Chasing 1/4 200yd with Browning .300 Wm Boss

AHoup69 said:

Hello all!! I reload and love to shoot and, I have been reading for quite a long time in these posts and wanted to say Thank you ! for sharing your vast experience and knowledge because it has been very inspiring!!

Found the article that shows how to file and open up the A-bolt 1 & 2 magazine allowing for longer OAL so I'm excited to see how it turns out!

Also read a article on using the .375 A-Bolt 1-2 magazine in place of my .300 wm A-bolt 1-2 magazine but that is a 75-100$ test I'm holding off for.. Unless someone can help validate that statement!?

Looking forward from hearing from yall!!

Here's to one hole shots!!

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asd9055 said:

Are you talking about converting your magazine to the 375H&H length? I don't know how the Browing magazine is, but the WIN M70 BOSS 300WM has a spacer that is spotwelded. I drilled the spotwelds and removed the spacer. You will need a Browing 375 H&H follower in your magazine and then you can load longer COAL cartridges.

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AHoup69 said:

Awesome information!! Thanks! I'm not competent enough to attempt this sadly. I have seen a few images of people filing the aluminum block on the bullet tip to allow for longer lengths .. just not secure enough in my ability to pull that off!!

I am ordering an additional magazine for test purposes and I will let yall know how it goes!! Crossing all fingers and toes!!

Regards,
Aaron Houp

PS: These are the images I found on the web in which I am going to attempt this project!!
Thank you to those who posted these images on the internet originally and who have shared their customizing process!

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asd9055 said:

Remember, you will need to make sure it has the 375H&H follower to work, not just the magazine box if they are sumilat to M70 or WBY MKV. I don't know how it is in a Browinung

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AHoup69 said:

Appreciate the help!! I am working on filing out of the aluminum frame to make room for the longer length!!

It is not pretty but they cycle through fine and now have room for 3.52 on the lower bottom round at the top its 3.57!! Started at 3.29 so I am happy!!

Thanks to all that supported this little project!!

Excited about searching for a solid hard hitting load for a 200gr Berger in my .300 Win Mag!!

Kind regards,
Aaron Houp

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CouElk said:

Welcome aboard.

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asd9055 said:

Browining magazines are totatlly different than Win M70 and WBY MKV. The latter two have a spacer in the back of the mag box.

I did convert my M70 300WM to handle 3.6" maybe even 3.7", I dont remember now, But I never floowed through develpoing the loads. First covit hit, then compnonents were not to be found and I had a couple of 300WBY already developed and ready to go. Maybe now I will go back to testing the 300WM.

@Calvin45 might give you some direction or pushing it

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AHoup69 said:

When I purchased this back in 96 the only reason I went .30 cal was the Boss took the recoil off the .300 wm .. it kicked more like a .270 .. that allowed me to get the distance and flexibility of .30s ! I was actually leaning on the 7mm but ultimately decided on the old reliable.! The Boss and Nosler BT 150gr were punching sub .477 holes at 200yd 3x for a factory gun back then in 96 .. so I was elated .

I never hunted bigger than south Texas white tails.. which rack nice but are skinnier than a hungry rat!!

We are moving to Ketchikan Alaska and it's a place that should give me access to maybe use this old gun with some Berger 210s if I can punch single holes at 200yd !! If not I will have to chase down what this gun likes to eat!

I appreciate all your support and advice and wish you the best!

I read this forum like a book so I will be around!

Kind regards,
Aaron Houp

"May you punch one hole shots!"

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