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6x45AI ??

bighornbob

Gold $$ Contributor
Does any one know if this has been done? I have not seen it on any forum. I have a great 6x45 and love it.
I’m looking at a 6x47 but I think the AI conversion to my 6x45 would be very close to the same velocities

Bob
 
You may want to clarify which 6x47 you are talking about. By the context of your post I am assuming you are talking about the old 6x222 Remington mag. Which I have just built one on a Ruger number one but I have not fired it so I do not have any information on it yet. I would agree that the 6x222 mag would be about the same velocity as the 6x45 AI. Pretty close anyway. BUT you could always AI the mag case !!.;):)
 
The 6mm-204 will do the same thing with no fire forming, pretty simple wildcat. I built one in 2006 and used it for control work and competition coyote hunts. The 204 case has slightly more capacity than the 223AI, think of it as a 222 Rem Mag Improved 30 degree and will feed very nicely.

I use a 204 Ruger FL Bushing die with the gut removed and add the correct bushing and a spindle for a 223 with a tapered 6mm expander ball. The Hornady 243 Seater with the sliding sleeve works perfect for seating.

I built mine on a Savage action and ordered a 6x47 Rem prefit barrel as the neck and throat were already in the correct place and and just opened the chamber with my 22-204 reamer with a 6mm pilot on it.
 
Yes I am referring to the 6/222mag as my 6x47.
The AI conversion to my 6x45 would be the most cost effective due to the amount of 6x45 ammo I have loaded.
I am doing load development in my 6x45 this weekend using heavier bullets 70-80gr I do not know what twist rate my barrel is, either. I will measure the twist rate tonight before loading too heavy of bullets
Bob
 
I've built one. 12 twist McGowan barrel on Howa 1500. Running 60 gr Sierra's @ 3550. Bad medicine for coyotes. Also have a 6x204. They run really close.
 
I had a reamer made for a 6x204 throated for the heavy's, 95gr SMK's and its a great cartridge. I was in the same boat thinking of doing a 6x45 and then figured I would AI it but then stared looking at the 6x47 and then thought about improving that. After looking at the .204 case it is basically a 222 mag Improved as stated above and the brass is easier to find that 222mag brass. Plus there are no special dies needed, I just used a 204 bushing die with a 6mm bushing and used a 204 Forster Micro seater with the seating stem changed. it shoots the 90gr TGK's nice too along with the 87gr VMAX. It also shoots the Badlands Bulldozer 80 gr monos lights out! I have a 28" 8 twist Kreiger LT palma.
 
6-223AI, 6tcu, 6x45AI. I don't know if there is any real difference in them but I have a 6-223AI currently and have had a 6tcu in the past.

It's a killer little round. Probably the best wildcat based on the 223 case.
 
6x223AI , 6x45AI, 6TCU are approximately the same. The big difference is that there is a standardized reamer for the 6TCU and there are factory dies. Otherwise, case capacity is near identical depending upon where you get the reamer. All of them are formed from .223/5.56 brass. Fireforming is easy.

I mocked up a 6x45AI and had a custom reamer and dies made. This was an expensive path that was unnecessary... at the time I didn't know about the 6TCU.

Do yourself a favor and don't go recreating the wheel.
 
I loaded 68gr, 75gr and 80gr test loads tonight. I will know more Sunday morning at the range.
I am going to look at the 6TCU vs 6x45AI. It depends on the reamer availability.

Bob
 
6x45 dies are available
223AI dies are available
6TCU dies are available

no 6x45AI dies
... so are you planning on using a 223AI Bushing Die with a 6mm neck bushing?
Somthing to keep in mind is that the 223AI is not SAAMI, and nowadays there is chambering variation by how much the gunsmith cuts/setting back the barrel for the AI chamber. The traditional setback (PO Ackley) is becoming less popular as gunsmiths are making adjustments (setting back deeper... shorter chamber) in response to current factory ammunition, which is being loaded short to very short in order to ensure 100% reliable extraction out of every AR15. Off the shelf ammo even by same manufacturer and same headstamp cases may vary in length to the shoulder (key measurement for crush fit for fire-forming) by as little as .004" and as much as .015". I learned this the hard way with a PO Ackley setback...+50% of all factory ammo failed to fire (light primer strikes) because the location of the shoulder was too far back/short to properly form a crush fit shoulder. I gave up on using factory ammo and had to shift entirely to new virgin brass (LC) and load my initial cases for fire-forming.

If you go with the 6TCU you know that the reamer and dies will match.
 
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It seems like most 6TCU's have a really long throat since they are generally TC contenders. Just something to consider when getting a reamer.

I use a combination of 6TCUand 223AI dies for loading my 6-223AI. It's a killing rifle not a benchrest rifle in my case.
 
Oso said:
6x45 dies are available
223AI dies are available
6TCU dies are available

no 6x24AI dies
... so are you planning on using a 223AI Bushing Die with a 6mm neck bushing?
Somthing to keep in mind is that the 223AI is not SAAMI, and nowadays there is chambering variation by how much the gunsmith cuts/setting back the barrel for the AI chamber. The traditional setback (PO Ackley) is becoming less popular as gunsmiths are making adjustments (setting back deeper... shorter chamber) in response to current factory ammunition, which is being loaded short to very short in order to ensure 100% reliable extraction out of every AR15. Off the shelf ammo even by same manufacturer and same headstamp cases may vary in length to the shoulder (key measurement for crush fit for fire-forming) by as little as .004" and as much as .015". I learned this the hard way with a PO Ackley setback...+50% of all factory ammo failed to fire (light primer strikes) because the location of the shoulder was too far back/short to properly form a crush fit shoulder. I gave up on using factory brass and had to shift entirely to new virgin brass (LC) and load my initial cases for fire-forming.

If you go with the 6TCU you know that the reamer and dies will match.
Click to expand...
Great information. Thanks
 
dk17hmr said:
It seems like most 6TCU's have a really long throat since they are generally TC contenders. Just something to consider when getting a reamer.

I use a combination of 6TCUand 223AI dies for loading my 6-223AI. It's a killing rifle not a benchrest rifle in my case.
Click to expand...
Mine is hunting build also. Missed coyote this am he came in so close I couldn’t find him in my 6x lowest setting on my scope. It has 3-10 Nightforce on it now.
 
A 223a reamer made to a 6mm neck. Set freebore to bullet.

Use 223a sizing die just change the bushing. Use 223a seater.

223 headspace gauge. Set headspace to zero or even a bit more.

Seems pretty simple to me.
 
I HAVE A 6TCU REM 700 1/8 HART BARREL 26'' THIS IS A AMAZING LITTLE ROUND I USE H-335 FOR VARMINTS I SHOOT 75GR V-MAX DEADLY FOR DEER I SHOOT 85GR SIERRA 1530 BTHP AND ITS A SHOW STOPPER OUT TO 300YDS I LOVE THIS LITTLE BUGGER
 

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Just look at the reamer print. I think TC throated a majority of their barrels to keep pressures down. I have had a pile of them over the years. Once in a while you may find one with a decent throat. A lot of times they shot no better than the others.

Barreled up a little rifle in 6TCU. Zero freebore, fed a steady diet of AA2200,H335 and 55-80 grain bullets.
 
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