Home Forums Hunting & Shooting AR and Tactical Rifles Velocity of 338 Lapua with 20 inch barrel

A friend of mine wants to buy a Barret bolt action in .338 Lapua.
It has a 20 inch barrel.
I told him it will be loud and he will lose some velocity.
what do you guys say?

You don't lose as much vel in the Bigger Bores when you chop the barrel length off as you do in the smaller bores . My guess he would lose a couple hundred FPS going from a 26 to a 20 inch. Chronograph would be the only real way to know

Ammo was $150 per box of 20 so we need to chronograph
pdq
whelennut

I think I would take a second look at the Armalite...

I would be interested to know how it plays out though. Gotta be loud at 20 and I assume a brake too. Ouch.

200 fps less.

300 grain Scenar ammo:

2725-2750 in a 24.5" Barrett MRAD
2625-2650 in a 20" Barrett MRAD

Get the 20" MRAD and put a TBAC can in it, btw. Perfect setup. Run 300 Bergers and Retumbo. Lapua brass only.

I would not shoot that on a bet.

If you do, muffs & plugs.

time to start loading your own ammo or eat the cost of factory ammo. Rifle is totally useless if you can't afford to shoot it

Isn't getting a short barreled 338LM defeating the whole purpose of the cartridge?

you would be better off with the 338 Federal and the short barrel , at least you will have some of your hearing left

That's what I was thinking. IMHO it's like re-building a 69 Camaro and putting a 4 cylinder in it!

Kind of like a 2 1/2 inch Model 66 357 that the FBI used to carry a few decades ago?

It was purchased yesterday against my advice by m
y friends stepdaughter.
I will run it over the chrony and let you know how the 250 gr factory ammo does.
I can't wait to see her face when she touches this off.
whelennut

Are you asking about the velocity of the bullet or that of the butt when it comes rocketing back through your shoulder?

Did you guys see the accurate velocities that Greentimber posted? A .736+ BC bullet at 2650 is a serious "long range" capable combination by all standards.

Compare that to the world standard .308 168-175gr at similar velocites...

A 20" .338LM will effectively engage targets beyond most people's ability to hit them under field conditions.

Sometimes (most times) extra barrel is just extra barrel.

Why would we compare the 338LM to the 308? They are two entirely different classes.

Because the question was posed about the short barrel defeating the purpose of the cartridge. I made the comparison because these standard .308 loads are widely considered suitable for targets up to 800 yards (and beyond for many users).

The .338LM even with a 20" barrel far exceeds the capabilities of the standard and most common long range precision cartridge so it purpose is certainly not defeated.

I was stating its superiority based primarily on drop and wind drift, but there is also a very serious upgrade in down range energy and penetration. Again the short barreled .338 serves a real purpose.

I agree the .308 and .338LM are in two entirely different classes.

I would not shoot a 20" 338 Lapua without a suppressor. Maybe it's different for you young guys with healthy ears.

Sometimes extra barrel is just extra barrel, and sometimes it enhances the shootability of a rifle.

Have to disagree with these numbers, I cut 3" off my barrel and lost 150fps

Agree on the bullets and brass, never had any luck with Retumbo. RL25 and H1000 have worked best for me.