We had a lot of fun recently on medium bore kicking the subject around of what is the most under appreciated, under-developed medium bore caliber. And why?



Please notice we are talking CALIBER...not cartridge. So please do NOT list your pet cartridge. Just caliber.



So if you think the world is over-looking something, here is your chance to sound off. Any caliber from .14 up to 6.5mm. What are we missing? Why would it be great? Why do you think the gunmaker/shooters have ignored it?

Last decade's winner: Bob (now doing better with +p and light mag)

Current winner: 250-3000 (damn those 24 bores!)

1st Runner(s) up: Most all of the lesser 6.5 bores.

2nd Runner up: 6.5x55 (special mention), at least by US ammo dealers.

The now nearly complete passing of the 250-3000 is truly one of the great tragedies of rifle history. Modern pressures (like the 53,000 CUP 22-250) and a less restrictive standard throat and this baby would have made the 260 an entirely superfluous undertaking. Even with its insulting pressure limit and pedestrian-speed 100 gr loads it still carved out a notorious reputation in the antelope/blacktail/whitetail communities up, down, and across North American. Great round.

JMO...

9.3

Sorry Pecos, I guess I didn't follow the rules. Oooops. I just get so emotional when I get going on the 25 bores... Maybe my tirade can be considered an answer to your third paragraph...

9.3

6.5

.25 caliber.........nothing factory based on a .308 ?

This is not going to be exiting!



Id say ,25 cals

Nowadays in the U.S. it's the .25s.

I think I'm gonna have to go with Fish and cast my ballot for the 6.5 as the most under-developed small bore. There are some fine 6.5 cartridges available, but none of them seem to ever achieve any significant popularity or really last. I've always been a fan of the 6.5 bullets with their great sectional density and other good points and any case from the /06 on down will build a super cartridge. Anything that holds any more powder than the /06 is mostly a powder-burning barrel eater, i.e. totally inefficient.

The .25 bore strikes me as a funny (strange) situation. There have been several superb .25 caliber cartridges over the years. Each one has had a devoted following and for some good reasons. Someone said the 250/3000 and I'd say AMEN. It's a wonderfully pleasant and efficient cartridge. And everyone who has touched the old .257 Roberts loves it. Same pretty much goes for the 25/06. It's a flat shooting hotrod.
But nothing ever seems to last for the .25s. Sooner or later everyone seems to lose interest in the latest darling.

Yes, there are some good .25 caliber cartridges based on the .308 case too. How about the .25 Super for example?

And then we get to the .243/6mm story. Over the years I've listened to how wonderful this caliber is until I've about puked. I thought the world would never get off the 6mm.

FINALLY the fascination with 6mm seems to be waining. Shooters today seem to be of two minds. They either love 6mm or they hate it. Don't expect any new factory offerings in this bore soon.

The .224 caliber? Boy, we've mined this hill up one side and down the other and it's been the real mother lode for shooters. Seems like anything we can dream up with .224 bullets makes a good cartridge. The 22/250 has probably reached the immortal status and thanks to the military, so will the .223. The 220 Swift is a legend that not many shooters will ever get their hands on a real one. Sad for them.

I'm surprised no one has mentioned the .17 caliber? An interesting caliber and doubtless fun to play with...but I don't think much will EVER become of it.

What about the small bore "Odd Balls" like .228 and even .230 or the .20 caliber?

Yawn. They've never gone anywhere and I figure never will.

Bottom line in my little mind about the small bores is shooters in this bracket seem to be a fickle bunch. Today's hero is tomorrow's hasbeen.
We don't seem able to pick a favorite.

But I think the 6.5 still has the greatest potential for the immediate future. There's a lot of good bullets ready and waiting. We just need to dream up the cases to drop them in.

Probally what keeps the pot boiling on the small bores is that we have such a GOOD field to chose from. When you've got a candy store full of great little cartridges from the Hornet up to the 6.5/06 to play with, it's hard for us not to run around and want a taste of all of them.

And I don't guess anything wrong with that. There's just too much to love about the small bores and all of them are pleasant to shoot and effective as hell IF the hunter sticks with the right animals for the gun.

Does anyone see any new calibers coming out in the small bores? Any new cartridge cases coming available to use as platform for wildcats?

I admit I'm often perplexed by the way shooters hop around in small bore rifles. We just can't seem to pick one and run with it.

I agree with those liking the .257 caliber, because all it takes is a faster twist bbl and the bullet weights could go to 140 grs or so.

This gives an upper limit of .303 for Sectioinal density, and let's it compete with the 6.5's for big game while retaining the lighter 60 to 80 gr bullets for varmints.

There is an old wive's tale about over-stabilizing light bullets from the dark ages when bullet technology and manufacturing were primitive, but there is very little penalty to pay with modern bullets for spinning them "too fast". No, you don't want this when shooting small bore BR matches, but I guarantee that a 70 gr .257 bullet of proper design and construction will shoot 0.50 MOA usinf an 8 inch twist in the same BR rifle that shoots 0.25 MOA with a 10 or 12 inch twist.

Just like the 6.5s, the .257 cal is right at the point where serious SD and BC can be derived from bullets of reasonable length, giving the rifleman great flexibility and effectiveness from the associated calibers.

The 25-06 in particular is begging for more length and weight in the bullet department so slower powders and higher load densities can be achieved. It will easily launch a 140 gr bullet with .303 SD and .530 BC at 2900 fps with 17 FP free recoil in an 8.5 lb rifle. Why anyone would want a 7mm Mag over that I will never know.

