I'm not working with a wildcat cartridge but I hear you guys do this alot.

I have some brass with the shoulder set too far back and want to fire form back to correct size.

How far into the lands do I seat the bullet?
What powder load do I use. A book listed starting load, or more, or less?

Thanks

Trigger I don't think you are going to push the bullet very far into the rifling. You will come up against the rifling with the bullet then you will push the bullet deeper in the case neck.The bullet should be seated out far enough that you feel firm resistance on the last 1/3 of the bolts rotation when you close the bolt .I would use a normal starting load of a medium burning powder. NOT a max load and not a reduced load. Rather than re-adjusting your seating die try putting a 3/4 to 1/2 in electrical reducing washer under your seating die. If one is not enough add another until you feel the right amount of resistance when you close the bolt. The washers can be found at most hardware stores for a few cents ea.

I get my measurement at the lands, then run another .005" into the lands for a good firm contact. Then I use a medium charge of one of the fastest powders for that caliber/bullet and light em up. The fast pressure curve and bullet in the lands gives a great form every time,..even in AI calibers.

I hadn't heard of this technique before. I thought the proper technique was to neck up to just more than the neck diameter, and then gradually push the shoulder back with the resizing die until you can just cam the bolt closed, and then use a light load to fireform?

Dull, rigorous, unimaginative, orthodox fellow that I am, I would have said that that technique would not work: the striker will push the case forward, the front of the case will stick to the walls of the chamber, and the case will stretch just in front of the web until the case head is back against the bolt face. Could be the primer will show false pressure signs too, as it flattens when the case head backs up. I'm not convinced the striker won't hammer the bullet deeper into the rifling, making excess headspace.

Anybody want to educate me and expound on this a little?

If you do as snowman said, it owrks fine. Your firing pin can't impact the case hard enough to push the bullet deeper, unless you've got one heck of a firing pin spring.

The first time I used this technique was in 1968.FRED Barnes built a 6mm-06 IMP that wound up being a 6mm-.270 IMP as the reamer went in about .050" too deep.In my wildcating I'ved used the technique quite a bit since than. What I want to share is the fact that than and still today I use slow and fast burning powders. In the 6mm-.270 I know I was using a near full load of H4831 cause that is all I COULD AFFORD.The full load didn't b
scare me as I figured the rapid brass expansion and the bullet moving down the barrel increased the capacity fast enough to keep the preesure within reason but high enough to put good form to the brass.I'm not advocating using slow burning powders; just passing on some info. I would, however, like to hear from anyone who has experienced any problem in fire forming with max loads of 4350 or 4831.It would also be nice to chit chat by E-Mail with some one knowledgable about fire forming. roger

An intermediate load of IMR4895 is very good for fireforming my 338-06 AI and 223 Rem AI, seating the bullet up against the lands.

You can accomplish the same thing without wasting bullets by using a few grains of Bullseye or some other fast burning pistol powder, fill to the shoulder with cornmeal and hold it all in place with a tuft of tissue paper in the neck. This doesn't give a perfectly formed wildcat shoulder like using rifle powder and a bullet but it pushes the shoulder out to keep the case head against the bolt face to control headspace.

Both were suggestions from R. W. Hart & Sons, Nescopek, PA who built my rifles.

I've fireformed .375rum to .404jeff. using pistol powder & cornemeal. It works fine, you have to experiment abit w/ powder weight to get good shoulders. I use some old IMR4227/poly tuft/cream of wheat & a bit of candle wax to seal it. Point downrange & let it rip. Clean your bbl. & chamber thoroughly before shooting bullets down that bore.

I've tried seating bullets out into the lands for fireforming in my 338-06 AI, and directly gave it up. I saw the same thing that SDS thought of: the neck tension was not great enough to hold everything in place when the striker hit. I partially seated bullets into the case and let the bolt finish the seating and drive the bullet into the lands during chambering.

I got nicely formed shoulders, but a nice bright stretch ring near the case head too. IMHO, that method is a good way to ruin brass - at least in the mauser I am working with. Other rifles with weaker firing pin springs may be able to use this method, but I can't (in this rifle anyway).

I now neck up to .358 caliber, then back down to .338, adjusting the sizer so that there is a nice crush fit just as the bolt cams shut. The brass is held like a vice and fireforming is 100% reliable. I can use whatever bullet I want (or no bullet and cornmeal).

quote:

Originally posted by fredj338:
If you do as snowman said, it owrks fine. Your firing pin can't impact the case hard enough to push the bullet deeper, unless you've got one heck of a firing pin spring.

No, but it can impact hard enough to push the case forward over the bullet which results in the same thing - a stretched case.

The captian has it right!!!!!!1
Just form a false shoulder and load and shoot as normal. I had to do that when a blacksmith put an improved chamber in a 257 Roberts without setting the barrel back. It is the easy way to do it and positive.
Lyle

Hi All: I like the cornmeal/fast pistol powder
method..prime undersize parent case, drop 6-7 gr.
of fast pistol powder such as Bullsye..fill with cornmeal, pack it in to within 1/16 inch to top of case, put a drop of Elmers Wood Glue sealed atop.
Let glue dry & fire. I've formed radical cases this way that would split if any other method with bullets used. After the cornmeal fire form, you are now OK with full loads..
Tom