LEARNED FROM 20 SHOTS WITH DASHER BRASS

[Cool Tool]

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.

I may be wrong but if you hit this new brass unfired with a fullhouse load you just destroyed long life for that brass I would be curious to how long that brass last keep us posted.

 

[CaptainMal]

SavageDasher was at the shoot today. He saw the brass and watched my test. Longevity is just one of his issues with it. He did not like the smaller capacity as his load of H4350 would probably not fit in this brass to give the velocity he wants. Then he literally "went off" on how my pressure signs would shorten the life of the brass. He really does get 20+ loadings with his Lapua Dasher brass.

George - YOU are still doing that test with those few pieces shot over and over. YOU tell us. I would like to know just how many loading you do get from one. Those few of mine shown with high pressure are now mixed in the tumbler with all the others. I lost track of them already.

 

[dmoran]

CaptainMal -
I hit a few brand new Shiraz/Norma with full charges equal to formed Lapua's upper node loads (+3000-fps). In my opinion, that was to much and the Shiraz/Norma's need to be fire-formed there first time with a mild charge. And even for the 2nd firing should not be a upper node load yet - IME

Made 3 sets to comparison test with. A set from Shiraz/Norma, a set from Lapua6BR, and a set from Norma6BR. Started them all by fire-forming them with the same charge (27.7<>RL15), and shooting them with the same identical loads to each cycle there after, progressively hotter. No doubt do to the metallurgy indifference, they adhere/stretch differently. After the 1st-firing the average capacity on the Shiraz/Norma's was 40.62, verses Lapua at 41.54, verses NormaBR at 40.68. After the 4th-firing they averaged 41.12 compared to the Lapua at 41.68, and NormaBR at 41.16.
** (all capacities measured with H380 <> averages from 3 cases of each)
Both the Norma and Shiraz/Norma remain softer on a whole, that continue to adhere/stretch for a couple firings before settling in, in comparison to the Lapua's.
From these volume variances and the base/web variances occurring, until they settle in it is to my own opinion and how I myself will pursue with them, the charges should be varied as well, linearly to the volumes indifference, until they have settled in.

In closing, there different and act different and react different then Lapua made 6Dasher's, which stands to good reason. What happens with and works in Lapua made 6Dasher's should not be expected to be the same with Shiraz/Norma's. Charge levels, velocity potential, base/web expansion, neck tension, etc., should not be looked as direct cross over to or from the Lapua made Dasher's -- IME&O
Donovan

 

[savagedasher]

Here is my take on the brass. The pressure I seen on the primers was high. The head didn't seem to be expanded .
Time will tell on that.
If it checks out I will have a reamer made that will let's me move the shoulder forward .040 or about and shoot H 4350 without using a long drop tube Larry

 

[Shiraz]

I may be wrong but if you hit this new brass unfired with a fullhouse load you just destroyed long life for that brass I would be curious to how long that brass last keep us posted.

BINGO!!

I mentioned this a couple of times previously already on another post, and many already grasp that. In fact it is better on the second firing to also not be at the top end.

You MUST NOT fire new brass with heavy pressure loads. Fireform in your chamber with a couple of grains, at least, lower and then work your loads and speeds up to where there is a balance with accuracy and speed that one is satisfied with.

 

[CaptainMal]

Donovan. Three to four firings and the capacity went UP about 1/2 a grain. That's a lot and would have a major affect on performance/tuning. Your conclusions will now add to my mental data bank as I look for a reasonable load to try and tune. Sure would hate to think I have to rip 300+ rounds down the barrel just to get the cases stabilized. So much for using more than a hundred cases. I'll probably just leave the others alone if that's an issue.

 

[Shiraz]

. Sure would hate to think I have to rip 300+ rounds down the barrel just to get the cases stabilized.

Small tip - I use a worn out barrel that has the same chamber for fire-forming brass, thus eliminating any use of the premium barrel/s used for matches. That way you can also use reject or junky bullets. I usually just shoot at a mound on the first fireforming.

 

[Cool Tool]

Donovan. Three to four firings and the capacity went UP about 1/2 a grain. That's a lot and would have a major affect on performance/tuning. Your conclusions will now add to my mental data bank as I look for a reasonable load to try and tune. Sure would hate to think I have to rip 300+ rounds down the barrel just to get the cases stabilized. So much for using more than a hundred cases. I'll probably just leave the others alone if that's an issue.

Sir I will be testing later this week I will keep you posted on progress an the life I see under 3000fps I don't think it is nessasary to shoot above that you have to make judgement as what to do if the wind is bad an shoot the condition the brass will give a lot of life and good accuracy if you manage it properly I will keep you posted on how many firings I get when it gives up the ghost.

