Thread: 6x45 Rem barrel

I finally received what was supposed to be a pre-chambered 22" long fluted S/S 6mm TCU barrel but it wasnt.
I had to make a chamber cast to actually work out what it was.
Someone had used a .223 reamer with a 6mm pilot then followed it up with a 6mm neck and throat reamer which made a very long necked crude 6x45 chamber with some interesting dimentions.



I threw it in the lathe today and shortened the chamber end 10mm then rechambered it with a correct shorter neck and throat 6x45 reamer and it has come up very nice.

I have threaded it for my switch barrel CZ 527 Varmint and look forward to working up a load for it.



While The 6mm TCU was my intended build and would have offered a bit more performance it wasnt enough to warrant importing a custom reamer and die set. Ill just grab a set of 6x45 as soon as I find some on offer. I managed to neck up and load a few loads to test over the chrono using my 6ppc dies this afternoon which will have to do for now.
27gr of H4895 with a Nosler 70gr bullet got me just over 3000fps. Should go well with the 80 and 90gr bullets.
Will test it with some BM8208 too.

Well done... this is a great thread to help push the 6x45

Where & what brand of barrel is it?

Mathias will be eagerly watching & he still has me seriously thinking of a 6x45

Originally Posted by Seventenths

Well done... this is a great thread to help push the 6x45

Where & what brand of barrel is it?

Mathias will be eagerly watching & he still has me seriously thinking of a 6x45

It was amongst a bunch of second hand barrels Ive picked up from Guncity Christchurch, they have a heap of take off barrels from back when Robbie Tiffen was doing their smithing. Im unsure of the brand and wouldnt trust GC even if they told me what it was.
Ive purchased quite a few, some have been perfect others have had shot out throats etc but most are reusable for the little CZ, Sako or Zastava actions as they have very small action threads meaning they can be trimmed up quite a lot and there's still enough diameter left to fit them. At $99 per barrel they make great testing rigs for new wildcats and new to me cartridges such as this little project.

I actually picked up a .223 mini Mauser project for this build too but changed my mind when I saw how good condition and pretty this little barrel was. It deserved a home on my CZ 527.
I was going to build the other mini test this cartridge then sell it on but somewhere along the line the 6x45 really grew on me.

I have another 6mm 1-10" twist trueflite heavier profile barrel that I could fit to the other mini Mauser in 6x45 or a lighter 1-9" .223rem if someone wants it?
I had changed my plans to possibly opening up the bolt face and making something on the Russian case bases such as a .22 Grendel, .22 PPC, 6mmPPC, 6.5 Grendel or a subsonic .338 Grendel.
I was going to do a bit of a build thread for it then flick it off but I happy to listen to suggestions at this stage.

Are the potential choices based off using reamers you already have? I.e. the Grendel series? 22 Grendel looks useful especially with a 1/8 twist.

Have you done much more with the Dasher? I saw a bit of information about that one on another thread. Have you done an in-depth write up on that experiment at all?

I'm also fascinated by this 6x45 as well - seems like a brilliant wee cartridge. Read a lot about it a couple of years ago before I actually got shooting again. Definitely want to have one once I've got all the other kit sorted that one needs when starting out hunting and shooting again from scratch!

Watching with interest I've tried BM8208 with the 75gr Sierra and found the pressure was higher for the same velocity as my preferred H335 load. I gave CFE223 a twirl as well and that suited the 80-90gr bullets nicely, better than H335. Good to see some interest in this round.

Clever stuff wingman.

Originally Posted by Steelisreal

Are the potential choices based off using reamers you already have? I.e. the Grendel series? 22 Grendel looks useful especially with a 1/8 twist.

Have you done much more with the Dasher? I saw a bit of information about that one on another thread. Have you done an in-depth write up on that experiment at all?

I'm also fascinated by this 6x45 as well - seems like a brilliant wee cartridge. Read a lot about it a couple of years ago before I actually got shooting again. Definitely want to have one once I've got all the other kit sorted that one needs when starting out hunting and shooting again from scratch!

