RL17 vs. H4350 Temp Stability?

[spclark]

Looking for end-user experiences with these two.

Been working up a 7mm wildcat based on 7-08 but w/ ~ 13% greater case capacity. Using 168 & 180 Berger VLD's I'm loading 48.2 & 47.0 grains RL17 giving 2,900-2,800 fps / SD<10 right now with promising results.

Both are seated to just touch lands with no more than 0.120" bearing surface behind neck mouth in this Very Short-necked cartridge called 284INCH.

Where I am it's been a slow-to-warm spring. As such my testing's not seen a day over 50. I selected these two based on QL scenarios (thanks Sheldon!) yet not having burned much RL17 before I'm cautious about looking for a higher node with warmer weather inevitable despite Alliant's marketing hype.

H4350's my Plan B but drops me down ~ 100 fps.

Using Lapua's superb Palma brass so case heads are up to it, but still....

 

[shoot4fun]

I would say watch out for the RL17 as temps rise. I shoot it in my 6.5CM with the 140/142 class bullets but when I tried it in a straight 7MM08 there were pretty severe issues that arose. Got nowhere close to the max Hornady data for the 162 Amax before primers were piercing and pockets were toast.

 

[dragman]

While RL17 can be a little more picky a smaller node perhaps it's really not that bad. the H4350 is still the easiest choice between the too, but a smart loader can deal with RL17 with no problem.

 

[spclark]

My first experience with RL17 was just after it appeared, back around 2007. Tested in a then-new 6XC 30" with 105VLD's it was clearly the fastest-speed choice among the five I was trying out that day but not the lowest vertical; at 600 yards the winner was quite evident.

Later on I tried it - briefly - with DTAC115's where again in excelled in velocity. That day was 85*+ & sticky-bolt became evident. Cratered primers too which prompted me to have the FP bushed.

I agree on the smart loader part, why I looked for others' input here!

 

[Ont0001]

I've had some experience competing with RL17 for a couple of seasons when it first arrived.
Found in my experience, it performed best near max loads ,produced the highest speeds and
gave single digit deviations. Used it in both the 260AI and the 284 Shehane.
Due to the temperature spread over the days I shot match, I found I had to optimize 2 loads.....
a cool weather morning load and a hot weather afternoon. If I tried to shoot the entire spread with
either , it would either fall out of node or be too hot to shoot.
It is still a good powder,but must be used with an understanding of it's nature.
I would think if top speed were not an issue,the H4350 would be more suitable for your goals.
Regards
Gord

 

[Berger.Fan222]

I've had some experience competing with RL17 for a couple of seasons when it first arrived.
Found in my experience, it performed best near max loads ,produced the highest speeds and
gave single digit deviations. Used it in both the 260AI and the 284 Shehane.
Due to the temperature spread over the days I shot match, I found I had to optimize 2 loads.....
a cool weather morning load and a hot weather afternoon. If I tried to shoot the entire spread with
either , it would either fall out of node or be too hot to shoot.
It is still a good powder,but must be used with an understanding of it's nature.
I would think if top speed were not an issue,the H4350 would be more suitable for your goals.
Regards
Gord

My results are consistent with these observations. A great H4350 load will be a great load across a range of conditions. I recommend due care not leaving ammo in direct sunlight, but other than that it's relatively insensitive.

Double-base powders from the RL series are a different deal. A good (but hot) load under one set of conditions can be too hot under other conditions.

It's not worth the extra fiddling to me for 100 fps.

 

[spclark]

Thanks for your posts.

Gives me further motivation for getting more experience with H4350 before wasting any more bullets and time with RL17.

 

[taliv]

i use both in 260AI over many years and when i tested it in this cartridge the magnetospeed showed a .57 fps / *F change for H4350 and 1.7 fps / *F for R17. those numbers were consistent with what i saw on targets too. I never had groups open up or a change in SDs at different temps for either.

 

[STOMP442]

In my experience, R17 works really well and is very consistent in smaller cases. R17 works excellent in my experience in the .22-250 with heavy bullets and also the .250 Savage with the 115 Bergers. I have also had good results in the .243 using the heavier 95gr plus bullets. That being said the most inconsistent cartridge I ever tried it in was the 6.5-284 and the .270wsm. I was having very extreme differences when shooting in the cool Arizona mornings vs the much warmer Arizona afternoons. I am a firm believer that the load density of reloader 17 greatly effects how stable and resistant to temp change the powder can be. These are just my experiences and your mileage may vary.

 

[dragman]

If I ever go back too a 284 RL 17 is absolutely first powder on the list.

