LEARNED FROM 20 SHOTS WITH DASHER BRASS

[CaptainMal]

Had Eric Bostrom build me a new dasher with the old reamer specs. on a Stolle Kodiak action using a Bartlein ( from Bullets.com) 7.5 twist and his new-style ARS tuner.



Broken in with 21 choreographed shots and Lapua brass, I got 3051 fps with 33.4 gr. of Varget and NO pressure signs. I accented the "NO" for a reason. Also got .4 MOA during some of that shooting.

Yesterday I loaded 20 Norma Dasher pieces, trimmed 1.560" to fit my 1.563" throat and neck-turned to .0125+-". CCI 450's, 105 Berger Hybrids, Varget...

Started at 32.4 gr. and got 2970 fps. That's high compared to Lapua. No pressure signs.

**** My purpose for the test was pressure and velocity - NOT accuracy. My target is out at 240 yards. All 3 shot groups were sub 1/2 moa in spite of the grass, my casual techniques and totally ignoring wind.

32.6 gr. (4 shots now) went to 2990 fps and no pressure signs.
32.8 ( 5 shots) went from 3023 - 3037 fps with one, ironically the lower velocity one, showed the start of a primer blank.
33.0 gr. (5 shots) ran from 3044 - 3057 B U T near blanked a primer. Look...

I should have stopped the test but the other four shots did NOT show a problem.

33.2 gr. and I stopped. 3072 - 3079 fps Stupid fast with just a hint of primer issues. Nothing even remotely close to that one at 33.0 grains. WAY too fast anyhow - I quit.

Ironically the top two test loadings were UNDER 1" in group size at 240 yards. I mean "under" with no try on my end. Actually, apprehension shooting due to pressure and velocity signs.

Back at the loading bench this morning and I measured all heads. I detect no change in size.

Primer pockets, including the horrible near-blank one are all under .1735" That's the size of the depth gauge from K&M. I would have to force it in if I wanted to measure. Their "No Go" primer gauge measures .1750". Conclusion is the primer pockets did not enlarge at all. GOOD!

I now have three shell holders for this brass. The Hornady #2 sizes brass .004 smaller than the one I got from Bullets.com. Another, an RCBS #2 sizes .002" LARGER than the Bullets.com one. CHECK YOUR SHELL HOLDERS IF YOU HAVE MULTIPLE! Mine in the same press yield different results.

Draw your own conclusions. I am not a professional loader with machine tool experience. Just a guy named "Joe". I will now load 32.9 gr. and below for my accuracy/tuning tests. Compared to my Lapua cases - these Norma ones give similar velocity around .6 grains or so - LESS. They also seem to handle obscene over pressure with no issues.

More to come.

 

[rcw3]

. . . . .

Back at the loading bench this morning and I measured all heads. I detect no change in size.

. . . .

More to come.

Don't want to be a "doubting Thomas" here but that just does not seem correct - - you're running 32.5+ gr or more of Varget in your tests with 105 Begers and there is no measurable change in the diameter of the web of the new Norma Dasher brass from virgin brass to fired brass?

Sure not my experience. Maybe when you say "head" you and I are talking different parts of the case (and who knows, maybe I'm a dummy here)?

 

[Gabe22BR]

I did a test yesterday myself. I had one almost blank as well, so I quit also. I was using the new Norma brass also.
My load was 34.3-34.9 gr of IMR 8208 xbr pushing a 88gr Berger, hbn coated

 

[dmoran]

Robert -
Here is base/web averages from a set of the Shiraz/Norma from the first 5-firings with a .4708" chamber.

I have fired those once more since in a different barrel, but have not logged those specs yet.
They were F/L-sized down to .4695-ish after each cycle.
Primer pockets remained firm/good.
Donovan

 

[CaptainMal]

RCW3...Remember that the Norma Dasher brass is rebated, much like a 284 case. The rim is about .003" SMALLER than the head. Knowing that, you can measure the widest part of the case in front of the rim like this. I took the picture this way so you could see what I mean. Normally, I would be perpendicular to the case. Obviously, my measurement was BEFORE sizing.



None of the cases showed any measurable expansion at the head. When they do, I look for enlarged primer pockets and general stretching. Saw nothing, including any change in my overall cut length.

Going to go through 100 of the 200 cases I have first before firing again. Appreciate the comments about five firings and no appreciable primer pocket issues. If that one alone did not expand after the hideous pressure signs with the primer, my take is they are good in that area.

 

[rcw3]

RCW3...Remember that the Norma Dasher brass is rebated, much like a 284 case. The rim is about .003" SMALLER than the head. Knowing that, you can measure the widest part of the case in front of the rim like this. I took the picture this way so you could see what I mean. Normally, I would be perpendicular to the case. Obviously, my measurement was BEFORE sizing.



