4350, IMR vs H in 6XC

[VooDooMagic]

Well, at least in my rifle IMR4350 edged out H4350. It seems that all the 6xc load advice offered up centers around the "H", but it pays to step out on your own and experiment a little. And although the two are adjacent on burn rate charts, they will exhibit unique characteristics one may not expect. Anyone else found IMR to perform better for them, especially in the XC with Norma brass? Just curious...

 

[Nomad47]

I haven't tried either 4350. I'm using RL-17. But I just had a muzzle brake installed last night, so I will see if POI or groups change as soon as the weather improves here in Ohio.

 

[hottshott526]

How much is the difference between the 2 - 4350's in charge weights for the accuracy? What rifle, bullet, primer, seating depth combo are you using?

 

[357Mag]

VDM-

Howdy !

My 6mm wildcat is similar in capacity to 6XC - 6 X 47 Swiss Match.

I have gotten great results, shooting both RL -22 and even I7828. But, the vel these poduce may be TOO SLOW for your application; expecially is you're one of those guys that simply MUST have 3,000fps Mv.

I'm not shooting ( at least not right now ) 1,000yd; so can tolerate great groups @ lower-than 3,000fps ( which the I7828 loads are ).

Some of my wildcat's best groupers:
Berger 88LD 42.0 RL-22
Sierra 95MK 41.8 RL-22
Berger 107VLD 41.5 RL-22

Sierra 85BTHP 43.7 I7828
Berger 88LD 43.7 I7828
Sierra 95MK 43.0 I7828

For me, use of RL-22 produced a "node" covering all 6mm accuracy bullet weights over a near 20gr span; requiring only .5gr of total
charge weight change. RL-22 produced almost as tight a "node" as the I7828, w/ .7gr net powder charge change over 20gr bullet span.


I could inter-change I7828 w/ I7828 SSC. Case fill differed, but accuracy remained the same.
In MY wildcat case shot in MY rifle, MY I7828 loads had cases completely filled; with mild compression of the powder.

RL-22 loads also filled the cases pretty good, but were not compressed. Any of the RL-22 charges listed could be shot safely under any of the 6mm bullet weights mentioned; and still group very nicely. This just seems to be a " sweet spot " for my gun.

Again, these two powderss are perhaps TOO slow in burn-rate; for your needs ?

With regards,
357Mag

 

[basshusker]

H is impregnated with whatever Hodgdon uses in the EXtreme powders that controls temp sensitivity. I have heard stories of guys going to Canada or Alaska using IMR or other non Extreme Hodgdon powders (exception is IMR 8208 XBR which has it) and their zero dropping significantly and missing longer shots because of reduced velocity in extreme cold. The hodgdon is more likely to hold the same velocities. Alliant added something similar in AR-Comp which is very similar to RL-15 without the temp variation headaches.

I found the IMR 4350 worked great in 300 Win but the H4350 didn't fair as well nor did H4831. I had to slow it down to H1000 to regain the accuracy. On the plus side had great velocities with the H1000 and CCI milspec white box primers. They seem to be a great match. Not quite a magnum primer but do well in magnums as well as non mags.

I find I use them as much as Wolfs/Fed Match in smaller applications and BR2s in mid size applications. Great primers.

I wish I could get the 7828SC with the temp stuff in or an H1000 SSC. I think it would be a great powder in a lot of applications. Like 6.5-284 etc.
Justin

 

[abishai]

I had to Finally concede that the H was more accurate than the IMR. The cost comes at a lower velocity but my ES and SD numbers were cut in half. The RL 17 can get you even more speed, I was getting 3150 out of the 17 (40g). 3100 out of the IMR (39.5) and 3050 from the H4350 . All loads were norma brass, wolf primmer, and coated 115 dtacs, 28" pac nor 3 L&G. On the 7th loading, the primmer pockets are all still tight. On a side note all rifles have a distinct personality, What works best for most does not work best for all. And the nine ring doesnt care how fast you hit it.

 

[WyleWD]

Well, at least in my rifle IMR4350 edged out H4350. It seems that all the 6xc load advice offered up centers around the "H", but it pays to step out on your own and experiment a little. And although the two are adjacent on burn rate charts, they will exhibit unique characteristics one may not expect. Anyone else found IMR to perform better for them, especially in the XC with Norma brass? Just curious...

I tried both of them and saw literally no difference in group size or performance. Mine is a 9twist and shooting 95gr bullets. WD

 

[Larryh128]

While not an xc, my loading in a 243 (and several other calibers)shows that the IMR version usually has a slightly better accuracy. The only rub comes in on what the conditions are when you do load developement. It is very possible to have a good load right now & it's too hot in July. For that reason only, my powder usually has an H in front.

