260 Rem and H4831SC

[86alaskan]

I've begun the process of working up my 260. I have a Savage SA with 2.85 max COAL, and a criterion 1-8" barrel at 22" long. I am using Remington brass BR2 primers and have an 8lb jug of H4831sc. Yes, H4350 would be better, but its absolutely unobtainable in AK. Is my 4831 too slow to effectively run the 143 ELD-X? I was getting 2700fps with 140SST and 45gr. Should I look for a different bullet or continue my work?

 

[OldManTA]

I've begun the process of working up my 260. I have a Savage SA with 2.85 max COAL, and a criterion 1-8" barrel at 22" long. I am using Remington brass BR2 primers and have an 8lb jug of H4831sc. Yes, H4350 would be better, but its absolutely unobtainable in AK. Is my 4831 too slow to effectively run the 143 ELD-X? I was getting 2700fps with 140SST and 45gr. Should I look for a different bullet or continue my work?

I have had excellent results with 45gr 4831/4831sc, Winchester case, BR2 primers and the Lapua 139, seated .015 off the lands in MY RIFLE. The barrel is a Remington 28" with all work done by the Remington Custom Shop. I suggest you back down a grain or two from that since you are using heavier bullets and Remington brass typically has less capacity than Winchester. Proceed with caution and good luck.
Tom Alves

 

[86alaskan]

Yeah, i hit 45gr with no problems with the 140gr sst bullets. I've run up a set ot test rounds for the 143 eldx and have them in .3gr inc. from 44-46gr.

 

[Deton8tor]

I run 46.0 H4831SC with no issues whatsoever in Lapua and Nosler brass. 48.0 is max and is compressed well. I get excellent accuracy with 139's and 142 MK's. I just tried the ELD-M by Hornady, jury is still out.

 

[86alaskan]

Thanks EOD, that's good info, how long is your barrel? are you mag feeding from a SA or single feed?

 

[jcampbellsmith]

I have my notes filed away, but I can see in summary that I shot

Hornady 140 Amax 46.4gr H4831SC in Nosler brass with CCI 200 primers. I estimate the COL would be 2.9 inches or a few thou less.

Regards

JCS

 

[86alaskan]

Are your barrels longer to utilize the powder better? I'm just thinking something a touch faster would be better. I get good ES from the H4831sc, but I only have a 22" tube because I run a suppressor on the gun. Don't want it to be too long in the woods.

 

[jcampbellsmith]

23.5 inches as per attached spec http://www.thestalkingdirectory.co....leries/p2948-remington-700-sa-in-260-rem.html Regards JCS

 

[jr600yd]

My experience with the 260 is this. I live in the south so most of my shooting is done at sea level or within 100 feet or so of it. My rifle is set up for any/any matches and has a 30" 1/8 barrel. I use Remington brass because at the time I began load development Remington was the only one making 260 brass and I bought a $#?t load of it. My rifle likes the 142 SMK's best and I shoot moly bullets. I've been told H-4350 is the go-to powder and I've had very good luck with it. It has produced good groups and velocity and I've won my share of matches with this combination. When this powder became scarce I switched to H-4831sc. Velocity dropped by about 50 fps with the same powder charge but the group size shrank considerably. In my rifle it's not uncommon to have five rounds touching at 300 yds in no wind conditions if I do my part. My rifle likes 44.5 grs of H-4831sc, wolf LR primer, Remington brass, moly 142 SMK at 2670 fps. ES 8 SD 3 for 3 five shot groups.

 

[86alaskan]

good to know JR, i ran a few through this weekend and had a node around 44.4 to 45gr. I'll be working in that area and toying with neck tension as well. I was sizing with a redding neck die without expander, which was giving 4 thou tension. I put in the expander and that reduced the tension to 1.5-2 thou. those are my next group of bullets to try. I'm hoping that there is a clear difference between the two so I'll know one way or the other what tension it likes.

 

[Deton8tor]

Alaskan, I run a 28" MTU on my .260. I do run a CDI detach system and run mag length bullets. I can run a 2.900 bullet, so I am not really hindered. That said, if I seat the 142 back to 2.825 or 2.800 I have a slight compression, which hasn't caused any problems and groups are still .3's and .4's. H4350 gives me a bit more speed, accuracy is very close to the 4831SC. Most of my data mirrors jr600, but I don't run moly bullets, naked only. As far as accuracy goes with both H4350 and H4831SC it is splitting hairs. Additionally, I have run up to 47.8 H4831sc, but maintaining a constant COAL was tuff. If you send me a phone number I can shoot some pictures of the last range day shooting both powders.

 

[rogn]

For what its worth , you may want to look at IMR 4451 as a good alternative. I started using it this winter ina short 6mm at 600 yds. The group sizes are slightly better than those with H4350 and this quirky barrel seems to like it. Working up a load with several bullets I put over a 100 rounds thru it without any increase in group size. In fact after cleaning it took 15 rounds to get back to stability. The barrel has been a dedicated copper fouler and the 4451 seems to have helped a bit. The long shot series with no degradation of accuracy was welcome. My load density in the 1.75" 6mm is about 90-95% and velocity and burn rate seem identical to H4350 in this cartridge. Also the powder seems available everywhere at this point, price shopping is worth pursuing as it varies about 25%. It is not the cheapest powder.

 

[STOMP442]

I put a 26" Shilen on one of my Ruger M77s and since I was in the same boat at the time and couldn't find any H4350 I used some H4831 I had on the Shelf. Results on groupings were impressive to say the least. My load ended up being 46gr as well which is slightly compressed in my Lake City Match brass that I am using. Velocity is is 2740fps which is a little slower than I would like but it shoots to dang good to change. I now have plenty of H4350 and I still can't bring myself to try it out.

 

[jr600yd]

Another powder I'm starting to work with is AA-4350. According to the urn rate charts it falls between H-4350 and H-4831. Preliminary testing has shown this to be valid. Who knows, this may turn out to be the best of both worlds ?

 

[jr600yd]

Oh, I forgot to mention. My testing has found that when the temperature goes above the mid 80's and the humidity matches it ( not uncommon in the south ) accuracy degrades with any of the 4350 powders. Groups open up and there is a fluxulation in velocity. Testing at 600 yds on F class targets has shown as much as 1/2 MOA change in vertical dispersion. Of course the closer the target the less their is. I have not found this to be true when using 4831. So,..... Like many southern shooters we have a "cold weather load" and a "hot weather load".