I'm just about to load my first rifle rounds...

[WillEver]

I finished putting together my first non-AR centerfire rifle, and I'm about to load my first rounds. I've loaded pistol ammo for years, so I'm not exactly new to this. And I've got a good handle on the process once I have fired brass.

But I'm loading fireforming rounds for 6 BRA with Lapua 6BR brass. Just handling the brass and bullets, it feels like I could almost jam one down in there by hand.

Do you typically run an expander through new brass before loading? I've got a Sinclair expander die and .241 mandrel. Lube the inside of the necks and run the mandrel through before the first firing?

Anything else I need to do differently because I'm fireforming? Lube, expand (or not), tumble, prime, charge, seat a bullet and let fly?

 

[RegionRat]

Sometimes, virgin brass necks can be out of round and dented due to shipping damage and handling when packed loose...

Even some of the newer ones that come in individual packaging can be out of round or dented, so I will typically mandrel before I chamfer.
I have friends who just load them as is, but they are only fire forming and don't care how this cycle shoots.

I use lube any time a mandrel goes into a neck. I also chamfer, then dry tumble to remove the lube, and if I am being picky (like running the fire form during a match) I also brush the neck with graphite.

With some care in the loading, there is no reason a fireforming shot cannot be good enough for club matches.

So, if for no other reason than to round them out or detect ones that are way out of round, an undersized mandrel is a way of checking their initial diameter as well as detecting ones that are damaged.

Many folks will also chamfer the ID and check initial virgin case length. I will assume this is for a No-Turn neck and you will use the brass as-is. I prefer to wait till after the first cycle to trim.

As far as seating force, it should be enough to make sure you get primer ignition. It will take a little trial and error to minimize the abuse of the bolt lugs, but at the same time getting a good ignition.

The bullets shouldn't slide with fingertip forces, but there is also no reason to go crazy.

Having a full set of gage pins or mandrels to measure the neck ID is nice. Having a way of measuring seating force is also nice, but not necessary.

With designs like Dasher, the new neck-shoulder junction can be done with a false neck, jam, or both combined.
With BRA, you can probably get away with just a firm jam.

I tend to work all this out in real time while loading at the range for at least as long as it takes to work out a stable recipe. YMMV

 

[straightshooter1]

I finished putting together my first non-AR centerfire rifle, and I'm about to load my first rounds. I've loaded pistol ammo for years, so I'm not exactly new to this. And I've got a good handle on the process once I have fired brass.

But I'm loading fireforming rounds for 6 BRA with Lapua 6BR brass. Just handling the brass and bullets, it feels like I could almost jam one down in there by hand.

Do you typically run an expander through new brass before loading? I've got a Sinclair expander die and .241 mandrel. Lube the inside of the necks and run the mandrel through before the first firing?

Having the case mouth loose enough to jam a bullet into the mouth doesn't necessarily present a problem except that recoil might cause bullets to seat deeper if they're being fed from a magazine. If you have that can give you a little more "neck tension" (if that's possible with your brass) you might go with a .240 mandrel. None if this is really critical while just fire forming.

Anything else I need to do differently because I'm fireforming? Lube, expand (or not), tumble, prime, charge, seat a bullet and let fly?

Sometimes, new brass case mouths haven't been chamfered and that's one thing I'll do in order to get good seating where I might even play with a little load development to get an idea where I might want to start once all the brass is fire formed.

As loose as you say the seating is, you may not need to bother with any lube in the necks to let the neck interference better hold onto the bullet.

Things will change after fire forming and if you're not already aware, when you tumble your brass you really don't want to remove the layer of carbon on the inside of the necks as that provides some benefit to seating with a lube. If you're inclined to wet tumbling, do so without any pins as the outside of the cases will clean up nicely and leave some of the carbon on the inside.

Like RegionRat mentioned, its a good idea to get a set of expander mandrel so that you use them to find just the right amount of "neck tension" that works for you.

 

[WillEver]

OK, I'll lube the necks, run them through the mandrel, chamfer and tumble. That sounds like a plan.

