7saum

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

So I talked to Bob at Berger today and ran the 2.987" OAL by him which puts the bearing surface at the neck shoulder junction with the 180 VLDH. He recommended seating the bullet out 5-10 thou longer (so bearing surface 5-10 though above neck shoulder junction) to avoid any donut issues that can form in the brass. He said this is how Walt sets up his guns and still has enough bullet in the neck to chase the lands when needed. He said this set up would also work for the 175 Elite. So, if i put bearing surface .010 above neck shoulder junction, that would give me an OAL of 2.997".

I had been looking at a lot of 7saum load data online and noticed that a lot of guys were at or above 3.00" OAL...some at 3.100" with h the 180. Maybe this is why?

 

[slowrunning]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

I'm having a short action, 7saum built with an 8.24 twist proof as well. I plan on running the 168 VLD's. At attainable velocities, they outrun the 180's and 195's out past 1k and don't give up much to wind.

I ran the 195's in a 28 nosler for a while and they are wicked at 3100. At 7saum velocities, the 195 doesn't catch the 168 till about 1500yds from what I can tell.

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

I'm having a short action, 7saum built with an 8.24 twist proof as well. I plan on running the 168 VLD's. At attainable velocities, they outrun the 180's and 195's out past 1k and don't give up much to wind.

I ran the 195's in a 28 nosler for a while and they are wicked at 3100. At 7saum velocities, the 195 doesn't catch the 168 till about 1500yds from what I can tell.

If you only mean in drop than you are right. I'm assuming that's what you mean when you say it outruns both the 180 and 195.The 180 and 195 outrun the 168 in energy and wind at 0 to however far you plan on shooting. This is a designated hunting rifle that I am building for killing animals, not paper or steel. Burning 60-62 grains of powder to get 1400 ft lbs of energy out to 950 yds @2800 fps mv is what turns me on. I have the rangefinder and optics to twist turrets all day. The difference in putting another few clicks of come up in a high speed 10 mil per rev turret takes seconds. I already have other guns thy will do what the 7saum with a 168 will do. I wanted something different.

 

[slowrunning]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

Drop is what I meant and the 195 is awesome. I killed a bull with one last year and my 7saum will be a dedicated hunting rifle as well. However, when comparing the 168 at 3000fps to the 195 at 2800, 9k+- elevation where I hunt, 1k yards, from bergers calculator:

Vel En Drop Wind 10mph
168: 2028 1534 -218 38
195: 2023 1772 -239 34

The energy numbers are both high enough they're negligible. 168 wins drop which is important to me, 10% less drop = more room for error (every shot has error). 195 wins in the wind, 4" of wind at 1k doesn't quite make up for the drop advantage of the 168 to me, but it does win.

So basically what I was trying to say before is that they're a wash. You really don't gain anything with a 195 at 7saum velocities except more recoil. My gun will finish around 9 pounds scoped so limiting recoil is important to me. Once you get the 195 to around 3000fps, theres not much that can keep up with it.

 

[Edd]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

Drop is what I meant and the 195 is awesome. I killed a bull with one last year and my 7saum will be a dedicated hunting rifle as well. However, when comparing the 168 at 3000fps to the 195 at 2800, 9k+- elevation where I hunt, 1k yards, from bergers calculator:

Vel En Drop Wind 10mph
168: 2028 1534 -218 38
195: 2023 1772 -239 34

The energy numbers are both high enough they're negligible. 168 wins drop which is important to me, 10% less drop = more room for error (every shot has error). 195 wins in the wind, 4" of wind at 1k doesn't quite make up for the drop advantage of the 168 to me, but it does win.

So basically what I was trying to say before is that they're a wash. You really don't gain anything with a 195 at 7saum velocities except more recoil. My gun will finish around 9 pounds scoped so limiting recoil is important to me. Once you get the 195 to around 3000fps, theres not much that can keep up with it.

Aren't you being a little selective with your preference?

The 15.5% difference in energy is negligible.
The 9.6% difference in drop is important.
The 11.8% difference in wind is merely a win.

 

[slowrunning]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

Preference was the right word. 4" of wind doesn't make the 195 worth it to me.

He hasn't found anyone here to give him the info he originally asked for and I'm about at the same stage he is with an almost identical build so I thought I'd share what I'm doing with him. Perhaps he hadn't considered the 168.

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

This is really good stuff. I love to compare and get opinions. So I ran the numbers for where I hunt (90% of the time) in south Texas using 63F at 500 ft. These velocities are obviously assumed for each bullet. 100 yd zero used for each, 10 mph wind and results are at 1k.

168 VLDH (3000 fps)-250.1, 58.6", 1074 ft lbs
175 Elite (2950 fps)-249.5, 54.1", 1181 ft lbs
180 VLDH (2900 fps)-261.7, 56.7", 1147 ft lbs
195 EOL (2800 fps)-266.9, 50.3", 1326 ft lbs

So what I'm looking for is something with a little more thump (energy) at distance. I shoot a GAP 6.5 4S quite a bit and it will outrun the 168 VLD with the 140 VLD as far as drop (-232.0) and drift (56.6")are concerned and only has 114 less ft lbs of energy at 1k.