 

[dmoran]

CaptainMal -
First, meant to congratulate you on your WIN today at your club match... Congratulations !.!.!

A little more input from me:
No cases, of any brand, or any caliber should be hit with full bore, upper node loads when there new if one desires consistent volumes, consistent wall stretch, and case longevity - IME

The Shiraz/Norma have appeared to me in cycle stretch specifications and volume growth to act and react very similar to the Norma6BR mother-case made 6Dasher's, but with 2 big advantages: 1) stronger primer pockets, 2) longer neck advantages.

The Shiraz/Norma have appeared to me to have great accuracy potential, velocity potential, and primer-pockets in comparison to Lapua6BR mother-case made 6Dasher's, but need to be prepped and loaded to there own set of demands, which are different demands then the Lapua6BR made.
Donovan

 

[Sheldon N]

Not to be flippant, but is the outcome of all this testing starting to suggest that 1) You need to "fireform" the Norma Dasher brass and that 2) Even with the longer neck the case capacity is about the same as Lapua BR?

 

[CaptainMal]

Sheldon - You are not supposed to have such good questions/conclusions.

 

[Shiraz]

Not to be flippant, but is the outcome of all this testing starting to suggest that 1) You need to "fireform" the Norma Dasher brass and that 2) Even with the longer neck the case capacity is about the same as Lapua BR?

Here's a way to look at it:

All brass (of any caliber) is made to certain specifications with plus and minus tolerances that is almost always different than your chamber specifications. For example, on my .300 WSM, I use factory brass and on some rounds, during fire-forming, I can hear the firing pin drop right before the round fires. What that means is that the there was a gap between the shoulder of the brass and the chamber (maybe just three or four thousandths of an inch) and the round got pushed forward when the firing pin pushed in and detonated the primer.

Then, the explosion takes place and the brass is stretched to your chamber dimensions. There is a lot of pressure required for that and the fact that it has to expand that brass forward and every which way causes increased pressures and that is why the well experienced shooters don't put full house loads on their first firings to preserve primer pocket stretch.

If one is not using hot loads for the Dasher then you may not have to fireform, but I still do it as good practice on all calibers and brands of brass to get the most accuracy in my chambers as I am certain at that point that all the brass is the same and consistent.

As far as case capacity is concerned the jury is still out and reports are still coming in.

 

[Jim Hardy]

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.

Captain:

Dont have much of a clue about the real world reason for it being so difficult to pull the bullets, but this is a "possible" reason. When you expand the necks with a mandrel, you have to be very careful not to let longer brass slam into the top while expanding. You might not even notice, but it can "crimp" the bullet in the brass. Just talking out loud and something you can inspect quickly.

Jim

 

[CaptainMal]

Thanks for the idea. I CUT my brass back .035" to fit the chamber throat made by an older reamer.

Also turned all my necks to .0125"+- and had a .243 pilot inside while doing it. I think it's related to virgin brass with no powder residue/lubricant in the necks. The difference in neck tension with news at the same size using the same dies - Lapua vs Norma - is significant.

Since pulling with an inertia puller is near impossible ( and I finally did shatter my Lyman) I devised a puller from a pair of smooth pliers and a piece of thin, damp leather. Using the press, like using the Davidson pliers puller, it worked fine. Still, like most collet pullers, there can be some bullet damage and even case neck damage if you grab too low.

Stopped making a campaign of finding a load and tuning. Since this brass obviously requires a fire-form, that mitigates what I thought would be an advantage over Lapua BR brass. I "only" have two Dasher rifles and do not want to make a campaign out of buying another rifle and somehow converting it to Dasher just to fireform. That would be quite costly and still require the 80 mile round-trip to a range where I can do that. Though I can and do shoot behind my house, repeated noise might bother others around me even though we all occasionally shoot. Of course, I could buy, license and pay to have a suppresser fitted. The whole expense and process just got silly.

It may take a while but before or after each match or practice I will just take 10 shots or so from that other rifle and try to prepare some cases. Then, the bummer, two heavy rifles to clean, carry and deal with each time to the range. Not easy for me. I sold my BAT to a member from Dallas because target rifles are a pain to deal with and heavy ones a larger pain.

Sometime this Fall I should have the fire forming done and be ready to try all over again. Of course, I will also have over a hundred rounds through the barrel that will be mostly expensive waste.

 

[Cool Tool]

Thanks for the idea. I CUT my brass back .035" to fit the chamber throat made by an older reamer.

Also turned all my necks to .0125"+- and had a .243 pilot inside while doing it. I think it's related to virgin brass with no powder residue/lubricant in the necks. The difference in neck tension with news at the same size using the same dies - Lapua vs Norma - is significant.

