Question - fireforming 223 for 7mm TCU

[jjohnson]

Hi, gents!

Quickie question for you - how much powder and stuffing do I need to properly and safely fireform brass when resizing .223 to 7mm TCU? I have some pistol powders like Bullseye and Unique that I could load under some Cream of Wheat or something and pop 'em into the atmosphere... but never fireformed brass before, and thought I'd better ask.

Or.... for the alternative on 7mm TCU, should I just load cast lead bullets on the low end and then shoot per normal at the pistol range to form them? I'm using a T/C Contender with 10" barrel.....

Thanks for any tips - I'm an old hand at reloading, but new to fireforming.

 

[highlander 5]

try 5 gr Unique with some fiberfill to hold the powder near the primer and use soap or canning wax as a plug. Just stick the case in the soap till it hits the shoulder and twist. You can form the cases easily enough as long as you have
a tapered expander.Check the most recent Lyman manual for cast bullet loads

 

[P-32]

When I was shooting 7 TCU I fireformed with a full charge of IMR 4227 and a 140 gr. bullet.

 

[trueblue1776]

P-32,
I'm trying to wrap my brain around your post, could you elaborate?

 

[Souris]

I recently started Fire forming some .30-30 brass for my 7-30 waters contender barrel.
I run the .30-30 brass through the full length sizing die which gives it an odd double necked look.
Then I load it with the lowest published powder charge (imr4895) and whatever bullet that I have in .284/ 7mm.
I go to the range and blow out the brass to my chamber and come home and neck size only.
I am REALLY happy with my 7-30 Waters carbine. 3 rnd grp at 100 yrds under a quarter while fire forming brass!

 

[243winxb]

http://www.castbullet.com/shooting/7tcu.htmWhen i had mine, i full lenght resized the brass in the T/C die. As i remember the full lenght sizing die should not touch the shell holder with the dies i had, as you could make the brass way to short. I had to play around to get the right head spacing. Then i loaded with a normal starting load with a jacketed bullet to fireform. Some necks will split. This was shooting a T/C contender 10" bbl.

 

[iiranger]

Many options...

Long ago in one of the gun magazines, a fella was forming / blowing out .219 Don Wasp with a half case of 2400, no filler, fired straight up... Little wasteful IMHO.

You could fire .223 ammo, probably, and that would blow things out at a low pressure with a .224 bullet lumbering down a .284 barrel. If the shoulder is right for your chamber... Probably won't get a sharp shoulder/ well formed case.

If you are not informed about headspace, Mr. Bellm, gunsmith, beats it to death. It is not only a safety issue, but in the T/C products it also contributes much to accuracy. Mr. Bellm's remarks can be read at bellmtcs.com ... helpful...

From there the old standard was a couple grains of Bullseye, fill with Cream of Wheat, fire. If you are way low, you can do it again... I used corn meal. Be a greenie. Fire it into soil or sand or paper and scatter on your lawn. Nice organic fertilizer. Unique is o.k. I used HS6 but seemed a trifle slow. If you are going to carry the rounds you plug the mouth with any number of things. Soap has been mentioned. Small squares of toilet tissue is mentioned. Candle wax or canning wax will work. (Messy if you use alot). Kapok used to be popular. No idea about availability today. Little need for a plug...

Since you are going up, you could use a tapered expander ball and then load a hot cast bullet load to fill things out. It does need to be warm or more or you will not get good headspace.

You will probably not get a case fully formed, but if you understand headspace, you should have a case safe with a full load and then be able to load for accuracy with the 2nd full power load.

It is "hit and miss" / "trail and error." Short of filling the case with bullseye and seating a bullet, you cannot do wrong. luck.

 

[P-32]

TrueBlue....sorry about that! Some times I forget not everyone knows what I'm thinking. Seems like I ran a 223 case in a 7TCU F/L die and then loaded the case with IMR 4227 with a 7mm 140 gr. bullet on top. The case after being ran through the 7 TCU die would head space on the shoulder but was not fully blown out. I still have a few of those old cases around. I found I didn't care for the recoil on a 10 inch TC. I went to 45 Win Mag which would knock a ram down at 200 meters even if hit in the toe nails.

 

[steveno]

when I fireformed my 223 cases to 7 tcu I just used the same load I shot after fireforming. it was just a little more compressed. I did have to use a softer primer like Remington or Federal to eliminate misfires in the fireforming. after the cases were fireformed then CCI primers would work just fine.

 

[P-32]

As Steveo reminded me I also used the same charge I was shooting when I was trying to knock the steel down.

 

[steveno]

I should add is that in fireforming the only thing that really supports the case to form the shoulder in the chamber is the extractor. I think that is the reason I had some misfires with hadr primers (CCI). the softer primers solved this problem

 

[peabody]

i've been known to just load a factory 55 grain 223, in the 7tcu, presto. instant 7tcu brass.

 

[EddieNFL]

TrueBlue....sorry about that! Some times I forget not everyone knows what I'm thinking. Seems like I ran a 223 case in a 7TCU F/L die and then loaded the case with IMR 4227 with a 7mm 140 gr. bullet on top. The case after being ran through the 7 TCU die would head space on the shoulder but was not fully blown out. I still have a few of those old cases around. I found I didn't care for the recoil on a 10 inch TC. I went to 45 Win Mag which would knock a ram down at 200 meters even if hit in the toe nails.

I've fireformed brass shooting matches. Not a big difference in POI. My load is is a 145 RCBS cast on top of 14.5 H4227 using spherical buffer to fill the case. I'm of the opinion a full load should be used to fireform.

 

[Walkalong]

I'm of the opinion a full load should be used to fireform.

While I have zero experience with this caliber, I agree with that statement 100% as far as fireforming in general goes..

 

[Kernel]

FYI, the February 2010 issue of Handloader magazine had a good article on loading the 7mm TCU using a 21" rifle barrel. Something like 10 different bullets, including two cast bullets, 12 powders, and 40 different loads. Also covered case forming.