.338 Win Mag 250 or 300 SMK

[Topshot]

That is exactly the kind of information that I am looking for.

I am confused, however, by one thing. You state that the Hornady 250gr match bullet has a higher BC than the SMK. According to the information that I have on these bullets, that is not the case. The Sierra SMK is listed as having a BC of .587 and the GMK is listed at .565, while the Hornady BTHP lists a BC of .465. Unless I am missing something, I have to think that the Hornady left a lot of potential on the table at 527 yards. I sure wish that Hornady would come out with a .338 A-MAX.

Benchracer,
The B.C. of the Hormady Match BTHP SST 250 grain bullet is .670 I think you are getting confused with the 250 grain Interlock bullet.

Hornady has done very well to produce this bullet. I have shot some very small groups with this bullet out of my .338WM at 440 yards. It shoots very flat and hits very hard.

For best long range accuracy, weight sort these bullets as some batches may vary in weight a bit.

 

[benchracer]

Topshot, I discovered my error after I made that post. I was looking at bullets on Midway's site and they had the wrong BC posted. Went to Hornady's site and they showed .675 for that bullet. I stand corrected, which changes my perception of your experience at 527 yards with the shoulder-hit Sambar stag.

Your experience has highlighted to me an oversight in my thinking. From the beginning, I have approached my long range shooting goals from a standpoint more suited to punching paper. That is to say that I have been focusing on MV and BC, while forgetting about terminal performance-- a factor just as critical to long range huntinig.

Thanks, again, for your insight.

 

[benchracer]

AZShooter:

Thanks for the lead on the JBM ballistics program. That is indeed what I was referring to. Haven't had a chance to play with the JBM program yet, but I'm looking forward to doing that.

I like the idea of the G7 BC and hope that it continues to gain acceptance. I understand that the G7 model gives much more accurate predictions than the G1 standard does.

I have seen quite a few references to Brian Litz's book while doing research on long range shooting. I think I may go ahead and get a copy. It looks like I have some homework ahead of me!

Yes, I have heard some rumblings regarding the soon-to-be-released Berger .338 bullets and am very interested. I've got to think that a 250gr bullet with a BC higher than that of the 300gr SMK would seem to extend the .338WM's usefulness by a pretty fair margin.

If some of the reports from the field of excellent terminal performance using Berger bullets are to be believed, a 250gr Berger in .338 could be just the ticket for the .338WM.

 

[edward hogan]

The Ticket for the .338win mag is a 338/300 reamer, preferably one with an AI shoulder.

Then, there is Reloader 17 which Alliant provides data for in .338win, but does not in .338-06. Lower pressures reported at prior max velocity levels, but don't ask Alliant to confirm that...

The cost of the Hornady bthp is so much more than the SMK of either weight, I can't get too excited. Have a 70moa vertical range in my scope so is the extra BC really worth the money, in a bullet you must sort by weight??? (Hadn't heard that one before; thanks!).

I live in Alaska, somewhat rural. Carry a rifle or .454 Casull whenever I go about our place or out on the trail. Am probably going to standardize on the Sierra 250gr GameKing for best value in BC, Cost, and Performance. Probably also try some 300gr smk too. After all a 300gr matchking even at 2400 fps is a helluva lot more than a 300gr from any Casull and has all that penetration mojo working for it.

Not likely to take an 1100 yd shot at any moose unless for sure the ground isn't swampy or muskegg, and few places are terra firma... There is hunting and there is killing. Choosing your ground is often more critical than your quary. Trophies are of no interest to me.

Funny how the longrange benchresters mostly flocked to the 30/338 over the .300win. Winchester and Rem continue to get it all assbackwards, thus the rum/edge and 338/300... Maybe that .338win makes a great longrange bag gun? Sure it does! Nice long neck, capacity that is optimum to 2500-2600fps, and high BC bullets...

I got rid of my .338 and 300 Ultra Mags. Not a velocity chaser. Still have .338win, .340wby, two .338/300s and a .338-06 to choose from. The .338/300 has almost all the power of the .340 and much greater flexibility in loading. Have fired 250gr bullets from 65 to 79gr of xmr4350 and no other case in the .338 family will give you that range of capability. Only wish my reamer was an AI shoulder design.

I carry for defense against large brown bear and moose and have made the choices I feel most appropriate. The .338-06 with RL17 pushing a 250 SGK, and with 5 rounds in the magazine more and more seems to offer all I need.

 

[benchracer]

edward hogan, I am intrigued by the 338-300 reamer you mentioned. That seems like a very sensible option for increased performance without going overboard. However, I have some questions:

Can it be used to rechamber an existing barrel?

Am I correct to assume that the 338-300 refers to a .338 bullet on a .300 Winchester Magnum case?

I have been looking all over the place for data on this cartridge and have found nothing useful. Could you point me in the right direction?

