View Full Version : 7mm TCU

12-07-2015, 11:33 PM
I formed my 7mm TCU brass using my standard RCBS dies. No issues or splits. The brass is once fired Dakota with the Lapua head stamp from CorBon 223 premium ammo.

i was going to load ww cast boolits with lube & gas checks for my loads through a 10" Contender.

can I use mild ~10 grain Unique loads for the initial fire forming?
Or do I need to ramp up to IMR 4064 or 4895 loads the first time?

12-08-2015, 12:31 AM
The TCU cases form very well with normal loads and also accuracy is usually very good. I have loaded for the 6.5 and 7 TCUs and just run the 223 cases thru the sizers and load and fire. Hard to tell fireforming loads from already formed loads.
You will want to us a load with high enough pressure to form the shoulder fully. Ten grains of Unique may not do that.
The TCU cases are very similar to Ackley Improved cases which P.O. Ackley recommended full loads to form the cases fully.

12-08-2015, 06:07 AM
I used to go to the gun shows and pick up some really cheap .223 ammo and just blow it out the barrel. It formed perfectly and the cases shot great on the initial reload. I did it for years and never hurt the bore or my score. I shot a lot of 40x40 and 60x60 shooting it that way.

12-08-2015, 07:44 AM
The way the op is suggesting will work. He is just making it a 2 step process. 1 initial low pressure fireform. Then a full house form.
As stated by others above the 7tcu is one you can really get away with 1 full house fireform and be done with it..
Either way works.

donald duck
12-23-2015, 12:07 PM
I have a T/C in 7mm TCU as well as a Savage Edge(Axis) with a Shilen 7mm TCU barrel. It is a tack driver. A very accurate load for me at 25 yds is 5.2 grains Unique. Form cases in two steps, first open case mouth to .25 and then to 7mm. Lose very few cases. Use Shaler Rislone for my case lube.

12-25-2015, 12:44 PM
I'm with the fire form with full power loads right from the get go group. One pass thru the full length die and then trim. Have also shot IHMSA 40/40's. Used 20 gr. 4895 with Lyman CB for chicken, pig, turkey, then 24 gr. for rams.