Does anyone know if there is any difference between these cartridges? I can't find a case drawing anywhere for the 6x45 A.I.

Thanks

Guessing it would look just like a 223AI but with a slightly bigger hole in the neck.

If there is a difference I cant imagine either having a distinct advantage over the other. I shoot a TCU and its replaced 223ai as my "go to" small cal. favorite. With an 8 twist and 95 gr Bergers the accuracy over distance is amazing.

Scott, don't you have a 6x45?

I do

How does it compare to 223 AI on deer? It looks like the 223 has more bullet options...

The ones on either end are 6x45, the black tipped are 223AI and the remaining two are a 6x45AI, well I necked up a 223AI and seated a 6mm bullet in them.

I've only killed one deer with the 6x45, but in my mind I think the 223AI is a better mousetrap with the bullets available for it, though you only need 1 GOOD bullet.

The 10pt went maybe 20 yards after taking a 70gr Ballistic tip right behind the shoulder (clipped the offside shoulder) with the 6x45. I like the cartridge and thinking hard about a 7mmTCU just cuzz.

In the past I owned a 6mm TCU super 14" Contender. Now I own a 6x45 in a Ruger #1.

I can't imagine buying custom dies and a custom reamer for the 6x45 AI when it's doubtful you'd gain any appreciable velocity over the 6mm TCU which is pretty much already an A.I. Besides it uses already a standardized reamer and factory dies....

GH

Agreed, I'd go 6mmTCU for those reasons, albeit you could run a 223AI bushing die for the 6mmAI, but it still don't make sense.


If there is any difference in case dimensions it ain't but a RCH.

How much do you think the 6 tcu would gain over the 6x45 say with a 80 gr Hot-Cor/Deep-Curl?

No idea, likely as linear as the 223/223AI comparison.

I do know the smith had a 6x45 reamer but no 6mmTCU. Another deciding factor...

How fast does you 223ai push those Sciroccos?

3K

Do you switch them out with Amaxs?

Although this doesn't really address the 6x45, Hornady states, "In fact, there are two versions of the 223 expanded to 6mm. These two,the 6mm/223 and the 6mm TCU(Thompson/Center Ugalde) are similar but not interchangeable. However, the 6mm TCU reloading can be used for the 6mm/223, starting at the lowest listed load and carefully working up."

Thinkin we kinda already know this, though.

I too would tend to believe that any difference between the 6mm TCU and the 6x45AI would be small being both share a 40 Degree shoulder arrived at via fire forming.

The only benefit I see to the 6x45 or 6tcu over the 223 and 223ai is they are legal in Wyoming where I goat hunt.

I had a 6x45 for a short time but never got to shoot any deer with it.

I remember getting a hair over 2900 with the 80gr Hot-Cor from a 22" barrel...

According to the cartridge drawing in the Sierra Manual, the 6mmTCU has a 40* shoulder. (Which would be the same as the A.I.)

In my experiements with the .223 Rem vs. the 223 Rem A.I., I found the A.I. version to be nearly the .222 Rem Mag. If you look at the 6x45 vs the 6x47 (6mm/.222 Rem Mag) you can see that it gains nearly 200 f.p.s. with the 80 gr. bullet.

Without actually building one, that's about the closest guess one will likely find...

Good info Grasshopper, I figured probably 150 fps...

I like what Steelhead said about only needing one good bullet/load. There's something to be said about the wisdom and simplicity of that.

Coyote, Deer, and Goat would be well within the capabilities of the cartridge and there are enough "good" bullets available that one or two are bound to give you accuracy to smile about.

Not that my opinion should have any bearing on the subject, but I do think it is a very smart cartridge.

All input is appreciated, and I agree I need one bullet...

Yep, thought I do run the 65gr Sierra GK and 62gr TSX a fair amount.

Do the sciroccos foul the bore pretty bad?

I don't know, I've yet to clean the bumblebee. All I know is the last time I shot it I took out a crow at 225 yards with the 75gr Swift, so I guess it's still shooting well.

Lol sounds like its doing fine...

Shooting Times Aug 93

Layne Simpson:

capacity:

31.3 - 45
31.9 - TCU
31.8 - 47 - 222 mag case

I do not believe there is a significant difference in these rounds IMHO. I'd say 50-100fps depending on weight, bbl length, and powder.

If 150-200 fps is gained, I'd wonder if that is comparing rounds at equal pressure.

Layne reported: Kimber 22" 2984 w/45 and in a Hart 20" 47 - 2932. Both 14 twist - both 85 Partitions over 748, 28 and 28.5 respectively. Twist not ideal for 85s, but it gives one a comparison.

None the less, I like all these rounds, but for simplicity would do a 45 non ai, or a TCU, unless I just wanted a different stamp on my bbl.

What I would do is be sure to use a fast twist, 8" preferably for me.

Thanks for the great info 65RB. I agree .6 difference in case capacity why bother with anything else than the 6x45...

I've seen the case capacities of all three to vary more like 1-1.5 grains in .224 caliber.

No doubt, makes of cases can make a .5 grain difference, if the 45 case is a Remington and the TCU/AI case and the 47 cases are Federals.

The 6 TCU makes a lot of sense with a ton of flexibility; since you are making something, make it the biggest/easiest.

Question - would the 6X45 be quieter than a 250 Savage?

No doubt brass brand affects capacities.

DJS, I would believe the 6 would be - my TCU was very mild - a crack, vs 6BRs that run a little more powder.

Neither would give me much concern, though I use plugs + muffs 99% of the time.

Good Question, I still have a 250 that I run 100gr's at 2900-3000 with 35-40gr's of powder. I use to have a 6x45 and ran 80gr's at 2900 with 26gr's. The 6x45 was quieter I thought and had less blast...

The 6x is a baby doll for sure...

I really like the cartridge.