 

[normmatzen]

I started with my 284 WIN BR gun with H4831sc. When that powder became too hard to find, I tried RL-17. I had plenty as I also use it in my Swiss K-31 as well as in my 7X57 hunting rifle.
I immediately found an improvement once I tuned the load. More MV and less pressure. And, I too found that RL-17 seems to work best at higher pressures. When I first started Bench Rest, I had a 243 WIN and started with H4350 and changed to H1000 for best barrel life. I wasn't loading a high pressure load as I was tuning for best accuracy at around 2900 fps with 105 bullets. So, when I tried RL-17 in my 243, it didn't like it at all which I blamed on the low pressure at 2900 fps.
As far as temp stability, I commonly take my ammunition to matches in an insulated bag to keep their temp about 70-75 deg. So when shooting , I take out just what I need for one target at a time and close the bolt just prior to firing so they don't soak in the chamber. I have not found any change with respect to ambient temp. I shoot at Sacramento where it goes from freezing to 110 deg! Of course the change in Density Altitude makes changes in the bullets ballistics.

Maybe it isn't quite as sensitive as we thought, after all, the Swiss Army used this powder for the GP11 ammunition for the K-31! I realize it gets very cold in Switzerland, but it also gets very warm in the summer. The Swiss made this ammo like match grade stuff so maybe they knew a bit more than we do?

Also, my QuickLoad says that for both my 284 WIN and my 7X57 RL-17 is the most efficient powder!

 

[spclark]

Thanks for your info Norm. I wasn't aware any 'commercial' ammunition used RL17, that's useful background.

I chose it for this cartridge based on what QL reported after I had case capacity to work with and a couple of candidates for bullet selection. H4350 was also indicated & proved out in testing to be viable.

Right now I have the chamber throated to work with Berger's 168VLD Target & their two 180's, the VLD Hunter & Hybrid. If I push the throat out any farther the 168's won't work (unless they're really jumped!) but I'll gain some case capacity that may well help H4350 reach that 2,800 fps velocity.

It's assuredly a work in progress! While I wait for the weather to warm up then some events I can shoot that are on the schedule, I'll be plotting a course of action to work up loads with both propellants that prove accurate and as easy on brass as possible.

Lapua's Palma brass is tough but with the necessary fire-forming I don't want to waste it. And since H4350 seems to be virtually unavailable (I've found 1#'rs) I'm happy to be working with RL17 for the time being.

 

[r bose]

Had a rifle built in 6xc about 2 years ago when H4350 was nowhere to be found. I read where RL-17 was being used so I gave it a try. Since then I've burned 10 pounds of it using 105's, 107's and last weekend 115 DTACS at just over 3000 FPS. The rifle amazes me how well it shoots. I've shot it in temps as low as 45 degrees and as high as 95 degrees here in SE Louisiana and I haven't had to adjust my charge at any time. I'm shooting at a prone target so my groups aren't measured in tenth's of an inch but it just hammers the wind.

 

[spclark]

You must have been using less than I did when I tried it back around 2007! I was seeing 3,200+ fps with the 115DTACS I'd had the rifle built to use, and clear ejector smears on the brass.

Ended up falling back to the 105VLD & later the 105 Hybrid at around 3,050 but not with RL17 or H4350 either for that matter. Tried 8208XBR one afternoon & of the five propellants I'd brought along (8208 was an afterthought, grabbed as I went out the door) it was clearly the best.

 

[r bose]

I don't over push em. I've shot the 105 hybrids at 1000 using 39.5g RL-17 at 3180 FPS. Now that the barrel is getting a bit long in the throat I switched the the 115 DTACS with 38.5g RL-17 at 3040 to be exact. All in Norma brass, 30" Kreiger 7.5 TW with regular ole Winchester primers. Both loads shot right at 1/2- 3/4 inch at 200 yards. Beats the heck out of my service rifle in the wind

 

[boltman13]

When competing or practicing in western Colorado I take particular care to keep my 6.5 CM amo out of direct sun light. I also only chamber a round just before breaking the shot as much as possible. My results with RE17 practice have never been satisfactory enough for taking to a match, perhaps due to other factors besides temp sensitivity but I am more than willing to give up about 50 fps for better accuracy, smaller ES and greater peace of mind with H4350. I also realize it is the go to powder for the 6.5CM, and it is hard to come by.

 

[majohnson]

When my 6.5CM bolt gun was built the only powder that people refereed to loading with was H4350. It did preform well and I was getting consistent results. Then a friend recommended RL17, he was using in his 6.5 x 47 and was able to achive a higher FPS even using a shorter barrel.

Loading it in my 6XC with 105 Hybrids, I am able to get just under 3300 FPS and sub .375 moa accuracy with no pressure signs or stiff bolt. But living in Northern Colorado, I am shooting above 5500 feet in elevation. As for temp sensitivity, I keep it out of the sun and even in higher temps still have not seen sign to worry. I just started loading it in my AR in 6.5CM with great results.