I have been stumped by this one for a while now. In any Weatherby catalog ,in the back they list a option for their Accubrake.Under the Accubrake performance heading this always catches my eye.
Cartridge 30-378 ,180gr x-bullet ,rifle wt.,scope&mount 9.75 avg. lbs ,recoil energy ft.lbs 55.1 unbraked,25.9 braked
Cartridge 338-378 ,225 gr. x-bullet,rifle wt.,scope&mount 11.75 avg lbs.,recoil energy ft.lbs 46.3 unbraked,21.8 braked.
Could some one explain this to me?I always though that bigger the caliber bigger he recoil.
Example would be a 270 win. vs 30-06,or 300 win.mag vs 338 win.mag.But this one just stumps the hell out of me.Also what calibers do the felt recoil compare too?I E the 30-378 25.9 and the 338-378 21.8?Lastly in the long run which caliber would last longer?I E Barrel burn out?
I guess what I really want to know from any of you 338-378 shooters out there is what caliber does your braked 338-378 feel like when you fire it?What made you pick the 338-378 instead of the 30-378?

you have to look at the gun weight. heavy gun less felt recoil.

HERE IS a way to figure out the recoil yourself that takes all the variables into consideration.

http://www.biggameinfo.com/RecoilCalc.aspx

ARMA:

I don't own a Weatherby, and never would in either of those calibers especially. I don't see the need for them in my world at all.

What I was going to pass on is that several years ago, a friend who was new to Elk hunting had been convinced by his granddad that he needed a 300 Winchester when I suggested a 30/06 instead. Of course he went with what Grandpa said. Then he could not get the rifle zeroed.

I stopped by the range with him and mounted a less powerful scope on his rifle. His was a 300 Win in a Model 70 with a BOSS on it. He was shooting factory 180 grain Remington ammo out of it.

In my truck, I had a 30/06 with a BOSS on it in a model 70 also. I also happened to have some Remington factory 180 grain ammo, that I was trying to use up.

I was really surprised at the reduction in Recoil that the BOSS gave the Magnum. I then fired my 30/06 with the same set up and same rifle, and it reduced the recoil less than the Magnum with the Boss had.

So two Identical rifles in two different 30 caliber chamberings. The 300 Mag with the BOSS had a lot less recoil, than the 30/06 with its Boss. Same 180 grain bullet by same manufacturer.

My conclusions were that on the magnum any BOSS or Muzzle Break does is job! Also the bigger the caliber the bigger the percentage in recoil reduction.

Don't know if that helps, but it made a believer out of me on muzzle brakes.

Cheers
seafire

Thanks guys for the responses.Seafire you may have hit upon somehing here!At least to my pea sized brain.I guess why I am so interested in this is because I have a Weatherby Accumark 30-378 mag.It is now has has been the single most accurate gun I have EVER owned in my 43 years on this earth.Recoil with the factory brake is not bad at all.But on this forum and others I have followed a large number of 30-378 owners have since rebarrel their 30-378 to 338-378 mags.And have been better pleased with the larger caliber.Weatherby states that the 30-378 is their best selling caliber even surpassing the flagship 300 weatherby.My thoughts on this were that because both calibers share the sme case and basically the same powder charge that the 30-378 greater recoil braked or un-braked was due to the smaller caliber barrel .308 vs .338 IE Its easier to get anything out of a bigger hole than a smaller hole.But your assessment may be more to the truth here.
I still would like to here from any 338-378 shooters out there.How bad is the recoil,, braked or un-braked, is the 338-378?

My scenario is exactly what you described. I own a Mark V that was originally a 30/378 w/ Accubrake. I bought it the year they came out. I shot it for a couple of years and liked it a lot but got tired of the blast so in 2000 I sent it to Shilen and had them rebarrel it in 338/378 and I haven't looked back. I absolutely love the gun and I use it for everything. One thing to note is that the recoil is not for the faint of heart. I had them put on the largest barrel that would fit in the stock in the longest length they could make in 338 (29" finished). Anyway it's about a 12.5 lb. gun with Burris scope, bipod etc. which helps cut down on the recoil some but it's still plenty stout. Far worse than my 8lb. 300 H&H. All of the recoil calculators I've found put it somewhere in the mid 50 lb. range. It took a while to get used to the recoil but now it's no problem. I have no regrets about stepping up in caliber and removing the brake. The bullet selection in 338 is every bit as vast now days as 308. Plus you have the option of going a lot heavier.