 

[WillEver]

One other quick question. When fireforming, why is it important to have the bullet in the lands?

 

[BuildingConceptsllc]

One other quick question. When fireforming, why is it important to have the bullet in the lands?

It gives you pressure and makes sure the brass expands fully and keeps things centered to the bore. This is typically done with a lighter load.

 

[WillEver]

Ok, thank you

 

[spife7980]

One other quick question. When fireforming, why is it important to have the bullet in the lands?

If you are forming a case you want the case head up solid against the bolt face. That can be accomplished via brass or bullet pressure.

The ackley chamberings were typically arranged so that the neck-shoulder junction stayed in the same place from parent cartridge to ackley chamber. To keep the case head up flush on the bolt face they took a smidge off the barrel shoulder and that makes headspace clearance just a smidge short, just enough short so that the neck-shoulder junction of the case just touches the chamber creating a mechanical interference keeping the case up solid. This ensures that all case growth is the shoulder going forward and not the base stretching to fill empty space behind it after the neck has sealed.

You can also jam a bullet into the lands to apply that rearward pressure from the case to the bolt face.

 

[Rocketmandb]

@spife7980 has it right. You don't need to jam these, though it certainly doesn't hurt. I load a bit light on powder (about 1.5 gr below my normal load at 29ish of h4895 and use some of my last Berger 105 VLDs. The funny thing about this is that this round is so insanely stupid that with an essentially random load and random seating depth, I'm still getting sub-.5 MOA groups at 100 yards while I form.

 

[supercorndogs]

Once you have a shoulder measurement for your chamber, you may end up with some new brass that is short compared to your chamber. In those instances you can use the bullet jam method to blow the shoulder forward also.

 

[WillEver]

Well, I finally got to the range, but I ran into a little problem.

The load I took to the range was new Lapua brass, Hornady 105 Match, CCI 450 and 29.8g of Varget (2.25 oal).

After the first round, the bolt lift felt a little heavy. After the third round, I shut it down. I got slightly heavy bolt lift on all three, and there's a shiny swipe from the ejector on all three case heads. I didn't want to take a chance with signs of pressure.

The load seems reasonable on paper, from what I've read. I cleaned the barrel before going to the range and there's no lube on the cases. I'm not sure what else to look at. Or is it just a matter of trying a lighter load?

 

[straightshooter1]

Well, I finally got to the range, but I ran into a little problem.

The load I took to the range was new Lapua brass, Hornady 105 Match, CCI 450 and 29.8g of Varget (2.25 oal).

After the first round, the bolt lift felt a little heavy. After the third round, I shut it down. I got slightly heavy bolt lift on all three, and there's a shiny swipe from the ejector on all three case heads. I didn't want to take a chance with signs of pressure.

The load seems reasonable on paper, from what I've read. I cleaned the barrel before going to the range and there's no lube on the cases. I'm not sure what else to look at. Or is it just a matter of trying a lighter load?

I thought you said you were loading for an AR???

Without a chrono, doing load development is like being almost blind. It appears you've found the pressure limit, so now to load a series of cases progressively lighter and see where the pressure signs stops and which loads do best on target.

 

[supercorndogs]

Well, I finally got to the range, but I ran into a little problem.

The load I took to the range was new Lapua brass, Hornady 105 Match, CCI 450 and 29.8g of Varget (2.25 oal).

After the first round, the bolt lift felt a little heavy. After the third round, I shut it down. I got slightly heavy bolt lift on all three, and there's a shiny swipe from the ejector on all three case heads. I didn't want to take a chance with signs of pressure.

The load seems reasonable on paper, from what I've read. I cleaned the barrel before going to the range and there's no lube on the cases. I'm not sure what else to look at. Or is it just a matter of trying a lighter load?

Does a loaded round extract easily? Have you confirmed your bullet is not jammed at 2.25?

 

[WillEver]

I thought you said you were loading for an AR???

