7MM SAUM IMP looking for info

[bobinpa]

I am thinking about building one and I'd like to hear from those who have tried it. Please give me the good and the bad. Any reason not to do it?
What grain bullets are you running? What velocity? Etc etc....
Thanks in advance!

 

[TZaun]

I ran one with a 35° shoulder in F-Class for a couple years. H4350 and 184 Hybrids around the 2875 fps area seemed to shoot the best. I highly recommend ADG brass over the Norma. Biggest downfall to me was barrel life. 1100-1200 was all I could get using this combo.

 

[Sniper338]

7 sherman short

 

[rardoin]

RL-23, H1000 and N165 will give much better barrel life than H4350...particularly the latter two. My first 7 Sherman Short barrel running 190’s at 2780-2800fps lasted 1800rds before it started opening up a little. It thrived on H1000/N165.

 

[Preacher]

All the ones I've done loved H1000 and the 140 and 162's...
Hunters, so never worried about barrel life to much.
Mine has only about 1000 rounds on it in 4 years, not seen hardly any movement yet..

 

[bobinpa]

Thanks for the replies... This will be a heavy barrel for informal matches and ground hog hunting. Going to run the 180 class bullets. Considering twist rates at the moment.

 

[rardoin]

For the 184’s and less go with a 9tw. Proven precision in the 180/184 hybrid at mid/long range.

 

[Punkinslinger]

I ran one with a 35° shoulder in F-Class for a couple years. H4350 and 184 Hybrids around the 2875 fps area seemed to shoot the best. I highly recommend ADG brass over the Norma. Biggest downfall to me was barrel life. 1100-1200 was all I could get using this combo.

I run a 7 RSAUM with a 35 degree shoulder, my take on it,,,, reinventing the wheel would be easier and more fun, or maybe inventing a new mouse trap ? Gahhhh makes me pull my hair out. Worst piece of advice, from TZaun "Build an F-Class rifle, it'll be fun" he said ! I used to be fun loving and a jokester now, just a crabby 7 RSAUM shooter.

 

[bobinpa]

I run a 7 RSAUM with a 35 degree shoulder, my take on it,,,, reinventing the wheel would be easier and more fun, or maybe inventing a new mouse trap ? Gahhhh makes me pull my hair out. Worst piece of advice, from TZaun "Build an F-Class rifle, it'll be fun" he said ! I used to be fun loving and a jokester now, just a crabby 7 RSAUM shooter.

I know I am opening a can of worms here but why? Is it hard to tune? Hard on barrels? What has you pulling your hair out?

 

[Punkinslinger]

It is extremely hard on barrels 1,200 rounds , shooting like a house afire, then set it back got another 350 out of it.

I've tried180’s , 184’s , 183’s and 190’s I’m currently working on the 190’s it likes a

 

[Punkinslinger]

A lot of neck tension

 

[Punkinslinger]

It is extremely hard on barrels 1,200 rounds , shooting like a house afire, then set it back got another 350 out of it.

I've tried180’s , 184’s , 183’s and 190’s I’m currently working on the 190’s it likes a

7,000 thousandths neck tension

 

[Ranger188]

@Punkinslinger what powder and how fast are you pushing your bullets?
Do you turn your necks?

 

[Punkinslinger]

I've run H4350, H4831SC, H4831, H 1000, 7828SSC, some of the Reloaders, some Vihtavuori, always ended up back at 4831 or 4831SC. I've run the 180's from 2820 all the way up to 2920 shot the 180's best at 2860-70 range. As the barrel aged I've had to run them at the 2920 range.

Currently shooting (testing) the 190's with .007 neck tension, chamber is a .311" neck, yes I turn necks, loaded round dia is 307. I've always had random vertical, had the guy's at Defiance ship me a new cocking piece to achieve .250" firing pin travel, so far that has accomplished what I'd hoped, no more random vertical. It has been a snow less winter here on the prairie and the mirage coming off the black dirt is awful. I shoot out my reloading room window, to the east, almost as soon as the target is illuminated with enough sunlight to run the scope at high enough power to actually see the orange dot at 1K, the ground is alive. I've taken a gen set and lights out to illuminate the target and shot in the dark, but not enough light to illuminate the scope.

Current specs for the 190's I'm testing.
Norma brass (as TZaun say's go with the ADG)
CCI 250 magnum primer
H4831 59.34 grains guessing 2870 fps labradar does not like cold temps.
190 hybrids sorted by length into .002' lots
.040" off the lands
Ezell tuner
Kreiger 30" 1.25 straight not 100% on twist with this one maybe 8.5, can't say for certain

All the guy's I know that have shot the 7RSAUM or a variant of it have moved on to a newer better mousetrap, when this barrel is gone I'm moving on to a different mousetrap.
To answer your questions, hard to tune even harder to keep in tune and barrel life.

 

[DocDoc]

You must have tested and see a difference. I would think that beyond.002-.003 you are just expanding the neck with seating the bullet.

 

[Longrange57]

Standard 7mm RSAUM is hard to beat! Mine shoots just about everything, 162 eldm, 180 hyb or vld, 184.
Loves the 180 vld. 8.5 tw Kreiger.....shot these about 2 hours ago!

 

[Longrange57]

Fun rifle to shoot!

 

[tom]

I'm going to try one in a hunting rifle fairly soon. Hopefully it likes rl23, as I have some of that.

Tom

 

[RDavies]

I havent tried a 7 SAUM imp but have had numerous SAUMs and never got past 1000 rounds in F class with decent consistent accuracy so im a little surprised at people saying they got longer barrel life with more case capacity.

 

[Longrange57]

1,000 rounds 4831sc and 1400-1500 rds H1000 for me