quiet load for 308

[NSP64]

I have a Saeco 195 gr Hp PB boolit I would like to launch as fast and as quiet as I can from a 21" barrel.
I have 231, unique, 2400, H4895, Universal clays.

[Larry Gibson]

Use the 231. Start at 6 gr and work down. Make sure each bull clears the barrel as you work down to what you want.

Larry Gibson

[NSP64]

Thanks Larry, I will try it. I have used 231 in 308 for lighter boolits, just didn't know where to start for heavies.
Loaded some up with 10.0gr Unique and had a smokefest @ 1285 fpsa 2.5" groups @ 100 yrds.
I will work some up and down with Unique and some for 231.

[Larry Gibson]

For such loads consider the less powder used, the faster the burning rate, the sooner "consumed" in a given barrel equals less exit pressure which equals less noise. That's why 22LR are much quieter in longer match rifle barrels than in 18 - 20" barrels.

Larry Gibson

[NSP64]

I understand the concept I just wasn't finding any loading information for Winchester 231 powder.
I loaded up 6.0, 5.8 and 5.6
Is 6.0 max.
I'm using cases that are neck sized, have the primer holes enlarged, and I'm using large pistol primers .
6.0 shot the best giving 1" @ 100 yards. And 950 fps. Primmers look normal, not flat.
Attachment 75559
Loaded 40S&W for scale
I might bump up 6.2,6.4 see if they open up.
5.8,5.6 started opening up.

[dragon813gt]

I'm assuming that a 6 grain load produces next to no recoil? I can't believe that a charge that small clears the barrel. But I don't venture down into loads like this.

[Larry Gibson]

NSP64

Is 6.0 max. (?)

No, I just knew it would be subsonic. The bullet going sonic will increase the noise dramatically with the "crack". Increase a bit but you'll probably start getting the "crack" above 1050 fps.

Larry Gibson

[NSP64]

Thanks Larry.
I will increase a little at a time to see when I get a crack.

[Ford SD]

Use the 231. Start at 6 gr and work down. Make sure each bull clears the barrel as you work down to what you want.

Larry Gibson

Great information as usual, but wondering would this work for all most any cast bullet ?

Would you decrease charge for lighter bullets to keep it subsonic or start at 6g of W231 and work down ?

Would this work for everything from 130g to the noe 247g whisper bullet ???

Gascheck or no gascheck?

How position sensitive would this load be?

It might be a great load to start new shooters with so they get used to the big rifle that has no bark

Neck size the brass and good to go

thanks Larry for all the information

[Larry Gibson]

Ford SD

Great information as usual, but wondering would this work for all most any cast bullet ?

The specific charge won't.....read on.......

Would you decrease charge for lighter bullets to keep it subsonic or start at 6g of W231 and work down ?

Yes. for example; with a 90 gr SWC 3.2 gr works very well in the .308W.

Would this work for everything from 130g to the noe 247g whisper bullet ???

The concept and powder (231) will work but again the specific charge will vary for accuracy and keeping the bullet sub-sonic.

Gascheck or no gascheck?

I prefer to use an actual FB'd plain base cast bullet for such. Some GC'd designed bullets will shoot fine w/o the GC and others don't. I think the determining factor is how concentric to the bore the bottom of the bottom driving band is. If it's not square and concentric then on exit it's tantamount to having a bad muzzle crown as the adverse effect on accuracy is the same.



How position sensitive would this load be?

If well fire formed cases are used to get a good gas seal w/o case obturation (there won't be any with a load as such) so the full force of the primer is contained in the case and the rifle is not positioned at and extreme angle up or down these type loads with very fast burning and easily ignitable powders are not generally "position sensitive". I prefer Bullseye myself and most often use it for such loads. I have, however, also used quite a bit of 231 with such loads. In addition to the well fire formed cases it is also quite beneficial to drill out the flash holes to a maximum of a #28 drill. This alleviates the potential of the reduction of case headspace set back from repeated firings of such loads. Drilling the flash hole also allows the flash to get into the case faster filling the case with flash. This greatly alleviates powder position sensitivity. Some worry this may increase the pressure of regular loads but I have thoroughly pressure tested such cases with drilled out flash holes in the .308W with loads using the 311299 (200 gr) cast bullet over 4895 to 2200 fps and found no indication of any increase in psi.

