Building a shorter 6x45 AR.

[nastynatesfish]

Hey guys.
So I was debating on doing a 6arc. Same thing. Shorter barrel to be more handy. It’ll be used for coyotes and general plinking out and about in the desert. It’s also going to be suppressed.
I went with a 14.5” barrel from riches precision. I got dies and some 70gr Barnes varmint bullets to start with.
Not sure if some of you remember. But her about 2-1/2 years ago, I sold a bunch of Barts and Watson 6mm bullets for a buddy. Well talking to him and talking him out of a few boxes of 223 lapua brass. He told me that he found a good bit more while clearing stuff out.
He offered them to me along with a bunch of 85gr soft points.
I’m wondering if it would be sacrilege to shoot those up at whatever, or should I just sell them and buy some different bullets? I know they’re target bullets. But wondering how they do on coyote size animals?
Im looking forward to the rifle build. I’ve always had a fascination with the 6x45. And I like I can use range brass and not have to worry about losing it.
Does anyone have a recomendation on a mid weight bullet to use. I also need to get some faster powder. I don’t have much for lighter bullets.
Thanks for any info.

 

[JB10]

I have a 6x45 bolt rifle. Have not had a chance to take it out on coyotes but i stuck with a 58gr vmax. I did not want too Heavy to have rounds pencil through. I think it would matter what part of the country you are going to shoot. Most coyotes i shoot here in the desert are small and thin. I have tried the 224 55gr sp and two different coyotes took 2-3 more shots to put it down. I want fast expansion.

 

[SVT_Tactical]

The 58vmax would be my suggestion too. Could get speeds up to help compensate drop and should be devastating on coyotes.

 

[nastynatesfish]

I have a 6x45 bolt rifle. Have not had a chance to take it out on coyotes but i stuck with a 58gr vmax. I did not want too Heavy to have rounds pencil through. I think it would matter what part of the country you are going to shoot. Most coyotes i shoot here in the desert are small and thin. I have tried the 224 55gr sp and two different coyotes took 2-3 more shots to put it down. I want fast expansion.

I’m in souther arizona. We get some decent sized coyotes. I use the 55gr Hornady btsp bullets mostly.
I’ll have to see what I can find for the 58gr vmax. What kind of powder are you running?

 

[JB10]

I’m in souther arizona. We get some decent sized coyotes. I use the 55gr Hornady btsp bullets mostly.
I’ll have to see what I can find for the 58gr vmax. What kind of powder are you running?

W748 was what i stuck with since at the time i had the most of. It really likes N133 also. Im wanting to go to southern az this winter for coyotes. Did not get to make it there this past winter.

 

[Panzer22]

I built a 6x45 10.5in SBR about 10 years ago, got inspired by the KAC 6x35 PDW, but being a poor, I had to make the "PDW we have at home". Their version uses a 68 gr HPBT, and smokes a Mk18 10.3in ballistically, so 10 more MM of case had to be mo-bettah... and it was. Used a Bartlien 1/8 twist and 6X45 "Wylde" -ish reamer, and made a barrel. Its extremely accurate.

H322 and sierra's 70gr HPBT MK's were the most accurate, closely followed by the Hornady 87gr Vmax or HPBT, in that short barrel everything ended up around 2450-2550fps so heavier was a better idea, better BC, more energy, same speed, so why not? Another good bullet is the Speer 85 Gr SPBT, which I suspect is what you have, shoot those.

And it seems all the load data I could find I couldn't even get the max charge in an empty case, so its pretty hard to overcharge one with the 90gr and below bullets. H4895 works very well with the 80-90's. Its an awesome rd in a SBR AR. a 223 wont shoot mag length 85's at 2500... But the 6x45 will.

I have some sierra 90gr FMJ's and some Nosler 90gr Ballistic tips I never got around to trying in it I should revisit. Their other lightweight offerings look like they would be a good fit as well..

I think you are going to love the short 6X45 AR. Here is a fairly comprehensive load data set I found years ago online. Work up, etc, all the usual warnings. but gives you a good idea where to start and what powders work well.

 

[RussellJ]

I have a 6x45 bolt rifle. Have not had a chance to take it out on coyotes but i stuck with a 58gr vmax. I did not want too Heavy to have rounds pencil through. I think it would matter what part of the country you are going to shoot. Most coyotes i shoot here in the desert are small and thin. I have tried the 224 55gr sp and two different coyotes took 2-3 more shots to put it down. I want fast expansion.

I use the Sierra #1515 80 grain Varminter SP bullet in my 6x45 AR15 on coyotes. It just works!!!

 

[nastynatesfish]

W748 was what i stuck with since at the time i had the most of. It really likes N133 also. Im wanting to go to southern az this winter for coyotes. Did not get to make it there this past winter.

