![]() ![]() ![]() Those are my two primary objectives too! Yes, the less powder volume you burn the quieter things can be. It is little known and relatively new on the market but compares better than some of the more popular models for its noise reduction quality.įunny you should mention maximum quiet and precision. The fast pistol powders, in my experience, seem to suffer from this more than 57 do. Tipping the barrel down or up before chronographing your loads will tell you this. Some powders are more position sensitive in the case than others when lower volume charges are used. It is substantially more than the fast pistol powders. I would guess that it is about 1/3 to 2/5 of the case or so. I don't know the exact volume percent that 57 gives me in a 308 size case. Sierra makes a heavy round nose bullet also but I haven't tried it yet. This Saturday I decided to give up on them after repeated testing in my Whisper (I was only getting 3 to 4 inch 100 yard groups). Yes they are shorter but the driving area or something does not seem to like the slow speed or lower pressures. I wouldn't think that a 1:10 twist would make their accuracy any better. I haven't been able to get good subsonic accuracy with the Hornady 220 round nose in my Whisper or my 308. They will flop around in the air like a poorly thrown football and you can actually hear them wobbling through the air down range. If you use a bullet that is too heavy for your twist, you may have a hard time hitting the target at all. I would suggest that 180gr bullets be max for the slower 1:10 twist barrels. If all you have is a 1:10 twist barrel, you will have problems with accuracy if you go heavier than a 180-200gr bullet. A double charge of these (when measuring for subsonic loads) will not be over the maximum load listed in the manuals. With 57, you can visually inspect the charged cases before seating a bullet and easily see if there is a possible double charge. It is in the same class as Accurate 5744 but is a more bulkey powder.įast pistol powders will work, but there is a danger of a double charge of powder causing more pressure than is safe. They sell it in the metal IMR cans but you only get a 1/2 pound since it is so bulkey. It also has a higher nitroglycerin content for easy ignition.Īnother powder to try is IMR SR4759. In fact, the person I talked to over at Accurate powder tells me that it was designed to not be position sensitive with low charges in relatively big cases. It is not effected by low charges in a case. Accurate 5744 is one powder that I keep coming back to because it just works. There is dangers associated with using low volumes of slow powders. I always work backwards from the published starting load a little at a time until I reach a good subsonic speed.ĭon't use just any powder for loading subsonics in rifle size cases. I don't like to guess a subsonic load because that is where you may end up with a stuck bullet in your bore. What may work great in one gun may be too slow in another etc. I believe that this critical subsonic window is why there are not very many over the counter 308 subsonic loads. My bolt gun (18 inch, 1:10 twist) was way off of a good subsonic speed with the same load that worked great in my Encore. I find that each barrel will be a little different in resistance so one load recipe will not always work in a different barrel. My accuracy in this barrel with 220gr subsonics has easily been MOA at 100 yards. I have been using magnum primers and a good crimp on the bullet but this is not always necessary or desired. In my 308 Encore barrel (23 inch, 1:8 twist) I hit a good subsonic velocity at about 12gr of powder using a 220gr Sierra HPBT match bullet. I will chronograph each load for a particular gun and write it down in my log book. I then work backwards until I reach the subsonic speed I desire. I begin with a starting load of Accurate 5744 powder. I'll jump right in here and share my success with. ![]()
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