H4831sc & 140 gr Amax

[winmagman]

Is any one loading this combo in a 6.5-284? Hornady lists the max charge at 45.9 but that just strikes me a low since I did a search here and found people loading 49-52 grs with the 142 gr SMK. Is the bearing surface on the Amax so much longer than the SMK that it justifies 3-6 grs less powder?

Any way if you shoot this combo let me know what you found for a max load and approx. velocity.

Thanks in advance
Chris

 

[308sako]

I have been loading the 140 A-MAX and the 140 Berger, and the 142 Sierra with IMR 4350, and IMR 4831, and R22. The thing to do is work up in your own rifle and see what your rifle likes. I am at 52.5 with R22 and 49.5 with the 4350, best accuracy was with the 4350 BUT the pressures were a bit much. Cases only lasted 5 firing (loose primer pockets) and with a tight neck that was a lot of turning. The good news is that this is one of the most awesome cartridges you can play with at distance. I wish that I hadn't shot this barrel so much at short range, as the tube (a Hart) is perhaps the best I will ever own. By the way my overall length is about 3.150 with the 142 Sierra. Hope this helps.

 

[JD]

WinMagMan, Im shooting 52.0 H4831, 140 Amax, 210m, Lapua brass, @ 2950fps, 26" Rock barrel. With the 139Scenar, Im @ 52.5 H4831 @ 2960fps. Around 52gr. seems to be the load with H4831 based on alot of peoples data Ive seen.

Later

 

[winmagman]

Thanks guys
I just loaded up some test rounds this afternoon starting at 45.0 grs going to 51.0 grs. We'll see how they do for pressure.

I did a little looking around in the Hornady manual and found something a little curious. I looked at the 6.5-284 loads and the 260 loads for 140 gr bullets they had 5 powders listed in common and for all powders the max was 1.5-3.5 grs higher for the 6.5-284 EXCEPT for H4831 which was .1 gr lower for the 6.5-284.

Since I'm still on the steep end of the learning curve for reloading, can I get an explanation from anyone?

 

[308sako]

Regarding the reloading GUIDES. Having been the editor of an international automobile value guide for a mere decade I would wish to tell you that the term guide means just that: It is a guide not a bible. A guide is someone or something which will help get you into the vicinity or range which is correct for the application, but not do the final finishing for you. The reason for this is that all rifle barrels are individuals, while often quite similiar they are not the same. Reloaders who are on the shorter side of the learning curve are aware of this and will advise you to stick with the books, but to make your own decisions based upon your own observations of your conditions, components and equiptment. Now as to "obvious" errors, they may have been true for that rifle on that day in that lab. Go figure. Bottom line is to learn your own rifle and enjoy the ride safely. Good shooting.

 

[Mysticplayer]

Also remember that many BR rifles are shot at pressures that would make a ballistician head for the bomb shelter.

so it doesn't surprise me that loads seem conservative in a manual. Throw in pressure barrels, different lots of powder and you have a lot of difference between guides and your rifle's likes.

There is a very good article in the most recent handloader mag that gives some very good info on loading and monitoring pressure signs.

The obvious signs like needing a hammer to open your bolt, blown primers will always indicate pressures too high. However, many tight tolerance rifles will open the bolt with one finger and be way over pressure.

Just work up slowly and odds are, you will find the accuracy point before pressures get crazy.

Jerry