Fireforming brass.

[ShadeTree]

Got 40 pieces of new RP nickel plated 257 Roberts brass sent to me from the gent I bought the gun from .

Will need to fireform it to the AI chamber. Can do it a couple ways.

A. Jam an 87 grain speer into the lands and use around a starting load of standard Roberts data with a faster powder like H4895.

B. Keep the bullet off the lands and maybe use a false shoulder at a somewhat higher charge of H4895.

C. Use something like the cream of wheat method. Which I've never done.

D. Just load it up with a standard Roberts data load and shoot it.

Suggestions for best results?

 

[358 WCF]

Shade Tree,

I try a few (5?) cases at first, & reload them 2 or 3 times, to be sure the process is sound before doing a bigger batch. My procedure comes from experience by screwing up too many pieces of brass for the problem guns. Hopefully yours is a good & easy one. Only 2 of the Ackleys I've fiddled with fireformed new brass without a hitch. A couple others were real problems at first. Better to lose 5 pieces than a whole batch. Some new brass is short on headspace lately too.

If the headspace is correct no need to jam the bullet. Maybe try a case expanded to 6.5 & sized back to 257 a little at a time until bolt closes with some feel to see if a 2ndary shoulder is even needed. Lube your locking lugs well if you do it this way.

Once the mechanics of the headspace question is settled, I use a fairly stout charge of a quick to med. quick burning powder listed for the parent case. It takes energy to form the new case, so dont be too low key. A stiff standard Roberts load of 4895 should be fine & will fill out the shoulder better than a weak load.

Just a possible heads up... Keep an eye on the neck/shoulder junction with the nickled brass. I saw a thin line of brass color coming thru on all cases after the 2nd or 3rd firing & had a failure on the 4th with one of my rifles. The nickle didn't seem to like the shoulder angle change & cracked. The thinner brass underneath did the same & the neck stayed in the chamber after firing. No harm, an oversized brush from behind pulled it right out when I got home. It shortened the range trip, but at least I didn't ruin a whole bag of brass.

 

[gbflyer]

A.


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[ShadeTree]

358, all sound advice. Thanks for that.

I had figured on checking headspace before I got started so I knew what I was dealing with as far as how much the cases would have to stretch on top of forming the new shoulder.

My method for that is generally to strip the bolt so I have a good feel on closing.........use .002-.003 scotch tape on the case head, trimmed up. On factory chambers I like to see it closing with 1 piece of tape, getting tight or hitting a wall on closing with 2.

I have a 22-250 that takes around 6 pieces of .003 to get tight. :shock: That one gets a false shoulder and a jammed bullet for all new cases. I also use a stripped bolt when setting up for a false shoulder so I have a good feel for it getting snug right at the bottom of closing.

You also kind of answered my question on nickel plated brass. I've never used them before and didn't know if they were better, worse, or the same. Sounds like from your experience they are not quite as good and I'll need to keep an eye out for some things.

 

[SJB358]

A solid false shoulder will work wonders and as 358 mentioned should form cases up nicely. I kinda like to have a plain old FF load that I can shoot for accuracy as well as hunt with as well, should I have to just grab some ammo.

I am not a bullet land stuffer since the false shoulder creates a positive headspace and does the same work for me with less hassle.

 

[JD338]

ST,
A properly chambered AI should have a slight resistance when chambering a virgin brass parent case. If you have this, your set to go as the brass will be held in place for fire forming.
Another point to keep in mind is a Max load with the parent cartridge is the starting load for the AI chambering.
I have fire formed many cases for the 280AI and have not had any issues.
As already mentioned, just do a few at first so you can confirm your fire forming process.

JD338

 

[ShadeTree]

ST,
A properly chambered AI should have a slight resistance when chambering a virgin brass parent case. If you have this, your set to go as the brass will be held in place for fire forming.
Another point to keep in mind is a Max load with the parent cartridge is the starting load for the AI chambering.
I have fire formed many cases for the 280AI and have not had any issues.
As already mentioned, just do a few at first so you can confirm your fire forming process.

JD338

So JD, is that what you do when forming AI cases? Use the max standard data load? I have my own ideas to start out with and I'm sure it would work at least okay, but always better to rely on actual experience.

 

[JD338]

ST,
A properly chambered AI should have a slight resistance when chambering a virgin brass parent case. If you have this, your set to go as the brass will be held in place for fire forming.
Another point to keep in mind is a Max load with the parent cartridge is the starting load for the AI chambering.
I have fire formed many cases for the 280AI and have not had any issues.
As already mentioned, just do a few at first so you can confirm your fire forming process.

JD338

So JD, is that what you do when forming AI cases? Use the max standard data load? I have my own ideas to start out with and I'm sure it would work at least okay, but always better to rely on actual experience.

ST,

Yes this is how I fire form my 280AI cases. I have a very tight chamber, by design, and cut off R-P brass. The above information was given to me by my gunsmith in 2005 when he built the rifle for me.

JD338

 

[ShadeTree]

JD, that certainly is a good shooter! Excellent. I believe at least in theory that the 40 degree shoulder and minimal body taper helps case to case consistency of starting out centered in the chamber and aids in accuracy with the AI's provided everything else is kosher.

 

[ShadeTree]

Okay did some checking with that new factory brass and here's what I came up with. Using a stripped bolt I can just feel a beginning of snugness at the last closing of the bolt using 3 pieces of .002 scotch tape. A 4th piece makes it hit a wall about halfway down on the bolt closing.

