Going to get a new barrel from Pac-Nor in a 26" SS barrel in a 3-groove, not sure if I should get a 9 or 10 twist. I will be using mainly 140-160 grain bullet in the TSX or Accubond. I will be using for up to 500 yard shots, any comments would be appreciated.

1-9.

That's what I have.

quote:

Originally posted by Mohunt:
Going to get a new barrel from Pac-Nor in a 26" SS barrel in a 3-groove, not sure if I should get a 9 or 10 twist. I will be using mainly 140-160 grain bullet in the TSX or Accubond. I will be using for up to 500 yard shots, any comments would be appreciated.

Nothing slower than 1/9". You want to be able to shoot the longest, most streamlined 175-grainer in existence!

If they do make this go with it a 9.5 or a 9 or 10 will work also . My first choice would be a 9.5 .

Shoot Straight Know Your Target . ...

If a 160gr is the heaviest you will shoot, a 1 in 10 will do fine. Heavier bullets to 175 will require a 1 in 9. The 1 in 10 will allow lower pressure and slightly higher velocity.

I am pretty sure that 9.5 is standard. I had a 1-10" in a Ruger #1 and when the barrel got soft the 160 SBT's were tipping at 100 yds.

The Berger 180 VLD requires a 1-9.

Seems like 1-9 is the answer.

Has anyone had experience in shooting the 168 gr. Berger VLD at long ranges 500 plus, as to how they stablize in a 9 or 10 twist?

I'd go 1:8 for the 180gr pills,...nothing less than 1:9 though.

There really isn't any reason to do a 1-10 twist. I can think of many reasons to go 1-9 but no reason whatsoever to go 1-10.

Most, if not all 7mags come with 1-9 to 1-9.25 for a reason.

The 168 VLD performs best with 1-9.

I believe the man posted 140 & 160 grain pills , so a 1:9.5 " twist would be the best of all IMO.
Now I consider 140 to light for any thing over 300 Yd. again IMO . I prefer 156 -180 grs. my self with Ideal being 168 -175 .Least wise in the four decades I've used the 7MM Rem Mag. mine seem to preform well with those weights .

Shoot Straight Know Your Target . ...

I have a Krieger barreled M700 by Gre-Tan rifles in 1-10 twist and it shoot's 120 grain Barnes triple shock great as well as the 140 grain Nosler Accubond & Partition and 150 Nosler Partition. I don't shoot anything heavier since I have a .338 RUM to take care of that.

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There really isn't any reason to do a 1-10 twist. I can think of many reasons to go 1-9 but no reason whatsoever to go 1-10.

I use a 1 in 10" twist in all of my 7mmremmag and 7mmstw rifles.I use the 140gr mrx,140gr tsx,and 140gr ballistic tip with very good accuracy to 500 yards.I have taken several head of big game at over 400 yards,and many over 300 yards,including elk and moose,with great results.In fact all five people that I hunt big game with use 7mmremmags,and all use 140gr bullets.

I had a 7wsm barreled with 1-10 twist, 25" barrel for use with lighter premium bullets. If I ever build another fast 7 it will be the same twist rate. It groups good with Hornady 175 grain I-Locks and puts Barnes 160 grain coated X bullets into one ragged hole.

Forgot to mention the 1 ragged hole groups are, ofcourse at 100 yards. I regularly shoot this rifle at 600 yards and get 4 inch, 5 shot groups from the Hornady and X bullets.

quote:

Originally posted by Dr.K:
I believe the man posted 140 & 160 grain pills , so a 1:9.5 " twist would be the best of all IMO.

He did post that, but 1:9.5" is not an option for the 3 groove PacNor barrel in 7mm. He also posted a question regarding the Berger VLD 168.

That is where I'd opt for the 9 over the 10.

quote:

I use a 1 in 10" twist in all of my 7mmremmag and 7mmstw rifles.I use the 140gr mrx,140gr tsx,and 140gr ballistic tip with very good accuracy to 500 yards.

quote:

I had a 7wsm barreled with 1-10 twist, 25" barrel for use with lighter premium bullets. If I ever build another fast 7 it will be the same twist rate. It groups good with Hornady 175 grain I-Locks and puts Barnes 160 grain coated X bullets into one ragged hole.