Yes based around chamber and neck/throat reamers I have.. not worth importing new one off reamers for these kind of fun experiments.

I was leaning toward the .22 Grendel using fire formed .220 Russian brass to save neck turning but after building this 6x45 for myself I think it might be better to do a second one.. it will be much easier for the majority of potential buyers to load for too not to mention it will be a continuation of this thread for those interested.

I never got around to a write up on the 6mm Dasher barrel did I? Its a sweet little over achiever for sure. Settled on a load with the 95gr Nosler Balistic tip at 3200fps. It feeds great from the Desert Tech SRS mag but doesn't eject well due to the short case. I need to modify a heavier ejector spring for it but swapped the barrel out with the Creedmoor one for a recent culling job and have yet to get back to sorting the Dasher.

Originally Posted by Mathias

Watching with interest I've tried BM8208 with the 75gr Sierra and found the pressure was higher for the same velocity as my preferred H335 load. I gave CFE223 a twirl as well and that suited the 80-90gr bullets nicely, better than H335. Good to see some interest in this round.

I based my load on Hornadys load data which was a touch under the max load and a very full case for H4895 which they list as the best powder for the highest velocity with many bullet weights in 6x45

In previous experience with BM8208 in .22 and 6mm cartridges, Ive found it likes lighter loads not a full case and often shoots much tighter groups than any other powder.

While this little 6x45 screams with the lighter varmint type 6mm bullets I see no real advantage using it over a .223 which is why I want to develop a 90gr Nosler BT load for it which is a great little deer bullet as it has a thick copper base unlike the lighter jacket 60-80 varmint bullets available in 6mm.






The new Hornady 90ELDX is also a great contender for this test.
My only real limitation in the CZ 527 is mag length. Id say the other little internal mag mini Mauser will do better for the heavier bullets pulled out a bit longer. For this very reason I may have to stay with a lighter but more solid bullet in my CZ for deer.

Nice. Don't overlook two of Sierra's bullets for the 6x45, the 75gr HP varmint which has a heavy jacket for hot 6mm's, this performs like a Game King at 6x45 velocities and 85gr HPBT Game King if you want something a bit harder. These both have a similar COAL that I can squeeze into my Sako Vixen mag no trouble, without deep seating. Both offer fine accuracy in my 1:10 barrel.

Yes @southernman mentioned the same thing to me about the Sierra 75 and 85gr game king bullets. I may have to run something like that in my CZ due to being limited to a COAL of 59.5mm (2.35") for the mag to feed them.



He also shared a very informative link to a related fnh thread for those interested.

FishnHunt - New Zealands Famous Hunting and Fishing Forum Since 1995 - What 6x45 loads are you guys using?

The more I read about the 6x45 the more I really like it.
I think I have already convinced myself that I need to machine a second one on this other mini mauser unless a bunch of people are interested in seeing something else on it?
Happy to take requests on this project as it will be sold on cheap afterwards regardless, its just a bit of fun over the xmas break.

Ive just had a good look at the 24" 1-10" 6mm heavy Trueflite barrel and I can get a clean 20" to 21" 6x45 barrel from it.

crap i really shoulda kept my lh zastava 223 🤬😭🤬🤬

Originally Posted by quadhunter260

crap i really shoulda kept my lh zastava 223 ��������

Yeah ya should have.. this barrel would have been great on it

rub it in 🤪🤣🤣🤬🤣🤣🤣😭😭😭

Shit that HnF thread is nearly 3 years old. I've run a heap through mine in that time. Currently have a second 6x45 in the works, this time its gonna be 1:8 @ about 20" and lighter, esp after handling @southernman little Cooper

Just had a scratch through my projectile shelf and found some 80gr Speer soft points that could work well in the 6x45. The 90gr Nosler BT is very long so will limit powder capacity when loaded for the CZ 527 mag.

Left to right: Nosler BT 90gr, Sierra blitzking 70gr, Speer SP 80gr and Nosler Varmagedon 70gr FB