6x45mm twist rate

Talk about or share information about your centerfire rifles.
triggerfingers
Senior Member
Posts: 119
Joined: Wed May 10, 2017 8:39 am
.204 Ruger Guns: Cooper MTV 204 Ruger, Savage 12 LRPV 20 VT, Cooper MTV 6x45

6x45mm twist rate

Post by triggerfingers »

I plan on getting one of my bolt action rifles re-chambered in 6x45mm but my choice of twist rates are 1:14 or 1:10. I plan to shoot between 60 to 85 grain bullets. The 1:14 will not handle the 85’s, but should be fine with the 60’s to 70’s. The 1:10 will do all of the bullets plus more, but at the sacrifice of velocity. Which would you recommend?
Bill K
Senior Member
Posts: 2324
Joined: Tue Jan 18, 2011 10:00 am
.204 Ruger Guns: also now, a Savage switch bull barrel in 204R. 23 inch SS
Location: Lake Forest, Ca.

Re: 6x45mm twist rate

Post by Bill K »

Accuracy trumps velocity. I would go with the 1/10 . :)
User avatar
Rick in Oregon
Moderator
Posts: 4942
Joined: Thu Dec 01, 2005 4:20 pm
.204 Ruger Guns: Sako 75V, Cooper MTV, Kimber 84M, Cust M700 11 Twist
Location: High Desert of Central Oregon
Contact:

Re: 6x45mm twist rate

Post by Rick in Oregon »

Bill K wrote: Fri Nov 20, 2020 10:44 pmAccuracy trumps velocity. I would go with the 1/10 . :)
My mantra also. Agree 100%.

(What good is zippy velocity if you don't hit that dinky little target way out there? ;) )
Semper Fortis
Rick in Oregon
NRA Life/OHA/VHA/VVA

Oregon, East of the Cascades - Where Common Sense Still Prevails

Image
triggerfingers
Senior Member
Posts: 119
Joined: Wed May 10, 2017 8:39 am
.204 Ruger Guns: Cooper MTV 204 Ruger, Savage 12 LRPV 20 VT, Cooper MTV 6x45

Re: 6x45mm twist rate

Post by triggerfingers »

Thanks so much guys… That’s the way I was heavily leaning, but then you start to second-guess yourself.
jsh
Junior Member
Posts: 65
Joined: Sun Oct 08, 2017 5:29 pm
.204 Ruger Guns: Encore, savage LRPV

Re: 6x45mm twist rate

Post by jsh »

I would like to hear how your project goes.
I put together a 6TCU rifle a couple of years ago. I wanted a 1-10” myself, but all they had in the profile I wanted was a 1-8”. 55-75 grain was all I planned on using. All I have shot so far are a bunch of odds and ends of various odd lots I had that needed used up, 60-80 grain fire forming loads.
I have some 55-65’s patiently waiting.
Am hoping the extra rpm adds to the splat factor on prairie dogs.
User avatar
jpx2rk
Senior Member
Posts: 128
Joined: Sun Aug 14, 2016 5:25 pm
.204 Ruger Guns: Savage 12FV, R783/20P combo
Location: East TN

Re: 6x45mm twist rate

Post by jpx2rk »

I did a 10 twist which shoots the 58g up to 75g very well. I have not done a lot load development with the "heavy" ones yet, but loves the 58g vmax.
Master Piddler ;)
jsh
Junior Member
Posts: 65
Joined: Sun Oct 08, 2017 5:29 pm
.204 Ruger Guns: Encore, savage LRPV

Re: 6x45mm twist rate

Post by jsh »

Loosing speed from fast twist, any ideas of what the loss is?
triggerfingers
Senior Member
Posts: 119
Joined: Wed May 10, 2017 8:39 am
.204 Ruger Guns: Cooper MTV 204 Ruger, Savage 12 LRPV 20 VT, Cooper MTV 6x45