I’ve got a bunch of n133 I can use I was planning on trying it. You’d be god to come during the winter. Cause AZ is just preheating now…

 

[nastynatesfish]

I built a 6x45 10.5in SBR about 10 years ago, got inspired by the KAC 6x35 PDW, but being a poor, I had to make the "PDW we have at home". Their version uses a 68 gr HPBT, and smokes a Mk18 10.3in ballistically, so 10 more MM of case had to be mo-bettah... and it was. Used a Bartlien 1/8 twist and 6X45 "Wylde" -ish reamer, and made a barrel. Its extremely accurate.

H322 and sierra's 70gr HPBT MK's were the most accurate, closely followed by the Hornady 87gr Vmax or HPBT, in that short barrel everything ended up around 2450-2550fps so heavier was a better idea, better BC, more energy, same speed, so why not? Another good bullet is the Speer 85 Gr SPBT, which I suspect is what you have, shoot those.

And it seems all the load data I could find I couldn't even get the max charge in an empty case, so its pretty hard to overcharge one with the 90gr and below bullets. H4895 works very well with the 80-90's. Its an awesome rd in a SBR AR. a 223 wont shoot mag length 85's at 2500... But the 6x45 will.

I have some sierra 90gr FMJ's and some Nosler 90gr Ballistic tips I never got around to trying in it I should revisit. Their other lightweight offerings look like they would be a good fit as well..

I think you are going to love the short 6X45 AR. Here is a fairly comprehensive load data set I found years ago online. Work up, etc, all the usual warnings. but gives you a good idea where to start and what powders work well.

That was my idea on going with the 14.5”. I can get at least better better velocities that the same length 223. I’m actually taking apart one of my 14.5” 223s to do this on. I built two pretty identical minus glass. Not sure if I’ll take the middle or right one apart. Ones got the 1-8 credo the other has the 1-4 credo.

 

[rjtfroggy]

I built a 6x45 10.5in SBR about 10 years ago, got inspired by the KAC 6x35 PDW, but being a poor, I had to make the "PDW we have at home". Their version uses a 68 gr HPBT, and smokes a Mk18 10.3in ballistically, so 10 more MM of case had to be mo-bettah... and it was. Used a Bartlien 1/8 twist and 6X45 "Wylde" -ish reamer, and made a barrel. Its extremely accurate.

H322 and sierra's 70gr HPBT MK's were the most accurate, closely followed by the Hornady 87gr Vmax or HPBT, in that short barrel everything ended up around 2450-2550fps so heavier was a better idea, better BC, more energy, same speed, so why not? Another good bullet is the Speer 85 Gr SPBT, which I suspect is what you have, shoot those.

And it seems all the load data I could find I couldn't even get the max charge in an empty case, so its pretty hard to overcharge one with the 90gr and below bullets. H4895 works very well with the 80-90's. Its an awesome rd in a SBR AR. a 223 wont shoot mag length 85's at 2500... But the 6x45 will.

I have some sierra 90gr FMJ's and some Nosler 90gr Ballistic tips I never got around to trying in it I should revisit. Their other lightweight offerings look like they would be a good fit as well..

I think you are going to love the short 6X45 AR. Here is a fairly comprehensive load data set I found years ago online. Work up, etc, all the usual warnings. but gives you a good idea where to start and what powders work well.

Thank you for posting the chart. I looked at it and saw a mistake on some that I loaded for testing, and I am on my way downstairs to pull the bullets and re do (I over charged 10 rounds).
Thankfully I looked and caught my mistake. Mine are for a bolt gun but I like to stay in safe levels.

 

[JB10]

I’ve got a bunch of n133 I can use I was planning on trying it. You’d be god to come during the winter. Cause AZ is just preheating now…

Trust me i know, i live in Gilbert. Im not ready for the heat.

 

[nastynatesfish]

Yeah. You guys get it bad. I’m in Safford. Almost to New Mexico

 

[5spd]

I've built several 6x45s on ar15s and savage actions.
18" to 22".
Not a fan of 16" or less bbls.
Pdog, coyote loads with 55 vamageddon, 58vm, 65vm bullets, deer antelope 80, 85g speer, sierra bullets
H335 and Xterminator powders are your friend in the 6x45.

 

[nastynatesfish]

I've built several 6x45s on ar15s and savage actions.
18" to 22".
Not a fan of 16" or less bbls.
Pdog, coyote loads with 55 vamageddon, 58vm, 65vm bullets, deer antelope 80, 85g speer, sierra bullets
H335 and Xterminator powders are your friend in the 6x45.

I’m kinda a vihtavouri fan. How about n120/130/133? I’ve got n133 already. I was planning on that to start. Then look for with h332 or h4198

 

[5spd]

I’m kinda a vihtavouri fan. How about n120/130/133? I’ve got n133 already. I was planning on that to start. Then look for with h332 or h4198

V133, h332 I've used in my 24" .223 pdog rig & ar15s, good powders and bet they will be as good in the 6x45.
I've not used them in the 6x45 myself though.

 

[SecondsCount]

@lb-ft

 

[rjtfroggy]

As I stated I went back and checked the rounds that I thought were over, but much to my surprise I did not have an age related "brain fart" and all was well within limits.(self imposed).