Ignition, esp. primer and case web

:D

I bet I looked at that post 4 times looking for what action, and didn't see that. :eek:

I think the weight is pretty insignificant since the real force is being made by the spring. In proportion, the mass is probably 1/40th or less of the total spring pressure, even if that spring is completely sprung. The distance it moves is ,imo, important.
 
Here is my two cents worth. From what i have seen of my own and others combinations, when it comes to small primers and some cartridges, there seems a need to go to the 450 mag primer. Now that should tell most of us that all is not well.
I had a 6BR once, it showed plenty vertical at long range, and even short, with the 205M, so i went the 450 route and the vertical closed up. Powder was the usual Varget, pills were 107 SMKs and all in a 700 action that had been bushed back to the 62 thou firing pin. Spring preload was 19 lb. I adjusted the spring to a stock Rem item at 26 lb preload. Nothing changed. So out of frustration i took 12 BR cases, reamed the pockets to accept LRPs and the problem went away. Now i know very well that this is very unusual in a 6 BR.

It doesn't end there. With better things to do with my time than ream 6BR primer pockets to LR, i took the barrel and just extended the chamber for the then new 6x47 chambering using the new 6.5x47 Lapua brass. Well the vertical came back. CCI 450 primers again, and it did close up, but again like the same barrel when a 6BR, nothing spectacular. So then i went to Lapua 308 cases, resized and shortened to fit the 6x47 chamber, but with 210 Ms in as primers, the vertical disappeared. Now that is number two example.

Number three. 30x47. Yep, using Lapua 6.5x47 cases once again, nothing but vertical at 600 yards. Four to six inches of it. Sometimes less. But groups were always more vertical than lateral. So once again off to the great 308 Lapua brass, 210Ms and many hours sizing and shortening cases, then fire forming, and my first competition group at 600 yards was a 1.6xx", mostly lateral. Went on to win the match while surrounded by some very hot shooting rigs in great calibers.
So do you think i am skeptical of the small rifle primer? You bet ya.
The story can go on as i have seen numerous other examples, not with the 6 or 30 BR, but more with the 6.5x47 based cartridges. As for Matts example with the new 308 cases, never in a thousand years will i go that route. I will leave that one to others.

Tony.
 
Tony
As usual I should know better than beleive "the hype", but I had to give it go and I thought being a Lapua product would have been a "non issue". Oh well live and learn.

Matt P
 
@ Phil

I have heard from a reliable source (a noted gunsmith other than Dwight Scott) that Scott & a few others increased the weight of BAT firing pins, and got better groups. Sample size greater than 1.

@ Tony

Your report parallels that of Joel Kendrick, who has been shooting a 6x47 reformed from .308 cases (LR primer) for a number of years, with considerable success. He tried the SR Lapua, and went back to his cases formed from LR .308.

* * *

One of the reasons I started this thread was we get all kinds of reports.Most are of the "this happened to me" variety. What the doctors call anecdotal. A few are theoretical -- the model predicts such and such. But many of the so-called theoretical conclusions are really anecdotal, where somebody mistook one or two tries for exhaustive testing, such as how many people view Palmisano and Pindell testing of small primers and small flash holes. Best I remember, their testing as limited to the .220 Russian, the .222, and the 7.62 x39 (think of this as the LR twin of the .220 Russian). While their results were no doubt accurate, you can't extend them to other chamberings without further testing.

That is the problem with empirical results. You need a coherent model to extend beyond "Well, in MY rifle . . ."

Which is why I wanted to ask Al what made him think the cases with small primers would come to dominate long-range benchrest. Because there was more support for the hole in the case head? Because we don't have "weak" enough large primers? Now I thought it likely Al was just extending urban myth, but Al also does a lt of serious testing, and when he says something, it pays to listen.

We need more information from all parties on WHY. And that will require testing, I think. But experience and speculation are necessary precursors to testing.

For example. If it is the support of the primer hole by a lot of hard brass, is there any way to work-harden the case head before that first crucial firing. Shot peening maybe? Something? If so, a lot of brass with very good dimensional quality control suddenly becomes useful in the high-pressure world of benchrest.

