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300 weatherby to 300 PRC

JAG0588

Active Member
Joined
Dec 19, 2022
Messages
25
Location
North Dakota
I am looking having a 300 weatherby mark V rebarreled to a 300 prc. Is there any concern doing this? Will the longer 300 prc bullets feed? Will they eject just find out of the action if not fired? Any info will be helpful.

Thanks
 
First off, the bullets will be the same length. Because they both use the same 30 caliber bullet.

The CARTRIDGE length may be different.

One issue with the Mark V action, is the length you can load a cartridge and still be able to get it out through the ejection port.
COAL for both of my Mark V's is limited to 3.360".

Seating a bullet to the lands (factory 7mm Weatherby barrel) is 3.630".

In other words if i load to the lands, i can't eject a loaded round without pulling the bolt. And on Mark V's this requires squeezing the trigger.
Something i'm not going to do!!
 
That was exactly my concern about the length of the cartridge vs ejection port. 300 prc max length (loaded round) is 3.7". 300 weatherby max length (loaded round) is 3.560".

Any no one running long heavy bullets in their 300 weatherby? If so are you only loading to 3.560"

Companies making the 300 prc must have an ejection port of 3.7" or bigger?
 
The 3.630" COAL on my Mark V's do fit in the magazine.

I was dared to take a Dremel to my ejection port. :eek:

You could have the ejection port opened up by a smith. But if it's been Ceracoated or blued, your gonna have to redo the whole receiver to get it to match.

Personally, i'd leave the Mark V action as a 300 Weatherby and get another action to build the 300 PRC on.
 
The 3.630" COAL on my Mark V's do fit in the magazine.

I was dared to take a Dremel to my ejection port. :eek:

You could have the ejection port opened up by a smith. But if it's been Ceracoated or blued, your gonna have to redo the whole receiver to get it to match.

Personally, i'd leave the Mark V action as a 300 Weatherby and get another action to build the 300 PRC on.
thanks for the info. Greatly appreciate it. Was really thinking of buying the 300 weatherby. Has the short throw action/ ag composite stalk. Trigger tech trigger. Just didn't want the caliber prefer the 300 prc. Very interesting that in a weatherby you can't hardly load to the lands without pulling the bolt to eject the unfired round.
 
The 3.630" COAL on my Mark V's do fit in the magazine.

I was dared to take a Dremel to my ejection port. :eek:

You could have the ejection port opened up by a smith. But if it's been Ceracoated or blued, your gonna have to redo the whole receiver to get it to match.

Personally, i'd leave the Mark V action as a 300 Weatherby and get another action to build the 300 PRC on.
@std7mag have you compared your 7WBY bolt to the 300WBY bolt? Look at the bottom of the two bolts and compare the "bolt stop" channel. The 300WBY should be longer because it can eject a 3.6.
 
@std7mag have you compared your 7WBY bolt to the 300WBY bolt? Look at the bottom of the two bolts and compare the "bolt stop" channel. The 300WBY should be longer because it can eject a 3.6.
No, i haven't.
The modern Mark V rifles i have is 7mm WBY & 257 WBY.

My 300 WBY is a German made Mark V & may be different.
It's locked up in the safe.
Bought it for an investment, not to shoot.
 
No, i haven't.
The modern Mark V rifles i have is 7mm WBY & 257 WBY.

My 300 WBY is a German made Mark V & may be different.
It's locked up in the safe.
Bought it for an investment, not to shoot.
The bolts have not changed! I too have a German and I checked them. Compare the bolt stop channel on the bottom. You will see that the 300 is longer. A machinist can duplicate that on the 7mm for longer extraction

I just made a 3.744 dummy 300WBY which does not fit in my mag, and it ejects just fine. This confirms that your limitation is your bolt stop channel. My magazine will accept 3.7" easily. maybe a few thousands longer
 
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The bolts have not changed! I too have a German and I checked them. Compare the bolt stop channel on the bottom. You will see that the 300 is longer. A machinist can duplicate that on the 7mm for longer extraction

I just made a 3.744 dummy 300WBY which does not fit in my mag, and it ejects just fine. This confirms that your limitation is your bolt stop channel. My magazine will accept 3.7" easily. maybe a few thousands longer
This is good info as well ASD, So with you making up a dummy round of 3.744", and it ejected it. Rebarreling a newer mark V action to 300 PRC should be no issue?
 
This is good info as well ASD, So with you making up a dummy round of 3.744", and it ejected it. Rebarreling a newer mark V action to 300 PRC should be no issue?
Talk to gunsmith that has worked in weatherbys before you do. Is the bolt face the same for both cartridges? I don't know much about the PRC
Max Mag length about 3.7" measure yours.
The changes on bolt stop channel would have been for the 7mm
 
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