All Day with Norma Brass for 6-12

[CaptainMal]

Actually the numbers should read .6 gr - 1.2 gr.

I tested using Varget, Norma 6 Dasher brass and a home-made loading apparatus set up to deal with the wind and weighing out charges. Tried a simple balance scale but air movement was so bad, even tucked into a box, it was useless.



Conclusions:

1. Norma brass is tough.

2. Sometimes Norma brass may need to be sized before first use. I had a few pieces that needed a firm bolt closing.

3. Unfired Norma brass needs to be treated as a fire-form. Figure a reasonable load with your Lapua and do the first firing 1.2 grains LOWER for new brass. This will yield reasonable velocity and no pressure signs.

4. Fired Norma brass yields about the same velocity as Lapua with approximately .6 grains less powder for the same velocity.

5. Sometimes there are spikes in velocity. I could not figure out why. Shooting 3030fps +- 5 fps shot after shot and then ----3051 or 3044 fps. No pressure signs and nothing I can measure to figure it out. Slight higher pattern but only 200 yards. Wondering about the chronograph also.

Did not shoot for groups @ the 200 yards I set up my target. Mostly got 1/2" -3/4"groups showing horizontal wind issues. Seating depth and tuner testing next.

I am not a "professional" loader, shooter, gunsmith, lathe operator etc. You pros will find my methods quite crude for this forum. For those of you in my state - knowing #3 and #4 above will get you going on your own testing. I am under 33.0 grains with my particular rifle.

 

[watercam]

Good to know, thanks!

 

[Cool Tool]

Actually the numbers should read .6 gr - 1.2 gr.

I tested using Varget, Norma 6 Dasher brass and a home-made loading apparatus set up to deal with the wind and weighing out charges. Tried a simple balance scale but air movement was so bad, even tucked into a box, it was useless.



Conclusions:

1. Norma brass is tough.

2. Sometimes Norma brass may need to be sized before first use. I had a few pieces that needed a firm bolt closing.

3. Unfired Norma brass needs to be treated as a fire-form. Figure a reasonable load with your Lapua and do the first firing 1.2 grains LOWER for new brass. This will yield reasonable velocity and no pressure signs.

4. Fired Norma brass yields about the same velocity as Lapua with approximately .6 grains less powder for the same velocity.

5. Sometimes there are spikes in velocity. I could not figure out why. Shooting 3030fps +- 5 fps shot after shot and then ----3051 or 3044 fps. No pressure signs and nothing I can measure to figure it out. Slight higher pattern but only 200 yards. Wondering about the chronograph also.

Did not shoot for groups @ the 200 yards I set up my target. Mostly got 1/2" -3/4"groups showing horizontal wind issues. Seating depth and tuner testing next.

I am not a "professional" loader, shooter, gunsmith, lathe operator etc. You pros will find my methods quite crude for this forum. For those of you in my state - knowing #3 and #4 above will get you going on your own testing. I am under 33.0 grains with my particular rifle.

You were saying your velocity is 3030 average is that on the first firing of new brass were you getting the speed of 3040 plus after the barrel got warm.

 

[CaptainMal]

No.

New, unfired brass would show pressure signs. That other post had some thinking that was new brass going that high. It will and it did, even higher. The issue there is pressure signs abound. Fastest I get out of new brass, that I think is just below pressure signs, is 2,980 fps or so. I always shot 33.5 grs. of Varget in my BAT, Stolle Panda and Savages' with Lapua brass that had obviously been fire formed. Now I find you get to go about .6 gr. below that for the same velocity and safe pressure with the fired Norma. When I tested higher, pressures seemed OK but the velocity spiked above 3050fps almost immediately.

That spiking issue has me wondering if maybe I should drop another .1 gr. Of course, it was reading 110 *F on my truck temperature gauge when I started up to return home.

New unfired Norma brass showed me wide variations in velocity and some pressure signs when I tested that same powder amount. Had to drop another .6 gr. to get a good starting point with the unfired stuff.

For anyone spotting that IMR 4166 note - I tested three and they showed about 8 fps less than an equal amount of Varget with no pressure issue. Those were unfired cases so ES and target results were ordinary.

 

[Phil]

What chamber dimensions do you have on your Dasher reamer???

Phil.

 

[CaptainMal]

Phil...Don't know.

All my rifles were built and/or modified by Eric Bostrom @ Bostromgunsmithing.com. Obviously you could get that information from him. SavageDasher works closely with him also. You could PM him for the same information.

Know he uses PT&G reamers. I had my Forster .2655 neck die set custom built from his reamer pattern. Contact Eric through his site or SavageDasher here.

 

[Phil]

Thanks.......


What does your fired brass measure at .200????

Before resizing?

Phil.

 

[savagedasher]

Phil...Don't know.

All my rifles were built and/or modified by Eric Bostrom @ Bostromgunsmithing.com. Obviously you could get that information from him. SavageDasher works closely with him also. You could PM him for the same information.

Know he uses PT&G reamers. I had my Forster .2655 neck die set custom built from his reamer pattern. Contact Eric through his site or SavageDasher here.

The reamer is .2705 no turn neck with.135fb
The cases I trim to 1 .550. With 012.5 neck . After the case is fire sized That will give you the case capicity you use for loading . In your chamber not only does the capacity change from who made it it very from one to the other from being made . Till now we had only one case to use The new brass has changed it all. We now can make a longer dasher and still matain neck length .
For me it won't work because of the internal capacity . But I like the idea of increasing the internal capacity and keeping enough neck . Hats off to Bullet dot com. Larry

 

[TAJ45]

. Sometimes there are spikes in velocity. I could not figure out why. Shooting 3030fps +- 5 fps shot after shot and then ----3051 or 3044 fps.

My first thought was seating pressure being higher than the others in the velocity node. The reason I say this, our club has an F Open shooter who shot with the US Team in Ireland this summer. He has some sort of gage gizzie he purchased that displayed a pressure/force reading when seating for his plain ol' .284. He separated the rounds that for some reason had a higher reading and kept track when practicing. He said they were ALWAYS out of his group. Now, I do not know if he had velocity readings for any of those - I don't remember if he mentioned. I also do not know his reloading regimen re sorting or bearing length, which I think conceptually, could show a difference in velocity. Just tossing ideas and a fwiw, Tom.

 

[CaptainMal]

Thanks Larry. I wrote that down in the die box.

Will anneal again in case that neck tension is an issue in the hope I get them all the same.