 

[AZShooter]

Benchracer,

If you are considering going with a wildcat another would be the 338/375 Ruger. It is very similar to the 330 Dakota. Being a shorter case it would fit better in a standard length action and magazine. It should also offer a slight velocity advantage over the 338/300 win mag.

Rick Bin of 24 hr campfire made one. Here is the some of the thread:

Ask Rick Bin Questions About the .338-.375 Campfire - 24hourcampfire



88.5 of Ramshot Magnum behind the 225-grain TSX grains to reach a max safe pressure of 50,000 psi.

It's a 24 inch barrel.

At 82, 83, and 84 grains, the chrony did not register due to a shadow. Next cease fire I re-arranged and began getting some love:


86 grains
1] 2820
2] 2784
3] 2817
Avg 2807
ES 35.70
SD 19.97

87 grains
1] 2890
2] 2868
3] 2862
Avg 2873
ES 28.03
SD 14.73

88 grains
1] 2842
2] 2851
3] 2917
Avg 2870
ES 75.38
SD 40.95

89 grains
1] 2966
2] 2955
3] 2954
Avg 2958
ES 12.32
SD 6.63

---------
I am seriously considering this chambering. Just recieved notice that my backorder from Midway will arrive soon. It is a bag of 50 375 Ruger brass. Now I can see for myself how it fits and feeds from a Standard sized Remington. I figure it will be my next build after my 358/338 RCM is finished.

What ever you decide enjoy the ride.

 

[edward hogan]

Clymer makes the reamer I have, or PTG can make you one. Really might only need a .300win mag reamer. All you are doing is lengthening the chamber body by .15 or whatever the dimensional difference is.

If you have a barrel vise and action wrench to remove your barrel, you can probably improve your barrel. I use a large tap headstock and wd40 for lubricant. Also own a RCBS Precision Mic and use it to set headspace. I figure that I want my chamber to be just about .0005" over the length of brand new unfired brass. Run the brass through a .300 win FL minimum sizing die (if you want a standard) before you mic it.


I am not a velocity chaser. Have never seen anything decent come out of Ruger when it comes to precision centerfire rifles. The .338/300 will get you about the same performance as the .338rum, 330 Dakota, or .340wby. I have improved 4 barrels for the cartridge; 3 rem 700 BDL sporter barrels and a Pac-Nor in Palma contour for my TRG42. Also have a .338 TRG-s that will likely be "improved", but hasn't yet.

I extrapolated my own data using the 250gr Sierra and Hornady bullets and XMR4350. Started off with 65gr and worked up to 78gr. Fired more of the 79gr than any other in the BDL and it was plenty accurate.

Last year I decided to standardize my gear. I am selling off all my 7mm and .338 brass and pulling the 200gr smk from my .300win loads. The 200gr will be used in .30-06 and the .300win cases I plan to keep will all be necked up. I have also setup a .338-06 in 22" barrel for walkabout rifle.

Plan to try some 300gr match bullets in the .338/300 TRG42.

I have a couple of spare .338/300 BDL barrels. If anyone wants to try the ctg just email me and we can get you squared away. [email protected]


As far as what works; in a BDL barreled action with my light loads, the .338/300 recoils very mildly. Would have expected much more from a non-braked barrel with 250gr bullet. I never saw any significant pressure signs.

What better magnum case is there than the .300 Winchester? A lot of match ammunition is mfd in the chambering, cases are cheap and plentiful, you get much more room to seat bullets in your magazine box, and you burn lots less powder.

Only thing I am thinking is getting a reamer with improved shoulder and no belt. Would be real easy to lathe off the belts (if you have a lathe) and I know Ackley shoulders are simply more beneficial to precision.

Alliant touts its Reloader 17 powder in the .338win. That stuff may really be The Ticket. Maybe it would be Cat's Meow in the .338/300 too? I wonder if any of the longrange benchers are using it in their .300/338s?


I know the .338/300 offers longer barrel life, cheaper shooting, and less hassle obtaining components. I also own a 274gr NEI flat point mold and intend to cast and shoot some of these in the months ahead. A 2200fps load with bullet cast in wheelweight alloy would likely rival the .50bmg for penetration. My .454 Casull with .345 gr ww cast bullets will penetrate 27" of Cottonwood slab and not deform.

If you aren't slaving to beat the wind any of the High BC .338 bullets can perform and give you great barrel life. I have owned two .338rum, .300rum, and a 30-378. While they were fun to own and shoot, (I never did detach a retina!), with barrel life in the 400-600rd range and getting under 70 loads per pound of powder just took the fun out of ownership for me. I am a hunter, not a stand shooter or a longrange game dispatcher. I figure the Mk4 scopes I own with 100moa and 75moa of adjustment enable me to shoot milder rounds and still get hits.

The beauty of the .338/300 is; if you own a .338win you don't even have to rebarrel, just ream it, neck up your .300win brass and go shoot.

