[ftsibley]

Loaded up three rounds to go and check everything out before i got busy working up loads to fireform. Here are the before and after pics. shooting 100 gr BT over 41gr imr4064 at around 3250fps. These are reduced loads for the fireforming. Have to go pick up my AI sizing die monday so hope to have 50 pieces of brass fire formed by then.



took the three shots to get zeroed will try for some groups this afternoon and tommorrow.

 

[Xd357]

Will you be able to get good groups while fire forming?

 

[ftsibley]

my gunsmith said the above mentioned load should group pretty good said should be 1/2" 5 shot or better at 100. I am really excited about seeing what it will do once i get the AI loads worked up.

 

[300 ATLAS]

ftsibley,
While fireforming using a bullet will give you 100% formed AI cases and yours look good, it is using up 10 – 15% of your barrel life! A better option is to use the Cream of Wheat method and get 85 -90% formed cases. A true P.O. Ackley Improved cartridge is set up with .004” of crush fit on the parent case at the neck/shoulder junction. So no bullet is required to get proper headspacing, not that a bullet jammed into the lands will give you the proper headspace.
I use the Cream of wheat method to form both 6mm Dasher and .300 ATLAS (Improved .300 WBY) cases.
Dasher: Prime, Throw 9.0 grains of Unique Pistol Powder, Fill with Cream of Wheat Cereal to the top of the case mouth, Thump the case until the COW settles at the bottom of the neck. Then take ¼ sheet of toilet paper rolled into a cylinder and stab it in the case mouth. Tack a Cluster of Allen Wrenches and use the largest on that will fit to pack the TP down tight. Spray the case with Hornady One Shot or WD40, load and shoot. (Start at 7.0 Grains and work up).
ATLAS: Prime, Throw 14.0 grains of Unique Pistol Powder, Fill with Cream of Wheat Cereal to the top of the case mouth, Thump the case until the COW settles at the bottom of the neck. Then take ¼ sheet of toilet paper rolled into a cylinder and stab it in the case mouth. Tack a Cluster of Allen Wrenches and use the largest on that will fit to pack the TP down tight. Spray the case with Hornady One Shot or WD40, load and shoot.
I would recommend starting at 11.0 grains of Unique and then work up until you get cases formed like you want them. Unique is Lot# sensitive. Clean the Barrel every 25 – 30 rounds and go slow. Try not to get the barrel to hot.
Check out these links on the subject.
http://www.the-long-family.com/260AI.htm#Unique_and_Cream_of_Wheat_Method_Perfected
http://www.6mmbr.com/260AIforming.html

Have fun!

 

[ftsibley]

thanks for the information and links ATLAS...... so someone actually found a good use for Cream of Wheat...... my mom used to cook that crap for us for breakfast.... couldnt put enough butter and sugar on it to make it acceptable.

just a squirt of wd40? or liberal application to the case? i am assuming its to ease extraction after the firforming.

 

[300 ATLAS]

Just a light misting coat. It will work w/out anything, but the lube will keep the cases from wanting to stick to the chamber walls during firing. It just makes a better formed case.

 

[Beladran]

you should have gotten tim to get you some die blanks and cut them with his 25-06ai reamer.... would have been an exact fit to your chamber

 

[ftsibley]

got redding type S dies for now. Trying real hard to figure out how to get that 12x42 Niteforce scope on top of the gun. the $ needed vs the $ got ratio is pretty wide right now. I am going to have to come up with something b/c i put the bushnell 6500 on my 300 and it just isnt going to cut it on that gun, so the 6.5x20 will be going back on the 300.