Thread: Seriously underrated 6.5x47 Lapua

Originally Posted by Wingman

Yip all of about 100fps more.. but I bet there is no one that could tell the difference in recoil between those two cartridge loads in the same rifle.

What I find really interesting with this discussion is that in the past, to gain greater velocity a bigger case and more powder was needed. Now I am seeing that concept change from a bigger case to a more efficient for calibre case.

Originally Posted by Moa Hunter

What I find really interesting with this discussion is that in the past, to gain greater velocity a bigger case and more powder was needed. Now I am seeing that concept change from a bigger case to a more efficient for calibre case.

Thats always been my jive.. high efficiently bench rest style cartridges with heavier bullets and short actions

Originally Posted by Wingman

Yip all of about 100fps more.. but I bet there is no one that could tell the difference in recoil between those two cartridge loads in the same rifle.

The lower the recoil the easier to shoot a really light rifle. I thought that a 260 AI would be where it's at but that thought is clearly wrong. I am now wondering how light I could go with a single shot rifle ??

is a SIMILAR weight/shape projectile at a SIMILAR speed with somewhere around 15-20 grns LESS powder than another often slighted cartridge that is often said "to boot like a mule".....

Recoil energy formulae typically attribute an average of 4700 ft/sec (or similar) departure speed to the mass of gas escaping behind the bullet treated as a point mass of the same weight as the starting powder charge leaving in the same direction as the bullet. Sum the momentum of the bullet and powder, apply conservation of momentum using the rifle weight, and then calculate the recoil energy from the resulting rearward velocity of the rifle.

For a given weight of rifle and barrel length within a single calibre, bullet energy plotted against rifle recoil energy follows an efficiency curve for different cases and bullet weights. More efficient cases may move their data points somewhat above the average, and the converse is also true. The same applies to the suitability of powder in its ability to transfer energy to the bullet. But where a shooter chooses to operate on this curve depends more on where it is felt the optimal trade-off exists between bullet energy and rifle recoil. Tussock has identified what he considers to be the sweet spot on this curve for 6.5mm (probably also factoring in the ability of this calibre & bullet weight to kill red deer sized critters at normal hunting ranges), and it is a 140gr bullet in a 6.5x47 with a suitable powder - and I'm inclined to agree with him.

Originally Posted by Wingman

...and chambered it with one of Dave Mansons match reamers...

Wingman, please tell me a bit about your reamer: your freebore length and neck diameter (clearance) choice and perhaps your thinking that led to these dimensions? I think I would be right in saying that these are likely to be the two variables with everything else staying much the same at standard CIP - unless you also requested the leade angle be tweaked?

Originally Posted by Puffin

Wingman, please tell me a bit about your reamer: your freebore length and neck diameter (clearance) choice and perhaps your thinking that led to these dimensions? I think I would be right in saying that these are likely to be the two variables with everything else staying much the same at standard CIP - unless you also requested the leade angle be tweaked?

Somehow I have lost my custom reamer for a Sako 75 action. I guess one of my relatives thought it was a drill bit. Keen to see the answer to this.

Originally Posted by Tussock

Somehow I have lost my custom reamer for a Sako 75 action. I guess one of my relatives thought it was a drill bit. Keen to see the answer to this.

Was @gimp original 6.5x47L done with this reamer?

Originally Posted by madjon_

Was @gimp original 6.5x47L done with this reamer?

I don't recall. Have to ask him. I bought it from pacific tool and gauge. It was not actually expensive. I had it set up so I could seat to the lands in a Sako box magazine from memory. It was a while ago.

Originally Posted by Puffin

Wingman, please tell me a bit about your reamer: your freebore length and neck diameter (clearance) choice and perhaps your thinking that led to these dimensions? I think I would be right in saying that these are likely to be the two variables with everything else staying much the same at standard CIP - unless you also requested the leade angle be tweaked?

The rifle is predominantly a hunting rifle so this school of thought was always foremost on the build specs. Tight neck reamers and long freebores with crazy lead angles for secant or hybrid ogive bullets would limit the range of suitable hunting bullets and adds possible mechanical complications in the field which I wanted to avoid.
The reamer was ground to cut a .298" neck, my loaded non neck turned neck measures .290" and the free bore length set up for the 139gr Scenar at .235". This puts that bullet in 100% neck to bearing surface contact with 5 though jump and a 2.73" COAL.
The lead angle is std CIP.
The 130gr TMK is very much the same dimensions as the 139gr scenar with the same boat tail and ogive shape, other than the plastic tip they almost measure identical which has made for easy tuning of that load.
I look forward to testing some other bullets but early signs show its really not that fussy to load for.

6.5x47L aka the 6.5 creed-before

Originally Posted by Nick-D

6.5x47L aka the 6.5 creed-before

Still waiting for clarification on the barrel length for 6.5Creedmore. Can I get 2800ft/sec comfortably with 140s and a 20" barrel?

Originally Posted by Tussock

Still waiting for clarification on the barrel length for 6.5Creedmore. Can I get 2800ft/sec comfortably with 140s and a 20" barrel?

The internet says yes.

https://www.nzhuntingandshooting.co....eedmoor-44462/

Originally Posted by gqhoon

The internet says yes.

https://www.nzhuntingandshooting.co....eedmoor-44462/

Just to confuse you more

https://www.nzhuntingandshooting.co....7-lapua-43552/

https://www.nzhuntingandshooting.co....7-lapua-45237/

https://www.nzhuntingandshooting.co....eedmoor-38108/

@outdoorlad are you running your 6.5x47L on an M mag on that nice Tikka of yours? Any OAL issues if so?