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

I believe you can apply the laws of cantilevers to determine how much stiffer the barrel is in a 243 compared to a 308.

On a muzzle diameter of .600”. The 243 has about 10% more steel across the diameter. Stiffness increased at a rate of 4:1 ( it’s strange John, that ratio comes up so often!).

We can conclude the 243 is about 40% stiffer given the same barrel contour.

I had an ULW in .300 Wby. After some work by Hill Country Rifles it shot about 1.0 MOA with 180 grain Partitions, 3-shot groups.

One problem is the barrel really heats up fast. After three shots, I stuck a hose from a battery powered air mattress up the barrel and ran air through it for 10 minutes before shooting more.

Another problem was recoil. The perceived kick was much greater than my .375 H&H Model 70. that's bound to affect "accuracy."

This ULW Mark V might be my winter project, pray for me.

41

Float the barrel from 2” in front of the recoil lug and work up a load. It will shoot. They put a good barrel on the ultralight.

On paper the mkv ultra lightweight seemed like the ultimate rifle for me for several years. The problem was the ones in on weatherby cartridges seemed notoriously in accurate and and I didn’t want a smaller rifle. I got one in 300wby, between the whip on that 28” barrel, the recoil and the clunky bell and Carlson stock I didn’t keep it long.

It wasn’t fun to shoot, it wasn’t accurate and it was not easy to carry in thick brush.

I’ve had experience with 2 of them in 300 Weatherby. Neither one shot well. With some loads I could get 3 to group ok, but then both would climb right up off the target.

I shot my 2nd Grizzly with one of them. Sold it after that. Went to a M-70 SS Classic in 338 WM. I’ve never looked back.

I have one in a 300wm with a 24” tube. Shoots excellent after bedding the rifle and free floating the barrel.

It came with a pressure point and as with almost all rifles bedded that way, poi shifts occurred when you were slung up.

Negligible poi shifts with it free floated and shoots accurately. I believe the 300 Weatherby only came with a 26” tube as well.

My 300 Wby UL stacks 'em on paper & on the back of the truck. My 280 Wby UL does too.....but, it took me owning three to find one that'd shoot as it should. Could not be happier now.

I’ve had 3, 257, 240, and a 300 Wby, all with talleys, all leupolds, all shot under a inch with factory fodder. Pards 270 Wby shoots very well too, it’s his only rifle. Just took it to Wyoming with me last month after a 7 year hiatus….





Only gets fed 130 Hornadys. Bullets mean far more than headstamps!!! 😂😂

My Weatherby ULW 338-06 throws darts with the 200gr Speer, 210gr NPT. I think I’m mostly surprised that it shoots 4320, RL15 & IMR 4064 almost equally well with these bullets. I’d love to find another one in 280.

Boy I’d love to have that rifle!!

i purchased a 338 Lapua Weatherby Accumark Mark 5 new this rifle shot horrible even with a good Night force scope on it, i called Weatherby they were no help at all wanted me to send rifle and a check for around $150.00 for them to check and decide how this rifle shot within their specs 3 shot 100 yd. groups so i told them to forget it. so i had a new Brux barrel chambered in a 338 Lapua with a new end port on barrel also ,this rifle now shoots 1/2 inch - 5 shot groups at 100 yards off my cement bench and is a joy to shoot now. i am not at all impressed with Weatherby`s customer service , i also have a 257 Weatherby mag. Accumark and this rifle is impressive how it shoots too with some things redone on stock and trigger.

Uuuuummmmm the 338 lapua isn’t a ulw, but cool story anyhow

I had just the opposite experience with WBY customer service. Bought a new ultralight in 300wby. Shot very well using my reloads of 7828 and a Nosler BT @3150fps. I was able to go to 3200+ with max book charge.
Anyways trigger had some creep and since it was a new trigger I sent it in. Stock came back with pin holes that hadn't been filled. I had not noticed these before and called C.S. They paid for a return. I asked if they could put a different stock I believe the outfitter, I liked the color scheme better. And asked if they would range certify after. They did all of it for me. Groups were with a 180gr TTSX load at .52 and .73.
I havent shot the rifle since getting it back. Hopefully is shoots as well for me as it did in their shop
Jeff

Few questions. I'm assuming they fixed the trigger for free. But how much was it for that new stock and for doing the range certification? And did they use Factory ammo to range certify?

They did not charge anything. This was about 2016-17 time frame. They said since the stock had a defect and needed replaced anyways no big deal
Jeff

P.M. me

Mine is accurate enough.
George

yep your right its just a Accumark that is suppose to be accurate and it was a expensive new rifle that shot horrible and still pisses me off yet with Weatherby`s customer service department. sure it now shoots better than any factory Weatherby accumark 338 Lapua but it cost me another $ 500.00 to put a Brux barrel on this rifle which is a much better barrel and the machinist " Greg " does do a lot of bench rest rifles that have won some titles. but the point is for that kind of money that factory Weatherby rifle should have shot much better 1 - 1/2 inch 3 shot groups at 100 yards is terrible , now i can shoot 5 shot groups at 100 yards 1/2 inch once i replaced the barrel , that new factory rifle should have with a factory barrel should have shot 3 shot 3/4 inch at 100 yards at least. maybe i am to fussy but Savages do it with a cheap rifle , so does Ruger and Remington they all shoot groups under an inch. >> shame on Weatherby if Roy was alive this would not have happened !