7 RUM 9.25 twist

[WeiserBucks]

I've got a 7 RUM on the way , for the sake of this conversation it's a 26" Sendero. Time to order bullets . Will the twist handle a 180 Berger or 175 ELD ? I'm sure it won't handle the 195's , any recommendations?

 

[PGJPJ]

It's kind of fun to play around with the "Bullet Twist Calculator" on the Berger site. It says at sea level, you'd need to be able to push the 180 VLD at 3150 fps to get all the BC out of that bullet.

Superising (to me at least), the 175 Elite would take a bit more.

Otherwise, you'd be giving up some BC. Not sure how fast you can push it with the RUM.

 

[toddc]

My SAUM will stabilize 175ELDX with a 9 twist to the tune of .4 MOA at 1k. Any stability calculator is a GUIDE anyway. It may...it may not. Only 1 way to find out.

 

[WeiserBucks]

Speed won't be an issue, I just don't want to waste money and bbl life on bullets that won't work. I'm expecting some good info, 7mm Sendero's are very common.

 

[toddc]

Depends on the weather lol. At 5k altitude at 3200 it will hit 1.5 SG. I think it will 75% likely. Barrels are still very individual things. That bullet is borderline enough you will just have to test it. A 1.3SG will likely shoot fine but the BC may be degraded.
What is your altitude and weather?

 

[WeiserBucks]

I'll be shooting between 2-7k feet elevation, anywhere from the teens to 100+ degrees.

 

[WildRose]

Speed won't be an issue, I just don't want to waste money and bbl life on bullets that won't work. I'm expecting some good info, 7mm Sendero's are very common.

True, but Remington isn't building Senderos with the idea in mind of building them to shoot the new heaviest/long for caliber bullets.

If the calculator says you should be able to fully stabilize your chosen bullet at speeds that are realistic give them a try, if not I wouldn't waste the precious barrel life of your 7mm Rum.

 

[Lefty7mmstw]

I've got a 7 RUM on the way , for the sake of this conversation it's a 26" Sendero. Time to order bullets . Will the twist handle a 180 Berger or 175 ELD ? I'm sure it won't handle the 195's , any recommendations?

my lh lss 7rum tosses the 180 sierra to 3100 fps with a mild load of retumbo and does 1/2 moa or better with it if the trigger wiggler does his part

 

[Lefty7mmstw]

True, but Remington isn't building Senderos with the idea in mind of building them to shoot the new heaviest/long for caliber bullets.

If the calculator says you should be able to fully stabilize your chosen bullet at speeds that are realistic give them a try, if not I wouldn't waste the precious barrel life of your 7mm Rum.

my 9" ish twist 7rum lh lss does a better job of achieving accuracy with 175-180 grain bullets than my 8" twist shilen bbl'd 7stw...
the 7rum just seems to be better than the 7stw with heavies... My next 7rum bbl will be 7.5" twist to eat the heaviest stuff out there with ease...

 

[WildRose]

my 9" ish twist 7rum lh lss does a better job of achieving accuracy with 175-180 grain bullets than my 8" twist shilen bbl'd 7stw...
the 7rum just seems to be better than the 7stw with heavies... My next 7rum bbl will be 7.5" twist to eat the heaviest stuff out there with ease...

Bullet stability is but one factor in having a rifle shoot a nice group at 100yds.

Stability also increases with increased velocity even with all else being equal.