338-300 Win mag???

[montana_native]

I was in a pawn shop the other day and there was a 700 Remington with a Pac-nor barrel on the shelf. It was a 300 Win necked up to 338 according to the shop owner.

I can find next to nothing on this round in searches. I see Pac-nor has it listed under their Wildcat chambers.

Does anyone have any info on this thing? What kind of gains over the regular 338 mag?

Thanks.

 

[MagnumManiac]

It appears the 700 magazine is the only factory rifle that can accommodate this cartridge, all other magazines are too short to have the bullet seated out far enough, as a consequence, this chambering is limited. If held to 3.340", a 338 bullet would be way to far into the neck to have sufficient neck tension, and it wouldn't function correctly on the feed ramp.

I haven't found any load data for it as yet, but I did find data for the 300-338, which has the disadvantage of having a longer neck without an increase in capacity like the standard 300 Win Mag with the shoulder pushed forward and the neck shortened.

I can see no advantage to this chambering and I would forget about it for any serious long range work.
Cheers.
MagnumManiac.
gun)

 

[jwp475]

The 30-338 Win is basically the 300 Norma Mag of the 60's the case is a bit shorter than the 300 win Mag and has no problem with magazine length.

 

[montana_native]

Apparently that is why it hasn't caught on then. Thanks for the input.

 

[Long Time Long Ranger]

I agree with magnummaniac. I would leave the 338-300 winchester on the shelf. I can't understand that cartridge. The 30-338 winchester was kinda popular there for a while quite a few years back for people who didn't know about the 308 norma which it duplicates. Both are very accurate and a good 30 cal round.

 

[bcmoli]

I have owned this gun for the last 20 years now and have had nothing but excellent results with it. I use the barnes ttsx 225 grain bullet with 82 grains of RL 19 powder. This produces around 3150 fps with absolutely no signs of stress. This exceeds the factory ammunition for the .340 weatherby at a fraction of the cost for the rifle, brass and powder. I originally did go a little hotter but at the first signs of excess pressure ( ejector marks) on the casing I backed right off. So the 300 win mag brass is a little longer that the 338mag thus gaining a little extra powder. After buying the 300 win mag brass first you run them through the die to expand the neck from 300 to 338 diam. then handload at lesser charge i.e. 76 grains of RL 19 after that you have to fire form them which sharpens the neck slightly and chambers it for the rifle. For extra velocity I had the chamber long throated which seats the bullets out around a quarter inch which produces more powder capacity. This may seem a little radical for some people but after 20 years with no problems i would say it's safe enough. I recently bought a bushnell 6500 series which comes with the multiple reticle up to 600 yards. This scope was not designed for this cartridge so I found that up to 300 yards its dead on then 400 mark is actually good for dead center at 500 yards the 500 mark is for 600 yards and it still shoots 8 inches high with the 600 mark at 730 yards. Believe it or not I took two rounds at 730 and was shocked when I saw the holes 3 inches apart. Could be a fluke but i wont know until I try and duplicate it next time. So overall it's a heavy hitter and extremely accurate at close and long range distances. Die sets for handloading are available through RCBS if your interested.

 

[Long Time Long Ranger]

The 338-300 winchester falls exactly half way between the 338 win mag and the 340 wby on average. That is 100 fps faster than the 338 winchester and 100 fps slower than the 340 wby. That is the reason I could not understand the wildcat. Unless you had one of the magnum actions designed up to the 300 win mag but not long enough for the full length magnums like the wby or any of the full length H&H cases. Then you could get 100 fps over the 338 winchester. Just not worth it. Back when the 8mm rem mag came out in 1977 many of us necked it to 338 to duplicate the 340 wby with cheap remington brass. That was the purpose for it. The 338-300 winchester is a good hunting cartridge just not worth the trouble with the 338 winchester and 340 wby out there or the 338-8mm rem mag for cheaper brass to duplicate the 340 wby.

Bcmoli, you have an incredibly fast way beyond the norm rifle. Like I say your rifle is an excellent big game rifle. You are shooting ultramag velocities out of a rifle less powerful on average than a 340 wby. My 340 wby shoots a 215 grain sierra 3287 fps with 95 grains of 7828 for an accuracy load. The 250 grain accuracy load is 3056 fps with 91 grains of 7828. My 338 RUM shoots the 225 at 3260 fps max and my two 338-300 ultramags shoot the 225 right at 3300 fps. All of those velocities are with a 28" barrel. I like your long throat design and that is where you are getting the extra velocity. You definitely have done your homework and have a very nice hunting rifle. What might not make sense to me may be the greatest thing around for the next guy to wildcat. That is why they make all kinds.