Mark V 300 wby

[cb4128]

Need some advice. I have a Weatherby Mark V in 300 wby mag that I am trying to get sighted in/grouping well enough for my taste. This is the 2nd Mark V accumark in a weatherby caliber that I just cannot get to group to save my life. I have tried several different grain bullets and different types of bullets, all Weatherby brand. I get the first shot close to where I'm aiming, then the bullets just start to string within 2"-5" each shot across the target. I had the same problem with a .257 why that I sold a few months back.

I know this gun has some stout recoil, but each time I've tried to sight it in, it's either firmly seated in some sand bags or on a lead sled - so it's as steady as you can get.

Am I missing something here that Weatherby Mark V's in Weatherby calibers just are not that accurate? Or what?

I am considering piece-ing together a vanguard S2 in the same caliber to see how it shoots in comparison. For what I paid for this gun new, I could've paid for a custom gun on a remington action.

Oh, and I don't really have the time or equipment to reload, so that's not really an option.

Let me know what you guys think.

[LWD]

Honestly, I think it's a Weatherby quality problem. I've tried to get a good buddy's to shoot, and it just won't consistently. 1 out of every 3 or 4 shots is several inches from the others. We've tried a variety of things including bedding the gun into a new stock. Still a problem. It's a consistent problem with different bullets and powders. I've about concluded he's got a miscut chamber. Next to try is handloads in neck-sized only brass. I've noticed that the brass feels like it's really getting re-sized a lot when I full length size the brass, so we'll see what that does. If the chamber's not concentric, it probably won't help.

How old is your gun? This gun is early 90s vintage.

LWD

[cb4128]

I bought mine new from Cabela's 2 years ago...

[gator89]

I know of a couple weatherby's that I have personally seen and shot that wouldn't group worth a flip. But both of them were 30-378. I dunno I know lots of people who swear by the mark v, maybe it's a simple fix. Hopefully some of the guys who really know the ins and outs of weatherby's will chime in. Best of luck to ya!

[Randy]

Letting it cool off between shots? Weatherby's burn hot and some barrels cant take the heat.

Ive recently seen one other accumark that wouldnt shoot and was gotten rid of with less than 50 shots down the pipe.

[cb4128]

I probably have less than that down the pipe also...

I realize that I can pay $600 and get it "accurized" but I don't want to pour more $ into this thing then sell it. If I flipped it now, I could get a full custom gun for the cost of accurizing it + the $ from the sale.

[Legdog]

Letting it cool off between shots? Weatherby's burn hot and some barrels cant take the heat.

I have an older German Mark V .300 and letting the barrel cool is critical to grouping.

Not sure if that's your problem but that's my experience.

[fishdog]

call weatherby, they have been helpful with any issue ive had in the past. all of their guns are guarenteed to shoot 1 1/2" at 100 with factory ammo.

[32drawlength]

Consider something to dampen barrel vibration like this Limbsaver De-Resonator

[32drawlength]

I can sell you mine or check this link:

http://www.cabelas.com/catalog/product.jsp?productId=741294

[Muddy Bud]

My son has a mark v in 270 Wby. mag. We had a diifacult time getting it to group as well. Had the barrel free floated, trigger replaced and put a muzzle break on and finally got the groups under 1". I know you said you don't reload, but I played around with a couple loads and got that thing dialed in to 1/2" groups at 100 yards with Berger VLD hunting bullets. The only gun I have that likes Bergers and boy will that thing shoot.

[Darton]

It has to do with the heat. A cold bore shot out of all of my Weatherby rifles is spot on, but all shots there after without enough time to cool with have them walk a bit. I swear by them and they are always on my packing list. Their velocity and energy exceeds any other production rifle I have owned. The only other caliber that I use that is not a Mark V is the 264 WM.

[cb4128]

how long are we talking about between shots to let the bore cool down?

[Randy]

Probably overkill.

When its really hot outside Ive taken one shot with one of my really hot shooting .257 Roys thats pushing 4,000fps back inside and let it sit in the cool A/C for an hour or two. Atleast until knew the barrel was back to normal temperature of when I started when I was trying to shoot a one hole group.

[Shane]

Are the action bolts tight? That's the first thing to check. Check the rings and bases and makes sure they're tight too. If everything is tight, then start on the barrel.

Weatherbys usually do better with a pressure point under the barrel at the forend of the stock. A lot of times, if they're free floated, accuracy will go out the window. If yours is free floated, then try wedging a small piece of paper or something under the barrel at the forend and see if it groups better. If so, then get a new stock that still has the pressure point or add one to yours. If it already has a pressure point, then you might try shaving it down little by little to see if that helps. Maybe yours is one that does better free floated??

The Limbsaver De-Resonator can help too. Put one on and move it around until you find the right spot for it.

When I'm shooting a Weatherby (or anything else) for groups, I remove the spent brass and leave the bolt open to let the barrel cool for at least a couple of minutes between shots. Between groups, I'll let it cool for 15 minutes or so.

It's worth it to reload. If you don't do it yourself, try to find someone close to you that you could hire to reload for you. Have them load you up 3 rounds each in 1/2 grain powder increments from minimum to maximum on the particular load you are testing. Shoot 3 shot groups with each load, allowing cooling time (it'll take an afternoon). You'll probably find a recipe that works better than the rest.