17cal based on the 204 Ruger?

[Gary in NH]

Is there a 17cal cartridge based on the 204 Ruger? I know the 204 has more case capacity of the 17 Rem. Is there another 17cal wildcat that has the same or close to the same capacity as the 17/204 would have?

Got this question in my head as I was reading some reloading articles that I have saved from my hunting/shooting mags and one of the articles has a pic of several cartridges which has the 17Rem and 204 Ruger side by side.

[Jim in Idaho]

Before I did a .17 on a 204 Ruger I'd do one on a .223, like the Predator, or the Tactical .17. Since the the .17's on a 223 are already way overbore, you won't gain much with a bigger case. The Predator gets 4100 with the 30's, and I doubt you'd gain much more without burning a BUNCH more powder.

[Catfish]

What your talking about is the .17-222 mag. It was never very popular like the .17-223 or the .17-221( mach 1V). If I were going for a larger case calisity in the .17 cal. I would look at the PPC case or the BR case. You would not get enough extra case capisity with the .204 case to make all the effort and cost worth it.

[Gary in NH]

Thanks for your info. I wasn't planning on building a 17 with the case capacity of the 204 and with the info that was just given I have even more reason not to do so. I guess I will stick with my 17 Rem and make little pinpricks in my targets.

[Oleman]

I believe that P.O. Ackley once said that the regular 222 Remington case was the optimum case size for .17 caliber.

[Jim in Idaho]

Gary...strangely enough, the ballistic efficiency of the .17MKIV exceeds both the .17/222, and the .17 Remington. In fact the .17 Rem. exceeds the .17/222 by about 15%. The BE is the ratio of the bullet muzzle energy and the energy available from the power charge. In the case of the MKIV it's about 27%, the .17/222 is about 20%, and the .17 Rem. is about 23 or 24%. This is with 25 gr. bullets. I think the existence of the MKIV is why there are few .17/222's out there. Velocity of both cartridges is nearly identical, but the MKIV does it on 10% less powder. With the .17 Predator the BE drops down to the <20% range, even with a longer barrel. Remington did their homework when they designed the .17Rem. It's about the biggest case you can use and still have more than 23% BE.

[TX Jack]

PO Ackley had high regards for the 218 bee case necked to 17 cal. Dont remember his exact quote but something on the line of it being the most efficient or something to that affect. That caliber sure made a 17 fan out of me.

[Jim in Idaho]

Yup.....BE on the .17Bee is prettty close to the MKIV...not quite as good, but very close. Allowable pressure on the MKIV is a bit higher, which is its only advantage. You can get near 3400 with 25's in the .17BEE with only 12.2 grains of powder. You can get 3750 with 25's in the MKIV with only 15.3 grains. Of course the MKIV didn't exist in P.O.'s day, nor did a lot of the powders we have now.

[Mulerider]

Jim: there was a lengthy thread on the 17MIV history on saubier.com

http://www.saubier.com/forum/showthread.php?t=538

Apparently P.O. was very involved, but let O'Brien run with final development and marketing of the round. Great history.

I sure enjoy mine!

Greg

[Jim in Idaho]

That's really interesting, Greg. Obviously, I had no idea P.O. was still active at that point in time. I've never owned a MKIV, but in all the research I've done into the various center-fire .17's it always comes up as the best bang for the amount of powder burned. Since I mostly hunt coyote-sized animals, I'm partial to the .17 Rem., though, for it's energy with the 30 grain bullets. Thanks for the link and info.

[Rocky Raab]

Just for the halibut, as the fishermen say...

I have a formula to determine whether a proposed wildcat will be inefficient (and possibly very touchy) to load. Take the nominal caliber squared, times 1000. That will give you the largest practical case capacity in grains of water for that bore diameter. For the .17-caliber, that works out to right at 29 grains of water.

The factory .17 Rem has about 27 grains water case capacity, and the .204 case holds 33. So necking a .204 down to .17 would be beyond the "tipping point" of both efficiency and stability of burn. In short, not worth the headaches. (And also demostrating that the Remmy guys knew what they were doing when they designed the .17 Rem!)

I have a .17 Bee, but in a too-short Contender barrel. In a barrel 20" or so long, it would be a stunner. It isn't horrible even in a 12" barrel, but the velocity is nothing to build an infomercial on. BTW, I believe that the .17 Bee was the very first cartridge in .17, if my research is correct.