If not simply hardness, is the amount of brass supporting the hole also crucial? Can it compensate for a lack of hardness? We can find cases where there is more brass around the case head than a PPC with a SR primer pocket. We may have to go to "fat" cases, or rimmed cases. I, for one, don't want to do that work unless it really matters, but if it does, so be it.

The size and shape of the flash hole? Does a smaller hole reduce the pressure in the primer pocket? Al thinks so, is he right?

Moving from pure mechanical support of the case head, are the diameter, shape, and length of the flash hole factors in good ignition? Palmisano thought so. Remember the long-range case he drew up? Never made, to my knowledge, but with a two-piece case, someone could test it (and have steel heads, to boot). Worth all the work?

With "hard" and "weak" primers, can you "swap" a weak LR for a "strong" SR? -- the CCI BR primers seem quite "weak" to me. Is a LR CCI BR as weak as a CCI 450? I dunno. Anybody?

For all you who don't \want to go there, fine. But Ignition is important stuff. If all you want to debate is the relative merits of this chambering, this gunsmith, this brand of action, this brand of barrel, this type of bullets, whatever, have at it. It bores me, because I believe the most important answers aren't there.

Consider this. Suppose we are stuck with lead bullets. Can any breach loader shoot with a muzzle loader? Not likely. Now, as far as pure rifle performance is concerned, we are left with the essentials: Barrels, bullets, powder and ignition.

* * *
My anecdotal story. I got a new barrel for a HG. Chambered with the same reamer. Powder out of the same jug. Same bullets, down to lot number. That barrel shot better with 215Ms than the 210Ms I have been using. Another new barrel. Everything still the same. Now the 210s again shot better. Why? Was the new barrel "tight," maybe? I dunno.
 
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Question for you guys that have had vertical problems, have there been corresponding variations in velocity when you were experiencing the vertical?
 
Good question.

For ME, weighing powder 'to the kernel' has really changed my outlook on this. Now that my ES is fully controlled, and since I shoot nearly everything over the chrono, any marked vertical on my 350yd testing butt becomes a ??? (350yds is where my "tuning vertical" for 600yd shooting should be max'd, and flipped.)

Guys with ignition problems, try different primers. Don't waste any time on "hotter" VS "colder" and all that jazz... just try different primers.

opinionsby


al
 
@Charles,

I'd agree on the Bat's. I re-timed mine, made a new cocking sear and added about .150 of fall. Mine shot better too.

@Boyd.
Question for you guys that have had vertical problems, have there been corresponding variations in velocity when you were experiencing the vertical?
Click to expand...
Amazingly enough, not all the time. In some cases yes, but for the most part, I attribute most vertical issues to other things.
 
Lynn said:
I am not a scientist and my only testing facility is the range but after the big Obama presidential scare that caused all the shortages I noticed 10 non-fires with the new CCI 450 Magnums and my father has had 22 non-fires.I still have 4000 of the pre-Obama primers and have never had a hangfire or non-fire in that same lot of 20,000 primers.16,000 trouble free rounds fired then and now with the newest 3000 we already have 32 non-fires in the same actions.It isn't the powder as changing back to the older primers eliminates all non-fires.
Click to expand...
Sometimes we tend to forget.

How long back was it when it was being said on various web sites that CCI were reporting that the reasons for the shortage of their primers on the shelf were "sensitivity issues"?
 
Alinwa
This is part of it.

I have seen this problem on MANY BAT actions,I have three of them). The firing pins on the BAT are too light, the spring are too light IF you have almost any head space! I got 10% failures with just .002" of head space and 100% at .004" of head space. A stiffer firing pin spring helps some. I add weigh to the firing pin which fixed the problems with failure to fire on my actions. The weight was added between the front of the spring and the pin.

John Kielly
Sensitivity,soft cups,hard cups,brisance,moon phase it does't matter what you call it click nothing means bad.
Waterboy
 
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Lynn,

I have a friend with a 3 lug Bat that's causing him some heartburn. How much weight do you add & in what form?

