6.5 Osprey Mag Photo

[03Rick]

Many have been wondering what the 6.5 Osprey looks like. I have attached a photo with a 120 grain Nosler.

 

[CA48]

What is the parent Case?

 

[03Rick]

It is a 300 Norma Mag. with a rebated rim to .532, necked down to 6.5 and formed with a 35 deg shoulder. I like this round because it is only 2.494" and I chambered my 26" barreled 264 WM over. I can get 2 of these rounds in the mag. and one in chamber.

 

[CA48]

Who makes the brass. And with the case rim rebated to .532 over .590 will this have any negative or positive effects concerned with accuracy?

Also what is the expected velocity out of a 26" bbl with the 140s

 

[03Rick]

The brass is Norma from MidwayUSA. We are lucky as we have 3 gunsmiths here in P AZ. to rebate the brass for me. The barrel is McGowen 26" 1:9 twist on a commercial 3000 Mauser action in an Osage stock full glass bedded. The accuracy at 100 yds. averages 3/4" with my 3-9 Weaver. With the 120 grain Nosler pushed out at 3600fps at an estimated 59,650psi. from my old load program. I like this cartridge because I won't have to load Hot to get good velocities. With the 35 deg. shoulder and only .014" case taper the thrust on the .532 rim seems fine.

Am also in the process of looking for the Quick Load software to see if it will give me some loads based on the volume of the Osprey. Attached are some of my other cartridges for comparison. Am also trying to decide on a 18-24 power scope with external adjustment turrets. Any suggestions?

 

[03Rick]

Who makes the brass. And with the case rim rebated to .532 over .590 will this have any negative or positive effects concerned with accuracy?

Also what is the expected velocity out of a 26" bbl with the 140s

I just ran the 140 Berger and it should get 3600+fps at around 59,850psi

 

[Swamplord]

Sounds cool ! gotta love the 300 and 338 Norma Mag cases...

your cartridge sounds very similar to my 6.5 Prometheus (minus the rebated case head) just wondering if you can share your load data ?

have you tried the 160 gr Matrix bullets in the 6.5 Osprey ?
also, what is the neck length ?

my rifle is completed and any load info you can share will help me get started on mine and in turn I will submit my results

thanks

 

[03Rick]

I have only worked up loads with the 120, 123 and 140 grs. to date. Powder is hard to find on the shelves these days so have only used what was available. Here is my loads:

123 gr. Hornady
70.5 grs. PP4000 for 3400 fps @ 50,000 CUP

120 gr. Nosler
81 grs. N170 for 3450 fps @ 49,000 CUP

140 gr. Nosler
82.5 grs. US869 for 3250 fps @ 50,000 CUP

NOTE: The above loads were worked up in my rifle using Norma brass and are not recommended for reloads in any other rifle. If the above powders are used the charges should all be reduced by a minimum of 10% or more as a starting point.

The neck length is 0.255" or the same as the 264 Win Mag. neck with 0.278" free bore.

This is a rechambered 264 Win Mag on a 26" barrel with a 1:9 twist so not sure how well it will stabilize the long 160 grainers.

[FONT=&quot]My primary goal with this project was to develop a 1,000 yd. (low recoil) deer, sheep and antelope cartridge.[/FONT]

 

[65WSM]

How much water does the case hold with the bullet seated to the lands?

It looks like a candidate for VhitaVuori N-570. I can pour a caseful into the 6.5 WSM and almost get to 3300 fps instrumental with 140 gr bullets. With the extra volume you might get to 3450 fps with that powder.

Of course, Retumbo, should be an excellent powder with 129-130 and almost as good as N-570 with the 140s. Don't forget the 160 Woodleigh.

Especially with the heaviest bullets, Reloader 33 and Norma 217 are worth trying.

 

[03Rick]

Your right except where can I locate these powders? Every supplier I know of is sold out of them. I was lucky to get the PP4000. Do you know where I mite locate a 1lb. canister of these powders N 570, US869, H 870, Norma 217 or Retumbo so I can load for the best speed and accuracy? If I could find some of these powders I would like to try the 160s' to see how accurate they are in my 1:9 twist.

The case holds 107.3 grains water to top of neck and 103.3 with the bullet seated to the lands which is also the bottom of neck with the 123 gr Hornady.

 

[DocB]

I have only worked up loads with the 120, 123 and 140 grs. to date.
[FONT=&quot]My primary goal with this project was to develop a 1,000 yd. (low recoil) deer, sheep and antelope cartridge.[/FONT]

Sounds like an intriguing and ambitious project.

Although I am a 'rookie' at reloading and padiwan ballistician, but based upon what I have learned, I can't see a 120-140 grain bullet having much 'umph' at 1000 yds. Despite the velocity, wouldn't a round that light be susceptible to even light winds at that range? Would a round that light have sufficient remaining energy to be considered terminally lethal?