So actual headspace on this new brass is likely .0065, remotely possible as much as .007. Right on the verge of certainly benefiting from using a false shoulder on initial firing to minimize case stretch ahead of the web for overall longer brass life from here on out. But certainly not to the point of being critical to get reloads out of the cases from there forwards just setting the die to bump shoulders .002.

What you all think? Use a false shoulder, or just load up and shoot.

 

[SJB358]

I’d false shoulder myself. I don’t like case stretch and do it with anything that doesn’t fit snug upon initial chambering.

 

[ShadeTree]

I’d false shoulder myself. I don’t like case stretch and do it with anything that doesn’t fit snug upon initial chambering.

Yeah the right way to do this really with that slightly over normal headspace, any way you look at it. It's somewhat of a pain to get your die set up just right for a just snugging against fit on final bolt closing with a false shoulder, but not that bad really compared to many other things I do with rifles so I'll just do it right the first time.

 

[Charlie-NY]

If you don't mind doing it - have your smith set the barrel back one turn and properly headspace accordingly. This should also solve any future issues with fireforming cases.

Myself - I always jammed long bullets when FF for my 6mmAI.

 

[358 WCF]

I’d false shoulder myself. I don’t like case stretch and do it with anything that doesn’t fit snug upon initial chambering.

Yeah the right way to do this really with that slightly over normal headspace, any way you look at it. It's somewhat of a pain to get your die set up just right for a just snugging against fit on final bolt closing with a false shoulder, but not that bad really compared to many other things I do with rifles so I'll just do it right the first time.

Yeah, .006 is a little more than I like too. A jammed bullet may work fine in this case & is sure a lot easier. If you do the false shoulder I've had much better luck using standard dies to create the bump. Weird things happen to the shoulder & body sometimes using the Ackley die before fireforming. If you feel experimental, try one or two each way. I file a little notch in the rims to keep track of which cases were done what way.

 

[ShadeTree]

Good info 358. I've done the false shoulder out of necessity to minimize case stretch on initial firing of new cases on 2 different rifles that worked out nicely, but that was with standard dies.

I'm not following exactly why the AI die would cause an issue necking down the expanded case mouth to the right depth for the new shoulder since the parent case shoulder is shorter than the AI and the die should stay off of that, but I'll take your word for it and keep an eye on what's happening.

I might follow your advice and try a couple both ways and see how it's working out. False shoulder, and bullet jammed. Or might just try a couple with a false shoulder and if it's working well, stick with that.

 

[SJB358]

I just use a mandrel to expand up and then use the regular die to create the false shoulder.

 

[ShadeTree]

I just use a mandrel to expand up and then use the regular die to create the false shoulder.

Basically what I do Scotty. I use hornady expander buttons that can be purchased by themselves, and spin them on my RCBS stem. The hornady expanders are an oval shape much like a spitzer bullet and are much easier to expand up with, than the expander ball on an RCBS die.

I then neck down using the regular sizing die to create the false shoulder like you said. Although in this instance all I have is a 257 AI resizing and seating die, not a standard Roberts die for working with the factory cases. Can't see that being an issue, but I'll watch for it.

 

[elkeater2]

ST -The actual headspace fit of this brass is 3.5 pieces of scotch tape then. I don't agree with Charlie, and I wouldn't tell a smith to set a barrel back based on how 40 pieces of nickel plated R-P brass fit. Maybe if I had 400 of 'em and I knew that was all I wanted to use. ST, you got good advice here from the crew and it's obvious you know what you're doing. I guess my point is that you have determined what the headspace is with that brass, but not what the actual headspace is for the rifle itself. Having brass fit whatever you've got is key to fireforming without excess stretch - just like has been said here already. You asked for fire-forming suggestions for best results and got some good answers. Interesting discussion. EE2

 

[SJB358]

I just use a mandrel to expand up and then use the regular die to create the false shoulder.

Basically what I do Scotty. I use hornady expander buttons that can be purchased by themselves, and spin them on my RCBS stem. The hornady expanders are an oval shape much like a spitzer bullet and are much easier to expand up with, than the expander ball on an RCBS die.

I then neck down using the regular sizing die to create the false shoulder like you said. Although in this instance all I have is a 257 AI resizing and seating die, not a standard Roberts die for working with the factory cases. Can't see that being an issue, but I'll watch for it.

Yup, that works great too. Looking forward to seeing how you make out.

 

[ShadeTree]

EE2, I'd say that is correct. Just a beginning of snugness on the last of the bolt closing with 3 pieces of .002, and hit a wall with 4. I'd say actual is 3.5 pieces of tape for a reading of .0065. I checked it twice with both 3 pieces first, then 4.

I've done it before with good success, but this is a little different. On my 22-250 that has at least .018 headspace on new brass, I fireformed around 80 pieces with a false shoulder. I know on at least some of them I also jammed the bullet. From there of course the headspace issue disappears as I just set my die to bump the shoulder .002.

The majority of those cases have now been fired 4 times and look in great condition yet. They've been annealed more than once and I believe I annealed those before forming the false shoulder and first firing because of the amount they had to stretch up front, I don't remember for sure.

So I'm not afraid to experiment to get the job done, but this is a nice rifle and I'd like to get the job done proper, while not doing anything that is unnecessarily hard on it. Like you say I've gotten some good advice.

Edited to change my misprint of .065 to .0065.