6x45 (6mm/223 Rem) Added range report!

Greenbug · Dec 19, 2011

Any members have experience loading for this cartridge? I'm having a new barrel put on a Tikka action in this chambering. Hopefully it will be a good coyote rifle when I'm done. Just curious to see if any other members have tinkered with this round. I have lots of load data, and 350 pieces of freshly sized brass ready to go, just waiting on the gunsmith... So there is nothing really for me to do right now other then to drink a beer and talk about it.:beer:

nrc · Dec 23, 2011

I ran a 6x45 in a TC for awhile. Always wanted to build a bolt action, but never got around to it. What twist is your barrel?

Greenbug · Dec 23, 2011

I bought a Shilen match grade stainless 1:10 twist. Did you ever chronograph any of your ammo? I'd be interested to know barrel length/velocity/bullet weights you used. I'm thinking something in the 65-75 grain weight for bullets.

nrc · Dec 24, 2011

Sounds like a very nice setup. Mine was a virgin valley barrel (not sure if they used shilen blanks or not) 1:10, 14". Barnes 62gr Varmint grenades, and 85gr Nos partitions were both very accurate for me. I never did get around to chronographing the loads, sorry. I would expect you could exceed 3000 fps with any bullets under 70gr, and probably come very close to that speed with 80s, or 85s if you went to a powder like H322.

Many of the same powders that worked well for me in the 223 (varget, h335, rx10) worked in the 6x45. IIRC, reloader 10 was a stand out / most accurate.

When it is all put together post some pics - sounds like a fun project.

Greenbug · Dec 24, 2011

When I get it back from the gunsmith, I'll post some pics. Maybe a range report too!

Greenbug · Jan 12, 2012

I did some load testing on my re-barreled Tikka T3 Lite stainless in 6X45. For those of you unfamiliar with this cartridge it is simply the 223 Remington case necked up to accept 6mm bullets. Unfortunately I didn't have my chronograph in working order to test velocity on these loads, the sky screens broke when the tri-pod fell over last time I was using it.

I was testing the following loads (I refrenced the loads with numbers that correspond to the numbers written in black sharpie on the targets). All of these groups were shot after a barrel break in period of 150 rounds that I had done at a previous trip to the range. All groups are 5 shots at 100 yards from a bench rest at EEGC. It was a pretty cold morning at about 31 degrees with zero to about 2 mph wind. All loads were seated to 2.250" overall length. I used CCI small rifle benchrest primers on all loads.

I think I can not push the 85 grain bullets fast enough to stabilize correctly in the 1:10 twist. It seems to really like the 55 grain ballistic tips with most powders. It really likes the Hornady 75 grain HP's with H322!

Load #1 Nosler 55 Gr Ballistic Tip 28.0 grains Varget 0.744" group
Load #2 Nosler 55 Gr Ballistic Tip 27.5 grains H4895 0.912" group
Load #3 Nosler 55 Gr Ballistic Tip 28.0 grains H335 0.852" group
Load #4 Nosler 55 Gr Ballistic Tip 25.0 grains H322 0.550" group
Load #5 Nosler 55 Gr Ballistic Tip 25.5 grains H322 0.501" group
Load #6 Hornady 65 Gr V-Max 28.0 grains Varget 0.875" group
Load #7 Hornady 65 Gr V-Max 27.0 grains H4895 1.528" group
Load #8 Hornady 65 Gr V-max 28.5 grains BL-C(2) 1.646" group
Load #9 Hornady 65 Gr V-Max 24.5 grains H322 1.177" group
Load #10 Hornady 65 Gr V-Max 25.0 grains H322 1.164" group Off paper
Load #11 Speer 85 Gr Boat Tail SP 25.5 grains of H4895 2.188" group
Load #12 Speer 85 Gr boat Tail SP 26.0 grains of H4895 2.143" group
Load #13 Hornady 75 Gr HP 23.5 grains H322 1.015" group
Load #14 Hornady 75 Gr HP 24.0 grains H322 0.182" group!!!
Load #15 Hornady 75 Gr HP 26.5 grains H4895 0.606" group
Load #16 Hornady 75 Gr Hp 27.0 grains H4895 0.941" group

nrc · Jan 12, 2012

That's some nice shooting.

Fwiw - on the 85 grainers: The 85gr Nosler partition stabilizes much easier than the speer boattail. Down the road if you decide you want to hunt blacktail with the rifle, that would be a good bullet to try. I've shot that one in 6mm Rems with slower twists with good results.

Have fun.

Nate

Greenbug · Jan 12, 2012

nrc said:
That's some nice shooting.

Fwiw - on the 85 grainers: The 85gr Nosler partition stabilizes much easier than the speer boattail. Down the road if you decide you want to hunt blacktail with the rifle, that would be a good bullet to try. I've shot that one in 6mm Rems with slower twists with good results.

Have fun.

Nate

I suspected the boat tail design would be a contributing factor to the apparent lack of stabilization I am seeing. I'll try some 85 grain partitions when I get a chance. Right now I am focused on coyotes, so I am loading the 75 grain Hornady HP with the H322. Thanks for the tip!

nrc · Jan 12, 2012

With the groups you are getting with the 75s, there is no reason to look for anything else for yotes.

That said - if you like to tinker (and who else would build a 6x45 anyway) some day down the road take a look at the 62 grain varmint grenade from barnes. You would not have to worry about an exit hole...

Nate

Greenbug · Jan 12, 2012

I was looking at a box of those the other day, I'll probably try some out. Like you said I probably won't be able to improve on the performance of the 75 grain Hornady HP's.