RL-15.

Tried lots of different powders over the years with 140's, something around 760 range seems to give the best velocities, h4350 or RL16, in that area. Also worked up loads using CCI250's with the ball powder. All depends on the gun, but, 760,H4350 and RL16 are about optimum for the 7-08 w/140's.

I've used 140 partitions until X bullets came out and then started using them. Currently the TTSX. I just started trying the Accubond since I don't shoot anything larger than elk, usually cows.

I started with 760 and went to Varget about 10? years ago. In my ULA 20 with a Pacnor 25" match barrel at my altitude I chrono at an average of just over 3000 fps. The ULA has a long blind magazine and allows me to seat the bullets in the neck and to put powder in the case. It is about 1/2"-5/8" accurate. 760 did about the same.

You might consider using a stronger bullet for elk.

A stiff dose of Rl 17 will get a 140 knocking on 3000 fps. Very accurate in my Rem 700 lvsf with a Sierra Prohunter

quote:

Originally posted by kennedy:
Hi there. Whats the best powder to use for this cartridge? I loaded 20 up for my boss. His wife drew a tag. Cow elk tag. So we're wantin to know whats the best powder choices, and he bought 139 gr interlocks last year for deer. They should work for a cow. I got my books but just seeing what you all using. Thanks again.

Varget is what I use

AA4064 serria 140 bt 210 primers

IMR-4064, Varget, WW760 and its twin H414 are all good powders and max loads don't vary much in velocity, may 50 FPS on average..WW-748 is another good powder..The 7-08 like the .308 on the same case and both by design are not picky about powder.

I have not tried CFE223 in the 7-08 but I bet I could load up a sizzleing load with it at very little pressure..Its like H414 on steroids..

When I was loading for my 7mm-08 I got some interesting information from a fellow who preferred Win 748 powder in this case. I did try it with both 120 Hornady and 139gr. was fire forming with 43.5 gr in the case with 120gr bullets and was getting fantastic groups close to 1/2 inch at 100 yards. I did not chrony these loads. Fortunately I have several pounds of Win 748 powder. FS