6.5 PRC with Viht N165 & Hornady 140gn ELD-M?

[FCSA-UK]

Just wondering if anyone has had good results with the following combination: 6.5 PRC with Vihtavuori N165 & Hornady 140gn ELD-M?

I need to make a few rounds up so I could start getting some OD neck data for my die bushing selection, but may as well make up some rounds that will shoot pretty well, however only have N165 and the 140gn ELD-M to hand.

The published Viht data for lead cored 140gn bullet with N165 seems very low compared to QuickLoad, approximate maximum charge of 50gn's. When I put this data into Quickload I'm getting an MV of 2606ft/sec at a very low chamber pressure of 42129 psi! [Using virgin Lapua brass, H20 capacity is 67.1gn]

If I push it to 54.6gn, (so 4.5gn over the Viht recommended max), I'm getting a respectable 2815ft/sec at 54,930psi - which is still 10,000 psi under maximum.

So if you are using the above combo, what did you settle on?

Is the Viht data known to be so risk averse?

Many thanks.

 

[spife7980]

Know how to approach this safely? Start low and work up.

 

[Dogtown]

Is the Viht data known to be so risk averse?

I don’t know about it being risk averse, but some of their data is puzzling for sure. While QL has been a reliable ballpark predictor for me, I wouldn’t rely on it alone. If you’ve never used this cartridge/bullet mass/powder combo before then doing an initial pressure test should alleviate any of your concerns.

For example, I’m testing a new 265gr solid bullet in a .338LM at the moment. I have lots of experience with that cartridge and N570, so I have an idea of where the safe zone should be, but a totally new bullet with no load data tells me I should do a quick pressure test first. I know the book min for similar bullets is way too low and the max is conservative for this barrel. So I loaded five shots in 1gr increments starting about 80% of max and I figure I should see pressure around number 4 or 5, but if I’m wrong the worst I may get on the first round is hard bolt lift, but not likely. They also can give you an idea of what velocities to expect.