7MM TCU rifle

[Spindrift]

Those super- effective, small cartridges propelling ballistically effective bullets at disproportionate velocities using homeopathic doses of powder have bothered me for years . Like the 6,5 or 7 TCU, 6,5 Grendel, 6mm/.223 and so forth. They make my mind go in endless cycles, like this

Stage 1, looking at reloading tables. Wow, that little cartridge can propel a X grs bullet at Y fps, using only Z grs of powder! And it will fit a mini-action!

Stage 2..... but in a mini-action, there will be severe COL limitations on the longer bullets, infringing on powder capacity. It will probably work better in a standard short action.

Stage 3.... but in a standard short action, I might just as well choose that common standard cartridge, that can do everything the smaller cartridge can do, and more.....

Stage 4. Forget everything, then move to stage 1.

 

[Glaciers]

Spindrift you just described my go around of when I built a mini Sako A1. I wanted a small 6mm, but also wanted to get as much out of it as possible. This was 40 years ago and still had a case of magnum mania. I had the action and Peacock my friendly gunsmith at Langley’s Gun Room made all kinds of suggestions as to what to build. He was an old school Smith that did it all metal and wood.
Anyway he built me a beautiful rifle caliber 6x47. Back then there wasn’t any Grendel’s lurking around let alone other small cartridges. Well there was some, but the 6x47 was tried and true bench cartridge and that made since. The problem is the 222 magnum case which the 6x47 comes from is the length. It would have been a better choice for the 6x45 for COL, the extra length of the magnum case when bullets above 80 grain when loaded to proper length, the loaded cartridge won’t eject. I had the action bridge relieved slightly and that helped. Well it’s more of a problem in my head then anything else, but to use longer heavier boat tails The bullet has to be seated deep. I just have this aversion to having bases any further below the neck then needed.
But the 80 grain flat base SP Remington will clock at about 2800 fps Which is pretty respectable.
Well there’s my Stage #1 & #2 anyway. But, I need to play with it more and get over the small short comings and enjoy the little bugger. But, yet another but, the 25-45 of CW‘s, if I could get it bore out and rechambered.
Boy I need to see a gun shrink.

 

[Joshua]

A Tikka T3X Superlite in 7mm-08 weighs 5.9 lbs. Scope and rings will add a pound and some change. That’s a pretty handy and capable package at less than 7 pounds.

While I enjoy my Savage in 7mm-08. I wish I had spent the extra and bought the Tikka.

I love the idea of converting (basically free) 223 brass into something else. The problem for me with the 300 blackout or the 7mm TCU is that their downrange ballistics can get pretty borderline. There are just too many long shots across clear cuts in my area. And, if I’m deer hunting, I also have a bear tag in my pocket, 7mm TCU just wouldn’t be enough.

I’m just gonna keep trading .223 scavenged range brass for .308.

 

[RBHarter]

The thing about the things like the 6.8spc is that the original design and the current "non SAAMI" but still industry standard uses all of the "tricks" for going fast while dropping pressures and using the increased pressures ....... A physics's lesson lives in here some place ......it's right next to the identical stoke with a longer connecting rod reduces dwell time at the top of the stroke .
The other place where the "cheat" comes in is that a 22" 280 Rem , 7-08 , and the 7×6.8 is that each step down in case length gains most of a half inch of barrel . It actually makes the AR family cartridges even faster in a 16" barrel because the 06' needs that other 6" , and the 308 family needs at least 3" more to peak out .

So we take a short action with a skinny barrel and put it in a stock that can be lightened even more because it doesn't have to the carry through strength and related weight to manage the recoil . While you can't beat the equal and opposite law we can rearrange the way it happens and change the perception of it .
Now my head hurt .....

 

[RicinYakima]

..it's right next to the identical stoke with a longer connecting rod reduces dwell time at the top of the stroke .

The efficiency is not only at the top of the stroke, but at 90 degrees with the increased mechanical advantage to turn the crank. Lesson learned from racing Hudson flathead six's. You can run the next step high gear with the increased torque.

 

[Ian]

Far be it for me to be the voice of reason, but it sure sounds like a nice, lightweight AR-15 carbine chambered in the normal caliber would be a near ideal companion for bumming in the desert.

 

[RicinYakima]

Far be it for me to be the voice of reason, but it sure sounds like a nice, lightweight AR-15 carbine chambered in the normal caliber would be a near ideal companion for bumming in the desert.

I have one, built it with my son in 2020 for a pandemic project together. Mine is 223 and his is heavy weight 6.5 Grendel and both shoot fine. However, it is ugly. It feels like the M16 in my hands from 50 years ago. Every time I stop and see it I am unhappy. Got to be blue steel and wood. I know not reasonable, but how I feel about it.

 

[Ian]

I can't argue with that, Ric. Fortunately, I lack bad memories of the ugly but marvelous AR and hope it stays that way for the remainder of my days.

What about a Marlin 336 in 7-30 Waters? That's my own impractical but want one anyway and have since I was a kid rifle.

 

[RicinYakima]

That would be nice if I could find one I could afford from the collectors. I will think about that one.

 

[Jeff H]

Far be it for me to be the voice of reason, but it sure sounds like a nice, lightweight AR-15 carbine chambered in the normal caliber would be a near ideal companion for bumming in the desert.

You had to go and say something practical....

.....it is ugly. It feels like the M16 in my hands from 50 years ago. Every time I stop and see it I am unhappy. Got to be blue steel and wood. I know not reasonable, but how I feel about it.

...which is exactly my own impractical view of the thing too.


