Problems with Winchester 760 Powder for 308

[tkcomer]

Does anybody use Win 760? I'm using the Sierra 168 Matchkings and the max load for this combo is 49.2grs of powder. I started with 47.5grs of powder and it is up in the neck of the shell. 49.2grs would overflow the case. No way you could put that much in without it spilling it out, much less 53.5grs of powder listed for the 125gr soft point bullet. Cases are trimmed to 2.005”. I accidentally ordered this powder instead of the 748 I normally use, but since it is a good powder for 243 and they had loadings for the 308, I'd thought I'd use it. But this can't be right. Any ideas?

 

[Zak Smith]

760 is too slow, hence you run out of case capacity before you hit max pressure.

 

[ArchAngelCD]

Like Zak Smith said, you are using the wrong powder. If you want to stay with Winchester powders then change over to W748. It was designed for shorter casings whereas W760 is better when used for 30-06 rounds. If you don't mind changing powder companies, many reloaders have had good success with IMR4064 for reloading .308 rounds.

 

[tkcomer]

When I first got this powder a while back, I asked about using it in 308. Several people replied that it is a good powder to use. Not “the” powder mind you, but they had very good success with it. My problem is the load data from Sierra and even Speer would overflow the case at max charge. I'm staying one step below max and still I would have to compress this powder to load a bullet. If I tap on the shell, the powder will drop to about where the neck starts. This is my first time using it as I am now out of 748.

 

[Grumulkin]

In the 308 Win., Wincheter 760/H414 is good with 180 and 190 grain bullets. For 165 & 168 grain bullets I use IMR 4064.

Don't use Winchester 760/H414 in a semiauto since it's too slow & could damage the op rod.

 

[tkcomer]

It's for a bolt gun and I'm using Federal brass with standard primers. The Hodgdon site even lists load data for it.. There is a lot of load data for this powder in 308. I'm not trying for a max load. Never do. To big of a wuss. I just don't understand how they they get that much powder in that case and seat a bullet. There is no mention of compressed loads like some of the other powders. 47.5grs of powder is halfway up the case neck on my shells. I haven't even settled in on a load yet or have I loaded a single shell, but I'm 1.7grs under max and this case is just about full. Sierra lists over 52grs for the lighter bullets. No way could I put that in these cases. I'll admit it. What I'm reading versus what I'm seeing is making me doubt using this powder or trusting the load data.

 

[Bad Flynch]

You may be using military cases and they will not hold as much. Years ago, when I shot one particular .308 bolt gun, my very best all-time load for the Sierra 168 (then it was the "International"), was a near maximum load of H414 (WW760), around 47.5 to 48.5 grains with a military case; I have forgotten just exactly how much. That load has shot very well in several bolt rifles over the years. I think I used a CCI BR-2 match primer, too. This powder very much likes near max loads in the .308.

Try Winchester cases if you insist on more powder. Some people think that these ball powders shoot better with hotter primers, so try a W-W large rifle primer; they were made for ball powders.

 

[tkcomer]

You can see some pics here: http://www.pixagogo.com/8855594622 Scroll to the bottom and then click on the pic to make it bigger. Click on original at the top to really blow it up. That's 47.5grs in a Federal case. You would have to compress that to seat a bullet. Much less try and stick the max charge in that. I don't think a max charge would fit. Much less a max charge in the lighter bullets.

 

[snuffy]

Are you using a funnel with a long drop tube? Even then, do you simply "dump" the powder in all at once? Try using a long drop tube on the bottom of the funnel, THEN pour slowly onto the side of the funnel, to cause the powder to swirl, or circle the sides of the funnel.

This causes the powder to settle into a smaller space than it would if dumped all at once. You will have enough extra room to seat the bullet without compressing it.

You CAN compress powder charges. Ball powder cannot be compressed as much as can extruded powder, it already has less space between individual granuals.

 

[tkcomer]

I'm using the RCBS Uniflow with the standard rifle funnel on the bottom. Plus none of the manuals say that this is a compressed load. Like they do other powders. The Sierra book even mentions the drop tube for max compressed charges. This is not a max load.