6×45 thoughts

[AWS]

If you want to save pelts stick with your 223, I use a 222 Rem for most of my pelt hunting and it does just fine. My goto rifle from 1966 to 1996 for control work was a Rem 600 in 223, PacNor rebarreled it to 6x45 and it just comes out for punching paper or some off season control work.

Even light bullets it is hard on fur if you get anywhere near the edges and a much higher chance of big exits. The only two bullets I've had any luck with for saving fur is the 58gr V-max and the 55gr Nosler Lead-Free and then it is iffy. The flatbase 52gr Speer HP in the 223 is an awesome pelt hunting bullet, I use it in the 222 Rem, 223 Rem, and 5.6x50R Mag.

Now if you just WANT a 6x45 go for it, it is a very accurate and easy wildcat to work with.

 

[RussellJ]

I have been looking at this caliber and was thinking about building one for coyotes. What is your experience with it and is it worth it over a 223 for under 300 yard shots. My plan was just a used 223 savage a d swap the barrel out. I have a 6mm creedmoor that works but with the 108 eld i use really messes them up. Was thinking about a slower twist to shoot the lighter bullets for less pelt damage

I have a Pac-Nor barreled 10 twist, Pac-Nor trued 700 Remington 6 x 45mm rifle. Shooting 80-grain Nosler Ballistic Tip bullets right at 3000fps. Extremely accurate rifle with 27grn of IMR 8208XBR powder.

 

[nativecat01]

I have an A.R. 15 with a shilen Wlth 1/8 a twist barrel It is very accurate are you 70 grain ballistic tip on prarie dogs I can easily hit a dog out to 400 yds I have taken the 85 grain Sierra’s out past 800yds on steel. It has to be very calm and really need to listen to shoot 800. The 85gr would probably be best for coyotes

 

[AckleymanII]

Food for thought, 6-204 Ruger, has 30* shoulder

easy 204 die conversion

60g Sierra HP does not mess up pelts

Feeding issues will NOT exist with a 6-204 Ruger

JGS has the reamer print for lighter bullets

 

[JB10]

Looks like i got some thinkin to do on what one. If anything ill have another fun target rifle!!

 

[Oso]

6x45AI = 6TCU ... effectively the same.

I have an 6x45AI. One other idea if you are looking for more velocity then consider a 6mm Grendel (aka 6mmAR)

 

[Bc'z]

6x45AI = 6TCU ... effectively the same.

I have an 6x45AI. One other idea if you are looking for more velocity then consider a 6mm Grendel (aka 6mmAR)

Did you go with a 223AI bushing die for sizing? I found Forster has a competition seater.
I'm asking because I'll probably go to improved after this barrel is done.

 

[Oso]

Did you go with a 223AI bushing die for sizing? I found Forster has a competition seater.
I'm asking because I'll probably go to improved after this barrel is done.

I had a custom reamer made and then a set of custom dies. It was a project of love for a vintage Sako, and my first real step into wildcatting. I over-thought the process and spent a lot of time doing studies of changes to case dimensions. A lot of work and money for minimal change. If I were to do it again then I would probably go with 6TCU for its standardized reamer and dies... keep it simple.

 

[Oso]

Did you go with a 223AI bushing die for sizing? I found Forster has a competition seater.
I'm asking because I'll probably go to improved after this barrel is done.

If you are wanting to max velocity &/or shoot heavy bullets then the 6mm Grendel (aka 6mm AR) is the best answer with an additional 5gr powder capacity over a 223AI case. I believe the 6mm Grendel beats out the 6mm-204 by a couple of grains of powder. Unlike the 204 case, the Gendel has the ability still fit inside standard magazine length AR and short mini-mausier actions (Sako, CZ 527, mini-Howa) with heavy bullets (long) without giving up case capacity, compressing loads, or spiking pressure as much as would be required in a .204 case.

Any way you choose, you'll have a fine rifle that will get the job done.

 

[1lnbrdg]

6X45 Shooting a lot of I-8208 95gr Sierra HPBT ~2900fps in a Bolt Gun 30" 1/8 twist barrel but they also shot well in a 1/10 twist also though that's not fast enough per Sierra. Shoots Darn Good at 600 yds.

 

[AndyTaber]

I shoot a 6x45 primarily for 300 yard competition. I do prefer it to the .223 and find it more accurate. After necking up the parent case I wonder how much there is to gain with the ackley improved shoulder. There really isn’t much shoulder left that the small change in shoulder angle would provide much benefit, or it seems so to me.