John
 
German,
In the case of Benchrest, it's not about lock time at all. It is about not disturbing the rifle in the bags. A heavy bolt lift can cause the rifle to rock as the bolt is opened and closed. In the course of several shots, this will shift the sand in the front bag so that the sand is pushed away from supporting the corners and more into the center, reducing roll stability. A light bolt lift also allows faster shooting, which is very important to many shooters' shooting styles. Lock time is more of an issue for position shooting, and if I remember correctly one of the most notable promoters of lighter pins and heavier springs is a fellow you might know of by the last name of Tubb. By adding weight to a striker assembly that gives indications that it is a little low on energy, you can deliver a heavier blow to the primer with the same weight spring, keeping the advantages of the light lift, and trading some lock time for improved ignition. Another way to keep the lift as light as possible for a given cam profile is to use a roller on the cocking piece. As I am sure you know, your three lug has this feature, and I am told that two lug BATS can be ordered with one. Jim Farley told me that the lift on his Black Widow action was made a pound lighter by the using a roller cocking piece.
Keep up the writing. I always enjoy reading it.
Boyd
 
I started this thread pretty much in response to some statements Al made, essentially that long-range BR will become dominated by cases using small primers. Far as that goes, there were some other statements Al made I disagreed with. From my perspective (could be wrong), Al is a relative newcomer to shooting Long Range Matches, but a long-time, very experienced experimenter/tester of rifles. There are a few differences; wining matches adds an emotional quality, so much so that "winning" can become an end in itself, different for "how accurate can we make things."

Now using small primers can be a plus in two ways -- or I can think of two ways, maybe there are more.

One is keeping the primer pocket from growing -- essentially the number of times you can reload a case before the primer pocket has grown too much.

I think I remember Al stating that this was more a matter of flash hole diameter, as the flash hole is what lets the pressure into the primer pocket to start with.

But whatever. If wining match means I only get one "match" firing on a case, so be it. It costs so much to shoot a match, the the cost of brass, and the time spent prepping it, cannot measure up to a win at, say, the IBS or NBRSA nationals or the World Open. And there are ways to shrink primer pocket, none of them fun, but do-able,.

The other way has to do with pure accuracy. I am flat not sure how small primers are linked to this, but figure it must be a matter of ignition. Having said that, I can't figure out how ignition problems are addressed by small primers.

As far as Lynn's "I don't want to think, I want to shoot" attitude, I have a lot of sympathy for it. Much of the time, I regret all the complicated things I have done with my rifles. Too expensive, too time consuming, too heavy, you name it. But they all pale when you get a win or top-10 in a big match. Does all the exotic stuff matter? I'm not sure. Sometimes I think so, sometimes not. Perils of competition. We all get bored with it, take a break, or even quit match shooting.

From the responses in this thread, It seems like so many things, "ignition" is too complicated for us to try and understand, even at the level of just why the small primer cases are "going to be the future."

* * *

It is interesting to note that the point-blank guys are suddenly getting enamored of .30s while the long-range guys are saying 6mms or small 6.5s.
 
Just to see if *i* can post . . .

Interesting developments. German Salazar has mentioned that he feels "weak" primers (lower flame?) work better. Tony Z has (1) gone to hotter primers, which helped, but then reamed the primer pockets to take Large Rifle primers and went back to a milder one, which was better still. Tony, did you also try increasing the flah hole size wit the small rifle primer?

* * *

I too have noticed that west coast shooters in the States seem to have different experiences than us in the Midwest/East/South. Back when the 6.5x47 Lapua case first came out, many Midwestern and East Coast shooters discovered that reaming the flash holes larger helped. West coast shooters, including Don Neilson, I believe, said they worked just fine with the small flash hole, and advised leaving them alone.

What gives? The temperature/humidity in San Francisco Seattle / Portland is quite different than southern California. But Australia, is seems to me, is closer to the US West Coast than the the Midwest/East/South, so you'd think Tony's experiences would parallel that region. Maye I have Australia wrong?

* * * hmm. Seems I can still post. But the "Administrator Panel" still looks different from all the other threads.
 
Charles
In e-mailing a few Australian shooters I get the impression that were Jeff Rogers lives the weather is a great deal different than further south.The distances mentioned were staggering on the order of 2200 miles.
If one was to transpose a image of California onto the eastcoast you could picture Don shooting in Florida and the rest of us shooing in North Carolina.Barry Bluhm,Bruce Duncan and Don are all in the same neck of the woods and shooting the same case sucessfully.Lou Murdica isn't shooting a 6X47 or 6.5X47 at any of our matches recently and Don is his gunsmith which is puzzling.