I can't argue logically against Ian's suggestion, but I find I'm also in RIck's camp - I like to like the guns I'm using and I was not fond of the M16 when I had to sleep with it and it still doesn't make me feel good handling one like other stuff does. I did actually handle and shoot a really nice, modern AR in 300 BLK a couple months ago. Irrationally, it just didn't feel right. Nothing against them, but I done did my time with it.

If we're going to get all practical about things, how about a CZ 527? All the dandy little AR cartridges fit in one and it was available in several chamberings toward the end, like the 300 BLK and 6.5 Grendel. I replaced the American stock on my 222 and put on a Youth Carbine stock. I have an older Leupold 2-7 Vari-X II on it and it's a joy to tote and shoot. I still plan to cut the barrel to 18.5" or 20", so it will be even handier.

I also have a Youth Carbine in 7.62x39 with 40 rounds of cast through it, but set it aside because my 30/30 Contender does all it will do, plus. I keep waffling over selling it or rebarreling it to 350L, 6.5 Grendel or...who knows? I shouldn't be thinking like that, because I actually have NO "project guns" holding things up for the first time in many decades, but they are so small and lightweight. I wonder if someone makes a "25 Grendel" or a "25 PPC" reamer... I shouldn't be thinking like this.

Nope, nope, I'm going to stick with my Contenders. I've gone 'round and 'round on this and always end up right back here.

I do not have to worry about wolf packs, so MY preferences are based on some different criteria too.

 

[RBHarter]

ARs .........a necessary evil I suppose.
I've done what I can with the silly minimum tools tinker toy guns . They grow on you after a while I guess. I bought kit guns and a complete assy . The heavy 20" rifle barrel removes any weight saved by the design and the 16" A2 carbine types .

The Stevens 200 is about 8# but it also has a 22" heavy barrel when I get the walnut and pecan cut for slabs it'll be even heavier than with the cheap plastic factory mess .

 

[Joshua]

You need a .24” or larger for deer in Washington. I have two 80% receivers laying around that I haven’t done anything with yet, mainly because of this little law. There is probably a 6.5 Grendel in my future.

 

[RBHarter]

If one is going to "build" a x39 especially a 7.62 and more so in an AR blow it straight as in a rimless Herritt or AI . Cheap brass , fire form from factory , and a remarkably efficient case . It adds 10% or so to the 300 Bo and really does get it barking at the heels of the 30-30 .

 

[Jeff H]

A Tikka T3X Superlite in 7mm-08 weighs 5.9 lbs. Scope and rings will add a pound and some change. That’s a pretty handy and capable package at less than 7 pounds.

While I enjoy my Savage in 7mm-08. I wish I had spent the extra and bought the Tikka.

I love the idea of converting (basically free) 223 brass into something else. The problem for me with the 300 blackout or the 7mm TCU is that their downrange ballistics can get pretty borderline. There are just too many long shots across clear cuts in my area. And, if I’m deer hunting, I also have a bear tag in my pocket, 7mm TCU just wouldn’t be enough.

I’m just gonna keep trading .223 scavenged range brass for .308.

Howa makes a shorter-than-short action too now, but I have no idea how light it is. If they only trimmed the length, it may not be much different than a short action. The Zastava M85s weren't terrible. Parts may be an issue and extractors seemed to be something you'd want a spare or two of. They weren't all that Mauserly, in that respect, but neat little rifles, and Bell & Carlson made a nice composite stock for them - something I'd like to see for the CZ 527, but that'll never happen. All the aftermarket stocks for the 527 contradict the petite action - large, heavy, bulky "target" stocks.

336 in 7-30 Waters? It's still popular in the Contender Carbine, but it's still a single-shot, and those wolves,... I'd see the single-shot differently if I had that to deal with.

 

[RBHarter]

Look hard at the 6.8 SPC . It's well balanced more case than the Grend and uses straight mags .

 

[RicinYakima]

Having made stocks from planks before, the stock issue isn't a big deal. Small action and skinny barrel and four round magazine would be good.

The word in the woods is that if you shoot two or three wolves, the rest will run; they are not stupid or they would not have taken over as the apex hunters.

Sorry, 6.8 or 6.5 isn't in the picture.

 

[Jeff H]

....Small action and skinny barrel and four round magazine would be good....

Sounds like a 527. That little action is cute as a bug. The magazine hold five, but there is a conversion done to make them three and almost flush with the bottom of the stock. It seems a bit extravagant at $100, but I've considered executing the modification on my own. Extra five-rounder or two in the pockets and you're all set.

Not to push. I just get all excited about these little guns. I've fantasized about an 18" barreled 527 with a slender full stock, rear peep, post front in some chambering or another, but don't know what. 9x39, maybe? Probably wouldn't do the 250-yard varmint thing that well, but there are others which would.

 

[RicinYakima]

There are places between the sage brush that you can see badgers, groundhogs and others. Not many, but some at times. The main varmints are sage rats, miniature prairie dogs half scale.

 

[fiver]

ground squirrels... Belding.

those kind of get my goat.
i hate to waste a good 223 round on them, but man sometimes you just gotta...
the 22lr is kind of my favorite, but i've come close to purchasing another rimmed rim fire round a time or two just,, well cause.

i've probably shot them with everything from the 45-70 on down, including a shot gun, more than once...
and have no qualms using my deer rifles with cast bullets intentionally to get in the practice.
those same cast loads have taken care of badgers, skunks, a real sick sheep, and a couple of coyotes with minimal recoil too.

 

[Missionary]

When we lived in west Indian on a gravel road the opposite side was a built up bank along a field. Dandelions had take over and the owner wanted grass. So after a couple days of good soaking rain I go out a Roller in 43 Spanish and dug them out by the roots.
The brass needed fire-formed also.