Advice on 7mm TC/U Reloading

[CSHS]

Buddy got a Thompson set and we're going to reload for the 14" 7mm TC/U barrel.

No info in my Nosler manual. Hodgdon online load: 120gr bullet, 25-27gr H335, COL 2.410. Using H335 cause it's what I have on hand.

Planning to get a RCBS full length set to form 223 into the 7mm TC/U brass.

Really appreciate any tips you have on reloading or just the gun in general. Looked at at lot of info on line, but am feeling a little blind on this.

He had some old reloads that came with it and it shoots great.

 

[Magnumite]

I use a Redding BR set. You need to fire form after sizing. I load a grain or two under my load and just use those loads for practice. After fireforming I load to spec. There is a alternative method of fireforming but never used it. I don't recall it but a pistol powder is used.

I use Win748 powder and lighter Nosler or Hornady bullets. 110 - 120 grain I think I don't have my log book in front of me. Those loads were developed for standing shooting as well as free style and from a 10" barrel. I'll get the recipe in a little while. Varget may be used as well.

 

[Magnumite]

I used 28.5 and 30.0 grains of 748 behind 120 and 100 grain spitzer bullets, respectively. I used 4895 as well, couldn't find the data for it. All these were moa or better. The 100 and 120 grain bullets were used more for shooting form reasons than for ballistic characteristics. The ballistic stats on the 100 grain bullets are not great.

 

[Magnumite]

My T/C reloading manual shows 27.3 to 30.8 grains of H335 with a COL of 2.550" using a Sierra 120 grain bullet.

Hornady bullet info doesn't show H335 but 748 goes from 27.8 to 30.6 grains with 120 grain bullet. Powders used include RL-7, H322, IMR 3031, IMR 4895, WIN 748, BL-C2. Same as always, start low and work your way up.

Across the board, IMR 4895 is one of the best performing powders.

Velocities at max loads and 120 grain bullets tend to run in the 2300 - 2420 fps range.

 

[Hippy]

I have been using RL-7 @ 2400= FPS in mine for 25 years it will shoot 1" out of a 14" with a 4X Redfield and 120 Gr Sierra's

Good Luck

Jim

 

[byf43]

Love the 7mm TC/u!!!!!!


Sierra 140 gr Spitzer.
26.0 gr H-335
Winchester cases necked up.
Federal 205M primer.


Sub-MOA at 100 yards off of sandbags.

This load was AWESOME for IHMSA at 50; 100; 150 yards for chickens, pigs and turkeys.

Same load, but, go to Sierra 160 gr. Spitzer would knock the rams over (with authority!) at 200 yards.

 

[CSHS]

As always, I can count on you guys for good advice. Thank you very much.

 

[Blacksmith101]

I have the previous edition (fifth edition revised 2000), before they split it into two volumes, of this manual:
https://www.midwayusa.com/product/5...ding-manual-calibers-17-bumble-bee-to-7mm-tcu

In the 7mm TCU section, 35 pages long, they have the following sub headings that include loads for bullet weights of 100 gr. to 175 gr.:
Hornady Bullets
Nosler Bullets
Sierra Bullets
Speer Bullets
Lyman Bullets
RCBS Bullets
Accurate Powders
Hodgdon Powders
Vihavori Powders

The general recommendations for case forming are to use new unfired commercial brass and use a fast powder for the fire forming with the bullet touching the lands. For subsequent reloading neck sizing is recommended because the small shoulder area is easy to set back which will cause head space problems.

 

[CSHS]

Do you suggest annealing the cases? Before I size from 223 or before I fireform?

 

[byf43]

Do you suggest annealing the cases? Before I size from 223 or before I fireform?

I never have.

I found that by lightly chamfering the casemouth before opening up the neck helped reduce the possibility of splitting the mouth.

Either spray with "Dillon Case Lube" or the homegrown equivalent, or, dip the casemouth in powdered graphite. (Lube those puppies up! Not too much, though!)


Slow, even pressure worked for me.

I've never loaded 'light' to fireform the cases.

I have sized and checked to make sure that the brass chambered and the TC closed/latched on the empty brass.

The 7mm TC/u is one fantastic cartridge.

 

[CSHS]

Wanted to report back with my 7mm TC/U success and thank all for the info. Finally shot them, no problems. As accurate as the shooter could be.

I used on-hand supplies. 26g H335, CCI 400, 120g Hornady.

Did not lighten the powder on the first firing to fire-form. Attached is a before and after fire-form pic. Die-formed on the bottom, fire-formed on top. Makes it a little sharper at the shoulder.

 

[byf43]

^^^^^Lookin' good!!!!!!!!



How'd they shoot??????

Accurate????????

 

[CSHS]

Shot great. Good 100 yd groups considering the shooters.