 

[AZShooter]

EH,

Nice write up! Now you are talking! A casual mention of it earlier didn't do much to inspire me. It now sounds like something I'd try. I really like the idea of multiple sources of brass. The 338/375 Ruger is interesting but not being able to buy any for almost 3 months sucked. Hornady has the exclusives on that brass. Dakota brass is WAY too pricey.

I too am a hunter and would only want a rifle that is a repeater. So what about magazine length to accomodate a 250 gr bullet without stuffing it deep inside the case? Wyatts can only go so far. What is your solution?

thanks for those details.

 

[edward hogan]

AZShooter,

I have been thinking about another switchbarrel for my TRG42. As a tactical rifle, seems to me the finest combo would be a .338/284...

You look at Robert Whitley's inset article in the German Salazar RL17 article on 6mmbr.com and you will see Whitley reports 180gr Berger 7mm bullets at 3000fps plus from the standard .284 using RL 17.

I extrapolated my data by comparing .300 and .330 Dakota cases because they had same capacities, and the .300 and .340 wby cases because they were same dimension aside from neck diameter.

I'm sure if you necked up the 6.5/284 Lapua case you might even beat Whitley's data some. But getting same or better than .338/06 velocity from the .284 case necked up to .338 with the excellent BC of the Hornady bullet, who would ever need a TRG-22??

Pretty easy to buy a .473" bolt body from BerettaUSA. Then the same std magnum magazine should work...

I think having a 5-10K rounds fired barrel life would be IT... Not to mention superb accuracy from that excellent case.

Just some ideas. Have also thought of a .532" rebated case head for the .338 Norma or the short Lazzeronis, but you still have the barrel life issues due to capacity. Actually the .330 Dakota shortened a bit and trimmed to .532 (would you even need to trim it?) could be a great one....

 

[edward hogan]

RE oal of loaded .338/300

I was using an LSS action from a .300rum I bought in 03. Never fired that one, just pulled the barrel and put on the .338win barrel.

Have a Sendero SF mag box on my desk right now. It measures right at 3.7" oal; so figure 3.6 or maybe 3.65" max oal for loaded cartridge. A once-fired .338/300 case (from my chamber) measures 2.595"oal. With a 250gr Sierra GameKing being about 1.4" oal you can seat the bullet way out there in a Rem 700.

With a Hornady 200gr, you can seat to just below the cannelure and have no bullet protrusion into the neck of the case. Not to say this is conducive to accuracy, but you have a great range of seating potential. Neck length is about .285" on my fired case.

Beauty of reaming your own chamber is you can shorten the case body dimension and get all the neck length your original barrel offered. All sorts of options there.

Also if you start with a standard or .510 case body diameter, you could improve/ream for next up dimension .338 case. .330 dakota and then Ultra mag. In theory as you ream for a larger chamber you get a new throat area that maybe isn't burned?

 

[AZShooter]

Say, you have the rifle looney disease pretty bad! I also read that article on RL-17 and have used it in several midsized cases. To get 3000 with a 180 in a 284 you have to have a very long barrel.


Thanks for the details on the 338/300 win mag stuff.

 

[banjo318]

Load them as long as you want, you'll be lucky to push the 250 gr faster than 2600 fps out of a factory length barrel. Do your calculations from there for the 300 gr.

Simply put, the .338 Win Mag is better suited with bullets less than 250 grain.

Sorry mate, with a 24 inch 1-10 twist barrel. You can achieve 2750 fps in a 228 win mag. I hate those folks that just think. Well a 7mm remington magnum cant push a 175 grain bullet all that fast, Why should a necked up version be any better? Well its much more efficient than the 7mm remington magnum. Im not dissing the 7mm rem mag by any means. I own one. But the 338 win mag is much better than most people think.

 

[bigngreen]

Sorry mate, with a 24 inch 1-10 twist barrel. You can achieve 2750 fps in a 228 win mag. I hate those folks that just think. Well a 7mm remington magnum cant push a 175 grain bullet all that fast, Why should a necked up version be any better? Well its much more efficient than the 7mm remington magnum. Im not dissing the 7mm rem mag by any means. I own one. But the 338 win mag is much better than most people think.

WOW, you hurt my brain dude

 

[X-man]

Sorry mate, with a 24 inch 1-10 twist barrel. You can achieve 2750 fps in a 228 win mag. I hate those folks that just think. Well a 7mm remington magnum cant push a 175 grain bullet all that fast, Why should a necked up version be any better? Well its much more efficient than the 7mm remington magnum. Im not dissing the 7mm rem mag by any means. I own one. But the 338 win mag is much better than most people think.

I think you are missing out on the fact that the 250SMK is 30% longer than a regular hunting bullet.
You can get 2750 from a regular bullet, but a 250 Match King takes up an enormous amount of room...There is just no way unless you long throat the chamber and have a mag box long enough to take the length....or single feed it.