6ARC

[665.0coupe]

I’ve heard of guys running 50 grains in .243. What exactly is the goal here? Bragging rights?

Coyote hunters still was fast flat shooting light bullet weight stuff. PRS type guys are loading for lower velocities with heavy bullets for reduced recoil and a little more flight time to help spot shots.

 

[Aisin]

Seems like .22-250 is perfect for that.

 

[665.0coupe]

Seems like .22-250 is perfect for that.

For coyotes or PRS?

 

[Aisin]

For coyotes or PRS?

I know its good for coyotes

 

[Chevy_man]

I’ve heard of guys running 50 grains in .243. What exactly is the goal here? Bragging rights?

Pretty much. At 1000+ it can make up a few yards error, but not all that much. The one nice thing about shooting a 6mm with a higher bc bullet that far, is a call that would miss with a 308 can still hit.

It's also handy that nobody can "borrow" some ammo.

 

[[486]]

Seems like .22-250 is perfect for that.

that was my thought re: 224 valk, but then remember the hype is all about it fitting into stanag magwells
same with .243win/6mmarc
pay a little more, deal with less component availability, etc, but it's cooler

I'm enough of a cheapass jerkoff that I gotta ask
why not start with something .308 based, in a long action bolt gun, start out with a shorter case like 35mm or so
then as the throat gets burnt run your reamer a li'l deeper in there until eventually after several iterations you're using '06 cases
at that point set the barrel back in the action to start over again

or is the barrel's accuracy potential at higher round counts not only in the throat?

 

[665.0coupe]

that was my thought re: 224 valk, but then remember the hype is all about it fitting into stanag magwells
same with .243win/6mmarc
pay a little more, deal with less component availability, etc, but it's cooler

I'm enough of a cheapass jerkoff that I gotta ask
why not start with something .308 based, in a long action bolt gun, start out with a shorter case like 35mm or so
then as the throat gets burnt run your reamer a li'l deeper in there until eventually after several iterations you're using '06 cases
at that point set the barrel back in the action to start over again

or is the barrel's accuracy potential at higher round counts not only in the throat?

I think that would be the opposite of the cheapass way to do it. Every time you re-cut the chamber to a new cartridge then you have to start with different brass and dies. Then you are on to working up a new load and new dope. Not to mention potential magazine changes or messing with the mags to get them to feed every new cartridge.

I've never rechambered a barrel, but I think generally guys cut the tenon off and set the barrel back one time and then the lands are wore out enough that it's not worth it after that.

 

[[486]]

I think that would be the opposite of the cheapass way to do it. Every time you re-cut the chamber to a new cartridge then you have to start with different brass and dies. Then you are on to working up a new load and new dope. Not to mention potential magazine changes or messing with the mags to get them to feed every new cartridge.

I've never rechambered a barrel, but I think generally guys cut the tenon off and set the barrel back one time and then the lands are wore out enough that it's not worth it after that.

I kinda figured on halfassing the die set, using the short dies to size the shoulder for fireforming, then only neck size from there, make it basically straight walled behind the shoulder so you'd use the same reamer for all of them, use one of them lee push-through bullet sizer dies to size the base of the cases if they started getting hard to chamber, etc...

Last bit there has the info I needed to crush the idea before it wasted my time though.

 

[665.0coupe]

I kinda figured on halfassing the die set, using the short dies to size the shoulder for fireforming, then only neck size from there, make it basically straight walled behind the shoulder so you'd use the same reamer for all of them, use one of them lee push-through bullet sizer dies to size the base of the cases if they started getting hard to chamber, etc...

Last bit there has the info I needed to crush the idea before it wasted my time though.

Oh, you are talking about basically the same cartridge but the body gets longer every time you rechamber. I assumed you were talking about starting with something like 6br then going to 243 then to 6mm-06.

 

[Roc Doc]

Well I've been having some problems with it cycling reliably, but finally took two buffers, two BCG's and found the combo that works best, (after adjusting the gas block. I'll shoot it at the gas gun match on the 23rd.