None of the cases showed any measurable expansion at the head. When they do, I look for enlarged primer pockets and general stretching. Saw nothing, including any change in my overall cut length.

Going to go through 100 of the 200 cases I have first before firing again. Appreciate the comments about five firings and no appreciable primer pocket issues. If that one alone did not expand after the hideous pressure signs with the primer, my take is they are good in that area.

Not sure why you are showing me a picture of how you measure the head (web) of your cases. I use a micrometer that is small enough to measure just the web area forward of the extractor groove which IMO is the place to be - - so I don't know what to say.

Dmoran's chart above shows an expansion progression that is at least somewhat representative of what I normally see. No expansion at all from virgin brass makes no sense to me - - hence my original query to your post.

Personally I feel Norma brass is softer in the web area (than Lapua) and touchy that way - - I have had to be real careful with it and if I run a hotter testing loads, some cases can easily be toast in one firing.

Today I shot 30 rounds of once fired Norma Dasher brass through a rifle I just had put together with the newest Norma brass Kiff reamer Shiraz sells for it - - 29.5 gr of H4895 with Berger 108 BT and BR-4 primers and some had hard bolt lift (Borden Action with plunger ejector) with shiny brass shear off from brass squeezing back into the ejector. My normal load with Lapua brass with H4895 and that bullet is 31 gr. - - don't know what to make of that. That barrel is a PacNor 7.5 twist and I also had a Bartlein chambered up for that action that I have not shot yet.

For me the brass is good for mild to moderate loads but watch out with hotter stuff - - just my freebie observations and opinions for what that's worth.

 

[CaptainMal]

Thanks for the information. I have nothing small to get into that groove and measure. Always measured the head as shown.

There was never any even remote hint of a hard bolt lift. Not even a lift with anything but normal lift. I even returned some cases into the chamber before resizing and after removing the firing pin. Just a normal touch was all I felt. Then I resized and checked the feel again to get it sized right before bolt "free fall". I like the hint of a feel and resizing about .002 or so was all I needed.

Loaded 25 at 32.9 gr. Shooting 600 gong tomorrow but with a different Dasher I have. Maybe after I will test some more if I take that rifle? Maybe not? Late morning or noon around here in South Florida can sure get hot and a bit windy.

 

[dmoran]

CaptainMal -
Here is where I measure them at:

The case heads (rims) very in diameters on mine, that measure from 0.466 to .468 for the most part, that have not changed and typically don't. The extractor grooves very as well, from 0.405 to 0.407-ish on mine.
Donovan

 

[Cool Tool]

OKAY GENTLEMEN here is my test with this new brass I turned the necks on 60 pieces of brass fouled the barrel each time I shot and dedicated 6 pieces of brass for the test I have shot this brass 11 times without annealing then I annealed an shot 4 more test groups after that primer pockets are sound I don't hit cases hard on new brass my loads are 2960 fps on average things look good on this brass as far as good brass life here is some results after 11 firings I will let you guys be the judge good or bad.

 

[CaptainMal]

.4685" is what all the unfired and fired pieces that I checked measured. I do measure as shown above with both mike and vernier. My picture measurement above also works because the rim is rebated and not touched. Just measured some grooves. Not reliable as from new. They are quite different in size.

George. Was waiting for your test. Good to read the brass holds up. As for groups, you did not provide distance, type of rifle, bullet etc. No reason to comment. I'm just happy you worked to share and explain your tests. Thanks.

 

[Cool Tool]

Robert -
Here is base/web averages from a set of the Shiraz/Norma from the first 5-firings with a .4708" chamber.
View attachment 985223
I have fired those once more since in a different barrel, but have not logged those specs yet.
They were F/L-sized down to .4695-ish after each cycle.
Primer pockets remained firm/good.
Donovan

what powder charges were you running at each numbers on yourgraph

 

[Cool Tool]

.4685" is what all the unfired and fired pieces that I checked measured. I do measure as shown above with both mike and vernier. My picture measurement above also works because the rim is rebated and not touched. Just measured some grooves. Not reliable as from new. They are quite different in size.

George. Was waiting for your test. Good to read the brass holds up. As for groups, you did not provide distance, type of rifle, bullet etc. No reason to comment. I'm just happy you worked to share and explain your tests. Thanks.

its nice for you to reply the groups were shot at 300yds the bullets are 103 vapor trails it is a light gun used in 1000yd benchrest

 

[dmoran]

what powder charges were you running at each numbers on yourgraph

27.7 <> RL15
31.4 <> RL15
32.74 <> RL15
33.12 <> RL15
34.54 <> RL16

 

[Cool Tool]

27.7 <> RL15
31.4 <> RL15
32.74 <> RL15
33.12 <> RL15
34.54 <> RL16

I had 4667 new brass 1st firing ,469 at 200 line 2nd .4695 it has stayed there since but I have not exceeded 2975 muzzle velocity.

