P.O.ing the 260.

Talk about your Varmint Rifles and other firearms here!
User avatar
Rabbitz
.338 Lapua Magnum
Posts: 2421
Joined: Sun Mar 25, 2007 9:05 am
Favourite Cartridge: 222
Location: Barossa Valley, SA
Contact:

Re: P.O.ing the 260.

Post by Rabbitz »

OK. This has been bugging me for weeks.

So I'll ask. P.O.ing? What does it mean?
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

Rabbitz wrote:OK. This has been bugging me for weeks.

So I'll ask. P.O.ing? What does it mean?
P.O. Ackley

This best explains

https://en.m.wikipedia.org/wiki/P.O._Ackley


Sent from my iPhone using Tapatalk Pro
User avatar
Rabbitz
.338 Lapua Magnum
Posts: 2421
Joined: Sun Mar 25, 2007 9:05 am
Favourite Cartridge: 222
Location: Barossa Valley, SA
Contact:

Re: P.O.ing the 260.

Post by Rabbitz »

I thought he was AI?

But there ya go learned something.

:)
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

All loaded up for the next session. 5 rounds each 44gr 2209 srp&lrp

5 rounds each 45gr2209 srp&lrp

Velocities and groups to follow.

PS. Using the same 10 cases throughout this test.


Sent from my iPad using Tapatalk Pro
Ol 55
.308 Winchester
Posts: 1714
Joined: Mon Aug 02, 2010 7:57 pm
Favourite Cartridge: 20 PPC
Location: Hunter Valley NSW

Re: P.O.ing the 260.

Post by Ol 55 »

kickinback wrote: Sat Oct 27, 2018 9:53 pm All loaded up for the next session. 5 rounds each 44gr 2209 srp&lrp

5 rounds each 45gr2209 srp&lrp

Velocities and groups to follow.

PS. Using the same 10 cases throughout this test.


Sent from my iPad using Tapatalk Pro
When is the next session?
Gary
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

Hopefully tomorrow night.


Sent from my iPhone using Tapatalk Pro
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

The facts

Targets were shot off a bipod on the tailgate.

Tikka t3 varmint, factory barrel with AI reamer run in, factory stock and Harris bipod.

No1 was shot without a rear bag Nos2,3+4 made use of a rear bag.

Image

Image


Sent from my iPhone using Tapatalk Pro
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

The latest
Same cases

Sm primer 47gr 2209

2906
2874
2889
2906
2892
Image

Large primer 47gr 2209

2913
2933
2894
2905
2913
Image

Sml primer 47.5gr 2209

2905
2914
2924
2900
2908
Image

Large primer 47.5gr 2209

2964
2922
2937
2936
2942
Image





Sent from my iPhone using Tapatalk Pro
Ol 55
.308 Winchester
Posts: 1714
Joined: Mon Aug 02, 2010 7:57 pm
Favourite Cartridge: 20 PPC
Location: Hunter Valley NSW

Re: P.O.ing the 260.

Post by Ol 55 »

So where to now? Large primer?
Gary
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

Ol 55 wrote:So where to now? Large primer?
Gary
Still more room in the case


Sent from my iPhone using Tapatalk Pro
User avatar
trevort
Spud Gun
Posts: 12710
Joined: Thu Sep 14, 2006 9:21 pm
Favourite Cartridge: Tater
Location: Melbourne

Re: P.O.ing the 260.

Post by trevort »

Glen can you work out the neck diameter of your chamber by measuring the reamer out of interest


Sent from my iPhone using Tapatalk
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

trevort wrote:Glen can you work out the neck diameter of your chamber by measuring the reamer out of interest


Sent from my iPhone using Tapatalk
I’m not putting the tungsten carbide contact surfaces of the micrometer on the cutting edges of the reamer

Fired cases measure .2985”


Sent from my iPad using Tapatalk Pro
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

Of most interest is the case head diameter measurement. Large and small primer cases have both grown by .013mm


Sent from my iPad using Tapatalk Pro
Tony Z
.270 Winchester
Posts: 1366
Joined: Fri Oct 27, 2006 5:29 pm

Re: P.O.ing the 260.

Post by Tony Z »

Why is half a thou case head growth of interest?
Minimal considering the velocities you are getting. Now if it were 0.13mm, that would be a concern.
kickinback
50 BMG
Posts: 3991
Joined: Sun Jan 07, 2007 11:54 am
Favourite Cartridge: 260 Rem
Location: Lilydale Vic

Re: P.O.ing the 260.

Post by kickinback »

Tony Z wrote:Why is half a thou case head growth of interest?
Minimal considering the velocities you are getting. Now if it were 0.13mm, that would be a concern.
It’s the same between the small primer and the large.


Sent from my iPhone using Tapatalk Pro
Post Reply