doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com I JUST BOUGHT A CUSTOM FN MAUSER IN 30 COUGAR CAL

I JUST BOUGHT A CUSTOM FN MAUSER IN 30 COUGAR CALIBER

Its a nice looking rifle with a Striped Maple stock with several contrasting inlays. It was made in the 1960s. I don't have the rifle in hand yet. I should have it by early next week.

Here's my question .... what is a 30 Cougar? It doesn't come with brass or dies and I will do a chamber cast when it arrives.
So, in the meantime .. what is a 30 Cougar?

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

I really like the maple and the metal work but could dispense with the inlays and shape of the stock. But, that's all a matter of taste. What matters is that you like it.

...30, too young for a Cougar....

buckstix
This is only a suggestion: If the bolt face is opened for belted case, see if 300 H&H will chamber, if so fireform a case. If bolt face not opened up, fire form a 270 case. A fireformed case will give you a general idea and a couple or three can be used to set up lathe to make dies. Just easier than chamber cast, if it works.
Mike

Hello Der Ami,

I have done many dozens of chamber casts. I have the process down to where it only takes me 5 minutes to do a chamber cast. I will post pictures when done.

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

buckstix,
For whatever it is worth, if I remember correctly, the 30 belted newton is the 30-338. Your 30 Couger looks suspiciously like the 7x61 Sharpe and Hart necked up to 30cal. You didn't show the case length, so I couldn't check.
Mike

I did show the case length in the first picture ... 2.400" OL ... yes, case is very close to the 7x61 case.

I guess I should pay more attention.
Mike

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

buckstix,
After you were so adamant about chamber casts, I was disappointed you didn't show the ones for the 30 Couger. I usually had no trouble with "tip up" guns, but bolt action rifles always gave me trouble, especially with the cerrosafe running into recess for the locking lugs and hampering removal, as well as measuring the part of the case length between the bolt face ant the end of the barrel. I had to remove the barrel and measure the action, as if I were fitting a new barrel. I was interested in seeing how you do it quickly.
Mike

Hello Mike,
I generally clean the chamber and bore with original Hoppies #9 - then I plug the bore with a tight fitting cleaning patch about 1" into the rifling. I use 140 degree cerrosafe and use a small tapered dish with a spout to pour the melt into the chamber being very careful to not overfill the chamber. It takes me only 5 minutes. However, in this case I used a method that I developed over the years. Since I saw that the chamber had a recess for a belted case, I inserted a 300 Win Mag case and tried to close the bolt. I measured how far the bolt was from closing and cut that amount from the case mouth. Then I annealed the shortened case 4 times with a propane torch, each time heating to bright cherry red, and instantly quenching the hot case in cold water. (This makes the case so soft you could pinch it closed with your fingers) I take the softened case and thoroughly lube it with Corbin bullet swaging lube and insert it into the chamber. I then use a 10" long - 5/8" diameter hardwood dowel and hammer the soft case it into the chamber until the case's belt contacts the belt recess in the chamber. The softened case forms itself into the chamber and you now have an EXACT FIT example of the cartridge. This method only takes about 3 minutes and you have a better indication of the unknown cartridge. I used that "chamber cartridge" to setup the shortened resizing die and formed 20 pieces of brass.

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

https://www.answers.com/histor..._rm_osbahr_gun-maker

I looked at the link, it says

"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 regarded among hunters and collectors, contributing to his reputation in the firearms community. The company is no longer in operation, but its products remain sought after by enthusiasts."

FYI, if your rifle was built in the 1960's, the 1960's are not considered part of the "early 20th century". I am not sure how much faith your should put into the above quote.

It's an "AI" generated messaged. its total nonsense.

buckstix,
Thanks,
Mike

well, I tried to do a google book search and found an entry, all i could get was a snippet "Osbahr and stocked in quilted maple by Phil Young" from the American Rifleman Volume 103 page 113, I hope someone
has this issue and can provide more information

There are 12 issues for American Rifleman Volume 103 .. one for each month ... i.e. 103-1 ... 103-2 ... 103-3 ... etc.

well, you can look through them all, for all I care

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

Hello all. I finally had a chance to take the action out of the stock... the action was stamped ... FN - made in BELGIUM ... I also found a stamp on the barrel .. R.M.OSBAHR ... the date ... 08 16 60 ... and CARMICHAEL'S ... (while searching the internet I found a M1-Garrand with a barrel that had a similar stamp and a 1955 date) ... I also found the M-2 Canjar Match Trigger and that the action was glass bedded. No wonder its such a good shooter.

http://www.buckstix.com/buckpics/30cougar-detail.jpg