Re: 6x45mm twist rate

Post by triggerfingers »

jsh wrote: Thu Nov 26, 2020 7:20 am I would like to hear how your project goes.
I put together a 6TCU rifle a couple of years ago. I wanted a 1-10” myself, but all they had in the profile I wanted was a 1-8”. 55-75 grain was all I planned on using. All I have shot so far are a bunch of odds and ends of various odd lots I had that needed used up, 60-80 grain fire forming loads.
I have some 55-65’s patiently waiting.
Am hoping the extra rpm adds to the splat factor on prairie dogs.
Looks like I’ll find out in about 6 to 8 weeks… I’m having one of my Cooper model 21’s MTV re-barreled in 6x45. Already have cleaned up a bunch of 223 brass and sorted it. Plan on starting off with Sierra 70 matchkings for target work and also have available Berger 65 and 68 flat base target/varmint. I have Sierra 85 grain Gamekings standing by for heavy testing. The dies will arrive today and have 2 powders for testing, RL 10x from the Berger manual and H 335 from the Sierra book. Would like to find some H322, but we all know what “fun” it is trying find powders and primers right now.
triggerfingers
Senior Member
Posts: 119
Joined: Wed May 10, 2017 8:39 am
.204 Ruger Guns: Cooper MTV 204 Ruger, Savage 12 LRPV 20 VT, Cooper MTV 6x45

Re: 6x45mm twist rate

Post by triggerfingers »

Looks like it will take longer to get the Cooper done. Will have to wait for them to get another barrel in. Should be ok and back in time to work up some loads. Great customer service at Cooper, keeping me in the loop and all.
jsh
Junior Member
Posts: 65
Joined: Sun Oct 08, 2017 5:29 pm
.204 Ruger Guns: Encore, savage LRPV

Re: 6x45mm twist rate

Post by jsh »

6TCU, 1-8” twist 70 grain TNT running 2900 and change.
gemihur
New Member
Posts: 8
Joined: Fri Jan 19, 2018 11:52 am
.204 Ruger Guns: Thompson Center contender

Re: 6x45mm twist rate

Post by gemihur »

Mine is 14" Bbl from SSK and 1:10" twist
Had to build some remedial woodwork on this one
Powder of choice IMR 8208 with 62 gr. bullets = shoots lights out
Image
User avatar
Rick in Oregon
Moderator
Posts: 4942
Joined: Thu Dec 01, 2005 4:20 pm
.204 Ruger Guns: Sako 75V, Cooper MTV, Kimber 84M, Cust M700 11 Twist
Location: High Desert of Central Oregon
Contact:

Re: 6x45mm twist rate

Post by Rick in Oregon »

gemhur, just have to ask.....what is the purpose of the old 'military style' forearm handguard on a varmint rig? Never seen that done before on a rig set up for accuracy. Most rigs are set up so that the forearm in no way actually touches the barrel when it's free-floating. I would also think the full enclosure would trap barrel heat; the enemy of a nice barrel.

Enlighten us please......inquiring minds want to know. :wink:
Semper Fortis
Rick in Oregon
NRA Life/OHA/VHA/VVA

Oregon, East of the Cascades - Where Common Sense Still Prevails

Image
triggerfingers
Senior Member
Posts: 119
Joined: Wed May 10, 2017 8:39 am
.204 Ruger Guns: Cooper MTV 204 Ruger, Savage 12 LRPV 20 VT, Cooper MTV 6x45

Re: 6x45mm twist rate

Post by triggerfingers »

Update…. I got the rifle back from Cooper and started my load development. Using H335 powder and Bart’s 68 gr. Ultimate bullets to start. I have some 80 gr. Dominators on order, but I figure they will be a long time coming due to component shortages. So far it looks very good.
Best group .202 moa and recoil in very manageable. I ended up with a 1:10 twist and very happy with the out come.
gemihur
New Member
Posts: 8
Joined: Fri Jan 19, 2018 11:52 am
.204 Ruger Guns: Thompson Center contender

Re: 6x45mm twist rate

Post by gemihur »

Rick in OR
I rec'd the 14" SSK Bbl with the front 9" turned down to .55" and wanted to use the barrel with a forearm designed to enclose the barrel's deficit.
As a single shot the heat buildup within the forearm is minimal. It is free-floated internally and has no contact to the wood other than a single mounting dovetailed escutcheon.
Post Reply