 

[centershot]

I have a 6 TCU and love it for prairie dogs. 9 twist. 80 grain bullets at 3,000 fps. Very efficient cartridge.

 

[Oso]

I shoot a 6x45 primarily for 300 yard competition. I do prefer it to the .223 and find it more accurate. After necking up the parent case I wonder how much there is to gain with the ackley improved shoulder. There really isn’t much shoulder left that the small change in shoulder angle would provide much benefit, or it seems so to me.

The answer is you gain 100-150 fps from increased case volume for powder.

The downside to the AI transformation is the shortening of the case neck as brass is used/redistributed to the case body expansion and blowing forward the shoulder. It would be great if you could actually find long .223 cases (1.76") to use for fire forming so that the end result for fully formed .223AI around 1.75" COAL. Unfortunately, most .223 cases are between 1.750" - 1.755"... and Lapua is a consistent 1.750". The end result is a 223AI with the COAL being closer to a 1.740" give or take a couple thousandths.

 

[Bc'z]

The answer is you gain 100-150 fps from increased case volume for powder.

The downside to the AI transformation is the shortening of the case neck as brass is used/redistributed to the case body expansion and blowing forward the shoulder. It would be great if you could actually find long .223 cases (1.76") to use for fire forming so that the end result for fully formed .223AI around 1.75" COAL. Unfortunately, most .223 cases are between 1.750" - 1.755"... and Lapua is a consistent 1.750". The end result is a 223AI with the COAL being closer to a 1.740" give or take a couple thousandths.

That's a lil tid bit of advice worth alot of saved frustration.
Now I know to start with 556x45 brass vs 223 to overcome the short case.
Thanks

 

[Oso]

That's a lil tid bit of advice worth alot of saved frustration.
Now I know to start with 556x45 brass vs 223 to overcome the short case.
Thanks

The only concern is making certain that you will achieve a crush fit when chambering the cartridge for fire forming. You will feel this as you close your bolt and experience a bit of resistance. During fire-forming process the junction point of neck and shoulder should make contact with the AI chamber creating a "seal". This seal does two things: (1) with an unformed 223 case in the AI chamber the neck/shoulder junction is sole point of contact to hold case in place so that it will be able to receive the force of the firing pin strike; (2) the seal prohibits gas from firing the case to escape backwards around the outside of the case. If you don't get a crush fit then (1) cartridge is not likely to fire as the firing pin strikes the primer the cartridge is simply pushed forward further into the chamber (light strike) and (2) if it by chance does fire then the case will not fully fire-form to chamber because some of the gas that has escaped backwards will counteract the pressure on the inside of case.

Word of caution - not all factory ammo is made to spec. By this I mean that it has become quite common for the shoulder position on factory ammo to be pushed back/short to ensure reliable feeding in any and every rifle...and moreover AR15. Don't invest heavy in factory ammo that you plan to use to fire-form into AI until you've test out a box to see if it will crush fit in your rifle. I went through a half dozen different flavors of major brands before I came to realize that only the Match Ammo was held to specs...this is also the most expensive of the ammo.

If you plan to use reloads then make certain to back off your resizing die, which if setup properly is currently bumping back the shoulder by 1-2 thousands or as much as 3-4 thousands for AR15's.

 

[SDWhirlwind]

I have had trouble with fire forming into the 6TCU. Seemed new Win 223 brass worked a bit better than new Rem but my problem is separating about 1/2" forward of extractor groove after 3-4 firings. Guessing they are not against bolt face tight enough? Even seat bullet out long to help. I also made an expander from a new RCBS decapping pin which is .250 diameter and I neck up the new 223 case with it using the RCBS primer crimp removal die with the furnished rod replaced with this tapered rod. I then run case into the 6TCU die just until it will chamber and then fire form. Better results but still rather short lived brass with usually only 4-5 firings and I neck size.

I know 222mag brass is hard to get nowdays and expensive but curious if anyone has ever given that a go or not? Also I wonder what length the Starline 223 basic is?

 

[Bc'z]

I have had trouble with fire forming into the 6TCU. Seemed new Win 223 brass worked a bit better than new Rem but my problem is separating about 1/2" forward of extractor groove after 3-4 firings. Guessing they are not against bolt face tight enough? Even seat bullet out long to help. I also made an expander from a new RCBS decapping pin which is .250 diameter and I neck up the new 223 case with it using the RCBS primer crimp removal die with the furnished rod replaced with this tapered rod. I then run case into the 6TCU die just until it will chamber and then fire form. Better results but still rather short lived brass with usually only 4-5 firings and I neck size.

