I JUST BOUGHT A CUSTOM FN MAUSER IN 30 COUGAR CALIBER

[Hififile324]

Can you tell what bolt face you have? .473" / .532" ??

 

[buckstix]

i won't have the rifle in hand until Tuesday

 

[Hififile324]

Good luck with you very cool rifle, and exciting gun project! Let us know what she is when you find out.

 

[buckstix]

Good luck with you very cool rifle, and exciting gun project! Let us know what she is when you find out.

I will let you know what I find out .... late tomorrow

 

[buckstix]

Here's the answer to my question .... what is a 30 Cougar? Thank goodness it had nothing to do with a 30-30 Winchester cartridge as some had opined. When the rifle arrived, a quick inspection of the bolt face showed it was a Magnum size. Inspecting the chamber showed a Belt recess. Testing with different brass showed a 300 Win Mag was too long. In my assortment of misc. Reloading Dies (I collect dies and have over 400 sets) I found a set of 30 Newton dies. In the box was a "belted" 30 Newton Sizing Die that I bought some years earlier. Since I will never own a 30 "belted" Newton rifle, I gradually ground the die's length until it produced a sized case that fit the chamber.

I formed brass by starting with a once fired 7mm Rem Mag case. I pushed the shoulder back using a 350 Rem Mag sizing die. Then I full length sized with the shortened 30 belted Newton die which de-primed and opened the neck to 30 cal. The formed case's neck was too long and had to be shortened to 2.400 inch case length. Last I polished the case and now its ready for loading. Finished cartridges were loaded with a Hornady 165g BTSP and 55g IMR 4895 and WLR primers. Range report will follow. I added a 4x Walther Scope in the rings that came with the rifle.

So, how did the 30 Cougar cartridge come to be developed? I believe this rifle was built in the late 1950s when the only 30 cal magnum cartridge available was the 300 H&H. By shortening the 300 H&H case and expanding the shoulder, the 30 Cougar was formed. In the early 1960s both the 300 Win Mag and the 308 Norma Mag came onto the market. The 300 Win Mag case is .200" longer, and the 308 Norma case is .150" longer than the 30 Cougar. So the 30 Cougar was actually an early "short Mag."

and as usual - your comments are welcome.

http://www.buckstix.com/buckpics/COUGAR-FORMING.jpg

http://www.buckstix.com/buckpics/COUGAR-ID-SM.jpg

http://www.buckstix.com/buckpics/COUGAR-SCOPE.jpg

 

[Kootenay Hunter]

Depending on how much case capacity you get out of the newly formed case, it seem to me that you will have a 30-06+ level of performance in a fun rifle. Congrats!

 

[Hififile324]

Wow! What a great report on a very unique cartridge. Maybe one of the first of the short mags. Thank You! This a great sport and hobby, the learning is endless...

Good luck with the shooting tests. That is some set up too!

 

[AZDAVE]

Can you just neck down 350 REM MAG brass?

Very nice to know it isn't a 30/30 based round

 

[buckstix]

Can you just neck down 350 REM MAG brass?

Very nice to know it isn't a 30/30 based round

No ... 350 Rem Mag brass is too short ...

Here is an update ... I went .. to the range and test fired the rifle .. excellent accuracy .. and I fireformed the cases .. see pics ... No signs of high pressure so I increased the load by 2 grains to 57g for the next test and I will post the results.

http://www.buckstix.com/buckpics/FIRE-FORMING-SM.jpg

http://www.buckstix.com/buckpics/COUGAR-TARG-SM.jpg

 

[93marlin]

No ... 350 Rem Mag brass is too short ...

Here is an update ... I went .. to the range and test fired the rifle .. excellent accuracy .. and I fireformed the cases .. see pics ... No signs of high pressure so I increased the load by 2 grains to 57g for the next test and I will post the results.

http://www.buckstix.com/buckpics/FIRE-FORMING-SM.jpg

View attachment 709277

http://www.buckstix.com/buckpics/COUGAR-TARG-SM.jpg

View attachment 709276

That's really a great shooting rifle in a very interesting wildcat cartridge!
Well done!!

 

[Andrew NOLA]

I thought I was a dedicated reloader until I read the above.

I admire your dedication

 

[buckstix]

I thought I was a dedicated reloader until I read the above.

I admire your dedication

This was an easy one ... look at this link to see what I had to do to make brass for this super rare cartridge...

Thread 'A Rare 9.5mm cal. Peterlongo Take-Down Mauser - cased'

Oct 20, 2024

A Rare 9.5mm cal. Peterlongo Take-Down Mauser - cased

I wonder if anyone else saw this at auction this weekend. Its the best Peterlongo I have ever seen. The 9.5 caliber is actually a .375 caliber - but not sure if its a 9.5x57, or a 9.5x60 cartridge, or ?? ... anyone with info on what this caliber might be, please chime in. And .... its on the way to join its big brother here in Wisconsin.

as always, your comments are most welcome.

http://www.buckstix.com/buckpics/peter-000.jpg

• buckstix
• Replies: 7
• Forum: .375 & up

• 

 

[93marlin]

No ... 350 Rem Mag brass is too short ...

Here is an update ... I went .. to the range and test fired the rifle .. excellent accuracy .. and I fireformed the cases .. see pics ... No signs of high pressure so I increased the load by 2 grains to 57g for the next test and I will post the results.

http://www.buckstix.com/buckpics/FIRE-FORMING-SM.jpg

http://www.buckstix.com/buckpics/COUGAR-TARG-SM.jpg

After thinking about it and checking measurements, your 30 Cougar cartridge is extremely similar to the 7x61 S&H. The length of the Norma brass that I use is 2.4 inches and it is a belted cartridge.

 

[buckstix]

After thinking about it and checking measurements, your 30 Cougar cartridge is extremely similar to the 7x61 S&H. The length of the Norma brass that I use is 2.4 inches and it is a belted cartridge.

Yes, but 7 rem mag is much more available and cheaper than 7x61 S&H ... and I had over 100 pcs of once fired 7 mag brass.

 

[Grumpy gumpy]

I don’t know if I would have cut down 30 newton dies, but the end result was worth it. Will you get a set of proper die’s made now?
Gumpy

 

[buckstix]

I don’t know if I would have cut down 30 newton dies, but the end result was worth it. Will you get a set of proper die’s made now?
Gumpy

I cut down the "belted" 30 Newton resizing die. I still have a set of regular 30 Newton dies. I won't be ordering a custom 30 Cougar set. Too expensive and I can reload with what I have.

 

[buckstix]

A member on a related forum, found this about my rifle's builder.

Who was rm osbahr gun-maker? - Answers

R.M. Osbahr was a gun-maker based in the United States, known for producing high-quality firearms during the late 19th and early 20th centuries. The company specialized in custom-made shotguns and rifles, often recognized for their craftsmanship and attention to detail. Osbahr's work was highly...

www.answers.com

 

[buckstix]

I am back from my second range test. The cases used were fire-formed and had 2g H2O increased case capacity.
Load was increased from 55g to 57g IMR 4895. And, velocity increased from 2932 fps to 2970 fps.
This already exceeds the published max velocity of the 300 Win Mag with the same bullet and same powder.
No signs of excessive pressure and easy extraction. Next outing will be increased to 59g.
I am really starting to like this rifle ... a lot.

http://www.buckstix.com/buckpics/COUGAR-TARG-1-SM.jpg

 

[Grumpy gumpy]

Looks like you’ve got a really good one there.
Gumpy

 

[Hififile324]

Not only do you have a great looking rifle, you have a real shooter too! That's what I call a "Honey". Well done!