Sub 7mm choice

[Tim N]

Hi All,
A hypothetical F open question
If you had to shoot a calibre below 7mm what would it be?
It dosent have to be a current one.
with the components available what would you use?
I was thinking something shooting the berger 6.8 - 170gn projie, maybe 6.8 -284?

[Gyro]

Thats still bloody close to the 284win so surely would result in very similar dynamics ? I reckon a 260 Ackleyed case made from 308win Palma brass would tick a lot of boxes, so long as one is happy to deal with a whole lot of messing about in the shed prepping the brass.

[Steve N]

I have been having a play with a 6.5x47 and it is great fun. Not much bullet choice in 6.8/270 for F Class that I know of. If your barrel doesn't like the 170 Berger's you could be stuck. But I would be very interested to see how you go.

[shooter mcreid]

Tim I would love to pursue one of the 6.5s, probably the 6.5 creedmore. should still be very competitive with the 7s

[Gyro]

Does anyone know yet if the new 6.5cal 147 ELD-M is a suitable bullet to plan a serious F Open campaign with ? The BC will no doubt seduce many shooters. Im campaigning with the 140 Hybrids this F Open comp season just because they are 'proven'.

[Tim N]

with the 6.5 - 147 projies they might go the way of the 7mm 195s.
The BC is great but I haven't seen them used (that I know of).
Be interesting to see how the 6.5s go.

[macguru]

6x47 lapua

[Old Trev-39]

I shoot a 6.5 x 55 Rogue. With 140gr. J.L.K.Projectles at the speed I shot them, had same ballistics as the 175gr. Sierra M/K. Cannot get J.L.K. any more. Have done one test with the new 140gr. V.L.D. Copperheads and they look very promising.
Cheers,
Trevor.

[Chopper]

in the past I loved 6.5 x47 with 130 berger
but was not happy beyond 700
then I would use 6x47? chop

[macguru]

I would like to try a 6.5mm saum. I think it would move 130-140gr projectiles fairly quickly and cut through the wind. Probably best to get 2 or 3 barrels chambered at the same time, but if it works.... No problems with energy limits etc.

[BRETT B]

I would have to say 260AI. I am on my 8th barrel over the last 5 years and they do work well. 140 Berger @ 2950 all day , 3000 if you want to go at it a bit harder. Tried Palmer brass for a few years but small primer was too small to light up slower powders so LR Lapua was the ticket. They like slower powders like 2213/2217 which also help extend barrel life. Can also run soft with 41 gns of 2209 @2820 with 140 Berger and it will hammer the short ranges all day. In terms of Ballistics it is the closest thing I have shot to my 7MM at 1000 yds.

[Gyro]

So the question I ask is ; are the 7 mil cartridges actually incrementally better than the 6.5s as an F Open comp choice ? Did shooters move away from say the 6.5-284 for more reasons than just barrel life ?

[Steve N]

I would have to say 260AI. I am on my 8th barrel over the last 5 years and they do work well. 140 Berger @ 2950 all day , 3000 if you want to go at it a bit harder. Tried Palmer brass for a few years but small primer was too small to light up slower powders so LR Lapua was the ticket. They like slower powders like 2213/2217 which also help extend barrel life. Can also run soft with 41 gns of 2209 @2820 with 140 Berger and it will hammer the short ranges all day. In terms of Ballistics it is the closest thing I have shot to my 7MM at 1000 yds.

Brett what sort of accurate barrel life would you expect with the 140's at 2950 using 2213? Would you get 2000?
Does 2213 burn clean in the 260ai with 140s? I found it dirty in some 7-08ai loads.

Steve.

[bobeager]

Back in the early 2000's, F Class was getting a move on. We were shooting on the 10 ring target, and the 6.5 caliber was the "go to".

People tried everything. Long story short:-

1. Heavy 155 grain bullets by Lapua were a failure

2. Big overbore cases were a failure due to either bullet blow up or vertical stringing.

3. Cases that worked were of a similar capacity to the venerable 6.5 x 55 Swede.

Matt Paroz dominated F Open during this time with a 6.5-257 Roberts Improved running at moderate velocities. Matt could chime in here but I think around 2850 fps.

All attempts to drive the 140 grn 6.5's over 2950 ended in "tears".

[bobeager]

A chap from Canberra, Ian Lample, built a 6.5 Banshee. I am not sure, but somewhere over 60 grains of powder. I personally witnessed the test firing. A big bang, a streak of grey, and "poof" of grey "smoke" 100 yards or so in front of the firing point. Sorta feel you would experience some thing the same with 6.5 SAUM.