Sub 7mm choice

Get or give advice on equipment, reloading and other technical issues.

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Gyro
Posts: 147
Joined: Sat Jun 10, 2017 2:44 pm
Location: New Zealand

Re: Sub 7mm choice

#16 Postby Gyro » Wed Jul 26, 2017 3:04 pm

The 6.5 Saum is not new and has already a large following, mostly by the tacticool guys I believe who say good things about it for shooting steel. The barrel life question for it is much debated with one supposedly credible source saying its good for 2000 rounds plus if run at low pressures with slow powders where it still apparently delivers the kind of velocity that would leave a 6.5-284 for dead.

If you search "George Gardner" with that cartridge it's all there re the barrel life claims. Rob.

AlanF
Posts: 6613
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic

Re: Sub 7mm choice

#17 Postby AlanF » Wed Jul 26, 2017 5:15 pm

Well I've been there with a 6.5-284 and used to run the 142s over 3000fps with some barrels, barrel life about 1500 to 1800 rounds but using N165 (cool burning). But in the next few weeks I'll have a 6.5x55 Swede ready to go. Will try 130 VLDs initially. The 6.5x47 is probably a better performing chambering, but F-Open is all about variety, and doing your own thing.

bobeager
Posts: 332
Joined: Wed Jun 22, 2005 1:29 pm
Location: Goulburn NSW Australia

Re: Sub 7mm choice

#18 Postby bobeager » Wed Jul 26, 2017 5:20 pm

Way to go Alan. I am starting to regret selling my 6.5 Swede dies.

Gyro
Posts: 147
Joined: Sat Jun 10, 2017 2:44 pm
Location: New Zealand

Re: Sub 7mm choice

#19 Postby Gyro » Wed Jul 26, 2017 5:36 pm

Yes Alan I read in your earlier posts about your "marriage" to that cartridge. I'm getting organized to campaign with one. Tell me if u will is there ANY down side to running a 6.5-284 with N165 ? Cheers Rob Kerridge.

AlanF
Posts: 6613
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic

Re: Sub 7mm choice

#20 Postby AlanF » Wed Jul 26, 2017 5:58 pm

Gyro wrote:Yes Alan I read in your earlier posts about your "marriage" to that cartridge. I'm getting organized to campaign with one. Tell me if u will is there ANY down side to running a 6.5-284 with N165 ? Cheers Rob Kerridge.

Not really. I changed to 7mm mainly because of slightly better ballistics and barrel life.

Tim N
Posts: 728
Joined: Fri Jan 25, 2013 8:18 pm
Location: Branxton NSW

Re: Sub 7mm choice

#21 Postby Tim N » Thu Jul 27, 2017 11:00 am

Starting to sound interesting.
Is there any real "odd ball" cartridges in the making out there?
The 270 cal looks good.
I believe there was some talk prior to Raton of the Aussies shooting their 270 hunting rifles at the FCWC 2013
This could have been some sort of propaganda put out to keep us off the radar.
We don't rise to the level of our expectations, we fall to the level of our training. Archilochos 680-645 BC

Gyro
Posts: 147
Joined: Sat Jun 10, 2017 2:44 pm
Location: New Zealand

Re: Sub 7mm choice

#22 Postby Gyro » Thu Jul 27, 2017 5:31 pm

I'd like to see somebody win a big shoot with an "odd ball" cartridge ! If F Class comp shooting comes down to having the gun hold good vertical, then making good wind calls then why not ???

watrob
Posts: 42
Joined: Thu Oct 20, 2016 3:02 pm

Re: Sub 7mm choice

#23 Postby watrob » Tue Aug 01, 2017 10:07 pm

Try a 6.5x47 Lap Imp, case holds around 2 grains more powder which means that a high load of 2208 still leaves air in the case when shooting 140gr Berger VLD's. With a 28" barrel your close to 2900 FPS, at 1000 yard your hitting the target at over 1730 FPS still, Lap cases with SF primers and still if needed you can add another 1 grain of powder and still not have a compressed load.

A standard 6.5x47 Lap with 140gr bullets at a 1000 yards was hitting the target at just over 1430 FPS.

I can get to 3000 FPS but that's pushing the primers and case to hard. I also shoot a 7mm/300 WSM Imp and that's hitting the 1000 yard target at just over 1800 FPS, so the Lap Imp is a great light gun.

This was the first time I had shot the rifle so my loads are still under development and only the second time I have shot 1000 yards, have attached a screen shot of the 3rd target (forgot to grab the others) but the second target was better with 5.67" group.
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AlanF
Posts: 6613
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic

Re: Sub 7mm choice

#24 Postby AlanF » Wed Aug 02, 2017 10:01 am

watrob wrote:...With a 28" barrel your close to 2900 FPS, at 1000 yard your hitting the target at over 1730 FPS still...

How are you measuring the 1000yd velocity? According to the Berger ballistics calculator, it will be more like 1550fps. Your figures indicate a G7 BC of about 0.360 - no 6.5mm projectile comes anywhere near that.

watrob
Posts: 42
Joined: Thu Oct 20, 2016 3:02 pm

Re: Sub 7mm choice

#25 Postby watrob » Wed Aug 02, 2017 3:03 pm

Hi AlanF, the electronic target system for the 1000 yards comp measures bullet velocity on impact, also the standard 6.6x47 Lap showed a impact velocity of around 1420 FPS. I know my muzzle velocity as I have tested my rifle as I own a chrony.

But you are right as the above target on checking is from my 7mm rifle, not the 6.5x47 Lap Imp, the 6.5 was hitting target at just over 1620 fps

If you full size the target image above you will see the printout in the top righthand corner of the target, I also Boron coat & point my projectiles, I did throw one bullet which hit the target at 1688 fps (high shot) as the growns from the gallery informed me and relugated me to second postion overall on the day.

Even at over 1600 fps at a 1000 yards its great calibre to shoot, less recoil and being only around 100 fps slower than the 7mm/300 WSM Imp which runs 26 grains more powder, I think the trade off is well worth it. I have actually tested another half a grain more powder but the groups started to open up, there is also still room for another further half a grain (without making a compressed load) but it would be flattening the SR primers and I don't think I need to shoot that higher node, which I have been told is around the 39.3 to 39.5 grains of 2208, some are running 41 grains of 2209.

I really built the rifle to shoot 300m Fly and was told to shoot it a 1000 yards and that I would be suprised how good it could be at that distance, the rifle has a pretty heavy barrel as the stock it is built on is a carbon fibre benchrest stock from a 6PPC, so I shoot it free recoil as weighs just under 17lb.


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