20" 338winmag what powder?

[Longshotjames]

I am starting load development for a 20" barrel on a 338win mag. I have H1000 and plan to start there, but does someone feel there is a better burn rate for the short barrel using 250-270Gr bullets?

I am not trying to make a barn burner but want to get best velocity out of the short tube.
This is a pack rifle that will be capable of taking elk under 700yds

Thank you for suggestions
James

 

[86alaskan]

I loaded my 22" 338WM with 250gr hornady PSP and a stout load of 7828ssc. I was getting good velocity and accuracy. Never ran that load out that far, but the accuracy seemed like it would hold up. I'd run 7828, RL22, RL26, IMR4350, H1000, Retumbo. anywhere in that range should get you going. I'd probably stick with 250gr unless you have a long barrel and freebore. My 250's were taking up a good bit of the top of the case and were compressing the powder a fair amount. You can probably get 2700ish if you're feeling brave, other wise 2600 range is what I'd expect from 20"

 

[Pa Grizz]

Winchester 760 work's best with 250 and 300 gr bullet's with my 700

 

[Longshotjames]

Thank you for the suggestions.

270edlX has a G1 of .757 which will carry more velocity past most any lower BC 250gr past 450-500yds even with lower MV to start with. That is enough incentive to try the heavier 270's for me.
James

 

[Mike 338]

H-414 has been a good one for me. Win 760 is said to be the same thing.

 

[Longshotjames]

H-414 has been a good one for me. Win 760 is said to be the same thing.

how is H414 on temperature sensitivity?

I live in Texas and shoot a lot in 90+ temps but hunt in Colorado and could see temps in the 20's

 

[sable tireur]

Re-16 under the Hornady 270 gr. ELD-X. Should get about 2,500 fps. which will maintain 1,900 ft/lbs. of energy at 700 yards. All of the Re-16 will be burned in the 20", actually less. I also think you'll find that Hornady is exaggerating that BC by quite a bit. But you should shoot them for BC as well as accuracy in order to build a proper drop chart.

Enjoy the process!

 

[Longshotjames]

Re-16 under the Hornady 270 gr. ELD-X. Should get about 2,500 fps. which will maintain 1,900 ft/lbs. of energy at 700 yards. All of the Re-16 will be burned in the 20", actually less. I also think you'll find that Hornady is exaggerating that BC by quite a bit. But you should shoot them for BC as well as accuracy in order to build a proper drop chart.

Enjoy the process!

I really thank you for the powder suggestions. I have a few Reloader powders I can dig through. how is temp sensitivity on the RL16? Would I be shooting little poofs after working up loads in the Texas heat?

As far as the BC on Hornady bullets, Thats a whole other discussion.
James

 

[Edd]

The barrel length doesn't change the powder choice.

 

[Longshotjames]

Edd,
I have often pondered this. Can you explain why barrel length doesn't matter for the powder choice? Based on that I should stick with my H1000 because I know it's not very temp sensitive and I shoot it most my other LR rifles so I have it on suppy. I would love to hear more about the mechanics of barrel length vs burn rate. Thank you very much for posting
James

 

[Edd]

Edd,
I have often pondered this. Can you explain why barrel length doesn't matter for the powder choice? Based on that I should stick with my H1000 because I know it's not very temp sensitive and I shoot it most my other LR rifles so I have it on suppy. I would love to hear more about the mechanics of barrel length vs burn rate. Thank you very much for posting
James

I don't think H1000 is the correct choice for a 338 Win Mag. I would want something in the H4350-H4831 range.

Here is a copy of something I just received from Hodgdon.

TIP OF THE MONTH
DOES MY SHORTER BARRELED RIFLE REQUIRE DIFFERENT RELOAD DATA?

We often get this question. In asking, the customer is unsure if the different barrel length will necessitate a loading data change in the powder chosen. Let's preface the answer with a quick guide on testing data.

