forming 7TCU

[Czech_too]

[SIZE=3]The last few years I've been telling myself not to pick up anything which would require me to get yet another set of dies, bullets & moulds.
You're already loading for enough cartridges I said. So what do I do but pick up another Contender pistol but in 7TCU.
No one else listens to me, so I guess, why should I.

After doing an appropriate amount of research, most saying to not use military 5.56 brass, but rather new .223 brass I figure to use some of this fully prepped range brass that I have a large quantity of. Hey, I'm frugal. So after acquiring a used set of die, for cheap, I took a small quantity of the prepped brass, stood it up in a shallow pan of water and annealed it, step one accomplished. Onto step 2, after liberally lubing the inside of each case mouth I proceed, with some caution initially, to run each case thru the FL sizing die. I was pleasantly surprised to find not a single split neck. This got my confidence level up a notch, so I went ahead and annealed some more brass and then re-sized it. I was cautioned to expect some split necks, but not a one was found. Maybe there's a reason why it's recommended to liberally lube the inside of the case neck? I'm sure that the annealing didn't hurt either.

The resulting cases have virtually no shoulder and after being loaded and fired have very little taper from the base to just below the shoulder, or what there is of it. The only thing I would do differently, if I had any new brass, would be to re-size the brass and then trim if necessary as I found that all of the prepped/fired brass is short by about .020" of the recommended trim length.

from left to right would be a .223, re-sized to 7TCU, 7TCU w/140gr. Sierra(previously fired case), 7TCU w/Hornady 154 gr.
https://i.imgur.com/qdWVP7c.jpg

[Nobade]

Years ago we learned to use 222mag brass to make those cases, that way it can be trimmed to fit the chamber. But since that's rare and expensive any more 223 will have to do. You'll love the TCU, it's an amazingly accurate and easy to work with cartridge.

[kbstenberg]

Czech You will be hard pressed to find a load that doesn't give you good to excellent groups. My powder of choice was H322. Kevin
I did have some problem with case shoulders collapsing. But not on a regular basis.

[LynC2]

It's a great little cartridge! I built a rifle just for shooting cast bullet silhouette matches and it is very accurate and cheap to shoot. :smile:

[Hamish]

New, military, several times fired, did them all in one slow pass with the Lee expander ball after Islington it well. Lost one or two every couple of hundred.

Easiest, least fussy cartridge I've ever messed with,,,,,

[upnorthwis]

I've done hundreds of them with no anneal and no neck lube and don't recall any spits. Give it a try. Also, no military??? new brass only??? I used to use the most tarnished/grungy brass I could find just to mock those people.

[Kraschenbirn]

No military? Whoever made that recommendation must have been trying to create a market for someone's overstock of .223 Rem brass.

During my IHMSA days, the second TC Contender barrel I bought was a 10" 7TCU along with a set of RCBS dies. Over the next 7 or 8 years, formed hundreds military cases into that caliber without any issue(s) I can recall. One thing I DO recall, however, is that military brass is a bit thicker than commercial .223 resulting in slightly less case capacity...not that it seemed to make any real difference in accuracy or case life.

Bill

[Walks]

I used 2-3 times fired R-P or F-C . Never lost a single case(350). Used SIERRA 150gr rejects for case forming. But if you're a T/C shooter you know all about that. 4+reloads, haven't lost more than 2 cases.

[Jeff Michel]

Wait till you try it in a rifle:mrgreen:

[Hardcast416taylor]

Woodchucks in my part of Michigan fear the mention of my friends name. He has a contender with a longish barrel and scope that is a pistol length variable. He has used mil - surp cases for as long as I`ve known he reloaded, never heard him complain about case losses.Robert

[GARD72977]

I have not formed 7tcu. I would wait to anneal the case until after you have naked it to 7mm. I have had good luck expanding cases this way.

If you notice the cases are not concentric try using a 6mm before you use the 7mm expander.

[Smk SHoe]

This was the first wildcat (ish) cartridge I loaded for in the late 80's. Only thing I did different was run them thru a neck expander that was somewhere in between. Maybe a 6mm. Loved that cartridge.

[Tom W.]

I remember reading in a gun magazine when the round first came out that the "inventor" of the load just put .223/ 5.56 rounds in the barrel a fired the cartridge. Poof! Instant fire formed cartridge... And he never said that the bullet rattling down the bore hurt ( or hit ) anything...

