[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]

Optimum .17

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]

17 MIV history

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]

Reforming advantage.

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