[DAA]

Sounds good in theory, but doesn't really work out that way in reality, in my experience. I've played with several cartriges that are considered over bore, like the .17 Predator, to very over bore like the .20BR, to extremely over bore like the .20-250. Friends have tinkered with others that I've been able to observe closely, like the .22-284, .25 WSM and 6 WSM. Sure, the returns are rapidly diminishing and efficiency is poor, but the cartridges have all been easy to work with and find accurate to very accurate, non tempermental, useful working loads for. And while it does come at a price, the raw performance of these hot rods is very satisfying - and useful in a practical sense, in the right applications.

The .17P I believe has very close to the same capacity as the .17-222 Mag. or .17-204, and I've found the increased capacity and performance over the .17 Rem. to be well worth the minimal effort involved (there were no headaches). For my purposes, at least.

- DAA

[Markbo]

Is the MK IV still a viable factory round, meaning does Remy still offer guns and ammo for that caliber? I don't ever remember seeing any, but then where I live there is precious little varmint shooting.

[Jim in Idaho]

I have no argument against the .17 Predator, Dave. It's obviously a dandy performer on coyote-sized critters, as are other overbore calibers. Not a thing wrong with them.....they're just a little less efficient....no big deal. I can't see any reason for a .17/204 with the availabilty of the Predator and other rounds based on the .223. I do think the Predator is about the limit for case capacity with the .17's though, and it's probably not a round you'd want to go burn up in the prairie dog, or rockchuck country.....LOL

[Jim in Idaho]

Markbo, the MKIV has never been a factory round. It's based on a necked-down .221 Remington Fireball case. Apparently, Remington is bringing it, or something similar, to the market this spring.

[DAA]

Jim, I know you don't have any problem with any of these cartridges. Just like you know I know that they really aren't efficient at all. Sometimes, for some purposes though, efficiency isn't even on my list of what's important. Other times, other purposes, efficiency becomes very important. That's why I have both a .17 Mach IV and a .17 Predator :).

What I was really responding to is Rocky's theory about determining the point where cartridges become touchy and not worth the headaches (using his words). I've played with some cartridges that are well beyond his theoritical line in the sand, and not found them to be touchy, or the source of any headaches. So I was just pointing out, that while I'd agree the theory sounds good, my actual experience has been that the theory doesn't match up to reality very closely.

A more useful metric for comparing theoritical efficiencies and potential for wasted capacity (no gains or tiny gains) is simply expansion ratio. It takes barrel length into consideration, and can easily be determined and compared across any combination of calibers and case capacities in an apples to apples fashion. Pair known expansion ratios with known results to something you might be considering, and you'll have a very realistic yardstick of expected performance to guide you. What it doesn't take into consideration is case design - which can and does have some small but measurable effect. The .17P and the .17PPC as examples. Very close to the same capacity and expansion ratios, but experience has shown us that the PPC case generally does generate a small but real gain in velocity. That is, it's more efficient, but you can't tell that from expansion ratio.

- DAA

[Jim in Idaho]

I agree, Dave. I also think the many powder choices we have today makes it easier to use those "touchy" cartridges, if you will. What you say about case shape is a HUGE factor. It's one of the reasons the MKIV is so flexible, and efficient. And, as you're aware, you need all the spedd you can get in the .17's, since there is so little bullet mass. Like the man said "speed Kills"...LOL

[Rocky Raab]

I have no bones to pick with anybody who likes very overbore rounds either, DAA. You pays your money and you... as they say.

But at a certain case capacity (or expansion ratio, which is simply one step farther down the "formula" road) you CAN have real problems with internal ballistics. The ballistics guys at Remington have all kinds headscratching - and more than a few headbanging!- incidents with the .17 Rem.

If I recall correctly, they had to come up with the very thick-cupped Rem 7 1/2 specifically to stop primer piercing in the .17 Rem - which they attributed to unpredictable pressure wave harmonics within the case during ignition. I call that "touchy" but perhaps you might not.

At any rate, if you look at a list of cartridges that many, many people have praised as "well balanced" or "easy to load" or "forgiving" or some such, you'll be surprised at how many of them fall right at or just below my formula's prediction for case capacity. It's telling.

[StevenD]

I can't see any reason for a .17/204 with the availabilty of the Predator and other rounds based on the .223.

I guess I see one advantage of beginning with 204 cases and that is resizing brass from 20 cal to 17 cal is easier than taking them from 22 to 17. Maybe a minor difference, but if it's available, why not?

[DAA]

...But at a certain case capacity (or expansion ratio, which is simply one step farther down the "formula" road) you CAN have real problems with internal ballistics...

Certainly. All I'm saying is that in my real world experience, your theoritical formula for determining the point at which this occurs doesn't work very well. That's all.