[NSB]

I shot the 7tcu for many years in silhouette matches. I just purchased surplus military ammo at gun shows and shot it out of a 223 barrel and fire formed it that way. I didn't do anything other than that and reloaded it. I just threw out several hundred cases that were loaded many times and still worked well when I got rid of both Contenders I'd been using (one for Unlimited and one for production single shot and standing). I never had a problem doing it that way and it must have shot good, I was in International Class in everything and also killed a bunch of deer with it. Why make it complicated?

[rockrat]

I shot IHMSA production with my MOA in 7mmTCU. I would swear it shot better using cases only necked up to 7mm but not fireformed yet. Bought the gun so girlfriend could go shooting silhouette with me.

Still have the gun, girl is long gone!!

[Alan in Vermont]

I remember reading in a gun magazine when the round first came out that the "inventor" of the load just put .223/ 5.56 rounds in the barrel a fired the cartridge. Poof! Instant fire formed cartridge... And he never said that the bullet rattling down the bore hurt ( or hit ) anything...

That is how I used to do mine as well, never lost a case in forming. Did 357 Herrett the same way, the 30-30 shoulder was a crush fit in the Herrett chamber for that first shot so the cases fit snug against the breech face. Just had to trim off the extra neck and done with it. Never had Herrett dies. I neck sized in a 38/357 carbide sizer, stopping short of the shoulder, expanded with a 35 cal "M" die and seated with a 35 Remington Lyman "PA" seater. FWIW, 357 H is virtually identical to 35/30-30 other than neck length.

[Stephen Cohen]

I shot IHMSA production with my MOA in 7mmTCU. I would swear it shot better using cases only necked up to 7mm but not fireformed yet. Bought the gun so girlfriend could go shooting silhouette with me.

Still have the gun, girl is long gone!!

The loyalty and devotion of a fine gun is beyond belief LOL. Regards Stephen

[fast ronnie]

I never annealed. I used graphite mixed in a pill bottle with shot to lube the necks. Dip the neck in and twist a couple of times. Never had one split, military or commercial. Loaded them the same. Was classed international as well. I just gave away on pay-it-forward a year or two ago some military that I had formed and never used. That brass will last a long time. Mine had been loaded and emptied many times, neck-sized only with mostly 139 grain Hornady's, sometimes 160 grain just to be different. It is a great round, and as said before, very accurate.

[badgeredd]

The simplest and easiest was to form cases is to get a boat load of 5.56 loaded ammo and fire it in the TCU chamber. Obviously no accurate, but dead simple forming process. I anneal all of the cases after firing and before trimming or reloading.

[mike69]

I have a 14 inch 7tcu contender barrel on the way should be here Monday . was going to ask about forming brass . It seems I always find my answers on here with out asking . I really like this group learned a lot since I joined .

[Nobade]

I have a 14 inch 7tcu contender barrel on the way should be here Monday . was going to ask about forming brass . It seems I always find my answers on here with out asking . I really like this group learned a lot since I joined .You'll love it. Wonderful cartridge to work with.

[Three44s]

My first Contender barrel that I acquired in the 7mm TCU is a 14” Super. My second is a 21” carbine. Still have and like both of them. I really like the carbine!

The one thing I have been disappointed with is the fact that the chambering is throated for heavier longer slugs. I nearly pulled the trigger on a 6.5 TCU barrel when I discovered that it also is long throated. I would like a little shorter throat for light for caliber bullets (j words) as I am a varmint shooter.

A long time dearly departed Cast Boolits member Junior1942 was a huge fan of this cartridge and he also wrote articles online about his work and experiences with it. A bullet he had good experiences with was the Hornady 154 gr. spritzers. My barrels liked also. I recall a ground squirrel I shot with my carbine barrel loaded with this bullet. No expansion but one very dead grey digger indeed.

Junior 1942 went to work and set up a mini chop saw and lopped the nose off a bunch of those Hornady 154’s and found a resulting slug that DID now expand at 7 TCU velocities.

VIVA the 7mm TCU!

Three44s

[Mr_Sheesh]

Getting set up for this round again.

My new Size/Expand/Decap die seems to INSIST on screwing the decap / expander stem in tighter, I have to watch out or it will get bent! Going to use a wrench on the darn thing, and, I think, find a short wrench to fit in the die set's box. And going to degrease the die's parts.

I found that graphite doesn't work too well for expansion (new Starline Brass), on my setup at least; So I use a regular case lube, then tumble the cases after.

I just wish I could fire form those here on the place I live but the local PD would get upset, so, nope... I'll go camping or something and form them :)

I plan to try the 7mm "Soup Can" bullet out. Should work on various targets well :)

[mike69]

Getting set up for this round again.