All our data is tested for pressure and velocity with instrumented equipment as established by the Sporting Arms and Ammunition Manufacturers Institute (SAAMI). The dimensions of the test equipment are established by SAAMI, both internal (such as chamber) and external such as barrel length. The barrel length is set based upon most popular usage. Rifle calibers are set at 24 inch barrels. Handgun calibers are set based upon the most common use at the time, i.e. a 45 Auto barrel is based upon the barrel length of a 1911, and a 38 Special barrel based upon a standard police-issue revolver.

The first thing to remember is that the chamber dimension does not change based upon application. A 223 Remington chamber is the same whether the gun it is in is a handgun or a rifle. The chamber dimension determines the pressure. So, the pressure is the same when fired in that chamber in a rifle or a handgun. The barrel length has no impact on the chamber pressure and hence the reloading data (powder charge and pressure).

The length of the barrel will change the actual velocity you observe. In general as the barrel gets shorter than standard the velocity will lower, and as the barrel gets longer than standard the velocity will increase. This does not change the reload data (powder charge and pressure), just the velocity.

Please note that there is no magic number for how much velocity is lost or gained by changing barrel length. This is because cartridges go from big to small and use varying amounts of different burn speed propellants. The only way to know for sure what the effect is with your different barrel length is to shoot over a chronograph.

So, the quick answer to the question is that the different barrel length will not change the reload data but it will impact the velocity you get.

 

[Longshotjames]

magneto results:
Hodgons lists a max load of H1000 for a 275gr bullet @ 2564mv out of a 24" tube

with my 20" barrel, after working up the the max load w/o pressure I am getting 2510mv with 270eldX

only 54fps slower than the test data 24"

 

[yorke-1]

I don't think H1000 is the correct choice for a 338 Win Mag. I would want something in the H4350-H4831 range.

Here is a copy of something I just received from Hodgdon.

TIP OF THE MONTH
DOES MY SHORTER BARRELED RIFLE REQUIRE DIFFERENT RELOAD DATA?

We often get this question. In asking, the customer is unsure if the different barrel length will necessitate a loading data change in the powder chosen. Let's preface the answer with a quick guide on testing data.

All our data is tested for pressure and velocity with instrumented equipment as established by the Sporting Arms and Ammunition Manufacturers Institute (SAAMI). The dimensions of the test equipment are established by SAAMI, both internal (such as chamber) and external such as barrel length. The barrel length is set based upon most popular usage. Rifle calibers are set at 24 inch barrels. Handgun calibers are set based upon the most common use at the time, i.e. a 45 Auto barrel is based upon the barrel length of a 1911, and a 38 Special barrel based upon a standard police-issue revolver.

The first thing to remember is that the chamber dimension does not change based upon application. A 223 Remington chamber is the same whether the gun it is in is a handgun or a rifle. The chamber dimension determines the pressure. So, the pressure is the same when fired in that chamber in a rifle or a handgun. The barrel length has no impact on the chamber pressure and hence the reloading data (powder charge and pressure).

The length of the barrel will change the actual velocity you observe. In general as the barrel gets shorter than standard the velocity will lower, and as the barrel gets longer than standard the velocity will increase. This does not change the reload data (powder charge and pressure), just the velocity.

Please note that there is no magic number for how much velocity is lost or gained by changing barrel length. This is because cartridges go from big to small and use varying amounts of different burn speed propellants. The only way to know for sure what the effect is with your different barrel length is to shoot over a chronograph.

So, the quick answer to the question is that the different barrel length will not change the reload data but it will impact the velocity you get.

I've been saying this for years but I've never seen it presented by a powder manufacturer, thanks!

magneto results:
Hodgons lists a max load of H1000 for a 275gr bullet @ 2564mv out of a 24" tube

with my 20" barrel, after working up the the max load w/o pressure I am getting 2510mv with 270eldX

only 54fps slower than the test data 24"

I'd look at slightly faster powders like H100v or H4831sc. I'm not sure if you can cram enough H1000 into the case to really take advantage of it in a 338 Win Mag

 

[Lefty7mmstw]

rl19 or h4831 are pretty much your best choices in a 338... I use rl19 with both 225's and 250's in my #1...