The beauty of setting up your dies correctly

[ReaperDriver]

It amazing what setting up your dies correctly can do for you. If you recall, I had some issues recently with Lapua brass failing and significant pressure signs with what should have been normal loads and it turned out to be incorrect headspace (read here).

So I found some promising loads after going back and resetting up my FL sizing die using Doc's instructions to get the headspace correct for my new chamber. So I went out and re-shot some loads across the chrono today and got these results:

Upper left (44.6 Varget) is a cold clean bore.

2nd group of the day was the best by far. Here's a closeup:

QL said I should be able to get up into the 2600's by going above 45.0 Varget/175SMK since I was using Win brass, so I tried a 45.5 and a 46.0. The plan was to stop the moment I got any pressure signs. But surprisingly even the 46.0 Varget/175SMK had no issues at all.

One thing that I did different this time as opposed to the times I was getting 1/2 to 3/4 MOA groups with the same load was I played with the neck tension a bit. On this batch of WIN brass, I tried two new tricks: 1) I neck sized the brass in two steps, 1st from .343 down to .339 and then I FL sized them with a .333 neck bushing which gave me very LIGHT neck tension. I think the .001 less neck tension really helped the accuracy. Thanks again to everyone for all the help and tips in my Lapua brass failed thread. Your help really got me back on track!

 

[ReaperDriver]

Re: The beauty of setting up your dies correctly

Oh, and on an interesting related side note - I just got in a couple boxes of brand new virgin Lapua brass this week to replace all the ones I had tossed due to the HS issues. SO I did what everyone says to do with virgin Lapua and that was to just prime it, laod it up and go shoot it. So I did a cursory "workup" while I was at the range. But what I noticed was the cases were pretty long (2.01 or so, but within max spec) and measuring the shoulder datum line - I could tell they were going to give me some extra HS (i.e. the shoulders were bumped shorter than my current setup). And the final thing I noticed when I was seating the bullets was the neck tension was HUGE. The necks were sized down to like .333 or .334. Si it didn't surprise me when I got these results compared to the properly fireformed brss above.

Not terribly stellar, but the brass will get the proper prep treatment now that its been shot.

 

[Swan]

Re: The beauty of setting up your dies correctly

Would be interesting to see the same "experiment" run at 300yds. Although, with Lapua 1x fired.

 

[vman]

Re: The beauty of setting up your dies correctly

Once you have your dies set properly and your not sizing back your fireformed brass too much you will find the lapua brass to be fantastic.

Glad you sorted out your rifle

 

[ReaperDriver]

Re: The beauty of setting up your dies correctly

Vman - I didn't mean to imply that lapua wasn't good brass. I love the stuff. I was just saying that it appears that virgin brass, because it's not been fireformed and resized correctly in that chamber, is not as good as it could be. That's all.

And Swan- yes, that's the plan is to run all the lapua 1x through and then do the proper Load workups at 300+.

 

[ggmanning]

Re: The beauty of setting up your dies correctly

I neck size my new Lapua and turn the necks or just neck size depending on the application. It does usually measure in the upper range of ideal trim length. Great brass nevertheless.