My new Size/Expand/Decap die seems to INSIST on screwing the decap / expander stem in tighter, I have to watch out or it will get bent! Going to use a wrench on the darn thing, and, I think, find a short wrench to fit in the die set's box. And going to degrease the die's parts.

I found that graphite doesn't work too well for expansion (new Starline Brass), on my setup at least; So I use a regular case lube, then tumble the cases after.

I just wish I could fire form those here on the place I live but the local PD would get upset, so, nope... I'll go camping or something and form them :)

I plan to try the 7mm "Soup Can" bullet out. Should work on various targets well :)

I'm thinking of trying the 7mm soup can or this one from noe 288-135-FN-F1 RG4 cavity GC (7mm Thor)
[288-135-FN-F1-112] haven't really decided which to get first

[Mr_Sheesh]

Nice meplat on that one! I suspect both will do well.

[marshall623]

My 10" 7TCU likes the 160 Lyman Sil. boolit over 20.5 gr of RL 7 . Wanting to try the RCBS 145 Sil. or the 150 Hunter from NOE in it .

Sent from my SM-G930V using Tapatalk

[3856imp]

7 tcu is easy size, fireform trim, keep like brass together

[Walks]

I used 7X30Waters FN in mine. Got great expansion, had good luck with the Discontinued HORNADY 7mm SSP bullet too. Just seated them out a bit.

I used once fired F-C & R-P .223REM cases, formed them with a full power load. Cases last 5-6 firings, trim after 3-4 firings, used Imperial sizing Lube. Worked great inside and out.
Military brass was harder to form, some splits, wrinkles. Not worth the effort.

[JSH]

I used and prefer LC brass. Annealing is not a must but solves a lot of problems. I actually had more issues with FC brass than any others.
The long throats were not really as much for heavy bullets as they were to keep pressure down.
IMHO to get the most and the best from this cartridge a custom barrel and a proper throat will make a huge difference.

[frankmako]

i started shooting 7tcu in the 80 for nra pistol silhouette matches. the only brass i used is military 5.56 brass.

[Eamonn]

What a thread to stumble upon just when I'm in need of a bit of kind experience ;-)
Sorry for going a bit OT but I just bought a 6x45 non TCU rifle built on a Sako L461 and I'm planning ahead and picking upp stuff here and there while waiting for the licence to go through.
I'm expecting it to be great little bird rifle.

So, are there any issues with the cheap Lee aluminium press (of recent vintage) with quick die bushings as to expanding the neck?
I can't really find any reliable info online. Just opinions that the press can do anything with ease or that it will explode when looked at.

[Nobade]

If you can find a better press I'd recommend it. But that one won't have any problems opening the necks to 6mm.

[Mr_Sheesh]

Eamonn - Going 223 to 7mm is indeed easy - I use regular case lube to do so, it just works better for me than graphite. I've been using a Lee Hand Press for this step so it's indeed very easy, as Nobade says. 6mm will be easier I'd think. It's good to have a VERY good press, I have several (used to have 5 RockChuckers but a family member "helped himself" -.-) - I use the weaker presses for depriming, and other very light work. The RC IV I have now is the only way to go for heavy case swaging, compound leverage helps there a LOT. (6mm forming from 223 tho is not going to require that :))

Enjoy your new caliber :)

[415m3]

I can fireform .223 into my 7TCU cases?? ******! I've been using a RCBS die for that

[Nobade]

I can fireform .223 into my 7TCU cases?? ******! I've been using a RCBS die for thatSure. Just fire 223 in your 7 tcu barrel and they'll form most of the way.

[Iowa Fox]

I can fireform .223 into my 7TCU cases?? ******! I've been using a RCBS die for that

You can but anytime I tried it I had crooked necks on the fired brass, plus it seems like a lot of extra work to me. Forming TCU brass on the expander in the sizing die is so easy plus it leaves you with brass that is ready to load and shoot at a match. Just remember lots of GOOD lube on the inside of the neck before you expand it. I purchased the first barrel I could get my hands on when Thompson Center first started chambering for the 7 TCU.

[Eamonn]

If you can find a better press I'd recommend it. But that one won't have any problems opening the necks to 6mm.


