Large case fire-forming method

[midgetorama32]

Does the cream-of-wheat/pistol powder method work well on Ultra Mag parent cases when fire-forming for a wildcat? A local guy has abandoned his 7mm wildcat project based on a 7 RUM and I want to preserve as much barrel life as possible if I end up buying it.

Thanks.

 

[canyonman1]

Depending on how much you are improving the case, the velocity and accuracy will not change much fire forming using a full charge and shooting vs. already formed case. When I fire form anything I load a near max charge and go shooting. When using the method you ask about, you usually don't get the large cases fire formed all the way. Better off getting bullets down range.If the rifle is new to you it lets you get accustomed to it that much faster. And its a whole lot funner than messing around with cream of wheat.
When finished you can then work up a load and adjust your dope accordingly.
Go shootin!gun)

 

[Innovative]

midgetorama32 ..........

I agree with canyonman1 about your "Cream of Wheat" loads. Save it for your breakfast if you can stomach the stuff. It's a lot more safe to use a reasonable load than filling the top half of your case with a filler. If the filler shifts you could be dealing with more pressure than you might think. I've seen this type of testing done with subsonic loads, and the results aren't very impressive, and it can be dangerous.

- Innovative

 

[Tyler Kemp]

On the other hand I like using COW to preserve barrel life. I shoot the round right after making them usually, so it's perfectly safe. Just fill with XX grains of Unique, the rest with COW, then push some wax on top to compact it all and hold it in. Then chamber and shoot...just keep upping the powder until you get the best results for a fireformed case.

 

[dirtball]

Got this from BOSS HOSS, Fill case with Bullseye, weigh it, use 2/3 of that weight with just enough of a piece of a cotton ball to keep the powder in place and fire. One step no scrubbing COW out of barrel, works great. Carefull not to over heat the barrel.

Dave

http://www.longrangehunting.com/forums/f28/fire-forming-method-new-cases-40473/

 

[midgetorama32]

With the Boss Hoss method, is there anything that centers the cartridge in the chamber or does it matter?

Thanks.

 

[dirtball]

With any fire forming method you MUST have some form of a false shoulder to keep the case from stretching at the web or in the case of non belted cases from the primer misfiring because of lack of a tight head space. If you are fire forming brass from a larger original bullet diameter only size down enough of the neck to get the bolt to close snugly. If you only "improving" a case it might be necessary to expand the neck up one caliber and then size the neck back down as above.

Dave

 

[midgetorama32]

With any fire forming method you MUST have some form of a false shoulder to keep the case from stretching at the web or in the case of non belted cases from the primer misfiring because of lack of a tight head space. If you are fire forming brass from a larger original bullet diameter only size down enough of the neck to get the bolt to close snugly. If you only "improving" a case it might be necessary to expand the neck up one caliber and then size the neck back down as above.

Dave

I have read about false shoulders. If I were to use a loaded round with the bullet seated into the lands, is that accomplishing essentially the same thing? I'm thinking that might be the best option at this point...

Thanks.

 

[dirtball]

We were originally discussing ways to fire form without bullets to preserve barrel life, but yes you can use a fully loaded round BUT make sure you have plenty of neck tension on the bullet.

Dave

 

[Boss Hoss]

With the Boss Hoss method, is there anything that centers the cartridge in the chamber or does it matter?

Thanks.

When you pull the trigger(I always shoot straight up when possible) the round will form to the chamber and if the rifle was built correctly then there are no issues.