 

[Roc Doc]

Well I sized the Lapua Grendel brass using a RCBS small base die, then following it up with a mandrel for final neck tension, and trimmed for excess neck length. Shot 60 something rounds yesterday after dialing the gas block back to factory setting, and adding an Omega 300 on the end. It cycled just fine, but accuracy went from under 1" at 100 to just over 2". Brass came out dirty of course, but they all had a "stripe" around mid case, so I'll process these with the bushing die, and with the same load see if it tightens up. I didn't think I'd need to fireform with all the steps I took, but maybe so.

 

[Lincoln]

For accuracy I would think you need to. I also would bet you need to work up a new load. Did you check the speed between the old cases and new? With the others (6AR and the rats) they say just size and shoot, figure out accuracy using the fire formed cases.

Not liking the Hornady brass?

I still would like to build a 6mm Fat Rat. Basically an ackley version of the 6 AR, 6 ARC, or 6 Rat. It adds a few hundred fps. But I’ve been buying for kids and a friend sold me an unfinished 7x300 wsm that took funds.

 

[Roc Doc]

For accuracy I would think you need to. I also would bet you need to work up a new load. Did you check the speed between the old cases and new? With the others (6AR and the rats) they say just size and shoot, figure out accuracy using the fire formed cases.

Not liking the Hornady brass?

I still would like to build a 6mm Fat Rat. Basically an ackley version of the 6 AR, 6 ARC, or 6 Rat. It adds a few hundred fps. But I’ve been buying for kids and a friend sold me an unfinished 7x300 wsm that took funds.

Yeah, so many variables. I will take these cases and work up a load. I think the case volume of rhe Lapua brass is probably smaller, but the fired cases showed zero signs of over pressure so I don't think thats a problem with 28.9g of LeverRevolution.

 

[Lincoln]

They might be running a little faster and it’s not what the gun likes. But I wouldn’t worry about it until the second load on the cases. I’m guessing you can see a more defined shoulder after the first firing. Might even see the shoulder move.

On my 243 Ackley I need to seat the bullet against the lands on the first load. The headspace is a little on the loose side and it has a tendency to not fire a good shoulder.

 

[Roc Doc]

They might be running a little faster and it’s not what the gun likes. But I wouldn’t worry about it until the second load on the cases. I’m guessing you can see a more defined shoulder after the first firing. Might even see the shoulder move.

On my 243 Ackley I need to seat the bullet against the lands on the first load. The headspace is a little on the loose side and it has a tendency to not fire a good shoulder.

I've got these loaded to mag length, and they're 105's so pretty long. It looks like I've got some stuff to adjust. I didn't want to do load developement till I had at least fired the cases, and yeah they probably do have a little less capacity than the Hornady, thicker brass and all that.

 

[Lincoln]

curious on how far off or into the lands you are. Bergers seem to like to be jammed in the lands (vld) and a hot load. Ive always had good luck with amax’s and match kings a couple thousandths off and accuracy was a little below published max.

You are most likely just seeing a fire forming and harmonics change. i would bet the sweet spot is +-0.3 grains from what you found on the hornady brass.

not sure how you got to your load but I have almost always found a spot by watching for a small group and then pushing it up in small increment. The group will open up some and then snap tight. Like it’s fooling you. Then push a little more until it opens up again. Load for the middle of that, usually that gives you a +-tenth where it really doesn’t matter. Unless you are shooting benchrest you won’t see the difference.

That said I was never better than a 1/2 minute shooter under normal shooting. Prone on a bipod. Since I spend more time letting kids shoot that’s probably 3/4 or worse now. As I’ve matured I pretty much quit if I get a 1/2 minute group and go shooting,

I was at a friends prs course and it took me close to 30 rounds to hit a 24” ram at 1200 yards. A little wind but I think the tears of disappointment was the problem.

 

[Roc Doc]

Yeah it's science, but its also voodoo. This is a gas gun so leans more towards voodoo. I'll do a loctite test after I resize this fired Lapua brass to see where the lands are, cause right now ive no idea, nor do I have velocity info, just was surprised at the jump in group size.

We'll see.