Eamonn - Going 223 to 7mm is indeed easy - I use regular case lube to do so, it just works better for me than graphite. I've been using a Lee Hand Press for this step so it's indeed very easy, as Nobade says. 6mm will be easier I'd think. It's good to have a VERY good press, I have several (used to have 5 RockChuckers but a family member "helped himself" -.-) - I use the weaker presses for depriming, and other very light work. The RC IV I have now is the only way to go for heavy case swaging, compound leverage helps there a LOT. (6mm forming from 223 tho is not going to require that :))

Enjoy your new caliber :)

Thanks, I'll keep an eye out for a used one. I regret passing on a Forster Co-Ax with a really nice price tag a short while back =)

[Mr_Sheesh]

Oh. Also. The expander stem on the 7mm TCU CAN or WILL, if you don't lock it down thoroughly, unscrew itself until it rams into the case web and bends itself out of shape; You will want to degrease the stem's threads and be sure to lock it down WELL with the lock nut, or you get stuck waiting for a replacement part. Or at least I did when I first formed these.

[JSH]

The Hornady tapered expanded balls work well for expanding.
My first 6x45, the only die I had for a while to size with was the Hornady 6mm neck die.

[mike69]

When I got my 7tcu barrel it cam with a set of redding dies . I've formed and loaded about 150 rounds for it for when weather gets better . Used my lee turret press think I only had maybe 3 necks split . I'm using the NOE 288-135 fn (thor) have flat nose and hallow points cast and loaded for it . Justing waiting to do some shooting with it .

[Eamonn]

The rifle comes with redding dies, I'll be sure to check them before use.

Skickat från min SM-G930F via Tapatalk

[buckweet]

My first Contender barrel that I acquired in the 7mm TCU is a 14” Super. My second is a 21” carbine. Still have and like both of them. I really like the carbine!

The one thing I have been disappointed with is the fact that the chambering is throated for heavier longer slugs. I nearly pulled the trigger on a 6.5 TCU barrel when I discovered that it also is long throated. I would like a little shorter throat for light for caliber bullets (j words) as I am a varmint shooter.

A long time dearly departed Cast Boolits member Junior1942 was a huge fan of this cartridge and he also wrote articles online about his work and experiences with it. A bullet he had good experiences with was the Hornady 154 gr. spritzers. My barrels liked also. I recall a ground squirrel I shot with my carbine barrel loaded with this bullet. No expansion but one very dead grey digger indeed.

Junior 1942 went to work and set up a mini chop saw and lopped the nose off a bunch of those Hornady 154’s and found a resulting slug that DID now expand at 7 TCU velocities.

VIVA the 7mm TCU!

Three44s

I'm going to try to duplicate Junior's 154 Hornady boolits.
I've have a chop saw.
I also just simply fire a .223 in my TCU chamber.
Perfect cases.

[donald duck]

I really like the 7MM TCU as brass is cheap to free and can be reloaded many times. My favorite load for 25 yds. is 5.2 grains Unique with a 120 grain gas checked cast bullet. use in my Contender 10 in. and 14 in. and my Savage Axis with a Shilen barrel. Much fun!!!! dd

[TCLouis]

Don't forget Junior1942'sa work with the "Soupcan" and WC820(N) powder, specially here on this site!
Link to his 7mm TCU project is here someplace

[muta4warrior]

I just picked up a couple Contender barrels (10" and 14" bullbarrel) along with 4-500 pieces of brass, couple boxes of 120 grn J things and a set of dies recently in 7mmTCU. I'll probably sell the 10" off and stay with just the 14" to get a little bit more velocity out of the load.

[kenyerian]

After reading this thread I am inspired to get mine out and play with it. I still have a couple hundred loaded up.

[buckweet]

After reading this thread I am inspired to get mine out and play with it. I still have a couple hundred loaded up.




You're going to love the 7mmTCU.
Don't sell off that ten inch barrel yet!
Keep it around.. I think you'll shoot it way more
Than you think.
I know I do .
Cheer's!!

[buckweet]

I just picked up a couple Contender barrels (10" and 14" bullbarrel) along with 4-500 pieces of brass, couple boxes of 120 grn J things and a set of dies recently in 7mmTCU. I'll probably sell the 10" off and stay with just the 14" to get a little bit more velocity out of the load.



My post was in reply to this post..
My bad.
And fat fingers..

[Walks]

I bought a 2nd sizer, back in the Day when RCBS Would still cut you a Special Sizer Die for a fair price and 3 fired cases. It works so well, that I Haven't had to form any new cases in years. But then I don't shoot it 600+ times a year either. And My loads are not as hot with cast as they were with those other types of bullets.

[muta4warrior]

Was at a local gun show this weekend and was basically handed a brand new sealed box of Hornady 7mm GC, so now I guess am on the lookout for a mould set and sizer/lube die for my Star..