I'll add that I like to cast bullets for such out of very soft alloy; 40-1 or WWs + 2% tin and cut with 70% lead. While not a .308W I like to cast the 323471HP (210 gr) cast of 40-1 and load it over 2.7 gr of Bullseye in the 8x57. It runs 538 fps, is very quiet and is very deadly on small critters.

Larry Gibson

[atr]

nice tread,,,so let me pick everyones brain regarding my .308 and heavy boolits
I am thinking of trying a 210 gr with 8 to 10gr of Unique.....
your comments would be appreciated
atr

[Larry Gibson]

nice tread,,,so let me pick everyones brain regarding my .308 and heavy boolits
I am thinking of trying a 210 gr with 8 to 10gr of Unique.....
your comments would be appreciated
atr

Should put you at or below sonic to start and 1200+ fps at top end depending on the actual bullet used. If a heavy enough cast bullet is used and you can keep it right under sonic at 1050 +/- fps then it's usually a fairly decent load. Can be a bit position sensitive though which is why I went away from Unique for subsonic cast bullet loads as such. The PSI is getting down where Unique isn't igniting and burning efficiently with cast bullets.

Larry Gibson

[atr]

thanks Larry,,,your comment are always much appreciated.
atr

[NSP64]

Well, I shot some with 6.4 gives me 1007 fps.
I adjusted the HP pin deeper then cast some out of pure (still 195 gr with deeper hp)
Shot it at 100yrds. No change in poi ( as compared to wdww)
Set up some 2ltr bottles with water @ 100 yrds.
Found boolit in jug 4
186gr and mushroomed .581.
Attachment 76154

Sounds like a 22 lr.

[nanuk]

NSP64, can we assume ZERO leading with PURE?

[Artful]

Just an FYI about noise vs velocity
the speed of sound is not a constant - and will vary depending upon conditions
calculation link
http://www.sengpielaudio.com/calculator-speedsound.htm
Sound pressure goes up as you approach the transonic speeds - nice chart for ya.


The other thing to consider in some powders is position in the case, this can significantly change the velocity.

some other links
http://www.quarterbore.net/forums/showthread.php?t=280

[UncleSarge58]

Here are some Articles on this Subject you may find Interesting:
http://members.shaw.ca/cronhelm/DevelopSubsonic.html
http://floydpics.wordpress.com/devel...erfire-rifles/
http://guns.connect.fi/gow/arcane1.html
I use Once Fired Brass Neck Sized Only (No Crimp) w/ Lee 170gr LRNFPGC (50/50 Lino & WW) Lubed w/ LLA & Moly Dust over 4.3gr Trail Boss w/ Rem Mag Primer for Approx 762fps.
With these I get 3/4-1in groups @ 50yds & 22 Short Quiet in my .308 M700BDL.
UncleSarge58

[helice]

C.E. Harris started a bunch of us on this road with the "13 grains of Red Dot" load. I found it to be way more than sonic but the Red Dot was very easy to ignite and really clean even in the lighter loads. I found straight walled cases to be quieter than the bottlenecked cases and heavy boolits worked best. In the 308 my 311334 was near spooky in its accuracy at just below sonic.

[groovy mike]

C.E. Harris started a bunch of us on this road with the "13 grains of Red Dot" load. I found it to be way more than sonic but the Red Dot was very easy to ignite and really clean even in the lighter loads. I found straight walled cases to be quieter than the bottlenecked cases and heavy boolits worked best. In the 308 my 311334 was near spooky in its accuracy at just below sonic.

Helice - are you willing to share your load? I'm just starting down this road. My chronograph got shot a few years ago....but 10 grains of red dot with 190 grain cast seems loader than what I'm looking for to punch paper in my back yard. My neighbors haven't complained but I want to keep it that way so I'm interested in developing a quiet 308 load for hundred yard plinking. Any advice is appreciated. BTW if Unique or 2400 would be a better choice I have those on hand too.

[OutHuntn84]

I worked up a load with some 190 grain PCed Loverlin boolits using 13 grains of Unique. Such a fun little poodle puff round! The only problem a had was delayed ignition if my powder was all down at the nose.