Not criticizing by any means, just curious about your project. I've read about Broz's 7mm-300WM and found it quite an interesting bullet / cartridge combination.

Good luck and continued success with your project.

Doc

 

[03Rick]

When I began this project I too looked at the 7mm/300Win. Mag. and found the recoil was a bit stiff and down range terminal energy not quite the equal with large over boar cartridges and as the 6.5mm with my goal to develop a longrange cartridge for deer, sheep and antelope (not moose or elk) with moderate recoil that would deliver a minimum of 1000 ft lbs terminal energy at 1000 yds. I next looked at the 270 bullets but found that they didn't have the BC/weight I was looking for. The 6.5 mm as a hunting round has very good BC bullets readily available on the market today as well as moderate recoil and good down range terminal ability.

As for the wind, I agree that it is a factor with all bullet types. For comparison though I site both the 6.5 123 grain and 140 gr. Hornady A-MAX as compared to the 7mm 140 grain and 168 grain Berger bullets. Using my load from a disk software ballistic results with a 26" barrel and a 10 mph 90 deg. cross wind the results are as follows:

6.5 Osprey Mag. (2.494")

6.5 Hornady 123 gr. A_MAX @ 3525 fps has a value of 1065 ft-lb of killing energy at 850 yds. and a wind drift of 43.4".

6.5 Hornady 140 gr. A-MAX @ 3325 fps has a value of 1014 ft-lb killing energy at 1000 yds. and a wind drift of 57.7"

7mm/300 Win Mag. (2.62")

7mm 140 gr. Burger @ 3290 fps has a value of 1014 ft-lb killing energy at 850 yds. and a wind drift of 48.4"

7mm 168 gr. Burger @ 2987 fps has a value of 1006 ft-lb killing energy at 1000 yds. and a wind drift of 63.1"

So in comparison, to come close to the terminal energy of the 6.5mm 123 grain bullet requires a 140 grain bullet in the 7mm/300 Win Mag. and to compare to the 6.5mm 140 grain bullet the 7mm /300 Win Mag. has to move up to the 168 grain Burger bullet.

Because the 6.5mm equals or exceeds that of the 7mm/300 Win Mag., I selected the 6.5mm as my longrange deer, sheep and antelope caliber.

I hope however, that this doesn't deter you from going forward with your plans for a 7mm/300 Win. Mag. as it is a fine cartridge also.

 

[DocB]

When I began this project I too looked at the 7mm/300Win. Mag. and found the recoil was a bit stiff and down range terminal energy not quite the equal with large over boar cartridges and as the 6.5mm with my goal to develop a longrange cartridge for deer, sheep and antelope (not moose or elk) with moderate recoil that would deliver a minimum of 1000 ft lbs terminal energy at 1000 yds. I next looked at the 270 bullets but found that they didn't have the BC/weight I was looking for. The 6.5 mm as a hunting round has very good BC bullets readily available on the market today as well as moderate recoil and good down range terminal ability.

As for the wind, I agree that it is a factor with all bullet types. For comparison though I site both the 6.5 123 grain and 140 gr. Hornady A-MAX as compared to the 7mm 140 grain and 168 grain Berger bullets. Using my load from a disk software ballistic results with a 26" barrel and a 10 mph 90 deg. cross wind the results are as follows:

6.5 Osprey Mag. (2.494")

6.5 Hornady 123 gr. A_MAX @ 3525 fps has a value of 1065 ft-lb of killing energy at 850 yds. and a wind drift of 43.4".

6.5 Hornady 140 gr. A-MAX @ 3325 fps has a value of 1014 ft-lb killing energy at 1000 yds. and a wind drift of 57.7"

7mm/300 Win Mag. (2.62")

7mm 140 gr. Burger @ 3290 fps has a value of 1014 ft-lb killing energy at 850 yds. and a wind drift of 48.4"

7mm 168 gr. Burger @ 2987 fps has a value of 1006 ft-lb killing energy at 1000 yds. and a wind drift of 63.1"

So in comparison, to come close to the terminal energy of the 6.5mm 123 grain bullet requires a 140 grain bullet in the 7mm/300 Win Mag. and to compare to the 6.5mm 140 grain bullet the 7mm /300 Win Mag. has to move up to the 168 grain Burger bullet.

Because the 6.5mm equals or exceeds that of the 7mm/300 Win Mag., I selected the 6.5mm as my longrange deer, sheep and antelope caliber.

I hope however, that this doesn't deter you from going forward with your plans for a 7mm/300 Win. Mag. as it is a fine cartridge also.

Not at all. I enjoyed very much reading and reviewing your data and am quite surprised with the terminal effects of the 'little' 123 gr round.

Thank you very much for sharing your research with us. I eagerly anticipate hearing the results of your hunts with this dynamic combination.

Good Luck, Good Hunting, and most of all...

Merry Christmas and Happy New Year!

Doc

 

[03Rick]

A Merry Christmas and Happy New Year to you and yours as well as all the viewers of longrangehunting.