 

[Lincoln]

Curious on what you find out. I’ll have to look into the loctite test. I’ve always split a neck and smoked them.

A friend once switched from winchester to Norma brass to get more consistent brass. It moved his point of impact 1/2 moa. No other change. He was pissed and depressed. Lol

If you are shooting some volume annealing the brass will help you get some life, Also even on my AR‘s I keep the brass per gun and just bump the shoulder a thou or two for a reliable feed. That helps too. With the sharper shoulder of the ARC you may need to go .003-.004 bump. I don’t neck size only or full length anything but pistol.

 

[Roc Doc]

Curious on what you find out. I’ll have to look into the loctite test. I’ve always split a neck and smoked them.

A friend once switched from winchester to Norma brass to get more consistent brass. It moved his point of impact 1/2 moa. No other change. He was pissed and depressed. Lol

If you are shooting some volume annealing the brass will help you get some life, Also even on my AR‘s I keep the brass per gun and just bump the shoulder a thou or two for a reliable feed. That helps too. With the sharper shoulder of the ARC you may need to go .003-.004 bump. I don’t neck size only or full length anything but pistol.

I use an AMP annealer every time, (except this first time as they're factory annealed). Using the Whidden micrometer case gauges, and some fired Hornady cases as reference to set shoulder position, (set back .004 from fired).

 

[Lincoln]

How may loads are you getting on the hornady cases? I would expect 8-10 unless the pressure is really high. Even then I would expect 5 or so.

 

[Roc Doc]

How may loads are you getting on the hornady cases? I would expect 8-10 unless the pressure is really high. Even then I would expect 5 or so.

The internet experts all complain that all Hornady brass is shit, but I've got well over 1k pieces of 6.5 CM that has been fine, not super consistent like Lapua, but not falling apart like some dudes claim. I didn't run it over pressure but towards the top of the range like I do all my loads as that's where the consistency seems to be. Anyway the 6 ARC necks got beat up on ejection in the gas gun, so I put a square of velcro on the deflector which fixed that, but I was still seeing some split necks and a couple loose primer pockets after 3 or so firings, which led me to go the Lapua conversion route...which is is first for me. So it's a journey.

 

[Lincoln]

I would switch too. But would probably use it up anyway. The main reason I asked is right now Hornady is available but I haven’t used it. Most of the internet bitches about Winchester brass and I have used a bunch of it. People get into what benchrest is doing and that’s more applicable when you measure groups in the hundredths or thousandth.

Lapua is generally a better brass and a preference, not required, of mine. I think you will be happier. Once you get the load sorted out I would try just a one step size and shooting a couple. From what I read about the wildcats that preceded the ARC accuracy was still good.

My gas guns are more standard and I have been using Lake City. It’s been holding up well. I got my kid a Howa mini action 223 and I’m trying to decide if I’ll use different brass for it just to make them easier to keep track of.

Your experience sounds like mine. Upper end but normally under most published max. You may find it’s different with the Berger. If they don’t shoot as good I would be tempted to mess with the seating depth some before getting too excited with the load.

 

[Roc Doc]

I would switch too. But would probably use it up anyway. The main reason I asked is right now Hornady is available but I haven’t used it. Most of the internet bitches about Winchester brass and I have used a bunch of it. People get into what benchrest is doing and that’s more applicable when you measure groups in the hundredths or thousandth.

Lapua is generally a better brass and a preference, not required, of mine. I think you will be happier. Once you get the load sorted out I would try just a one step size and shooting a couple. From what I read about the wildcats that preceded the ARC accuracy was still good.

My gas guns are more standard and I have been using Lake City. It’s been holding up well. I got my kid a Howa mini action 223 and I’m trying to decide if I’ll use different brass for it just to make them easier to keep track of.

Your experience sounds like mine. Upper end but normally under most published max. You may find it’s different with the Berger. If they don’t shoot as good I would be tempted to mess with the seating depth some before getting too excited with the load.

