reloading 7mm TCU with H322?

[Crashnrondo]

In the Nosler reloading book number 5 the H322 max load for a 120 BT is 28.5, Hodgen's max load for the same bullet is 26.  A 2.5 grain difference seems like an awfull lot, and if I use 10% less as a starting load from the Hodgen recomended max I think I will be below Noslers starting load. What to do? Thanks-Ron

[PDM1]

I shoot the 7tcu in a 10" and 14" barrel using H322 and find the Hodgdon manual to be right on.  The Nosler load sounds hot.   H322 is very flexible, I would start with the Hodgdon load and work up from there about .5 gr at a time.

Paul

[Ex-Cajun]

Keep in mind that the closer the bullet is to the lands the more the pressure increases.  If this is a factory 7tcu, then with the 120 grain nozler, your about 1/2 inch off the lands.  This also means that the accuracy will be pretty bad (as mine was).  I used the H322 in 4 different 5 shot groups starting at 25.5 and going up to 27 grains.  The cases nor primers showed any signs of over pressurization. I couldn't get a group smaller than 4 1/2 inches at 100 yards.   I'd feel secure in doing it again if I was going to shoot 120's again.  
I just purchased a box of Sierra Matchking BTHP's in 168 grain.  They should be long enough to reach the lands and I'll back off the charge quite a bit and start at the lowest recommended and go up until l get good accuracy or reach a max grain load, whichever comes first.  If I can get a way with a minimum charge and still get sub MOA, I'll be delighted!

[jason280]

I haven't tried any 120gr bullets in my TCU, but I have fired some fireforming loads with 130gr BTSP's.  My first groups averaged around 1", but I didn't shoot them much.  I did notice some flattened primers, which confused me because I was using a starting load of around 24gr of H335.  The load averaged around 2000fps, and I haven't tried any other loads yet.

I did notice that Nosler does list some hot loads for the 7mm TCU, especially compared with other books.  They show an especially hot load using RL-7, which claims 2400fps with a 120gr bullet out of a 14" barrel.  I can't remember the exact load, but it was well above (at least 2-2.5grs) what other books listed as max.

H322 should work very well with the TCU, but start low and watch for pressure signs.

[dammyankee]

:roll: Here is a group I fired today with Rel 7 and 130 grain Speer spitzers,I seated the Speers one caliber deep in the case and it seems to do pretty good,It is out of a factory super 14 inch.

http://img205.echo.cx/my.php?image=7tcucopy0oh.jpg

[jason280]

Group looks pretty good. How many grains of powder are you using behind the 135's?

[dammyankee]

:roll: 23 grains of reloader 7,It is a max load.