When you look at the numbers, the bullet that really stands out to me is the 175 Elite as far as efficiency, recoil, drop, drift and energy. Still had 1400 ft lbs to 860 yds where I hunt most of the time, would be better at a higher DA (alsojust using 1400 as a standard for a large animal like an elk...I kill a lot of WT down here out to 1000 yds with 900 ft lbs out of a creedmoor and drop them like lightning...I know it dosent take 1400 ft lbs to kill an elk but want to compare apples to apples). I do hunt out west for elk and mule deer a couple times per year and this will be my new go to gun for those hunts.

So gentleman, with those numbers run, the 175 Elite looks very tempting. I may be off on MV...if someone has better info, let me know.

Let's hear some input and cuss and discuss this thing! I'm not to proud to listen to others, especially those who have gone down this road.

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

I also believe that any bullet of the hybrid design will be more forgiving during load development...not so sensitive to seating depth. Another plus for the 175 Elite in my book.

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

The 175 Elite looks like it would give 7rem mag performance using the 180 VLDH without the **** belt to mess with and less powder. I just sold a custom 7mm R.E.M. Mag and am building this gun to replace its spot in my barn with equal or improved performance. I also just love the saum case...so easy to tweak that short fat column of powder to make a load just **** near one hole.

 

[slowrunning]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

The 175's do look pretty good. They must be relatively new as I hadn't heard about them till this thread. Not much longer than the 168 with a higher BC, should work in a short action. I may have to pick up a box.

 

[bigngreen]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

You will need to decide between the 175 and the longer bullets as there is a significant throating difference. The 180 HVLD and the 195 throating works good together n the SAUM with a .230 throat which seats you in he 3.070 range with the 180. The 175 puts you half way up the neck on the seating and would complement the 168's better than the 180's.
R26 and H1000 are the two powders.

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

You will need to decide between the 175 and the longer bullets as there is a significant throating difference. The 180 HVLD and the 195 throating works good together n the SAUM with a .230 throat which seats you in he 3.070 range with the 180. The 175 puts you half way up the neck on the seating and would complement the 168's better than the 180's.
R26 and H1000 are the two powders.

The quick reference sheet would have me believe differently about the 180 and 175 not working together, say if you throated for the 180.

180 VLD
Case base to neck shoulder junction =1.724
Bearing surface = .491
Nose length = .772
= 2.987
2.987-.772=2.215 base to ogive

175 Elite
Case base to neck shoulder junction =1.724
Bearing surface = .478
Nose length = .801
= 3.003
3.003-.801=2.202 base to ogive

The 180 is only .013 longer from base to ogive when seated at neck shoulder junction of case in example above...which would basically build in a .013 jump for the 175. The 175 being of hybrid design is going to be much less sensitive to seating depth and should like a jump. The 195 in the other hand is in a league of its own as far as length goes.


195 EOL
Case base to neck shoulder junction =1.724
Bearing surface = .524
Nose length = .874
= 3.122 with bearing surface at neck/shoulder junction
3.122-.874= 2.248 to ogive

3.070 seems really long to me for the OAL on the 180. That's puts the bearing surface .083 above neck shoulder junction. The farthest I have been advised to seat a dummy for throating of any bullet was .025 above neck shoulder junction. George at GA even recommended sending in the dummies with the bullet bearing surface just at the neck shoulder junction. Berger has told me .010-.015 above neck shoulder junction....I have been wandering about this and what is best. To seat at neck shoulder junction assuming that dummy will put me at the lands or building in some jump so I don't bury bullet in case when it comes time to probably have to jump bullet. Some VLDS I've shot have liked as much as .080 jump. I certainly don't want to eat up a bunch of case and loose the benefit of building the saum on a long action.

Can you elaborate a little more on your 3.070 OAL for the 180 for me and let me know if I have missed something with the numbers above. It sure looks to me like the 175 and 180 are much closer than the 195 and anything else.

Thanks

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

Also, I am ignorant to how freebore is calculated. I know what it is , but am ignorant on how to figure it. Can someone explain?

 

[Crowe284]

Re: Anybody shooting 195 EOL in 7SAUM w/ H-1000?

Did some more figuring after looking again at quick reference chart. This time I looked at base to ogive for the bullet itself:

180 VLDH-Base to ogive = .779
.779 - .243 (boat tail length) = .536 (bearing surface to ogive)

Case base to neck shoulder junction 1.724 + .536 = 2.260 CBTO w/ bearing surface at neck shoulder junction.

175 Elite-Base to ogive = .762
.762-.207 (boat tail length)= .555 (bearing surface to ogive)

Case base to neck shoulder junction 1.724 + .555 = 2.279 CBTO w/ bearing surface at neck shoulder junction

So, as you can see from this example which I think is more appropriate because I was not using the true bearing surface to ogive length, you can see that from cartridge base to ogive, the 175 Elite is actually .019 LONGER than the 180 VLDH when the bearing surface is seated at neck shoulder junction and will remain longer seating bearing surface at any level above neck shoulder junction.

Feedback please!