6x45 (6mm223) - Remington 700

[ExtremeX]

I have a Remington 700 with a 223 bolt face I want to rebarrel to a 6x45...

Does anyone here have a 6x45 they use primarily for target shooting. I wont be using this rifle for hunting, paper and steel punching only. Generally shooting between 200-800 yards...

Which barrel manufacture did you pick, what length did you finish the barrel at, and which twist rate did you choose?

On the Hodgdon load data site I am seeing bullet weights from 60 to 100 grains.

I shoot 105gr Amax in my 243, but I suspect too heavy might not be that great of a choice either... not sure what is a good mix between BC and velocity.

Any pointers?

[kendog4570]

I built one for 6mmintl on a 788 action. Amazingly accurate. Maybe he'll post the particulars (Barrel, twist, load, etc.). I believe it is an 8" twist Krieger, at 26", and we used a JGS #1048 reamer. Also built one for another calgunner on a 700, but haven't heard any range reports. That one was with a used McMillan 6x47 barrel he picked up at a gun show.
Let me know if I can help.

[6mmintl]

I had an old .243 dia. Kreiger 1x8" twist across the course 29" barrel that I had Ken set back the chamber end after 6000 rounds to 26.5" and thread for my 788 action.

I have shot every bullet made for it from 60-95 grain and depending on loaded velocity it a pure 3/8" or under one MOA shooter.

I have hit 40 out of 40 silhouette with it off the bench but you cannot drive 95 Bergers fast enough to put enough energy on the rams to reliably knock them over, 105-107 grain match bullets cannot be driven fast enough to stabilize beyond 500

For punching paper the 95 grain Berger (very close to 80 SMK ballistics) bullet is best beyond 400-700, otherwise any 69-77 bullet if good from 100-600 yards

Im rather surprised that in the 70's it was popular as a entry level bench rest or varmint cartridge, in the 80's it was very popular in the AR platform as a potential match rifle class rifle but dropped out of sight until the past few years where it is again gaining a following.

its an excellent target/varmint round if shooting proper bullets and using proper reloading skill set that can help you hone your wind doping and shooting technique.

[ar15barrels]

I have a Remington 700 with a 223 bolt face I want to rebarrel to a 6x45...



Does anyone here have a 6x45 they use primarily for target shooting. I wont be using this rifle for hunting, paper and steel punching only. Generally shooting between 200-800 yards...



Which barrel manufacture did you pick, what length did you finish the barrel at, and which twist rate did you choose?



On the Hodgdon load data site I am seeing bullet weights from 60 to 100 grains.



I shoot 105gr Amax in my 243, but I suspect too heavy might not be that great of a choice either... not sure what is a good mix between BC and velocity.



Any pointers?

Buffybuster (here and on CAPRC) has one that I built him.

[Flouncer]

Brass

Given the vast and bewildering array of brass, ranging from pure import junk to Federal Mil Spec to Lapua, what were you using ?

[buffybuster]

I got exactly what you're looking for:

M700SA rebarreled to 6x45mm (6mm-.223Rem). It's a 8-twist, 5R, I think Brux, cut to about 21", Med. Palma contour. It was a setback from .243Win.

Most every .308Win appropriate powder works well in the 6x45mm. I shoot 105's exclusively in my 6x45mm and get about 2600-2650fps with 105's. This gives about the exact same trajectory as a .308Win with 175's. It's a real fun rifle to shoot and my kids like it very much. No recoil, my 9yr old making hits at 500 & 600yds.

About 25grs of powder to shoot 105's to 2600fps. 6x45mm cases are made with a single pass of .223Rem/5.56 brass. I have buckets of 5.56 brass, so all my 6x45mm brass is Fire-N-Forget. I use AI mags with COAL about 2.5".

[MongooseV8]

I bet a 75 or 87 grain vmax would be a good compromise between velocity and bc. I think 26" would be a good finish length too.

[buffybuster]

I bet a 75 or 87 grain vmax would be a good compromise between velocity and bc. I think 26" would be a good finish length too.

My estimation is a 95gr match bullet in a 24-26" barrel would be the optimum balance between velocity, BC for long range performance.

[Jarhead]

6MM seems to be the trend for Long Range Precision Shooting, I chose to go with 6.5 CM for my build after breaking in with .308

[dwalker]

I have a 6mmx45 AR, shoots well. Does not like heavier projectiles, really likes the 75 gr range.

[russ69]

I have a bit of experience with the 6X47. That's a Rem 222 Mag necked up to 6mm. This was a common benchrest round before the 6mm PPC came out. The 222 Mag case was used because more powder capacity was needed to get the bullets up to speed. The 223 case is a bit short on powder capacity but near workable. The standard bullet was a 62 grain flat base match bullet. Twists were towards the slower side to match the 62 grain bullets. Overall it's a nice shooting cartridge for short to mid-range shooting. The PPC replaced the 6X47 and the 6X47 was retired.

[Khromo]

...6x45mm cases are made with a single pass of .223Rem/5.56 brass...

How do you get the cases necked up to 6 mm.? The only dies I saw at Brownell's were Forster full length sizer and seaters.

I've got a 6 mm. expander mandrel I guess I could use, but I don't like to guess about reloading!

[buffybuster]

How do you get the cases necked up to 6 mm.? The only dies I saw at Brownell's were Forster full length sizer and seaters.

I've got a 6 mm. expander mandrel I guess I could use, but I don't like to guess about reloading!

Most 6x45mm FL dies are available with a tapered expander. Inside lube the necks and run them through.

[ExtremeX]

Thanks everyone for the information... I think I am going to move forward with a 6mm barrel purchase and have my R700 reworked.

I will be ordering the dies this week so I can get a jump start on the brass.

I already have some 87gr VMAX, 105gr AMAX, and 105gr BTHP I use for my .243 Win, but ill pick up some 95gr match bullets based on buffybusters recommendation.

[LynnJr]

How do you get the cases necked up to 6 mm.? The only dies I saw at Brownell's were Forster full length sizer and seaters.

I've got a 6 mm. expander mandrel I guess I could use, but I don't like to guess about reloading!

Your 6mm mandrel will work or you can get an expansion from K-M Tools.