Home Forums Hunting & Shooting Ask The Gunwriters Mark V® Ultra Lightweight Accuracy

I’ve had experience reloading for 2 of these rifles, the 270 W was straightforward. I worked up a sub MOA hunting load on the 1st try after some research on the correct component combination. Went with the 130 TTSX & Reloder 23 and the Federal 215m primer. It’s a laser beam & kills everything we put the crosshairs on.

The ULW 300 W is the exact opposite, it has to be the most difficult rifle I’ve ever come across. I’ve lost track of the loads I’ve tried in it. It patterns more than groups.

I’ve tried all the usual tricks on it to no avail, it must have something to do with that long whippy barrel & barrel harmonics. Found a Hunting Shack factory load that shoots OK it’s using the Speer 180 grain Grand Slam, that’s a bullet which I like so l stocked up and am using that. Still bugs me I couldn’t get a reload I liked to work.

I wondered how those would shoot. You don't see many ultra light rifles with that stock design. When I first got in to lightweight rifles I spent a good bit of time talking to (more like bothering) Melvin Forbes, and a straight stock with no drop was one item he felt necessary, especially as recoil (and as a result muzzle flip) increases. His advice when I first started loading for light weight rifles was to sight in with my off hand on top of the scope and not to be afraid to apply some downward pressure. Maybe its just the difference in muzzle jump with the magnum.

Only have experience with one in 257 and it was very accurate. I would send the 300 back to Weatherby, if the customer service is as good as it used to be they will probably re-barrel it. Sometimes this doesn't pan out as they may test it in a machine rest which could eliminate bedding or other issues causing the poor accuracy.

Hadn’t thought of that option

From another forum...


“The 300 Bee in the ultralightweight config is a true bear to get to shoot nicely. Way too much whip for such a light barrel. I personally have NEVER seen an accurate one”

I'd contact Weatherby 1st. then I would full length bed the whole thing. I might to that even if they did put a new tube on it. Always sand out the channel and re-float it if you wanted.

Between myself and a friend, we have owned several of these but none where 300 WM. All responded very well to Devcon 10110 bedding and Timney trigger. Best of the bunch was a 338-06 that would one hole the 180 BT's but all where great shooters. Remove from the stock and check the contact points. Those are really nice stocks, but factory contact is very spotty.

I have a 338-06 that is a 1 1/4"+ 5-shot rifle after I bedded the action and reworked the pressure point. Before the work the rifle was a 2 1/2" 5-shot rifle and free floated it was a 2" 5-shot rifle. This rifle likes the pressure point but the one from the factory was poorly done.

A second one belonging to my son is a 30-06 and it behaved almost exactly like the 338-06 did. I when thru the same process and it will now shot around 1" 5-shot groups, again with a proper pressure point.

Groups quoted above are with factory loads that each individual rifle liked.

I have never had anyone not have some sort of accuracy issues with an ultralight in 300 win or WBY.

I had an UL in .30-06. Loved the feel, the weight, the point-ability.

But she didn’t shoot for shìt.

I did everything, powders primers bullets, even a bedding job. Fine for 200 yard hunting accuracy but by no means farther. I sold it and went Tikka, never to look back.



P

84.5 gr IMR 7828 stacks 180’s all day in my 300 Wby & 83.5 gr of the same in the other.

Had a Weatherby Ultra Lightweight in 300 WBY. Shot an amazing 3 shot group and thought I had found the perfect solution for a sheep rifle until it almost cost me a nice ram in the Brooks Range. Upon my return I found that the rifle would always throw one flyer in every group. Careful analysis revealed that the flyer was utterly random. Could be any shot in the group. Sent it to Weatherby and they returned it saying nothing wrong. Got a Weatherby employee in engineering interested. Returned rifle to him and he sent me a new rifle. Would not tell me why but I suspect a hairline crack in the receiver. Subsequently found that others experienced the same results in 300 WBY. My conclusion is that a 180 grain bullet at 3100 fps is too much of a good thing in a 5 1/2 pound rifle. Sold it new in box to my sheep guide and replaced it with a Win model 70 300 WSM in a 1 pound MPI stock. 100 fps slower and a 1/2 pound heavier but totally reliable.

I bought an ultra light Weatherby 300 win mag a while back and had troubles. It turns out it had little to do with the rifle.

The trigger came badly adjusted. Creepy and 4 pounds. Got it to just under 3 and crisp with out the stones.

Factory Weatherby pressure bedded fore end didn’t like the hard sand filled rest. Thick glove took care of that. Started showing some potential so I went ahead and glass bedded the action and 2” of the barrel and free floated it because of poi changes. Turns out that the pressure bedded fore stock was not the problem with the poi shift,,,,,,,

Leupold windage rings and bases wouldn’t hold the 16oz scope. The rear windage rings started to shear the windage screws. I put on a Warne steel rail and 3 weaver detachable rings. That took care of that problem .( poi shift) The thing kicks hard.

Once that was sorted, sub moa groups are the norm. Later I extended the bolt stop track and took out the magazine spacer that limits oal length. I can load cartridges up to 3.750 now in the magazine. Vlds will get to the lands with plenty of room to spare.

It’s become my favourite hunting rifle. Very accurate and light weight. Definitely worth the trouble.

Had the same rifle (see avatar)and had no problems like you described - the interesting thing about this rife (actually the load I used) was it shot the same at 300 yards as it did at 100 yards (1.5” three shot groups) was consist at it. Took a nice Dall Sheep in the Alaskan range with it and a nice bull moose on the same hunt - shooting 180 grain Accubonds at 3180 fps. My nephew now has the rifle but it was a joy to carry on those type of hunts.

PennDog

I gave mine in 300 Wby away.

My Mk V LW .30-06 is very finicky but shoots some loads very well. My other Mk Vs in 7mm and .300 Roy are excellent shooters but dang sure aren’t lightweights. Who the heck wants a 7 lb rifle in .300 Weatherby? Glutton for punishment?

I set a LW in .240 up for a friend. He bought it used from a pawn shop in NW CO but looked practically new.

After getting a load developed from Superior Ammo, the rifle is a drill. It shot factory ammo pretty good, notably the WBY SP, around 1" but the Superior NAB load is under 1/2".


He has a 30-06 and a 25-06 as well in the LW setup. All are pretty good shooters but the .240 is my favorite. I will get one eventually.

Our .243 Win UL is a tack-driver. Literally. Everything we've used.

Only fly is POI shifts with load changes are pretty drastic. So long as we stick with a particular load it delivers every time.

About 99% of the problems with the UL Weatherbys in 300 Bee is with the Indian not the arrow.

Cheers to that!

Had an ULW in .240 for a while--which my wife mostly used, after she found out how well the stock fit her. It shot very well too.

But part of the deal is that smaller-caliber cartridges result in stiffer barrels.