Lets assume H4350 is not an option......

[The Busby]

What would you guys say is a good replacement for H4350 in a .260 pushing 139gr Scenars out of a 24" Rock Creek. I can look at the burn chart like anyone else...I want to know what you have used and found to be accurate AND consistent. I'm thinking Reloader 17 may work well ?

Thanks.

 

[Temp9]

IMR 4350 or AA 4350? Doesn't get much closer than that.

 

[The Busby]

Ok.....so what changed when you shot IMR4350 and AA 4350 ? What was the change in impact, speed, etc.....from H4350. Did you find it sensitive to temp, humidity ? I realize these powders have the same "published" burn rate. That's not what I'm looking for.

 

[BoilerUP]

Reloader 17 or H4831SC

 

[Temp9]

Fair enough. I've never used IMR 4350, but I have used the other two. Don't own a chrono, so can't comment there. POI was the same. Accuracy may have been a bit better with H4350, but they were too close to say for sure. Also, AA 4350 has very good temperature sensitivity, but not as good as H4350. IMR 4350 has the worst temperature sensitivity of the three, by far.

RL-17 seems to be very popular with the speed junkies in the 6mm world. It's supposedly very temperature sensitive, though. I've never used it. H4831sc is also quite common, but again, I've never used it.

If you're trying to get out of working up another load, don't bother. Any powder substitution will require you to start over.

 

[BoilerUP]

RL17 worked great with 130gr VLDs in my 260. With 140s, 42.5gr RL17 gave me about the same speed as 43.3gr H4350 (2820fps).

It is temp sensitive but repeatable & predicable...but don't let ammo sit in direct sunlight, learned that one the hard way.

H4831SC worked great with 123s, and while I got pretty good accuracy with 140s I started running into consistent OAL issues with anything more than 46gr due to compression.

38 grains of Varget with a 139-142 is generally a very accurate (but lower velocity) option to H4350 too.

 

[58blackflag]

I've used RL-17 exclusively in both my .260s. It does seem to be a bit sensitive when it is very hot and humid here in SC. It still groups well but I get pressure signs if I try to shoot longer strings. It has gotten worse since using a suppressor (prob since heat cannot dissipate as quickly). Still, I haven't switched to anything else. I just try and be more patient when shooting. I also plan to lighten the load slightly on the next loading.
My current setup is quite similar to yours, SSC build with a 24" rock creek. My load is lapua brass, 41.7 grains of RL-17, 139 scenar, and a CCI BR-2 primer.

 

[phxfa]

IMR 7828SSC 46.5 gr and its ALWAYS available, just saw some at Bruno's, been using this before the powder challenge

 

[rmfield]

I've been running 4831SC with 139's and 142's in my last 3 260's and love the lot/lot consistency and insensitivity to temperature. Very accurate as well. Velocities are slightly lower than 4350, but not enough to worry about. I've tried 4350 and RE17, but keep coming back to 4831SC.

 

[The Busby]

Thanks fellas....this helps !!! 58blackflag....we are shooting almost the identical set-up. I shoot for Russel with an SSC, lapua brass, 139 Scenar, CCI BR2, and 42g H4350.

 

[ArmyJerry]

I am going to do a 8 pound adventure with IMR 4350, loading 300 wm (190 & 208) and 260 Rem (140 SMK-Amaxes) with it.

 

[khw9mm]

I use R-17 for my 6x45 and was about to try it for my .260. I may just skip that idea all together...


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[r50140]

4831sc worked for me. I could never get H4350 to shoot in my 260.

 

[jagged77]

If you can get hold of Vihtavuori powders N160 is very close to H4350 and gives near identical results.