Since pulling with an inertia puller is near impossible ( and I finally did shatter my Lyman) I devised a puller from a pair of smooth pliers and a piece of thin, damp leather. Using the press, like using the Davidson pliers puller, it worked fine. Still, like most collet pullers, there can be some bullet damage and even case neck damage if you grab too low.

Stopped making a campaign of finding a load and tuning. Since this brass obviously requires a fire-form, that mitigates what I thought would be an advantage over Lapua BR brass. I "only" have two Dasher rifles and do not want to make a campaign out of buying another rifle and somehow converting it to Dasher just to fireform. That would be quite costly and still require the 80 mile round-trip to a range where I can do that. Though I can and do shoot behind my house, repeated noise might bother others around me even though we all occasionally shoot. Of course, I could buy, license and pay to have a suppresser fitted. The whole expense and process just got silly.

It may take a while but before or after each match or practice I will just take 10 shots or so from that other rifle and try to prepare some cases. Then, the bummer, two heavy rifles to clean, carry and deal with each time to the range. Not easy for me. I sold my BAT to a member from Dallas because target rifles are a pain to deal with and heavy ones a larger pain.

Sometime this Fall I should have the fire forming done and be ready to try all over again. Of course, I will also have over a hundred rounds through the barrel that will be mostly expensive waste.

Okay captainmal here is my last group I shot after 17 firings brass primer pockets useable perfect no but respectable yes .700 for five shots at 300 yds.

 

[CaptainMal]

17 firings is all anyone needs to know.

 

[rcw3]

BINGO!!

I mentioned this a couple of times previously already on another post, and many already grasp that. In fact it is better on the second firing to also not be at the top end.

You MUST NOT fire new brass with heavy pressure loads. Fireform in your chamber with a couple of grains, at least, lower and then work your loads and speeds up to where there is a balance with accuracy and speed that one is satisfied with.

If I understand what you are saying - - the brass is soft enough that you have to fire your brass at least twice with milder loads just to work harden it enough so you can use the brass with a full power load without wrecking it?

Not exactly an appealing aspect for someone who just wants to load the stuff up, go out and shoot and have fun and not have to worry about all that or the related expense of double fire forming.

I thought the whole point of this Norma Dasher brass was to get away from having to fire form - - what did I miss?

 

[Shiraz]

If I understand what you are saying - - the brass is soft enough that you have to fire your brass at least twice with milder loads just to work harden it enough so you can use the brass with a full power load without wrecking it?

Not exactly an appealing aspect for someone who just wants to load the stuff up, go out and shoot and have fun and not have to worry about all that or the related expense of double fire forming.

I thought the whole point of this Norma Dasher brass was to get away from having to fire form - - what did I miss?

What you missed is that the guy that wants to just go out and have fun is not going to hot load the brass on the first firing like some guys that don't know better! This is so for all brass, not just this particular brass.

 

[dmoran]

If I understand what you are saying - - the brass is soft enough that you have to fire your brass at least twice with milder loads just to work harden it enough so you can use the brass with a full power load without wrecking it?

Not exactly an appealing aspect for someone who just wants to load the stuff up, go out and shoot and have fun and not have to worry about all that or the related expense of double fire forming.

I thought the whole point of this Norma Dasher brass was to get away from having to fire form - - what did I miss?

Robert -
Must everyone that has replied to this thread are after best accuracy potentials and best case life. For this "load it and shoot it and have fun" crowd that your trying to appeal to, they can do just that, and not have to worry about the anal stuff !.!.! It will work good for those intentions, just like any other brand/cartridge of brass.
My 2-Cents
Donovan

 

[rcw3]

Original pre-production video said the head of the case was going to be specially double struck in manufacturing so that it would be work hardened and the implication was it would be sufficiently hard to handle typical loadings people use with the Dasher. Also, info put out suggesting additional measures to be employed in manufacturing to guarantee superior case wall and neck uniformity, etc. Great - - loved the sound of all that! Whole point of factory Dasher brass in the first place is to make it a "plug and play" product and to get away from it being a "wildcat" and the PITA of having to fire form it and make it a product that would appeal to a broader market (i.e. like the "load it and shoot it" guys - - and there's one heck of a lot more of them than bench rest shooters - - far more).

So I am just processing this - - and there was a posting that seems to suggest that in order to get the case head hard enough to handle typical (pre Norma Dasher brass) Dasher loads you need to double fire form the Norma Dasher brass - - and that raises a question mark in my thinking.

At this point I don't know if the head on this Norma brass was double struck - - maybe it was, maybe it wasn't - - I have seen no info on that, but it doesn't really matter - - the stuff is what it is.

I would also guess that the thick rims were not some accident (requiring new shell holders and some extractors needing modification) but are a symptom of some Norma engineer's effort to counteract something seen on this issue - - but that's just a guess.