 

[racesnake]

Hey, Voodoo.....How's it going , man? The IMR4350 works better in my 240NMC which is about the same as a 6XC. I had good accuracy out of IMR8208 but started seeing my ES increase for some reason. So I settled on IMR4350. There is another powder (IMR4007) that looked promising but I haven't had time to thoroughly check it out. I shot a few in the early spring and it showed lower pressure signs with an increase in velocity.
If you see David C. say hi for me!
Dave

 

[ar15topgun]

H is impregnated with whatever Hodgdon uses in the EXtreme powders that controls temp sensitivity. I have heard stories of guys going to Canada or Alaska using IMR or other non Extreme Hodgdon powders (exception is IMR 8208 XBR which has it) and their zero dropping significantly and missing longer shots because of reduced velocity in extreme cold. The hodgdon is more likely to hold the same velocities. Alliant added something similar in AR-Comp which is very similar to RL-15 without the temp variation headaches.

I found the IMR 4350 worked great in 300 Win but the H4350 didn't fair as well nor did H4831. I had to slow it down to H1000 to regain the accuracy. On the plus side had great velocities with the H1000 and CCI milspec white box primers. They seem to be a great match. Not quite a magnum primer but do well in magnums as well as non mags.

I find I use them as much as Wolfs/Fed Match in smaller applications and BR2s in mid size applications. Great primers.

I wish I could get the 7828SC with the temp stuff in or an H1000 SSC. I think it would be a great powder in a lot of applications. Like 6.5-284 etc.
Justin

I'm going to have to disagree with the above statement to a degree. I believe that the actual air temp., air density, humidity% and barometric pressure and altitude will have more of an effect on the speed and flight of a bullet than the temp. of the powder in the brass. Try it on a ballistic program and I think you will see for yourself.

 

[fredjake]

Is anyone using IMR8208 xbr in the 6xc?

 

[racesnake]

In my opinion the temp stabilized powder, in this case Varget, is hype to some extent. Case in point: My 6BRX velocity drops 20fps between 60F and 80F. When shooting at distance this amounts to a few clicks. Has anyone else found this to be true?

 

[ar15topgun]

Racesnake it's not the temp. of the powder or the ingredients that changes the velocity it's the atmospheric conditions. Changes in air temp., humidity, barometric pressure, etc has a greater effect on velocity than changes in the powders temp. Try it using JBM calculations and you will see.

 

[racesnake]

AR...Are you saying that powder temp does not play a part?

 

[WyleWD]

Racesnake it's not the temp. of the powder or the ingredients that changes the velocity it's the atmospheric conditions. Changes in air temp., humidity, barometric pressure, etc has a greater effect on velocity than changes in the powders temp. Try it using JBM calculations and you will see.

Someone at JBM has obviously never left a clip full of 243 on the dashboard of the truck with the windows rolled up on a 100* July day in the Pdog fields, took them straight out and shot em. If they did, they'd rethink their calculations a bit. WD

 

[Nomad47]

I wish I could remember where I read it, but a test has already been done on powder and chamber temperatures. The guy took a cooler (with his cartridges in it) to the range to do his testing.
If you think about it, MUZZLE velocity will not be affected my ambient temperature. Ambient temperature affects how quickly a bullet slows down because it affects the air density.
And according to JBM, air temperature and barometric pressure are the two major factors affecting the bullet IN FLIGHT.

 

[racesnake]

If air (powder) temp does not affect velocity why do the powder folks put stabilizers in their powders. Why does a max load developed in the spring, at lower temps, start showing pressure signs when summer rolls around? Hey, it's chemistry!

 

[PALarson]

I tried 4350 in my XC and didn't like the results, tried varget and am able to shoot groups at less than .2 at 100. Shot it at 1,000 and had great results. Speeds over 3,000 with Berger 105 VLD's. I do use coated bullets, which may account for the success with varget. Just a little food for thought.
Paul Larson
LR High Master

 

[mikecr]

Yeah the testing I seen out there indicated that I4350 was more temp stable than H4350..
I have gotten better velocity using IMR4350, in 6xc, and 6.5wssm also.

What does 4350 mean anyway?

 

[Steve Blair]

What does 4350 mean anyway?

[br]
Mike, I think that the numbers are DuPont sequence numbers and don't have any meaning related to powder characteristics. Bill Davis wrote an article in the Rifleman a long time ago describing the history of a lot of the older powders. That is about all I can remember.