Throating 7saum for 195 EOL

[Crowe284]

So a couple of buddies and I made an epic journey from just north of the Mexican border in south Texas to visit the guys at GA Precision and Manners. Have to say that everyone we met was top notch as to be expected and I was blown away with the customer service and tours of their shops they took us on.

I am building a 7saum on a long action stiller predator with a proof research sendero contour barrel (8.24 twist) that will finish at 26 plus a gen 2 little bastard brake. Rifle will sit in a MCS-T Elite stock in elite midnight camo....should look sick.

I am wanting to shoot the 195 EOL out of this rifle and have the chamber throated for this bullet. I was told to make up and send three dummy rounds in so they could throat. However, I don't know where to start. I have an email in to George Gardner and I know he will get me fixed up but in the meantime I was wandering if anyone has any experience with this chambering and bullet.

How do you figure out what the ideal OAL is when making a dummy for throating? Do you seat where base of bullet is at neck shoulder junction or a bit higher and if so how much higher? I want to get all the case capacity I can out of the round. When you look at the efficiency of the saum and the BC of the bullet, if I could just get it to 2800 fps it is amazing.

If anyone has done this, would love to hear feedback especially as related to OAL, powder used and MV.

Cant wait to get her in my hands but gonna take 8 months or so (stock is primary reason) but I wanted this gun built exactly how I wanted it. Bet it will hammer!

Thanks,
Crowe

 

[lilharcher]

I'd call the guys over at Berger.....they'll probably be able to provide what you are looking for.

Otherwise, solely from an engineering perspective (starting point) - I would first start by selecting the optimal powder, which I believe is going to be H1000, then calculate the max load based on pressure (using a load calculator or calling Hodgdon). Assuming max pressure is achieved at a weight less than max case capacity, you will have your starting seating depth (providing max freebore). Now, how you dial it in from there, I don't know....

It looks like .180" freebore is the starting point for the 180 gr. pills, so you are likely looking at some # north of this.

 

[Crowe284]

Thanks for the reply, makes sense. H1000 is what I was figuring on trying and hoping works as it is what I use in my 6.5saum. Will give the boys at Berger a shout and see what they have to say. Thanks again.

 

[Crowe284]

Talked to Berger and they didn't have any information to give me on powder selection for this bullet and chambering.

I'm planning on initially trying H-1000 powder but wonder what minimum charge weight might be for performing seating depth test to figure out most accurate jump. I asked if they had any experience or information with that bullet and the 7saum and the answer was no.

For creating dummy rounds for throating it was suggested that I seat bullet to where the boat tail and bearing surface junction meets the shoulder and neck junction or just slightly above, which puts the boat tail below the neck and shoulder junction....that's all I got but guess it's good enough. Gonna have to tap the reloading section to see if anyone has any experience with the 195 EOL in a 7saum with H-1000.

 

[hseII]

Talked to Berger and they didn't have any information to give me on powder selection for this bullet and chambering.

I'm planning on initially trying H-1000 powder but wonder what minimum charge weight might be for performing seating depth test to figure out most accurate jump. I asked if they had any experience or information with that bullet and the 7saum and the answer was no.

For creating dummy rounds for throating it was suggested that I seat bullet to where the boat tail and bearing surface junction meets the shoulder and neck junction or just slightly above, which puts the boat tail below the neck and shoulder junction....that's all I got but guess it's good enough. Gonna have to tap the reloading section to see if anyone has any experience with the 195 EOL in a 7saum with H-1000.

Where did you end up with this?

I've got 2 boxes of 195 EOLs & I'm trying to decide if this looong barreled 7WSM built on a Long Action would be a waste of time & powder....

 

[Crowe284]

Ended up having GAP chamber barrel with a .180 freebore reamer thag I had Dave Manson grind to set the 180 hybrid up perfect and it also worked excellent with the 195. Accuracy with both Bullets was superb but I could not run the 195 fast enough to beat the 180 hybrid without loosing primer pockets after 2 firings on Norma brass to get there. Settled on a load of 62.2 gr of h1000 that pushes the 180 hybrid @ 2900 fps even with 1/4 MOA accuracy out of a 26" 8.24 twist proof barrel. The 180 hybrid has been lights out on game.

 

[hseII]

Ended up having GAP chamber barrel with a .180 freebore reamer thag I had Dave Manson grind to set the 180 hybrid up perfect and it also worked excellent with the 195. Accuracy with both Bullets was superb but I could not run the 195 fast enough to beat the 180 hybrid without loosing primer pockets after 2 firings on Norma brass to get there. Settled on a load of 62.2 gr of h1000 that pushes the 180 hybrid @ 2900 fps even with 1/4 MOA accuracy out of a 26" 8.24 twist proof barrel. The 180 hybrid has been lights out on game.

Thank You Sir. That's the info I was searching for.

 

[Rhovee]

.185 isn't even long enough. .200 is good for most 180's. Imo the 195 is to big for saum case. 180's with .200-.235 is perfect.

 

[Mxracer532]

I'm looking at having this same build done. Not sure on action/stock just yet but I may end up chambering for 180 ELDM's.

 

[bigngreen]

I like the SAUM set at a .235 throat for 195 Berger, 180 HVLD and the 180 ELD-M.