7 tcu problem

[dancast]

hi folks,
just a start, a 7 tcu, is a 223 case necked up to 7mm, mostly used in a t/c contender for silhouette shooting.
my prolbem is seating the rcbs 145gn cast bore rider bullet, with the rcbs seating die. i get a little deformed ring around the bullet nose. taking the die apart, it looks like i can shorten the bottom of the seating cup a little, so it does not make that ring on the nose when seating the bullet.
what do you think????? opened to ideas thanks....dancast

fyi: they also make the tcu in 257, 6mm, and 6.5mm flavors

[iron mule]

hello
and yes you are correct the bullet seater needs to fit the profile of the nose of the bullet to prevent it from doing this

another way you may want to do this is with some ex-poxy place some ex-poxy in the nose of the seater and use the bullet to form it to the correct deminsions
mule

[cainttype]

You might also consider adding an expander like a Lyman M die to your die set. They are designed for cast and will very likely reduce the neck tension ( and force required for seating your cast bullet ), allowing you to seat with less bullet deformation.

[country gent]

If you go the epoxy route coat the bullet with several coats of wax car wax or floor wax will work but you want a release agent there. One of the putty type will work better here a small bit of it in the seater and put the bullet into die and let cure.

[high standard 40]

What brand are your dies. RCBS makes a seater punch to fit their dies that is specifically for the 7MM 145. I know because I have one. The RCBS part number is 9696 and they list it for about $7

[jhalcott]

Do you KNOW if that little ring makes any difference in performance with that 145 grain bullet? I used a MUCH heavier 170 grain bullet to cull some deer a few years ago in MY 7TC/U carbine. I had a similar ring on those but the accuracy was still there, about an inch and a half @ 100 yards. Bag rested and a 2x7 scope.

[dancast]

hi cast bullet fans,
thanks for the thoughts on the ideas of the fixes that may be needed. yes it is an rcbs die set, and will try that part. i do have some m-dies(hornet), may try that also. i do not know if accuracy is effectived, but that nose does not look pretty, but i guess i could cull them rounds out for practice, or use them on the pig target at 100yds. thanks.....dancast

[quilbilly]

I have a Hornady die set for my 7mm TCU that leaves a small ring on my 130 gr RNGC and have not found it to have any impact at all on accuracy which is under MOA when my eyes, even with a scope are having a good day.

[JSH]

I would say the m die would be the fix. If you are deforming when seating it is a fair bit to tight. May even resize however much of the boolit you have in the case?
I have deformed noses when running through the lube sizer, but really question when seating.
Jeff

[44man]

Epoxy works great but the ring will have no affect on accuracy at all.

[brasshog]

The ring on it should have no real effect on accuracy for the average shooter (range). Are you shooting it in pistol or carbine form ? I ask to get an idea of your velocity. If your were to use a bullet like a VLD from Berger then that ring will most likely keep your bullet expansion to "iffy" due to the pressure caving in the hollow point area enough to cause an issue. Hence why they make a specific seater for that one bullet. Otherwise you should be good to go. If this is a hunting bullet you may want to do an expansion test at the most likely impact velocity/range if you don't use some the above listed fixes. I use a set of Redding dies for 7mm TCU loading.

My dies- http://www.midwayusa.com/product/617610/redding-competition-bushing-3-die-neck-sizer-set-7mm-tcu

[pls1911]

A coupl of other suggestions....
I shoot silhouette as well but with a 30-30. I do have a 7TCU, though I got sidetracked a few years back and never got beyond the 1st 40 rounds for forming brass.
Regarding bullet casting though, I did cast up several hundred RCBS SIL bullets... if you heat treat your bullet you will not have the ring problem.
Also, be sure to bevel your case mouth ...this allows an easy start of the gas check.

[upnorthwis]

I wouldn't worry about it either. Have shot several IHMSA Cast Boolit U-40's with damaged tips. Not that they all made the paper after filling out the forms and the match director sending them in. But that's a different subject.