In the bigger picture the 6BR/6Dasher seems to be doing quite well even on the eastcoast but I don't see a listing on which primer Thomas Ellington is using at Butner? Out here CCI BR4 or CCI 450 Magnums are very commonplace and we only see the Fed 205M being used in what is considered to be light loads.

Waterboy
 
Charles, yes i did take the flash hole out to 80 thou before i reamed the small primer pockets. If it did make any difference, i didn't see it. The cases reamed out to LR had the flash holes taken to 80 thou as well. Never did try LR and small flash hole. I need to say that i have had quite a number of 6 BRs, but only one gave trouble with vertical. I have heard of another but do not know what the cause, remedy or outcome of that barrel was. My case with that 6 BR is most definitely an anomaly.
Boyd, somewhere in this mix i did run shots over the chrono, but for the life of me i cannot remember what the findings were. Too much time and to many shots fired since to recall.

Charles somewhere along the line you have questioned where all this info goes and if it is worthwhile. I think that my experiences with a couple of cartridges where ignition was dubious, is a very small sample and should be taken with a grain of salt. Others have and do have great success with those cartridges. BUT, if others have had similar incidents, then all these grains of salt piled in together make a little pile. Then we may be able to see some sort of trend. I think this thread is very worthwhile and educational and hopefully it will go on to gather more information.


Tony Z.
 
Tony, I do have one interesting case to contribute to this. It is a 6mm wildcat built around the 6.5x54 M-S case. Brass is Norma. Now this case, and I believe the similar 6.5 Carcano and 6.5 Arisaka, as manufactured by Norma, has a thick web. Mine measures right at .110. (so, of course the flash hole is .110 long, too, and typical Norma diameter). It is rimless, so the case head is unsupported by the barrel.

These cases use a large rifle primer. I can loosen primer pockets with quite stiff loads, or milder ones over time. This leads me to believe Al is right about the flash hole being the single most important design factor in keeping primer pockets tight. "Design" as opposed to "construction," as I imagine harder brass would lessen primer pocket growth.

I have never used a rimmed case with a competition rifle, so have no evidence as to how well supporting the case in the area of the primer pocket would work.

In some ways, this chambering is a failure. The capacity of the wildcat is right at 52 grains water, full to overflow. Just 2 grains less than a stock .243 It shoots best with what amounts to a powder-puff load for this capacity case, 39.2 grains of H4350. Velocity is a bit over 3,000. In short, Dasher performance from a bigger case.

(And it just struck me as I type this, I haven't tried H-1000, sometimes quite successful in the .243, but too slow for Dasher & kin. Powders tried have been H-4350, VV N-550, Rel-19, and H-4831.)

The case shows a strong preference for the old Remington 9-1/2s, manufacture circa 1950-1960. I believe that was a different priming compound than current Remington manufacture. Federal 210s are nowhere near as good, 215Ms close, but not quite as good. CCI benchrest primer are as bad as the 210s, with Winchester LR in between. All the primers I had to test with.

I speculate, but do not know, that this preference for "hot" primers comes about from the long, small-diameter flash hole.

I get occasional vertical flyers. I can shoot multiple 5-shot groups without a significant flier, then one will pop up. In initial testing, I fired 3 consecutive 5-shot groups at 100 yards that agged a flat 2 with 105-grain bullets, which was quite encouraging. It is a tensioned-barreled rifle.

I've sort of given up on this chambering; probably a mistake. Worth testing would be to taper the flash holes. They are long enough I could get a significant cone shape, what Palmisano recommended. Then test primers again, and much slower powders.

Anybody else played with the Norma Arisaka/Carcano/M-S case? The 6.5x54 MS cases are considerably cheaper than the other two, and the dimensional qualities of the case are typical Norma, i.e., very good. Hardness also seems typical Norma.

Anybody know of another case with such a thick web?

Any way to work-harden brass before the first fireforming?
 
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Charles E said:
Any way to work-harden brass before the first fireforming?
Click to expand...
Exactly what I said above I wanted to try with my new cases. I have the technology, just never took the time. I think if you do the first work hardening in a direction of "smaller", the case would prefer to go there later. We open em up on the first firing, and then wonder why they want to open up.
 
Phil, I think your reply on hardening brass must have been in the non-post that vanished into the "advanced" aether . . .

Care to share?
 
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