Weatherby Mark V Feeding Issue - Amateur Gunsmith Advice Needed

[luvmystang67]

hey hunt-wa,

I have a 338-378 that is actually a rebarreled 1960s Mark V receiver.  I never validated that it fed well to begin with, but it came to me with a junky synthetic stock.  I picked up a new weatherby stock that was for something like a 300 WBY or similar, and hogged it out to fit my rifle.  I glass bedded the action, and it looks real nice.  I put the mag box and spring and follower back in and cant for the life of me get this thing to feed right.  I tweaked the mag box I did have and with 3 hours on the vice it almost wants to work, but still doesn't.  That one actually seems to feed at too high of an angle, and the round gets caught on the way into the chamber somehow.  I ordered a new mag box from weatherby, and it is VERY tight getting rounds into the magazine, but holds them nice enough. I also got a new spring, and tried that.  When I push my new round up with the new mag box, the back of the case drops below the top of the bolt and the bolt begins to catch the belt of the case and creates a jam.  I can't figure out what I'm doing wrong.  I don't think the stock has anything to do with it, the mag box is making contact with the receiver.  Everything is cleaned and lubed.  They are handloads, but are not above the max OAL.  I'm afraid to start tweaking the new mag box they sent...  Am I missing something dumb here?  I even tried turning the follower spring around, and that was a definite non starter.

Here's a video (or two) of my setup.  I'm going on a 5-day hunt this weekend and really want this to work.

https://www.youtube.com/shorts/6nQ4JB0L03I

https://www.youtube.com/shorts/UErMcE1U2ig

[Mike450r]

I would start by going back to the junky synthetic stock and see how it feeds the rounds. 

[luvmystang67]

I would start by going back to the junky synthetic stock and see how it feeds the rounds.

It doesn't feed either.  I honestly never verified that it did initially when I got it, but with either mag box, either my original (now beat up one) or the new one, the old stock doesn't facilitate normal feeding.  I don't recall that it ever did.

[jrebel]

I had the exact same thing happen with my weatherby mark 5 apex in 7prc.  I fought it for a couple weeks before sending it back to weatherby.  3 weeks later and it is back and working great.   

I would call weatherby and talk to one of their gunsmiths.  See if they can help you out.  My experience with their customer service was very positive. 

[G.R.K]

Wrong magazine follower  Post a pic of the follower.

[Reidus]

I'm not sure what a weatherby box looks like but maybe the feed lips need to match the taper of the cartridge? Sometimes you can tweak the spring so it applies more pressure in the front or rear. My guess is a feed lip or spring issue.

[luvmystang67]

The follower is just flat, which as far as I can tell is standard for the 378-based rounds.


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[luvmystang67]

I had the exact same thing happen with my weatherby mark 5 apex in 7prc.  I fought it for a couple weeks before sending it back to weatherby.  3 weeks later and it is back and working great.   

I would call weatherby and talk to one of their gunsmiths.  See if they can help you out.  My experience with their customer service was very positive.

Any idea what they did to it?


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[jrebel]

I had the exact same thing happen with my weatherby mark 5 apex in 7prc.  I fought it for a couple weeks before sending it back to weatherby.  3 weeks later and it is back and working great.   

I would call weatherby and talk to one of their gunsmiths.  See if they can help you out.  My experience with their customer service was very positive.

Any idea what they did to it?


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I don't.....The master gun smith at Weatherby said the early Apex models had this problem.  My rifle had lots of problems, of which were very common problems.  After loading and firing a round, I would go to open the bolt and it would catch on the catch on the case of the next round binding the bolt.  They polished the channel and rounded the bolt slot so this wouldn't occur any more.  When talking with him about the loading issues, he thought it may also require some grinding to change the angle of the round feeding. 

I will go look and see if I can see what was done.....I'll take picures and post them.  Should only take a few minutes. 

[jrebel]

I can't really tell what was done.  I do remember he said he may have to grind down and change the angle of the feed ramp.  The reason I remember this is he said he would have to remove the barrel (potentially) and they would have to re-cerekote the action.  I too have a flat follower, which appears to be the norm for their Mark V series.  I did notice when the rifle came back.....loading rounds is much harder than it was before sending it off.  Makes me wonder if the feel lips were spread to far apart??  Now as I load, it leaves small marks on my brass.  I really wish they would make a detachable mag option for these rifles. 

[luvmystang67]

Yeah, interesting. The new mag box they sent me also holds rounds MUCH tighter than my old one. And it kind of protrudes into the opening a bit, so that when you load a round the edge of the metal jams right between your thumb and thumb nail. I might end up manually tweaking this mag, same as the last one, to see if I can get it to work for this upcoming weekend.

Did yours ever feed well? Or did it have problems for the very beginning?


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[BULLBLASTER]

I would try and shorten the length of the feed lips on one mag (so the case is released sooner. Might try 1/8 or 1/4 inch at a time.

[jrebel]

Yeah, interesting. The new mag box they sent me also holds rounds MUCH tighter than my old one. And it kind of protrudes into the opening a bit, so that when you load a round the edge of the metal jams right between your thumb and thumb nail. I might end up manually tweaking this mag, same as the last one, to see if I can get it to work for this upcoming weekend.

Did yours ever feed well? Or did it have problems for the very beginning?


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I bought mine used and the previous owner had no issues.  Mine was so bad, I was forcefully trying to cycle a round and it through the live round out of the action and into the shooting bench.  It consistently would jam the nose of the bullet in the acrion (end of barrel threads) and lock up damaging the tip of the bullet.   

Now it feeds flawlessly.