Home Forums Reloading Big Game Rifles 20in .338 win mag firing solution

Hello everyone. I am trying to decide what type of powder to utilize in my Ruger M77 Hawkeye guide gun. The firearm shoots outstanding but has only a 20 inch barrel. Because Yogi said only I can prevent forest fires I am trying to keep this rifle from being as much of a fire breather and get some performance out of it as well. Here is what I have decided will be my main components so far for my upcoming black bear, wolf hunts with the need for some brown bear defense thrown in.

Hornady cases
Nosler 225 grain Accubond
CCI Primers

here is where I am stuck: I need to find a powder that will burn quick enough but also give me as much performance as possible. I have been looking at IMR 4831 / 4350 and RL 26. 4831 and 4350 has plenty of data but I just don't have any experience if it will burn enough powder up in 20 inches. RL26 I can not find much data on but was recommended to me by a friend at work. If you were to complete this firing solution what would you utilize as your powder? Thanks for the help in advance.

I'd approach a 20" barrel exactly the way I would one that was 22" or 24" or 26"

Accuracy trumps.

Yup. I wouldn’t expect RL26 to be the scnizzle but any 4350 variation would be a good place to start and likely end. I would avoid most heavily coated ball-type powders if you don’t want a flare gun effect. (Perhaps Hunter or Big Game would be an exception. I dunno.???)

I'd start with H4350

With my 26" barrel, I've had good luck with both H4831 and H4350. With shorter barrels it preferable to favor the faster powder, but no need to go crazy far in that direction. Just stay off the crazy slow for caliber side of the burn chart and you will do fine. The slowest powders for caliber produce the best velocities in longer barrels.

I would be looking at RL 16 & RL 17

My 20" Ruger Guide Gun in 375 Ruger like RL17. I see Alliant Powders list 338win in their load data too.

My 20" Ruger Guide Gun in 375 Ruger like RL17. I see Alliant Powders list 338win in their load data too.

+1. memtb

Almost ALL the powder that's going to burn, will burn within a couple inches in front of the chamber. The same powders that result in the highest velocity in a 24-26" barrel will result in the highest muzzle velocity in a 20-22" barrel.

The "flash" at the muzzle isn't powder that's still burning, but the hot gas reigniting when it hits the atmosphere's oxygen. Rifle powder contains it's own oxygen source, but by the time it leaves the muzzle is oxygen-starved. It's still plenty hot, however, and with the "new" source of oxygen reignites--but isn't likely to cause a forest fire, unless you insert the muzzle into a bunch of dry tinder.

My experience is different to the powders recommended so far.
Since I got my first 338, the ONLY powder that gave great accuracy has been RE19, the best part of that is the fact it runs 100fps faster than any other powder I tried behind the 225gr Accubond. I ran with a load in either Win or Rem brass, WLRM primer and 76gr of RE19 with 225gr Accubonds, this gave me 2890fps in a 26” barrel and 2820fps in a 24” barrel.
With 200gr bullets and lighter, 2 powders stood out for me, Win 760 and H4350.

Picking a powder is not governed by barrel length, it is governed by what performance you want.
For me, I look at several manuals, starting with the bullet manufacturers data, then look at several other sources and look for the powder that provides the HIGHEST velocity across all those sources, then I evaluate IF it is going to be sourcable, as Alliant powders here are impossible to get, then I will select the three TOP powders across those manuals that are the highest velocity providers. The reason for this is because those powders are the most suitable in efficiency for that expansion ratio. Then I will load 3 cases starting at 5% reduction from max and work up in 1gr increments and shoot groups, choose the tightest group and then do a ladder at 300mtr with +/- .3gr increments.



This statement about faster powders being preferrable in short barrels is complete BS.
The powder that provides the FASTEST velocity in a LONG barrel will also be the powder that provides the fastest velocities in a SHORT barrel.

It is time for this MYTH to be buried forever, it is simply false and misleading.

I am contemplating converting my Kimber Talkeetna to a 20-22" 338 WM. I know that I was getting 2930 fps in my 24" Ruger 338 WM with a 225 accubond w/ RL-17 so that is where I would likely start in my next 338 WM.

Lets do this I have a dull hack saw blade ready to do this!

Haha that’s too up town for me...I was just gonna file it down

You can use my dremel to grind in a nice crown..

Now we’er talking!!!!

Thank you everyone for the reply's, I think I am going to go with a 4350 or RE19. Think I might actually already have 4350 laying around. Will post how it goes, again thank you.