I know 222mag brass is hard to get nowdays and expensive but curious if anyone has ever given that a go or not? Also I wonder what length the Starline 223 basic is?

I was also thinking of creating a false shoulder for the FF process.
As for Starline 223 brass, quality is there in all regards except length.
I bought 1000 pieces a couple years ago was getting it prepped to run on my dillon with a lee crimp in last position.
To keep a consistent crimp I sorted into batches by length and trimmed for uniformity. Just my experience of course.
My vote is to start with new lake city 556, or once fired.

 

[Oso]

I have had trouble with fire forming into the 6TCU. Seemed new Win 223 brass worked a bit better than new Rem but my problem is separating about 1/2" forward of extractor groove after 3-4 firings. Guessing they are not against bolt face tight enough? Even seat bullet out long to help. I also made an expander from a new RCBS decapping pin which is .250 diameter and I neck up the new 223 case with it using the RCBS primer crimp removal die with the furnished rod replaced with this tapered rod. I then run case into the 6TCU die just until it will chamber and then fire form. Better results but still rather short lived brass with usually only 4-5 firings and I neck size.

I know 222mag brass is hard to get nowdays and expensive but curious if anyone has ever given that a go or not? Also I wonder what length the Starline 223 basic is?

I hadn't heard of anyone having this issue with the 6TCU, which should fire-form same as AI. Perhaps you have a slightly longer chamber. Have you considered trying the 80% Fire-forming Method (aka Cream of Wheat method / Cornmeal)? Its an extra step, but I believe that it would significantly reduce the chances of case separation.

Cut a .223 cleaning patch in half down the length...should now have 2 pieces. You will use the two pieces to form a (1) divider between power and CofW/Cornmeal, and also as a (2) plug in neck of case to keep CoW/Cornmeal from spilling out of case. Fold each 1/2 sheet in half (now size of quarter sheet) and place one in case while keeping it vertical so the powder stays centered at bottom of case in front of primer hole. Use a dowel or cheap round chopstick to push the patch toward the bottom of case, but don't force it hard to bottom or else it will displace the powder. Use a powder funnel and drop the filler (buy a container of generic plain cornmeal) into case and loosely fill it all the way to top of case neck. Insert the other half of cleaning patch (again folded over to form a 1/4 sheet size) and lightly tamp it down into case until the patch sits at base of neck/shoulder. Don't shoot this off in the house/garage or in backyard unless you are somewhere that permits firing of a handgun...it is that loud. Before inserting each cartridge into your rifle, wipe around the neck and should of case to make certain no spilled cornmeal, and you might need to use the chopstick if the patch has started to unfold or shift in the case neck. Also, bring along a can of compressed air (keyboard cleaner) to quickly blow out any debris/residue that might get left in chamber from burnt patch or cornmeal. Blow out chamber after each fire-forming shot. Inspect the newly formed 80% case to see if there are any indentations on or other surface irregularities...including any funny ring circumnavigating the case near the case web (sign of case separation). If there are any unusual marks around the shoulder or case neck then this is result of debris stuck to side of chamber or throat. Blow out and if continues then run cleaning brush and patch with jag through barrel a few times. With the aid of the Compressed Air, I only needed to clean my barrel after 75-100 case formings.

 

[AckleymanII]

The 223 AI does not feed well from most standard magazines, I can only guess that the 6 TCU will be the same feeding problems from a Rem 700 magazine?

I really do not want to spend the money on AIC Detachable magazine bottom metal, inletting for such, and magazines

6mm 204 ruger is dumb butt simple, no forming other than necking up, easy 204 die mods.

 

[rmr]

I've shot a 6TCU for 15+ years on PD's. gun is a std 700SA, BDL bottom metal and std magazine internals. Action was blueprinted / Krieger bbl. with a 58G bullet, seated as far out as possible (to jam), it feeds fine. it is also one of the most accurate rifles I've ever owned: when new it was running in the teens. with at least 6k rounds downrange, it still runs 1/4" - 3/8" I'm also still using the original batch of brass (winchester), i started with 500rds, i have something like 375rds left, lost primarily to sailing over the edge of the truck bed on afternoon PD feeding frenzies...