7-08, Win 760 question

[bdbrown66]

Anyone here loading 7mm-08 with Win 760 and 139/140gr bullets? I'm looking to load the 139gr Hornady SST's, and the load data is quite different between Hodgdon and Hornady. Hodgdon lists a range of 45.5-47.0gr with the 139gr Hornady bullet, and Hornady lists 40.1-48.9gr. They both seem to agree that 45.5-47.0gr will put you in the 2700-2800 fps range, but then Hornady goes well above and below that in their data. Just wondered if anyone here had any personal experience with this load. TIA.

 

[RL338]

I did use W760 with Hornady 139gr BTSP and Berger 140gr VLDs. One thing with 7-08 brass there is a large internal volume range. I use older Winchester brass which is roomy and if I remember correctly I started at 43grs and went to 48grs. I found it to be 1.5grs less than RL-17 for max pressure. Not knowing your brass capacity I would start around 42-43 and work up.

 

[bdbrown66]

I did use W760 with Hornady 139gr BTSP and Berger 140gr VLDs. One thing with 7-08 brass there is a large internal volume range. I use older Winchester brass which is roomy and if I remember correctly I started at 43grs and went to 48grs. I found it to be 1.5grs less than RL-17 for max pressure. Not knowing your brass capacity I would start around 42-43 and work up.

Thanks for the info. In this case, I'm going to use some .308 brass that I resized to 7-08. Don't know if that will make a difference or not.

What are you referring to as "max pressure?" Sticky bolt, flat primers, etc.

 

[RL338]

I went and dug through my notes for when I got my first 7-08. I started with Hornady 139gr BTSP and necked down 308 Fed. brass , can’t find my H2O capacity on them. I used 215M primers and settled on 45.5grs of W760 running just above 2800fps. 48grs was 2960s and on the warm side. Bolt was stiff on opening. I later bought a couple hundred of the old blue bag Winchester brass and RL-17 is where I’m still at. Old Win. brass , RL-17 , and Berger 140gr VLDs is all I run today.

 

[hunter24605]

I went and dug through my notes for when I got my first 7-08. I started with Hornady 139gr BTSP and necked down 308 Fed. brass , can’t find my H2O capacity on them. I used 215M primers and settled on 45.5grs of W760 running just above 2800fps. 48grs was 2960s and on the warm side. Bolt was stiff on opening. I later bought a couple hundred of the old blue bag Winchester brass and RL-17 is where I’m still at. Old Win. brass , RL-17 , and Berger 140gr VLDs is all I run today.

Reloder 17 is an all too often overlooked powder for the 7-08. It’s been a solid performer in both of ours. It’s my go to for them now. Especially with 140 NP’s and AB’s

 

[jimbires]

I have no experience with this combo . I looked in my books , and found the same as you found . that's a pretty small spread from min to max according to Hodgdon , and a pretty wide spread according to Hornady . H414 is supposed to be the exact same powder as W760 , but most of my info shows different amounts between the two . for safety I'd suggest using the Hornady data . start at the min and shoot a velocity / pressure ladder working towards the max .

I have three 7mm-08's . I use RL17 in one , IMR4064 in one , and H4895 in one . I find the 7-08's to be easy to get shooting well , they are not fussy at all . I expect W760 to shoot well for you .

 

[TackDriver284]

My manuals do show different data sometimes when I need information on min and max, I just use some common sense and pick a charge to start with which is below the middle charge right above minimum and work up a ladder in .5 increments to max and look for pressure. Other option I use is pick the next heavier bullet weight and use that middle charge to use for the lighter bullet weight.

 

[walkinhorseman]

I've used 760 with 139-140's in a couple 7-08's. I recommend magnum primers with 760. I had one Sako A1 that would shoot less than an inch at 100 yards for five shot groups at 2825 fps with 140 BT's. That was 48.0 grs and flattened primers. My other favorite 7-08 powder is IMR-4350. I tried RL-16 in one recently but it couldn't show me the velocity or accuracy of 760/IMR-4350.

 

[ShadeTree]

Bdbrown, not the 760 you asked about, but just more info here to draw from.

I've used 41.6 grains of Varget with the 139 SST you mentioned using, in 3 different 7-08's. In a Remington 700 it was right at a 1/2" gun. In a mountain rifle more like 1.25", but I tried some other powders in that rifle looking for something better, and the 41.6 of Varget was as good as any and better than most. The third was a Rem 788 carbine. I went right to that same load and bullet. The very first test with that setup it put 5 shots under 3/4". There may be better, but it works.

It is at the very top according to Hornady, middle of the road according to Hodgdon. So, it's probably not necessarily wise to do like me and go right to that load without working up.

On the different powder charge data noted above, I suspect it's possible that the reason for the discrepancy with the Hornady data is they are showing 4 different bullets on the same page according to what Jim posted. I don't see how the longer and tougher IB will run the same pressure as the shorter, softer C&C interlock. Even the SST is a tougher bullet than the interlock in my opinion. Could be their max data is covering them for the bullet that runs the highest pressure within that group. Hodgdon data using a 139 Hornady is specifically for the interlock.

 

[bdbrown66]

So, I have decided to start with 45.0gr and work up to 47.0gr in .5gr increments. That's starting a little below the min Hodgdon load (45.5gr), but this brass I'm using (Perfecta) seems to be thicker/heavier than my Winchester brass. I'm guessing that internal capacity is less, and I'll probably hit max pressure sooner. If the 45.0gr load seems too hot, I'll pull them apart and reload them. If not, I'll work my way up the ladder. At 47.0gr, I'm pretty much at capacity of the case, so I can't go much above that, even if I wanted to.

As far as using 760, I had a full pound and part of another sitting on the shelf. I wasn't using it in any of my other loads, so I figured I would try to find a use for it. I've got my first batch of test loads ready to go. We'll see.

Thanks for all the input. I appreciate everyone's wisdom.

Brian

 

[Divernhunter]

This is what I use in mt Tikka T-3 Lite. It has a short barrel