Twist rates & bullet weights 7mm rem mag

[Buffinnut]

My rem783 7mm rem mag has a 1:9.25 twist 24” barrel
It’s looking like it’s kind of picky on bullet weights.
I know that twist rate is better suited for 160grain ish but I was not expecting such horrible results with a bit lighter bullets.

I was burning through some cheap Winchester 150 grain power points for practice ammo. They were like 1.5-2 moa at 100 yards. At 200they were flying everywhere. 4or5 moa idk they were all over the place.
I then shot some Hornady interlock 139s and they were a little better but not great.
I was convinced something was loose until I shot the trusty Bergers and they were still good.
168 Berger hh shoot .75 moa or better @ 100 prone over my pack. 1moa @300 the other day with gusting winds prone with a tripod.
I shot a few 160 grain Norma tipstrikes today sitting with the tripod .9moa @ 200.

I’m wondering if I’ll be wasting my time trying to shoot the Ballistic silver tips I have in 140&150 grain or the 154 interlocks.
I’m assuming my 160 accubonds and 162 eldx will work well.

Is this consistent with what y’all experience when shooting lighter bullets out of a faster twist?

 

[Rob5589]

If you aren't reloading, pick the ammo that shoots well enough for your requirements.

 

[83cj-7]

To answer your question, you can’t over stabilize a bullet. The only exception to that would be driving a small bullet so fast from a fast twist that it vaporizes in mid air. Think 22-250 with an 8 twist barrel shooting 40 grain bullets at 4000fps. I am currently shooting a new Tikka in 7mm that shoots 120s and 168s equally well.

 

[brad407210]

You can go light without problems, my factory barrel likes 120's better than anything and my 1:9" Lilja barrel preferred 150's over 162's. If you can get under 2" with cheap practice loads that's doing good, sometime you luck out and find bottom shelf stuff that a specific rifle likes, but don't worry about shooting under an inch unless you use good quality ammo.

 

[Buffinnut]

If you aren't reloading, pick the ammo that shoots well enough for your requirements.

I plan on using the Berger 168s and have plenty of those. I was just just trying to work through some of my other ammo for training/practice. The 150s and 139s were so bad I was wasting my time.

 

[Buffinnut]

Thanks for the responses guys. Looks like I’ll give the other factory ammo a try and keep whatever shoots half decent for practice and sell/trade what this rifle doesn’t like. I was hoping to be able to burn most any loads for practice but apparently not. Have to be more selective with what I buy in the future.

 

[scott_co]

I just purchased a custom R Bros 7mm RM, and I plan on using HSM's 180 gr VLD hunting ammo or Hornady's 162 gr ELD-X.

Typically, my decision would be based on what shoot's best, but these days I may be shooting what I can find available.

 

[RifleDisciple]

I have an older 7mm RM that likes 140 Sierra's. I tried some 160 Speer HotCor but didn't get the accuracy I liked. I'm also shooting some old stock Nosler Solid Base 150s at about 1.25" which is alright. I really want to get something in 160gr but have not bought enough bullet types to test. I don't know my exact twist rate.

I just picked up some 160 Nosler AB and they are longer than I expected for a 160. Good looking bullet, I hope it shoots! The range I go to still had 1x 50ct each of 140 AB, 150 Nosler Partition, and 160 AB's. I went for the 160 since I already have a decent 150 grain, and I'll probably go back for the 140's just to try.

 

[menhaden_man]

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

 

[Ranger Rick]

I just purchased a custom R Bros 7mm RM, and I plan on using HSM's 180 gr VLD hunting ammo or Hornady's 162 gr ELD-X.

Typically, my decision would be based on what shoot's best, but these days I may be shooting what I can find available.

Great choice on your custom rifle. What’s your barrel’s length and twist rate?

 

[scott_co]

Great choice on your custom rifle. What’s your barrel’s length and twist rate?

Build specs:

• Proof Sendero CF, 26", 8.4 Twist
• Rogue LW Action, RIGHT HAND
• Manners EH-1, 13.5" LOP, 3 Studs
• Jewell Trigger
• BDL
• Saddle Cheekpiece
• Gen II LB Brake
• 20 MOA 1pc ring/base w/rear level cap
• Zeiss V6 3-18x50 ZMOA-2 Reticle