Back when ammo was cheap, SGA was selling 600 round cases of Lapua 55g .223 ammo for $287, so I bought two. I shot it up in practice and general blasting as it wasn't that good at long range, but now I have 1200 pieces of Lapua Brass, did the same thing with my 6.5CM when that Berger ammo was decently priced, so the only caliber I don't have good brass for is the 6GT, but so far haven't had any real issues with the Hornady in either my Open or Production rifle.

As far as different brass goes, I do the same thing. The Lapua goes in my 20" AR, and I use Privi Partisan for my 24...and two different dies as well, but considering the SAC modular die and just changing the shims if necessary.

 

[[486]]

Never done the precision reloading thing before, but I was just weighing 40 pieces of hornaday .223 brass I picked up (so it might be two lot numbers or whatever) but they were all over the place, like 3 grains of spread in the weight of the cases, two of them were 7-8 grains off the rest, so I tossed them in with the mixed blasting ammo shit

That kinda shit normal? Does it matter at all? I figure the weight is representative of the relative case capacity...

 

[665.0coupe]

Never done the precision reloading thing before, but I was just weighing 40 pieces of hornaday .223 brass I picked up (so it might be two lot numbers or whatever) but they were all over the place, like 3 grains of spread in the weight of the cases, two of them were 7-8 grains off the rest, so I tossed them in with the mixed blasting ammo shit

That kinda shit normal? Does it matter at all? I figure the weight is representative of the relative case capacity...

Some people say it matters. Something like Lapua brass might be more constant, but I don't know. I've never weighed a case. I know quite a few good PRS shooters and a husband/wife that have shot for team USA in benchrest/f-class type stuff. I don't know if any of them weighs cases, or bullets for that matter.

Getting standard deviations for velocity under 10 is the standard and it's not hard without weighing cases. The people I know will say that constant seating depth and neck tension has a larger effect on SD's than powder charge constancy.

 

[Lincoln]

Some people say it matters. Something like Lapua brass might be more constant, but I don't know. I've never weighed a case. I know quite a few good PRS shooters and a husband/wife that have shot for team USA in benchrest/f-class type stuff. I don't know if any of them weighs cases, or bullets for that matter.

Getting standard deviations for velocity under 10 is the standard and it's not hard without weighing cases. The people I know will say that constant seating depth and neck tension has a larger effect on SD's than powder charge constancy.

Think of capacity as a percentage. Big time F class shooters need minuscule advantages. For the rest of us it matters less. Most of our guns wouldn’t make the first couple tears of F class no matter what we do.

For @[486] I would just try them. Some guns would have a little vertical spread and some would shoot about as well as they ever do. I typically don’t bother weighing brass or care. I said above I normally shoot 1/2 moa on a good day. Most of the cool stuff doesn’t matter under that. I found powder and bullets can get that. Not always the logical choice either,

 

[[486]]

So y'all're saying I could probably get shit printing a reasonably consistent half inch group at 100 with the totally mixed and untrimmed range brass that 'drunken bumble bullets™' are made outta? :p
I can't even shoot that good, gonna be doing some learning.

Enjoying watching the saga of fancy wildcat loading for self-spotting whiz bang competition stuff.

 

[Roc Doc]

That kinda shit normal? Does it matter at all? I figure the weight is representative of the relative case capacity...

It is, and it isn't. The best way is to put a plug in the primer pocket and weigh the case, then fill the case with water and weigh it again, that will tell you the actual case capacity, but weight alone won't because one case could be heavier in the base external of the interior volume. But I'm damn sure not going through all that monkey-motion for shooting at MOA+ targets.

 

[[486]]

It is, and it isn't. The best way is to put a plug in the primer pocket and weigh the case, then fill the case with water and weigh it again, that will tell you the actual case capacity, but weight alone won't because one case could be heavier in the base external of the interior volume. But I'm damn sure not going through all that monkey-motion for shooting at MOA+ targets.

Huh yeah, doesn't take a lot of extractor groove variation to make up a couple grains worth of brass...

 

[Roc Doc]

These guys are getting 3150fps from a 20" bolt gun, and 3275 from a 22 with 70g Blitzkings and Noslers. Maybe, but I'd have to see it myself.