This is the correct answer.
The same powders that generate the highest velocity in long barrels perform the same in shorter barrels because the powder is burned in the first few inches anyway.
John

You are factually wrong. Long barrels favor slower powders, but so slow enough and they will plateau in shorter barrels before reaching maximum powder charge. By the same token, you don't have to go much faster to mitigate this effect. As I mentioned above, a small change, such as going from H4831 to H4350 can be enough for proper mitigation.

.................+2.............................Shamus....Here is what you do......You reload and treat your 20" 338 just as though it had either a 22" barrel, a 24" or a 26" er. So called flame throwers from shorter tubes are imo over exaggerated.

I own a 300 WSM Ruger Frontier w/ a 16.5" barrel and have yet to see all this so-called flame from the muzzle. Now I suppose if I were firing in pitch black darkness or during extremely low light then I might see some of these flames.

Yes. Pursue your velocity or performance. Use a chrony. But also pursue accuracy. Let the so called flame throwing chips fall where they may.

I agree with that 100%. I have 18" 325 WSM even and its not the fire breathing dragon I was told it was gonna be.

+2

Interesting, as I was eyeing a particular 18 1/2 inch 300 weatherby for sale locally at an attractive price, and like the rifle but dismissed it due to barrel length affecting performance of such a cartridge. Already have a long barrel one so I wouldn't be jumping into a different round. Might have to go take another look today. Nobody probably wants it due to the above mentioned misconceptions which I also held myself.

As a side note I had one of the 338 guide guns and although I never chrono'd it I never doubted the performance of the 20 inch barrel vs a slightly longer one.
I actually killed my farthest deer with a 18 1/2 inch 7600 in '06 with 180 round nose bullets which would probably be the last rifle you would pick for hunting over a field.
Overthinking is a bad thing most of the time.

When I was mentioning a fire breather I was joking some what. This rifle has a muzzle break on it so it does produce a good flash but nothing that will really start a fire obviously. Accuracy is my number one goal and doing more research I have found some good information on the 4350. I think my order in discover will be 4350, RE19, 4851. Is there a particular magnum primer that everyone recommends? I have only ever used CCI primers, but someone mentioned to me Winchester.

I would look at Ramshot Hunter.... it has been a great .338 powder for me and hits in the burn rate window of the powders you are looking at. YMMV

RL-19 for sure

Ruger SP-101, 2.5" .357 Mag....here is your flame thrower! Seriously though...it is a worthwhile experiment to find out what gives the best velocity/less flash & report for a short rifle. I hope you post your results when you find it!

I totally disagree with you.
Having a pressure trace shows me barrel length has nothing to do with slow or fast powders being preferred in short or long barrels.
Max pressure and burning of the powder occur within an inch or two of the case mouth, the burn rate doesn’t change this, all that changes is the TIME under maximum pressure, which is governed by burn rate, not barrel length. Even with a 16” barrel, the slow for calibre powder will have higher velocity than a fast for calibre powder. The reason is simple, the slow powder pushes the bullet for a longer time. Period.
Many believe that a faster powder will provide MORE velocity in a short barrel due to time, this is simply false, as a sloww powder expands for a longer time, even in a short barrel.

Unless my chronograph was lying to me (which I doubt), I've seen this phenomenon in the real world.

Why most people such as yourself don't believe it's because they are not using powders at the bleeding edge of slow for bullet weight, with compressed loads. It occurs in a narrow window, which is probably why you've failed to capture it in your limited testing, but it's still there.

As for the math and taking the integral of the quadratic to derive the area under the curve, so you're not telling me anything I don't already know, but there's additonal forces you are not accounting for, which is why experimentally, you are wrong.

...........................+2 and more. 416 RH is right.........Example: Using 66 gr of RL17 behind a 180 gr bullet, my 300 WSM shorty tubed Ruger Frontier gets just over 2900 fps. NO WAY can any faster burning powder do that. Short barrel loadings for top velocities? Just follow what works from the longer tubes.

Weatherby did a run of short barreled rifles in the 80's and I loaded for a 7mm Remington with the shorty tube.
It taught me that the same powders for a 26" barrel generated the best performance in a short tube so I did the test again with other rifles up to a 9.3x62 and found the same results. Also found a lot of lot to lot powder variation up to 6% per lot at that time, so many things have improved over the years.
Forget tube length and follow the reloading data for best powder vs highest velocity.
John