I know it's not a BIG 7mm, but...I read that everyone is saying the 7TCU is accurate. What does that mean to you? What's the acceptable 5-10 shot group size (50/100/150/200 yards)? For me I haven't found a good load yet. I'm still learning the 7TCU. I haven't shot a lot of rounds through my used 14" barrel. Yet nothing looks good to me so far. I have no idea how many rounds fired prior to me owning it! Appreciate your feedback!
7mmTCU Accuracy?
- Thread starter rmist
- Start date
JEFFPPC
Gold $$ Contributor
I had a 10 and a 14, both would do .75 to 1.0 at 100yds average. Always 3031 powder with various bullets. I shot IMSHA Silhouette standing. I never missed an animal because of the gun. Shot the 10 inch the most. Great game I hated to see go away. To much NRA influence in that a zillion classes were involved.
JSH
Gold $$ Contributor
It can be a challenge shooting off the bags. I shot better groups in Creedmoor a lot of times than I could off the bags, more practice I imagine.
I ran a lot of 150 grain bullets in mine. Powder, you name it I tried it, 748,H335,4895 and 2015 are what I used the most, no particular order.
Don’t get wrapped up in numbers. Let the target tell you.
Group size, I will suggest minute of chicken. Then you can tweak as you go. A factory barrel, you can forget about reaching the throat or even remotely close to it.
Not to turn you off the 7TCU is a fine cartridge. However I went through a large number of barrels before I found two I was happy with.
One other thing, brass fire formed in one may not get along well in other barrels.
I went to a 7-30 Waters for my “U”barrel.
I had an aftermarket 10” 7TCU when IHMSA came to their senses and finally allowed them for “P”. Let a fellow talk me out of it, one of those I wish I had back.
I ran a lot of 150 grain bullets in mine. Powder, you name it I tried it, 748,H335,4895 and 2015 are what I used the most, no particular order.
Don’t get wrapped up in numbers. Let the target tell you.
Group size, I will suggest minute of chicken. Then you can tweak as you go. A factory barrel, you can forget about reaching the throat or even remotely close to it.
Not to turn you off the 7TCU is a fine cartridge. However I went through a large number of barrels before I found two I was happy with.
One other thing, brass fire formed in one may not get along well in other barrels.
I went to a 7-30 Waters for my “U”barrel.
I had an aftermarket 10” 7TCU when IHMSA came to their senses and finally allowed them for “P”. Let a fellow talk me out of it, one of those I wish I had back.
SEM
Gold $$ Contributor
DONT trim the brass, Or I use Starline 223 Basic brass after forming no fire forming is needed it will move just a smidge, I trim the new unfired cases after initial forming to .004 short of the actual chamber after the first firing it will get about another .004 shorter then square it up, gets maybe another .004 shorter, With this length you can or at least get real close to reaching the lands.. Two of mine really liked the Sierra 115gr FBSP one preferred the HP with the long brass, Sadly it was one of the calibers I chose to drop on my quest to reduce
Main purpose is mostly paper punching. I'm used to accurate firearms with a lot of competition rifles. From benchrest to long range F Class. Now looking for this 7TCU to shoot. Used new Winchester brass expanded with Redding die without decap pin FL die. CCI 400 primer. H335 powder up to 26.5 grains now. Hornady 120 grain Vmax bullets ( have lots of them). Oal 2.700"
Probably .025" from lands. Haven't seen anything better than couple inches for groups at 50 yards. Has a 2.5x8 Leupold pistol scope. Shooting off bags without grip on bench. I did anneal after 1st forming. Then once fired afterwards.
Very new to this cartridge. All help greatly appreciated
Probably .025" from lands. Haven't seen anything better than couple inches for groups at 50 yards. Has a 2.5x8 Leupold pistol scope. Shooting off bags without grip on bench. I did anneal after 1st forming. Then once fired afterwards.
Very new to this cartridge. All help greatly appreciated
dhagerty40
Gold $$ Contributor
these are some tricks we have used for years with Factory TC barrels in IHMSA:
1. The 7TCU seems to prefer flat base bullets.
2. The 7TCU seems to be most accurate when the base of the bullet is seated flush with the bottom of the neck.
3. Saw you are using H335. H335 has not worked well with the pistol barrels. The most common powders being used are: H4198,H4895, N133 and N135
Factory TC Barrels are notorious for long throats and most you cannot get anywhere close to the lands. Aftermarket Barrels are completely different though! Most barrels also have a 1-10 twist.
I have owned 4 7TCU barrels over the years and with some work, Can get them shooting under an inch at 100 Yards.
Now, My present barrel is classified as the oddball though as it has a short throat, 1-9 and Left hand Twist. But this is the most accurate of all of them. I have yet to find a load that will not shoot under an inch!
1. The 7TCU seems to prefer flat base bullets.
2. The 7TCU seems to be most accurate when the base of the bullet is seated flush with the bottom of the neck.
3. Saw you are using H335. H335 has not worked well with the pistol barrels. The most common powders being used are: H4198,H4895, N133 and N135
Factory TC Barrels are notorious for long throats and most you cannot get anywhere close to the lands. Aftermarket Barrels are completely different though! Most barrels also have a 1-10 twist.
I have owned 4 7TCU barrels over the years and with some work, Can get them shooting under an inch at 100 Yards.
Now, My present barrel is classified as the oddball though as it has a short throat, 1-9 and Left hand Twist. But this is the most accurate of all of them. I have yet to find a load that will not shoot under an inch!
I have had a Super 14 in Contender in 7mm T/CU since the late 1980's. I have shot nothing with it except H335 and Speer 145 gn Spitzers with WSR primers. My original load was about 30 grains of H335. That load was creepy accurate but way too damned hot even though a half grain under listed maximum in Speer Reloading Manual #11. Both Speer and I have come to our senses and I now shoot 26.6 gn at about 1975 fps. I noticed that they have lowered their max from 30.5 to 28 grains. I once won a case of beer by outshooting a guy and his brand new 30-06 at 300 yds. with it. It doesn't get shot near enough now because I have been playing with gas guns the last few years but I did dust it off and kill a small doe at about 150 yds with it last fall. Last time I had it out I shot these two almost identical 100 yard groups.
ETA: The bottom group was shot first, top group was after a scope adjustment.
ETA: The bottom group was shot first, top group was after a scope adjustment.
Last edited:
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.