If you're ever in the Austin area. Stop by and I'll let you give it a go.

I have both the 30-378 and 338-378 in Accumarks and a 378 in Mark V Deluxe. I leave the brakes on the Accumarks so all I can tell you is based on such. I use light for caliber 185 grain TSX in the 338-378 and 168 grain TSX in the 30-378...I do not notice any difference in the recoil...both are loaded to a nominal 3500 fps same scopes, rings, etc. The unbraked 378 has substaintially more recoil obviously using much heavier bullets.

All the Accumarks I have seen shoot very accurately and the 30-378 and 338-378 will at very long ranges.

In the 30-378's we use Retumbo powder, Fed 215 match grade primers, and the Barnes TSX which have proved to be the most accurate hunting bullet we have tested. I have only fired about 300 shots in the 30 and 150 in the 338 and have not noticed any deterioration in accuracy.

Increasing the weight of a gun will, of course, reduce its recoil, everything else being equal. Even if the rounds are different, a significantly heavier large caliber might not kick any worse than a lightweight in a smaller caliber.

As to the effect of the BOSS (or any other muzzle brake), I suspect that if the powder charge constitutes a larger factor in the total recoil of a given system (ie., a magnum vs a standard round), it is probasble that the reduction in recoil caused by the brake would be greater for the larger powder charge.

338/378-250gr bullet
braked like a 3006 unbraked like a 375 H@H IMO
300 Sierra's a bit more

Picked the 338 for longer barrel life

Regards Martin

Thanks guys for all the responses.Martin thanks for your post ,thats the answer I needed the most IE (BRAKED 30-06 NO BRAKE 375 H&H)
I going to look in to rebarreling my 30-378 to 338-378.

Thanks again to everyone who posted on this topic.I told my local gunsmith what I was thinking of doing and he had a fit!He`s a good guy in his 50`s,and good at what he CAN do.I mean he`s a little limited on any full bore project,but mounting scopes,detailed cleaning,re-barreling old 98 mauser`s to 35 whelen(his favorite pastime)he is as good as it gets around here.But he is old school in that remington anything is what you should buy in a rifle.And 270 win or 30-06 is all you need to hunt anything with.If you think you need more knock down then have a 35 whelen built.But the thing he said that got my blood boiling was that at 43 years of age I was TOO OLD to handle a 338-378 let alone the 30-378 I already have.I told him I grew up hunting with a old 10 ga. single barrel shotgun since I was 12,and I still use a old remington 870 12 ga. slug gun plus my WIN. 95 IN 405 WCF if I can get some better sights on it to hit with.But he was sure that a 338-378 even with a brake is a young man`s weapon.So how old is to old?

Going by that rule I would have to sell all of my guns but my 308 and 350RM.

54

Regards Martin

I find it hard to believe the 338-378 would have less recoil then a 30-378, even if the the 338 is a pound or so heavier. The other thing to factor is the recoil pulse of those rounds is much faster then larger bores of similar weight and recoil levels. Not just a big jab, but a fast big jab. I don't like jabby recoil, I shoot unbraked big bores that dish out nearly 100 ft# of recoil, and they are tollerable because they don't jab you. I have absolutely no desire to shoot an unbraked 338-378, even if the recoil is 1/2 that of my 500 Jeffrey.

Based on the numbers provided, the breaked 338-378 will be similar to an unbraked 30-06.

Saying such guns are for younger folks is nonsense. So long as you don't have neck or shoulder problems, you can handle plenty of recoil. I would be concerned about the muzzle blast doing some bad things to the bones in your ears though, as even double hearing protection (plugs and muffs) doesn't protect them.

I have a friend who's in his early 70's and still builds and races 300 mph cars. Old is a state of mind.