Gentlemen

My choice is 6,5. It can handle anything from varmints to medium sized game.



/ JOHAN

Sabot - You raise another issue when you speak of twists and such. Most of the small calibers have actually been pretty heavily explored, even though a lot of the cartridges developed ever achieved any followings or noteriety.

New technologies in bullet design and construction plus seeing how all this can be impacted by rifle twist may open a new field where we can go back and take a second look at a lot of things with each caliber.

My fear with this topic is that we must NOT lose flexibility......the ability for any cartridge to pretty much shoot the full range of bullet weights available and shoot them well. Nor do I think much of ANY cartridge which must be loaded beyond efficient capacity for it to work right. As long as we can satisfy flexibility and efficiency, I'm for anything new some of you whiz kids can think up.

This is a tough call but I think I'll have to say the 25 cal, but the 6.5 is right on it's heels as far as being over looked. I just can't understand the infatuation that many have with the 6mm cartridges.

TDO - I was in college when America discovered the .243. The HYPE that was put out about this cartridge was incredible!

Well, what American shooters have discovered over the years is that the 6mm bore WON'T do everything. It is an excellent long range varmit cartridge and depending on the skill of the hunter and the bullets he picks, the 6mm can also be a good antelope and deer rifle.

But the failures on game animals with the 6mm have been spectacular. (Mostly because of piss poor bullets and incompetent hunters)

I think the golden age of the 6mm has passed. Most people I know today only think of .243 caliber rifles as good FIRST GUNS for their wives or kids. In other words, they don't even really EXPECT much from it. They just want something that goes bang and won't scare the young shooter away with recoil.

Certainly the .25 and 6.5 calibers are going to be much more easy to utilize as serious game hunting rifles. JMHO

I Always,felt that the 5mm, should have had a better run, It was a real fun round in the rimfire.. Now that Ruger is brining out the 204/5mm centerfire I'm hopeing its a keeper

I would have to say the 18 and 23.~~~~~~~~~~~~~~scott

I'm with Dave on this Pecos, I really would have liked to see more 5mm options. I guess the Ruger will have to do for now though. - Dan

My vote is not so much for an under-developed cartridge but rather an idea that perhaps would benefit from more exploration. Personally I'd be extremely interested in seeing bullet manufacturers bring out more 0.224 diameter projectiles in the 70 - 80gr range specifically designed for hunting small to small-medium game. The 5.6x57 has always fascinated me, and given the 22/250 and 220 Swifts credentials as long range varminters, I wonder how they would perform with heavy projectiles for the hunter that shoots varmints generally but hunts the odd goat, pig or kangaroo on occasion.
Cheers...
Con

I'll vote all of them, 6mm, why hasnt the 6mm-06 been commercialized, what a natural. 25 Caliber, great potential here. 6.5mm, same thing.
Last, but not least, yes 270 cal, even with WSM, there is more room.

Ditto AggieDog, 270 is the most under developed. Three factory rounds and 2 factory bullet weights is as un-developed as it gets (or is that actually perfection?).



Opps.

Lawrence Rifle Barrels is working on a .15 caliber, thats pretty under-developed because I don't think anyone else has worked with that bore before. Then there are the .19 calibers, with only Calhoon and one other custom bulletmaker offering bullets in this caliber. The .14's have always been pretty underworked, and probably always will be given their limited range of use. The .17's and .20's, while pretty unheard of 20 yrs ago, have really taken off over the past 3 years.

I second what Geo says, I think the sub-17's have some development potential. Especially if they go with a denser bullet material than lead.

My concern for the sub .22 caliber bores is that we are getting so small, that potential is severely limited.

Sure they will kill and rather well under the right conditions. But the more you reach the end of the spectrum, the more narrow and limited are your options. Velocity. Bullet Weight. Hunting conditions. Legal game. Etc.

I can't forsee the .15s, .17s or even the .20 ever being anything more than a novelty. In fact, I dare say the .17 has already proven how limited any such calibers will be in their supporters.

Don't mean to bad mouth these calibers, just calling to mind what I think are the facts.

I agree regarding the 6.5's. Bullets run from 85 to 160grs.
That's a pretty broad spectrum. Most of the calibers in 6.5 are quite accurate. We're starting to see stronger commercial actions now, and are no longer limited to the old military rounds. Best wishes.

Cal - Montreal

Are we talking under developed or under appreciated? The 6.5 has been put in every conceivable case from .223 to the big Lazzeroni, it just isn't appreciated. The 270 on the other hand is pretty much limited to the 270 Ren, The 270 Stimpy (VERY rare), the 270 Winchester, 270 Weatherby and 270 Short Mag and in relatively few bullet weights (regarding factory). That's what I call under developed.

Anyone who doesn't appreciate a 20 caliber has not shot a
20 caliber. Since there probably isn't one shooter in a
hundred who has, this is one very under-appreciated caliber.
The dispatching ability in those little pills on a coyote
has to be seen to be believed, let alone appreciated.

The industry could have done a LOT more with the 25 calibers,
which fits the "under-developed" category. One case in point
is the 25-06. Even with the limited assortment of bullets
made for it, she's a fantastic long-range p-dog slaughterer
with the Hornady 75gr HP (lot nicer on the shoulder than
heavier bullets, too), and a great cartridge for deer with
heavier bullets. Many a 25-06 shooter wishes more for their
pet cartridge.