7mm mag with cast boolits

[gtgeorge]

I am fairly new to rifle reloading with cast and am getting ready to try my hand at loading cast in my 7mm mag. I know there are many other better choices to load cast in and am doing that as well. I am sure magnums are not the best choice since they were designed for speed and loading CB in their place defeats that purpose but that is a rifle I have and would like to get it to shoot lead if it can be done okay.

With that said I have been following discussions concerning the gas check being installed inside the case and seems the bullet I have is going to require doing just that.

With so many very experienced and knowledgeable folks here I would appreciate any experience or feedback that can be offered to either help guide my way or shoot this project down. The mold I am using is an RCBS 7mm-168-SP and is casting 180gr lubed and checked with 3-3-94 alloy. I am using Hornady checks and looks like I will need to seat the bullet with the check well inside the case past the neck.

Tanks for any advice you can offer.

[375RUGER]

Have you done an impact slug of the throat? Or at least loaded one to see how far it needs to be seated? Impact slug will also tell you what size your boolit should be.
You can leave the top lube groove exposed if need be.

[gtgeorge]

I have not and have never done it before at all. Guess it is time to learn. I did hower do a dummy round which showed rifling marks very lightly along most of the nose and did a redneck adjustment by inserting bullet and marking a dowel inserted into the barrel and then to the bolt face the same way I determined my jacketed load that is loaded very long. What I came up with has the check well inside the case and any longer would not chamber. 101128

[runfiverun]

put some powder in the case and try it.
quite often the gas check being in the case is a non event.
if it gives you grief get the 145 gr version of the mold it has less drive band length.

oh yeah loads.
try 25 grs of 4895 and some Dacron [enough to touch both the powder and the base of the boolit with a little compression when seated]
or the ubiquitous loads of 16 grs 2400, 10 grs of unique, 10 grs red-dot.

[DLCTEX]

Hornady checks should be safe even below the neck. Test some after seating/sizing to see if they pull off easily. I'll bet they are stuck tighter than a tick. Checks can be further secured with a dab of epoxy when applying check, if they make you nervous.
You will need a powder that is not position sensitive and preferably bulky, such as SR 4759, which regrettably is being discontinued.

[gtgeorge]

I was thinking of using Trail Boss to start since it takes up a bunch of space and I tried it with some jacketed for soft loads before. I have never used a filler before and prefer not to add another learning curve yet. I do have some 4895 though. Also was considering Red Dot but really wanted to fill the case somewhat. Oh well maybe fillers are in my future :(.

The checks are super tight and I couldn't pull them off. They are really tight and this is the mold I posted about that someone butchered the gas check shank . I have to remove most of the excess to get the check on and then it would take a screwdriver to pry it off.

101176

[TCLouis]

I don't cast any of the heavies, but the 135 grain "Soupcan" performs well enough in my Husky Lightweight 7 mm Maggie and shows out in the 7 TCU also.

[Wally]

Been using the RCBS 168 SP-GC in a 7mm Rem Mag...shoots accurately. Tried the Lee 130 R...also shot well, but the RCBS was more accurate at 200 yards+.... This spring will try out an RCBS 145 Sil-GC...

[gtgeorge]

Would you share your load Wally and is yours seated deep as well? :))

[375RUGER]

This is the NOE 150 Hunter, it seats with the check into the case. 25.0g AA5744 pushes this one along alright.
101177