Weatherby Mark V .338 LM versus heavy weight

[davidjoe]

I’m not convinced the Mark V’s group size in recent discussions in .338 Lapua Magnum is a result of it, as opposed to our not holding it still. So I’m testing my ~13 pound Mark V against my ~26 pounder. Same box of Lapua 300 scenars, the best .338 bullet on the planet.



The Mark V sits in a McMillan off the classifieds and only weighs 13 pounds because of an NSX nightforce, nicer stock, and a bipod.



The barrel, by itself, opposing the weatherby is a Krieger that weighs as much as the whole MarK V rig.



The other gun has the benefit of Tom’s large ELR stock and a Phoenix bipod. Manners’ stock is inletted so precisely the gap to the Surgeon XL is microscopic, I don’t know how that can be pulled off. I don’t send my actions. Someone there really knows what they are doing.






My goal in future range visits as time allows is to close the gap between the guns.



The Mark V in the past has one-holed bullets and then a flyer results. It has shot nice 3 shots groups at .5 moa. I can’t get a 5 shot group that small, and this is bothersome to me because I believe its muzzleblast and loudness induce bearing down tightly and differently at some point in the string, causing flyers.

The ammo contains no “flyers”. I shoot out of the same box and it works well as shown by the heavy gun.

To my thinking, if some of the shots are touching, and in other targets they did, then that demonstrates the rifle’s group capability, which is better than one-off flyers are indicating.

I’ll post any improvements I can wring out of the Weatherby. Any suggestions on this subject of light gun flyer remediation? (It does need to stay on a Harris to remain practical.)

 

[martyj]

My mark V action in 338 edge

 

[MagnumW]

Lighter barrels need more tuning than heavier barrels. You are assuming the load used is equally tuned to both rifles?
At 1000 yards what are the results?

 

[Sandstorm]

You are assuming the load used is equally tuned to both rifles?

Im thinking the load needs more....either powder or seating depth....but it needs more.

 

[davidjoe]

Lighter barrels need more tuning than heavier barrels. You are assuming the load used is equally tuned to both rifles?
At 1000 yards what are the results?

Lapua makes a truly great factory loaded round that performs well in my TRG, H&S, and Savage single shots. It’s not a mildly loaded round, and over time I have periodically compared its POI at 600 to my own loads, when loading their 300’s.

They don’t leave much on the table, meaning it’s warm for factory loads. I tend to seat to their depth for ease of chambering in several factory rifles.

The lightest barreled .338 I have is this Weatherby. My theory with these several factory guns of moderate to light contours is that they can’t be expected to shoot long strings as well as heavy gun because the barrels will walk as heated, but the first few shots should possibly be comparable in group size.

The Savage single shots, (not stainless steel) which in laminated stocks were a real bargain at about $1,000 from a decade ago, at least the first one I scoped up and have used, have a contour lighter than the LRPV’s and honestly rival my heavy customs, for little more than the barrel’s total price.

I have watched Ian shoot at V2 and he actually holds the stock with his left hand, and I have sometimes shot tighter with the left hand on the barrel, and I might try techniques like this to “simulate” it being a heavier rifle. Very different from F-Class. When I shoot a factory gun like this off a bench, I almost feel that but for my shoulder, I could pull it off the bench with only my trigger finger, before it would fire. It’s interesting to have such different guns on two benches and alternate.

With a gun like the MV, I’d be happy to just eliminate the true flyers, and live with core group, whatever it turns out to be. I feel like the hold/flinch may account for flyers in such a light gun, but of course I’m paying close attention to that and don’t really perceive a correlation between “less” confident shots and outside impacts.

There’s a degree of redundancy in this lightest gun’s role, as the others, which I’ve had longer and am used to, can also be carried around. That tends to diminish the incentive to deviate very much and stock up on rounds that are best for just it, unless I really do have to to eliminate fliers, and I suppose this aspiration, which might not pan out, is why I do revert to comparisons with Lapua’s rounds.

 

[Sandstorm]

that they can’t be expected to shoot long strings as well as heavy gun because the barrels will walk

Absolutely agree with this. Its difficult to compare two completely different barrels with the same loads
even in other calibers. These are out of my wheelhouse for sure.
Its live with what you have or work up a load for the Weatherby.. in my mind its close but needs a push.
Its a familiar pattern in grouping for me...Id try a different bullet or ??

 

[TaperPin]

For a factory Weatherby many of us wold consider that not horrible, my big Weatherby was never more than a 1-1/2moa gun.

 

[std7mag]

Davidjoe,

I think your worrying about nothing.

Not too bad groups for a fairly stock 13lb Mark V in 338LM off a regular bipod.

Comparing it to your heavy barreled Surgeon at 26lbs with the slider bipod isn't fair to the Mark V.

 

[davidjoe]

Davidjoe,

I think your worrying about nothing.

Not too bad groups for a fairly stock 13lb Mark V in 338LM off a regular bipod.

Comparing it to your heavy barreled Surgeon at 26lbs with the slider bipod isn't fair to the Mark V.

There was another piece of info that I should have included. The Weatherby groups, and this includes several not pictured, they almost always started out with the first two shots being the closer ones together, in the groups, and the third or more being the spoiler.

The opposite would be that the cold bore is off, and the others group. I didn’t see that.

Then another outcome could be that the first two establish the spread and the third shot basically splits the difference.

But what I saw, that makes me think possibly hold faults creep in, Is that shots one and two are good, all the while roof rust is falling from the muzzle blast, as well as the “let’s not wreck this” over analyzing, and those could each manifest in a physical hold difference I think, which in turn makes me think the light gun maybe does have four or five good shots before walking. Which is all we really need from one.

 

[Bubba Boomstick]

My 338 Lapua Weatherby shot the same. Nothing spectacular.

Got it rebarreled into 300 Norma using Preferred Barrel blanks. It's a tack driver now. Factory barrel is being used a paper weight and a baseball bat.

 

[Ironworker]

My 338 Lapua Weatherby shot the same. Nothing spectacular.

Got it rebarreled into 300 Norma using Preferred Barrel blanks. It's a tack driver now. Factory barrel is being used a paper weight and a baseball bat.

How is the recoil on that 300 Norma?

 

[Bubba Boomstick]

How is the recoil on that 300 Norma?

Similar to a 300 PRC. Harder than a 300 Winchester Magnum. Softer than a 338 Lapua.

I run a Nomad-L 30 cal suppressor on it with a soft limbsaver recoil pad. I can shoot 20 to 40 rounds in a shooting session on my 9ish pound gun with suppressor with relative comfort.

If you keep the gun around 9-10 pounds, it is manageable without suppressor or muzzle brake. At 8 pounds and below, the recoil is harsh and you will want some kind of compensation from a muzzle device. My opinion is the weight of the rifle will make or break your experience with the 300 Norma cartridge. Many people want ultralight 6 pound hunting rifles, but this is the wrong cartridge for that application unless you want to go to the dentist.