Weatherby Mark V pressure ???????

[300winnie]

I have a .257 Weatherby Magnum in a Mark V Deluxe that I have tried and tried to get to shoot consistently. Just when I think I have things looking promising...it goes to frustration in a hurry. I went shooting last week and a load that showed promise (more than once) went to hell. A load that had been a pretty good load in the past shot like crap. I blamed it on the fouling in the gun (less than 20 rounds) and decided I was done playing this game...the gun was going up for sale to be replaced by something more accurate.

Well, I got to thinking today about the barrel and the barrel channel. From what I understand the Mark V's in wood stocks, the barrel should be free of touching the barrel channel except for the pressure pad towards the end of the forearm. I decided to see what I had going and got a dollar bill and tested for float in front of the pressure pad...looked and felt fine. As expected I was stopped at the pressure pad. I couldn't get anything to go through the gap behind the pressure pad so I unscrewed the barreled action from the stock, inserted my dollar bill and put things back together. I couldn't even wiggle the dollar bill. On top of that I noticed that the bluing is worn on both sides of the barrel from apparently "riding" the stock.

I am guessing that I need to relieve this pressure if I expect things to get better. I have no intention of removing the pressure pad...at least at this point. Am I thinking correctly? If I am, how far back towards the action do I relieve this pressure? Do I go clear back to where the barrel meets the action, or do I stop short (front of the chamber)?

Any ideas and help is greatly appreciated.

Thanks in advance.

 

[Guest]

Well, it could be the barrel, but before I went into a stock, if it shot well before, I'd consider taking the clean the crap out of it approach. If you suspect the barrel has a lot of copper (which a 257Wby might be prone to lay down, at those speeds) I suggest you try out one of the foaming bore cleaners (I have used Break Free's) and follow the directions on the can. It really took the copper out of a rifle of mine. In fact, see this thread:

http://noslerreloading.com/phpBB2/viewtopic.php?t=4595

After you clean it good (twice, to be sure you get it all) then you should try your known load, to see if it works well again. If so, then it is a fouling issue. If not, then start into the barrel channel. The fact that the gun has shot well prior makes me think the barrel pressure isn't the real issue here. It might behoove you to remove some wood later, but for right now, the scientist in me says to change one thing at a time.

 

[metallica]

Hey,

I was also having a similar problem with my Mark V ultra light wieght in the 300 wby. And after changing my shooting practices, only shooting 1 shot every 5 min. and cleaning after 15-20 rounds my gun is now shooting like it has never before.

Try cleaning the barrel again and brush the h%ll out of it and once you think its clean do it again. and once at the range slow your shooting and clean it while your out there after 15 rounds or so.

I have even found that my foul shots have gotten better going from 6"off the mark down to about 2" off.

 

[TBASTIAN]

I noticed the same with with my new Mark V Fibermark in .257 WBY MAG. I had a pet load that would shoot great, and then went south on me. I've since found another load which, so far, is shooting very well. It was crucial for me to keep the bore clean and make sure the barrel was cool between shots. I can usually shoot two from a cold barrel, then wait a few minutes before shooting the third and it does well. I'm crossing my fingers that the load sticks! Good luck with yours as well.
-TB

 

[Greg Nolan]

I had a new .257 Wby. Lazermark that I couldn't get to group in an 8" pie tin at 100yds with barnes 100gr. x bullets. I got about 1.25" groups with Nosler partitions in 115grs. I sold it. I wish I hadn't. Barnes x bullets dont compress and they foul the barrel with copper something awfull. I don't know what bullets you're shooting but the barrels seem to be real sensative to fouling, as has been mentioned. Don't give up too soon.
Good luck and good hunting.
Elkhunt :grin:

 

[metallica]

any up dates on your progress??