- DAA

[DAA]

I guess I see one advantage of beginning with 204 cases and that is resizing brass from 20 cal to 17 cal is easier than taking them from 22 to 17. Maybe a minor difference, but if it's available, why not?

Brass quality would by my primary reason. There is some really high quality .223 brass readily available. As far as I know, there hasn't been any premium quality .204 brass made yet. You could use good .222 Mag. brass, which a lot of guys have gone to the trouble to form into .204 Ruger, but then you aren't saving yourself any work in forming anymore.

Really though, when it comes time to sit down and form the cases (making whatevers out of whatevers), the difference between starting with a .204 neck and a .224 neck won't amount to more than a single press stroke, at the most.

- DAA

[Rocky Raab]

Do you have a better one? (I'm smilin' when I ask that, my friend.) I'm always open to learn something better. Like most of my "knowledge" about reloading, I probably read that formula somewhere, and have used it ever since. I've done some number crunching (NOT my long suit!) and it seems to fit pretty well with the picket fence of cases capacities we have in most caliber sizes. But if you have a more precise way to draw that line in the spilled powder, I'm all ears.

[DAA]

"Do you have a better one?"

Yup. I just try things, and see what actually happens. Rather than trying to predict them - because one thing I have learned is that these things really aren't very predictable.

Not picking on you specifically, but most of the guys I hear telling horror stories and proclaiming doom on anyone foolish enough to pursue a really over bore cartridge, are guys that have NEVER worked with one! Guys that have worked with them, know that a lot of hooey gets professed by the those guys.

- DAA

[Rocky Raab]

Nor picking on you. But that "method" sounds a whole lot like, "Hold my beer and watch this!"

I'm sure you use a bit more discretion than that, and surely you have SOME expectation of what will happen when you pull the trigger. I simply wanted to know how you derived those expectations. Sounds like it's just wishful thinking.

[DAA]

I already explained that. You must have missed it.

I take the hold my beer and watch this approach. Blindly stumbling around the edge of the cliff, only dumb luck saving me from certain disaster. It sounds like you pull a number out of your a** and decide it's too scary to attempt.

As long as we're both happy, that's all that matters.

- DAA

[StevenD]

Brass quality would by my primary reason. There is some really high quality .223 brass readily available. As far as I know, there hasn't been any premium quality .204 brass made yet.
- DAA

DAA

As far as premium 204 brass, probably not until Lapua gets on it. I haven't had too much trouble with the Hornady brass, but I haven't sized it down either.

I don't have much use for 223's so I don't deal with that cartridge much. The only 223 I do have is brand new, never been fired and will very soon be torn apart to make into something else.

Anyone need a stainless Howa 223 Barrel?:D

[DAA]

DAA

...The only 223 I do have is brand new, never been fired and will very soon be torn apart to make into something else...



"Torn apart to make into something else...". That's exactly what happened to the last remaining .223 I owned :D.

- DAA

[Rocky Raab]

I read it, DAA. We simply have different philosophies. You like to wing it.

I like to have some idea of where I'm going. Comes from being a pilot, perhaps. But I like predictions and guidelines. I use tested loading data when I can, but when I'm working on an untested cartridge (I've done several), I like to have a plan about where to go and more importantly, where to stop. I'm not too scared to go there, just like to have some idea of where the cliff edge is if I'm going to go running at it full tilt in the dark. And a number that fits the previously observed data isn't pulled out of my...ear.

Still cordial on this end.

[Theo]

Cordial? Not by any decent standards. You picked the squabble Raab, as much by persistent pomposity as by subtle condescension, despite DAA's demonstration of tact and adherence to the subject matter until justly provoked.

A more genteel and appropriate last response on your part might be; "Touche' Monsieur Affleck! Your sword is wielded effectively, and proves skill in marking a donkey such as myself."

[DAA]

I read it, DAA. We simply have different philosophies. You like to wing it.


Well... maybe my sarcasm wasn't clear enough, or maybe I just didn't communicate clearly. But, just to be crystal clear - NO, I do not "wing it". I was being sarcastic when I implied that I do.

As I explained earlier, it's pretty simple to use expansion ratio to compare efficiency and expected performance levels between fairly disparate cartridges. In an apples to apples fashion, that takes barrel length into consideration and uses real world results as a basis for evaluation. Not a theoritical number derived from a generic formula. This is the general yardstick that I and others have used when working with cartridges that are admittedly extremely over bore, and for which no load data exists. Personally, I think as a metric for making comparisons and charting a course into new waters, it is more useful and has more merit than your formula does.

