350 Legend subsonic?

[mattri]

All the moulds have pros and cons, guess I just need to pull the trigger and start somewhere.

[cwlongshot]

Pretty much YES!

CW

[mattri]

http://www.accuratemolds.com/bullet_...36-250BG-D.png

Just put the order in.

[cwlongshot]

Good luck!!

CW

[mattri]

First batch of rough samples.

[mattri]

Dummy round with a 170gr Hornady for scale.

[cwlongshot]

I shot some Saexo #352 245g with Herco from 7-11g. 11 was warm & 1460 fps.

CW

[mattri]

Good to know. I have Unique, Trail Boss, IMR 4227 and H1000.

[mattri]

That should be H110 my bad.

[mattri]

A buddy has QuickLoads going to work up some data- hope to have some initial loads soon.

[P Flados]

Mattri,

I replied to you about general load data on the other thread. Then I found you stuff here.

I have Quickload & will run some stuff if you can provide the 250 gr bullet length and the cartridge OAL.

I am betting Unique will work for subsonic. You H110 or possibly the 4227 look better for a super load with you 250s.

[mattri]

Hey thanks! Pm on its way.

[tomme boy]

depends on if bolt action or semi. 7gr unique should be sub sonic. It is with my bolt gun and the 200gr. Like 1040 if i have not forgot. plus i posted a link on the other thread with some data i found online

[P Flados]

Mattri has a bullet that is 1.050" long and COL is 2.285. This is quite a bit longer than will work in an AR. His barrel is 18”.

I ran some Quickload stuff. Normally I try to find some published loads with pressure data to run since QL is not considered real accurate for pressure. However, for the 350L, QL does not have bullets that match those used in any available load data with published pressure values. Note also that I had to “create” the case based on parameters of 0.355” bore, 1.71” case length and 36.5 gr water capacity (wiki data).

Fortunately, most guns that fire the 350L, can handle pressures higher than pressures that cause flattened primers.

The data below should not be considered accurate for pressure values. For the super data, start low and work your way up watching for pressure signs. I tried H110, but I did not like the case fill vs. pressure with the 250 bullet.

For a sub load, I ran QL with Unique. QL says much over 6.0 gr goes super.

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-17.1 40 5.80 995 549 17083 1093 100.0 2.097
-14.3 41 6.00 1014 571 18098 1126 100.0 2.045
-11.4 42 6.20 1033 592 19138 1159 100.0 1.997
-08.6 44 6.40 1052 614 20204 1191 100.0 1.952
-05.7 45 6.60 1070 635 21295 1224 100.0 1.909

For a Super load, I ran 4227 and got:

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-05.0 92 19.00 1590 1403 35351 3362 98.3 1.362
-02.5 94 19.50 1626 1468 38154 3429 98.8 1.320
+00.0 96 20.00 1663 1535 41168 3490 99.2 1.281
+02.5 99 20.50 1699 1602 44411 3544 99.6 1.243
+05.0 101 21.00 1734 1669 47907 3591 99.8 1.207 ! Near Maximum !
+07.5 104 21.50 1769 1738 51677 3632 100.0 1.172 ! Near Maximum !

[tomme boy]

1680 will get you to 1050 with the 250gr bullet and cycle the AR action. 4198 should also get you there. 1680 has a very large amount of gas produced when burnt.

[mattri]

Thanks guys for all the help, genuinely appreciate it!

Hit the range today with some initial sub loads using some extrapolated TB data.

Went conservative as it was the first outing with this boolt, only did 2 loads 6.5 and 7grs.

Both shot well, 6.5gr was around 890fps and 7gs was in the 940s. Both were very stable with good ES and SD#s, believe 7grs SD was 10.

Accuracy wasn't bad at all, about an inch at 50 yards and the rounds even feed out of the Savage's mag. Holes in targets looked clean, not tail wagging that I could tell.

Very small sample but excited so far, looking forward to more testing.

Snapped a couple pics but not loading even after resizing will keep trying.

Thanks again for help so far will post with more results!

[cwlongshot]

Good deal man!!

100% Im really enjoying cast subs WAY MORE than I expected too!!!

Now having used it ta get a deer Im even more excited with it!!

CW

[P Flados]

Mattri,

When I did the QL workups, I looked for TB under Hodgdon and it was not there. I looked under IMR today and found it. My bad.

It predicts velocities spot on with your data within 0.1 gr for charge. In the range from 8.4 to 8.6 it should transition to super.

Cartridge : .350 Legend
Bullet : .357, 250
Cartridge O.A.L. L6: 2.285 inch = 58.04 mm
Barrel Length : 18.0 inch = 457.2 mm
Powder : IMR TrailBoss

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 84 6.40 898 447 19276 793 100.0 2.170
-17.5 86 6.60 912 462 20241 815 100.0 2.127
-15.0 89 6.80 927 477 21226 837 100.0 2.086
-12.5 92 7.00 942 492 22231 860 100.0 2.047
-10.0 94 7.20 956 507 23255 882 100.0 2.010
-07.5 97 7.40 970 522 24300 904 100.0 1.974
-05.0 99 7.60 984 538 25364 926 100.0 1.941
-02.5 102 7.80 998 553 26448 947 100.0 1.908
+00.0 105 8.00 1012 568 27554 969 100.0 1.877
+02.5 107 8.20 1025 583 28679 991 100.0 1.848
+05.0 110 8.40 1038 599 29825 1012 100.0 1.819
+07.5 112 8.60 1052 614 30993 1034 100.0 1.792
+10.0 115 8.80 1065 629 32181 1055 100.0 1.766
+12.5 118 9.00 1078 645 33391 1077 100.0 1.740

[mattri]

Hey thanks for checking that out- will help stay right under the threshold!

[mattri]

Range report:

Tried loads of 7, 7.5 and 8gr of TB.

The 7gr was to confirm earlier data and help move zero for testing other loads, performed as before.

The 7.5gr load got around 940fps, ES and SD were ok as was accuracy, around an inch at 50.

8gr acted a lot like 7.5, don't know if the TB is starting to compress and get wonky but will have to revisit this.

As it stands subsonic loads with 250gr boolits out of a 1:14 do stabilize and I'm sure accuracy will improve with some more tweaking.

With a guessed upon 1 mil holdover and a little Kentucky windage was easily able to ring our little gong at 100, cute little noise it makes.

Also tried an initial super load, 19gr of IMR4227. P Flados' QL data was right on, avg vel was right around 1590, load was stable and accuracy was around .75 @ 50. No signs of pressure very mild to shoot, not as snappy as a 170gr jword at 2400.

Obviously just getting started but looks like we at least have a workable platform to start with- thanks so much for all the help so far and will post more as experimentation continues!