Neck Tension

[The Gun Pimp]

"Having said that, there are claims (admittedly from seating-force-gauge sellers) that sorting and grouping ammo by seating force produces more consistent velocity. However, my understanding has always been that (if the chamber permits) the case mouth opens and completely releases the bullet before the bullet starts moving; if this were the case how could tension/grip have an effect on ballistics or accuracy?"


Exactly!
Vince

[Ovenpaa]

:) So why do we bother, is this a feel good thing? A mate points every one of his bullets, Christel refuses to tumble her cases, I use a PB brush in a cordless screwdriver down the inside of the necks at a very specific rate. Some weigh to exactly one kernel and some will only use Arbor presses for pushing bullets in. I think we all do our own thing as we believe it makes for a more accurate bullet and accordingly is one thing less to dwell on at the firing point.

I was recently reading about the BR shooters in the US who years ago used to neck turn a very specific length of the neck so that once fired a register is formed inside the neck that allowed the shooter to just place the bullet in the neck by hand and always to the same OAL.

The interesting/scientific part is what has been proven to work physically and what makes us shoot better because we believe what we have built is better?

[Sim G]

One question, how do the scores of F/TR and F class compare?

[The Gun Pimp]

Sim G

Laurie Holland covered this topic in his write up of the recent F Class Europeans in Target Shooter magazine - Dec issue.
www.targetshooter.co.uk

Vince

[rox]

One question, how do the scores of F/TR and F class compare?

At the most recent World Championships the F Open and F/TR shot alongside so had broadly similar conditions (although the F/TR were on a more exposed part of the range, IIRC). The scores are available via the following links:

Open International Teams Match

F Restricted International Match

Discarding the top and bottom scores in the winning teams and averaging the remaining scores gives a difference of 31 points per man over six 2+15's, or 5 points for each 2 + 15 shoot, a pretty huge difference in favour of the 7mm/Open.

Bob.

[The Gun Pimp]

Bob,

The 308 can hold it's own at 800yds and even 900 but at 1000 yards we can get blown all over the target!

Cheers
Vince

[woody_rod]

Bob,

The 308 can hold it's own at 800yds and even 900 but at 1000 yards we can get blown all over the target!

Cheers
Vince

Against a 6,5mm of typical target shooting type, you would have a disadvantage at all ranges. Mine shoots less than 2/3's of the elevation of a 308 at all ranges, and about half the windage. That is 22 minutes of elevation at 1000 yards (above 300), with the 308 typically being 34-36. No matter how you look at this, the 308 cannot keep up.

[The Gun Pimp]

Woody,

I agree - the 308Win is inferior to say the 6.5x55 Swede but as an F Class round - on an F Class target it does well at 800/900 yards - check out a few past results from the League - in other words the 308 does shoot a 'possible' now and again - and don't forget, our set-up and rifle weight is at a disadvantage to an Open Class rifle.

The top three or four F/TR shooters would still be in the top ten Open Class shooters at most League shoots. Build a 308 into a 22lb Open Rifle and shoot off proper benchrests and you would see even more improvement.

Incidentally - check those come-ups - I'm using 28MOA from 100 yards to 1000 yards - some guys are getting their 155's to exit the muzzle at 3100fps! The F/TR guys have re-discovered the potential of the 308Win and there's more to come.

Cheers
Vince

[woody_rod]

Woody,

I agree - the 308Win is inferior to say the 6.5x55 Swede but as an F Class round - on an F Class target it does well at 800/900 yards - check out a few past results from the League - in other words the 308 does shoot a 'possible' now and again - and don't forget, our set-up and rifle weight is at a disadvantage to an Open Class rifle.

The top three or four F/TR shooters would still be in the top ten Open Class shooters at most League shoots. Build a 308 into a 22lb Open Rifle and shoot off proper benchrests and you would see even more improvement.

Incidentally - check those come-ups - I'm using 28MOA from 100 yards to 1000 yards - some guys are getting their 155's to exit the muzzle at 3100fps! The F/TR guys have re-discovered the potential of the 308Win and there's more to come.

Cheers
Vince

I get 3050fps from my TR with 12 twist barrel, and 34 minutes of elevation. In anything but ideal conditions, a 6,5 will outshoot the 308 in any form, otherwise everyone would be using them. The thing now is the 7WSM and 284's, this is due to ballistics, pure and simple.

It is fine to compare F/TR with other F/TR, but open is another thing altogether. A crappy day at 1000 yards will give a massive difference.

[The Gun Pimp]

Woody,

Couldn't agree more - the 308 has serious limits but that's what attracts us to F/TR - you gotta (try to) read the wind!

I ran a 6.5WSM for a while (i.e 450 rounds and the barrel was shot) - like a laser with 139 Scenars.

Cheers
Vince