7mm SuperMag

[ihmsakiwi]

Hope some of you more experienced guys can help.
I am trying to shoot cast in my newly aquired BF 7mm supermag. Problem; I have to seat the bullets ( RCBS and SAECO 145gr) below the shoulder or they will not fit into the chamber. I only shoot cast in all my other c/fire pistols and just don't get the same satisfaction shooting copper. ANY SUGGESTIONS?? Kind regards, Peter.

[jhalcott]

If this round is based on the "improved" 30-30 case, like the 30 Waters, You may have to use a different style of bullet. Some thing along the lines of the 311466. A 150 grain Loverin design.  A 287221 (120) or 287405 (150 gr) MIGHT work. another trick would be to paper patch a .270 bullet.I use a 280468 (109gr) wrapped with 2 layers of teflon tape in several 7TC/U barrelswith good to excellent accuracy. The LEAST desirable (to ME) would be to have the throat opened to accept the RCBS or SAECO bullets.  I did use the RCBS 168 fngc to fire form some 7BR cases with out any problems. They were seated below the neck and gas checked. The bore was inspected after each shot.

[mugs]

I use a Saeco 073 170 gr. in my BF 7 SM. It will chamber with only the gas check seated in the neck. But only if sized .284.
Mugs

[Johnch]

7 Super mag is a 357 Max case necked down
I had a TC barrel in it

I bet you need to nose size , I have to for several rifles with tight throats
I had to get a custom sizing die
You size the bullet nose first , but stop before the driving bands , with just a little spray on case sizing lube

I had a freind make it

Or you can have a Gunsmith lengthen the throat till the bullet you want to use just fits

Johnch

[ihmsakiwi]

I use a Saeco 073 170 gr. in my BF 7 SM. It will chamber with only the gas check seated in the neck. But only if sized .284.
Mugs

Hi Mugs,
Do you mean that you only size with a standard .284 sizer without nose sizing?? I  have the Saeco 145 gr, but it too needs seating below the neck. Peter.

[Steve P]

Peter, I shoot cast in my TC, but I have a shorter 135 grain pointed design bullet from Lyman.  It is an old old old mold.  I also use 5.56x50R brass and form it.  If you have access to the 5.56x50R brass, it works much better than 357 maximum cases. 

Good luck shooting,

Steve   

[ihmsakiwi]

Peter, I shoot cast in my TC, but I have a shorter 135 grain pointed design bullet from Lyman.  It is an old old old mold.  I also use 5.56x50R brass and form it.  If you have access to the 5.56x50R brass, it works much better than 357 maximum cases. 

Good luck shooting,

Steve   

Hi Steve,
Why does 5.56x50R work better than the 357 Max brass? Do you use the 135gr for silhouette? If so, does it take the rams? Peter.

[Steve P]

Yes, the 135 takes the rams.  I am working up a load now using VVN133.  Will see if it works any better than 748.  Used this barrel in a pinch at the WCC about 3 years ago.  Had 7TCU ammo, but left the barrel home.  Took 58x60 with it.  Mold 287442.  Here's a link: http://www.castpics.net/RandD/Lyman_moulds/lyman05.htm. 

Steve   

[ihmsakiwi]

Yes, the 135 takes the rams.  I am working up a load now using VVN133.  Will see if it works any better than 748.  Used this barrel in a pinch at the WCC about 3 years ago.  Had 7TCU ammo, but left the barrel home.  Took 58x60 with it.  Mold 287442.  Here's a link: http://www.castpics.net/RandD/Lyman_moulds/lyman05.htm. 

Steve   

Hi Steve,
thanks for that info. Curious about the 56 x 50R brass. Why do you say it is better? RWS brass is good, or s it something to do with neck length being a little longer? Peter.