No, I was saying this is my first NON-AR centerfire rifle.

It's an Origin and Criterion shouldered barrel.

 

[TheOfficeT-Rex]

Too hot. Ackley chamberings can be fireformed just fine with a medium load from the base cartridge. For reference, the berger manual lists max charge or a 105 class and varget at 29.4gn @ 2.4 OAL for 6BR Norma.

Double check your jam/touch number while you're reworking.

ETA: Spife mentioned it a while ago, but there should be 4k in crush if the headspace is set properly. That should make them chamber slightly stiff when you fireform and before you push the shoulders back.

 

[straightshooter1]

No, I was saying this is my first NON-AR centerfire rifle.

It's an Origin and Criterion shouldered barrel.

Oh. . . duhh, apparently I don't always read so well.
Thanks

 

[WillEver]

ETA: Spife mentioned it a while ago, but there should be 4k in crush if the headspace is set properly. That should make them chamber slightly stiff when you fireform and before you push the shoulders back.

I'll dial the charge weight back, and check the length to the lands as well.

But when you talk about the slight crush when chambering, can you give me an idea what it should feel like? I torqued the barrel on to the Zermatt specs, but I didn't get go/no go gauges.

 

[kthomas]

One other quick question. When fireforming, why is it important to have the bullet in the lands?

There's no need to do this with a BRA.

 

[kthomas]

Well, I finally got to the range, but I ran into a little problem.

The load I took to the range was new Lapua brass, Hornady 105 Match, CCI 450 and 29.8g of Varget (2.25 oal).

After the first round, the bolt lift felt a little heavy. After the third round, I shut it down. I got slightly heavy bolt lift on all three, and there's a shiny swipe from the ejector on all three case heads. I didn't want to take a chance with signs of pressure.

The load seems reasonable on paper, from what I've read. I cleaned the barrel before going to the range and there's no lube on the cases. I'm not sure what else to look at. Or is it just a matter of trying a lighter load?

Did you load the ammo with a jam into the lands?

 

[TheOfficeT-Rex]

I'll dial the charge weight back, and check the length to the lands as well.

But when you talk about the slight crush when chambering, can you give me an idea what it should feel like? I torqued the barrel on to the Zermatt specs, but I didn't get go/no go gauges.

Imagine loading any other caliber where the headspace is too long for the chamber. You’ll feel a little resistance on close. AI chambers are ‘shorter’ than their regular brothers so when you load virgin brass, the neck/shoulder junction is held firm by the chamber, and, on firing, the case shoulder is allowed to move forward from 30* to 40* and the case taper straightens to fill the chamber.

 

[WillEver]

So if I dropped in a virgin piece of 6BR brass, the bolt should be slightly difficult to close?

 

[XP1K]

So if I dropped in a virgin piece of 6BR brass, the bolt should be slightly difficult to close?

Not really difficult but you should feel it.

 

[WillEver]

Just chambering a fresh piece of brass, I don't feel anything.

 

[acudaowner]

remember to keep it fun , light and above all as safe as you can if not please send the video into the forums via live stream .

 

[TheOfficeT-Rex]

Just chambering a fresh piece of brass, I don't feel anything.

It shouldn’t just drop free. You have some fired brass yes? Should be able to compare to virgin and see if the neck/shoulder is moving forward.

Do the fire formed shoulders look crisp? If yes- back the charge down a grain to a grain and a half and keep going.

 

[WillEver]

Two pieces I fired today, along with a new piece

 

[TheOfficeT-Rex]

Sort of hard to get a good comparison on the shoulder from that angle, but it looks like they’re coming out just fine. If they come out like that with a lower charge and less extraction issues “you’re Gucci fam”

As an aside, 2.25 is about 150k shorter than I ever loaded any BRA (with 140fb). So unless you had a zero freebore varmint reamer, you can probably move that out. If you are touching at 2.25 or so, I’d hesitate to go straight to the benchrest guys loads in the 29-31 range. They’re loading jammed(or close to, generally), but with 200k more powder room.