 

[rcw3]

CaptainMal -
Here is where I measure them at:

The case heads (rims) very in diameters on mine, that measure from 0.466 to .468 for the most part, that have not changed and typically don't. The extractor grooves very as well, from 0.405 to 0.407-ish on mine.
Donovan

Dmoran - I don't think you have enough decimal places on the back end of that micrometer readout - - I'm not sure we can take your measurements seriously in light of that - - -

 

[dmoran]

Dmoran - I don't think you have enough decimal places on the back end of that micrometer readout - - I'm not sure we can take your measurements seriously in light of that - - -

When I first got that micrometer (Fowler), it kind of distracted me to....
But in a short time I became fond of it. Next updated to an electronic dial indicator and really like it as well. As I have aged, my eyes just can't grasp the standard inscribed measuring tools any more, and struggle with them, so I've been updating to electronic's with most everything.
Donovan

 

[CaptainMal]

Donovan. You have a unique ability to supply information and make people happy. It's nice to know of you.

Today I won the 600 yard shoot and after, set up my new Dasher for more testing. Failure but failure is informative. 32.9 gr. of Varget is also too much pressure for the factory-new Norma brass in Dasher with 105 Hybrids. I was shocked to see velocities in the 3040 to 3050 range and just the start of primer blanking. To me I read - STOP. Next test will be down to 32.7 until I can feel comfortable with what I see as pressure signs and reasonable velocity.

What I learned MORE was while pulling the bullets from those I loaded and did not fire. Literally broke my Lyman inertia bullet puller. Ordered a new one for the one that cracked today. It took literally 10 - 15 smacks to pull each bullet. No clue why there is so much neck tension. I expanded all necks as they were factory tight. Inserted a .243 pilot in each neck to trim the neck thickness back to .0125+-" I'm reading that as puzzling and will soon look at that issue. This is factory new brass that I have not fired or annealed yet.

 

[Cool Tool]

Donovan. You have a unique ability to supply information and make people happy. It's nice to know of you.

Today I won the 600 yard shoot and after, set up my new Dasher for more testing. Failure but failure is informative. 32.9 gr. of Varget is also too much pressure for the factory-new Norma brass in Dasher with 105 Hybrids. I was shocked to see velocities in the 3040 to 3050 range and just the start of primer blanking. To me I read - STOP. Next test will be down to 32.7 until I can feel comfortable with what I see as pressure signs and reasonable velocity.

What I learned MORE was while pulling the bullets from those I loaded and did not fire. Literally broke my Lyman inertia bullet puller. Ordered a new one for the one that cracked today. It took literally 10 - 15 smacks to pull each bullet. No clue why there is so much neck tension. I expanded all necks as they were factory tight. Inserted a .243 pilot in each neck to trim the neck thickness back to .0125+-" I'm reading that as puzzling and will soon look at that issue. This is factory new brass that I have not fired or annealed yet.

I have a question this pressure signs you observed feel us in what lead up to that such as was this notification on possible blanking on brand new brass or several times fired brass.

 

[CaptainMal]

George. Look up at the second picture from the original post. Obviously the right case shows serious pressure with the primer flowing around the pin. Now the one on the left shows just a hint of that issue. That tells me the pressure is close to or over as high as I would want to go.

Now these cases are new, unfired Norma 6 Dasher brass. They were not fire formed or sized to the chamber in any way. From measurement they are fine. I think just .003 - .004" less than the chamber. No headspace issues.

Now after once firing I will size them to just .002" below the chamber so I have just a tiny bit of "feel" with the bolt handle and no firing pin in the bolt to offer spring tension that covers up the feel.

If you tear through a primer with the firing pin there could be too much clearance between the pin and the bolt hole. If no the case and pressure is up, that primer flows around the protruding pin back to the bolt face or even farther by going into the pin hole. Not good and indicative of pressure issues.

My guess is that the second firing of this brass will have the case fit better to this chamber and possible an expanded interior dimension that reduces the pressure a bit. I want some "cushion" and do not want to deal with higher case pressures. I also want to shoot around 3,020 fps. or I may as well just use a BR instead of a Dasher.

It may be that I will have to use a different powder to get what I want. Bet I could get much lower pressure using H4350 but can I get the velocity and a good ES with the smaller capacity Norma brass?

Time will tell. Hope I have the time to play. That's where the fun is. Meantime my Stolle Panda, using Lapua cases, is wonderful using 33.5 gr. of Varget and getting 3030 fps with great performance and accuracy. I broke this new rifle in using near the same load and Lapua cases with no pressure. The difference is the case. I think I can get things to work.

 

[savagedasher]

From what I seen the primers were flattened way more then any posted .
My gun shoots 3070 and the primers show normal pressure.
My guess the H20 capacity is almost a grain smaller. Larry