I have no problem with a 10 twist 7mm barrel but when one opts for going with heavier bullets, the norm is to use a tighter twist. Getting good groups with the 10 twist should be easy to do with all bullets 160 and under.

You are not going to overstabilize the lighter bullets with the 9 twist. The 9 twist will cover all bases in the 7mag generally better than the 10 twist if the shooter decides to go with heavier bullets at some point in the future.

quote:

The 9 twist will cover all bases in the 7mag generally better than the 10 twist if the shooter decides to go with heavier bullets at some point in the future.

Actually myself and all of the people that I hunt with have gone with lighter bullets in recent years.With better bullet construction,we don't see the need for heavier bullets.

The faster and/or heavier a projectile the faster it must be spun to stabilize it. You cannot overstabilize a bullet yet the goal is to spin it no faster than necessary to keep it stable.So pick a pitch that will stabilize the heaviest bullet you intend to shoot. If a heavy VLD you want a 1-9".

Id go 1-9 thats what i have on my 280ack and it pretty accurate with 162gr A-maxs. i think you want the option to be able to shoot the heavier longer bullets like berger 180VLDS, even if you dont think you will shoot them, its nice to have the option if you change your mind a couple of months later.

Go 1 in 9 or faster! especially since long range shooting is on the cards

Not to try and steal a thread, but what do you think of a 1:9.5 in a .280 AI shooting 140's?

quote:

He did post that, but 1:9.5" is not an option for the 3 groove PacNor barrel in 7mm. He also posted a question regarding the Berger VLD 168.

That is where I'd opt for the 9 over the 10.

DOC;

Then I would agree!. I also would opt for a 1:9 twist . I wasn't aware PacNor didn't offer half rate twist . My ignorance .

One hears and sees animals of various sizes being killed with what ever weight and style bullet . I have a mental formula for animal type size too bullet weight ratio . I also carry generally no more than 3 weights of bullets with me ,most of time only 2 . I also practice regularly so I know where point of impact is .

I prefer humane kills and have seen perfect shot placement not drop an animal quickly or cleanly . IMO : because the bullet was to light or not of the right type .

It's a free country use what ever works for you . I now stay inside of 500 yd for any animal and generally no more than 400 for Elk sized animals . I can do a fair job off hand for I only have to shoot once . It also helps when using hand loads for top accuracy .

Shoot Straight Know Your Target . ...

quote:

Originally posted by stubblejumper:

quote:

The 9 twist will cover all bases in the 7mag generally better than the 10 twist if the shooter decides to go with heavier bullets at some point in the future.

Actually myself and all of the people that I hunt with have gone with lighter bullets in recent years.With better bullet construction,we don't see the need for heavier bullets.

Yep. I agree. That is why I load the 110 TSX for my bro in his 270 and for one of my 270s. Collectively, we have seen enough evidence from this combo that, inside of a couple hundred yards, there's no need for anything larger for deer size game.

With bullet construction advances, it is feasible to go with lighter, faster, flatter shooting, decreased recoil bullets.

If I built a 7mm RM for myself, it would be on a 1:8" twist.

Pro:

It will not hurt the performance of conventional 160gr to 175 gr cup and core hunting bullets in any way.

It will enhance the terminal performance of any mono soft or solid hunting bullet you would care to use, regardless of weight.

It will enable the use of longer bullets than 175gr cup and core or 160gr monos, for extended ranges, should this be the goal at some stage.

It will allow the use of very long VLD spitser bullets of any type of manufacture, to get to 1000yds and beyond, should that be the goal at some stage.

Con:

Bullets made from tissue paper jackets with baby powder cores will fall apart more readily on impact than what they normally do. This is probably not important.

General:

Twist has little influence on speed and pressure. From a 1:7" to a 1:10", there would be no measurable difference other than, possibly, a tenth or two less powder in the tight twist, for the same speed as the slow twist. Different primers would make a bigger difference than the rate of twist.

I would be reluctant to choose a twist rate and build a rifle that is tied to a particular length of bullet. You are forever psychologically attached to that choice. Slow twist rates have limitations in bullet selection. Fast twist rates are much more versatile and allows the application of the rifle to be changed as it suits the need.

yea, what Gerard said.