But even the above is getting well away from my original, very simple point. which is simply this:

You stated that your formula tells you the ""tipping point" of both efficiency and stability of burn." Beyond which, in your words, a cartridge is "not worth the headaches."

I am simply stating that no, your formula does not work for determining that point. My opinion is formed from having actually worked with a number of cartridges that are well beyond your theoritical "tipping point", without experiencing any strange "touchiness" or "headaches". Indeed, we have found a number of these cartridges you would theoritically dismiss as "not worth the trouble" to be no trouble at all, but rather useful for our intended purposes and achieving our goals.

That's it. If you want to read more into it, I'll take the time to clarify whatever is confusing to you about what I'm saying. But, the above really is all I'm trying to communicate here.

Again, simply put and not implying anything more - I think your theory for determining useful capacity is both incorrect, and not as useful as simple expansion ratio.

I will add one thing though... I make no claims that any numbers I might present regarding cartridges I've never worked with are anyting other than pulled out of my a** either. We both pull numbers out of our ears when getting into uncharted territory. I'm just very skeptical about such numbers I come up with, and tend to want empirical evidence before putting much credence into them.

- DAA

[Rocky Raab]

And I'll restate, simply put, that the formula I quoted (I don't claim to have derived it myself) relates case capacity to bore diameter. Expansion ratio relates case capacity to bore diameter and bore length. As all the burn takes place long before the bullet leaves the bore, if expansion ratio has validity, so does "my" formula.

But it's hardly more than counting angels on a pinhead, and I think we both agree fundamentally on most of it. It's a shame that the tongue bulges in our cheeks don't show up on the screen, or Theo would still have untwisted knickers. I read your humor, and was replying in kind - I thought. I'd meet ya for a beer any time, DAA...and buy.

I'll drop it now and retire to other threads.

[Jim in Idaho]

Actually, Rocky, all the powder does not burn before bullet exit with many of the commonly-used cartridges/powders. And, barrel length has a big impact on use of the overbore cartridges. Until I started using Quickload I wasn't aware of that myself.

[StevenD]

:D So that's why my 30-30 AI w/ it's 18 1/2" barrel posts a 16" flame ball out the end. I was wondering about that. LOL

[DAA]

I've seen data to support that these extreme overbore cartridges we are discussing will continue to gain velocity and make use of barrel length to the point of being ridiculous.

Definitely, barrel length is a significant factor in making any kind of evaluation of performance for this class of cartridge. And one of the big reasons why I believe good old expansion ratio is a more telling and useful metric than Rocky's formula. But combining the cold hard number (expansion ratio), with known real world results for similar expansion ratios, is what makes the number really useful.

As a specific example, I used my friend Blaine's extensive experience with the .22-284 when first evaluating potential performance of the .20-250. Different bore diameters, and different barrel lengths. But the expansion ratios for the two different setups were very close. So I felt like I had a good example of what I might see performance wise from the .20-250. Of course I wouldn't build an expensive custom rifle based on nothing more than that. Plenty of other guys have also built .20-250's and I sought them out and talked to them too (including the riflesmith who built my rifle). What they told me tended to confirm my early estimates and expectations. So I went ahead with the project and performance is pretty much just exactly what I expected. It ain't efficient. It ain't even practical for most people in most applications. The velocity gains over the smaller capacity .20BR are pretty small. And the barrel surely isn't going to last for many shots. But it isn't "touchy", or hard to work with, or cause of any headaches either. There just isn't any mysterious difficulty in working with it at all. I've found working up loads for it to be just as linear and predictable as any other high performance cartridge. Matter of fact, I tested a new load for a new bullet in that rifle on my lunch hour today, and the velocity was within 20 fps of what I predicted. The 38 gr. Unmissig's at 4310 fps shot a nice little clover leaf too, by the way - I can't wait to try them on coyotes!

By the way... I don't disagree with Rocky that there is a point where capacity is truly too much, and will start to cause issues not related to efficiency or what is practical. Where velocity gains will simply stop happening and quirky pressure events might start to appear. What I totally disagree with him on, is the accuracy of the formula he uses to determine the point at which this occurs. I've just seen too many real world examples of cartridges that are well beyond the line drawn by his formula, that simply do not have the problems he predicts for them.

- DAA

[Jim in Idaho]

LOL.....yeah Steve, that would do it...Ha ha

[Gary in NH]

When I originally posted this question I didn't expect this much response. I have been following it since the initial post and have learned a lot from you guys. It is amazing how much info/experience the membership of this board has. Thanks for the info......

[Jim in Idaho]

Yup....I think we all learn things from these threads....and this was a good one. Thanks for initiating it, Gary