I just shot some rounds for velocity in my 7mm TCU 14" using the 154 gr Hornady SP and 25.5 grs Varget. The bullets were seated to the base of the necks via eyeball. Cases were R-P. Primers were CCI 400. 25.5 grs Varget fills the case 1/2 way up the neck. No pressure signs and average velocity = 1767 fps.

Why did you choose the Hornady 154 SP? The bullet is a heavy jacketed interlock bullet meant for large deer and elk. I doubt you would get very good expansion on any critter over 100 yards.

Try the Hornady 120 V-Max/120 SSP. The 120 V-Max and 120 SSP are the same bullet. I had Hornady cut two new V-Max's vertically. The jacket revealed the interlock ring. When shot at 7mm pistol velocities the bullet expands like a single shot pistol bullet should. When fired out of a 280 Remington or any other high power rifle the bullet works like a V-Max should. Had great success with this bullet out of my T/C 14" Hunter barrel chambered in 7-30 Waters. I think reloader 7 would be a good powder for this choice.

I started with 139 Hornady's in my 7mm TCU on my son's recommendation, and they shoot great.

I suppose the lighter bullets would give more expansion, but I really like the accuracy of the 139's.

I use IMR 4895 and WSR primers, BTW.

I prefer shooting the cast RCBS 145 SP in my 7mm TCU, but back when I shot a lot of jacketed bullets I used the Sierra 120 gr SP and a Hornady 100 gr SP. Both regularly shot 1" or less 100 yard 3-shot groups. The box of Hornady 154 SP bullets I mentioned in the post above are 20 years old and are for an old 7 x 57 Mauser I hunt with in rainy weather.



A few weeks ago while researching an article on my 7mm TCU, I dropped samples of several different bullets into the chamber and let them stop against the lands. Then I miked the distance from the bullets's bases to the face of the breech.



That way, I could then easily determine a seating depth for each bullet which would put the nose of the bullet against the lands. The 120 SP can't be seated to touch the lands. The case neck is about 1/8" too short. Even just barely seated into the case neck, that bullet makes one heck of a jump before it hits the lands. However, the 154 SP is a perfect fit. With its nose touching the lands, its base is even with the neck/shoulder junction of the case. Looks to me like my circa 1980 T-C 7mm TCU chamber was designed around the Hornady 154 gr SP bullet.



If it ever stops raining I'll shoot a bunch for group. I hope it works because I just bought 2,000 154 gr SP "blems" from MidSouth Shooter's Supply.



Below is a photo of those various bullets placed at about their touch-the-lands position. Notice the perfect fit of the cast RCBS 145 SP and the Hornady 154 gr SP.

I guess it really depends on what your goals are

For Silhouette, the 139 is the balance for me, in that it is long enough to barely reach the lands (I seat at 2.7" oal) which gives me good accuracy, and it has enough mass to tip over the rams.

Many guys use the 154s with very good accuracy.

If I were to hunt with the 7TCU, I guess I'd try the 120s - but I haven't found them to be nearly as accurate in any of my 7TCU bbls (I've had 4).

While we're talking about heavier bullets, another one that is kind of fun if you find them at a good price is the 162gr Sierra matchkings.

The TCU isn't regarded as a "Whisper" <insert trademark here> but every one I've owned has a 1:10 twist and will completely stabilize the longer 7mm bullets at 1200-1400fps.

Have fun -

I finally did some shooting with the 154 gr SP "blem" bullets. Actually, I like to shoot clay pigeons placed on the dirt bank behind my 150 yard target, so I zeroed the 154 gr blems for that range. Load is still 25.5 grs Varget @ 1767 fps and with powder thrown from an RCBS measure. They shoot like a dream and with zero pressure signs. While adjusting the 4x scope, at 150 yards, I put 5 in 2 5/16" with 4 in 1 5/16". Moved the crosshairs a little, and the next 5 shots went in 2" exactly.

The scope zeroed at 150 yards for the 154 gr blems and Varget, I can bust 7 to 9 clay pigeons at 150 yards with 10 shots. My 4x scope's crosshairs are about 3/4" thick at 150 yards. I believe with a 10x or more target scope with fine crosshairs, the pistol/bullet/powder combination is capable of 1" 150 yard 5-shot groups.

I emailed Hodgdon "help" and asked why they didn't include Varget data in their 7mm TCU data since I seemed to be getting such great results. They answered that Varget wasn't suitable for the 7mm TCU because of low pressures and burning rate. Say what?

The 154 gr blems at 1767 fps muzzle velocity and 1545 fps impact velocity blow a perfectly shaped 8" deep x 6" diameter hole in my dirt bank.

Don't feel alone, pretty much got the same response when I wanted some updated data for a 7IHMSA project.
Jeff