Optimal speed for TSS

[Fabalis]

Hi Every body,

The TSS is not deformable and so can allow very high speed. High speed means a high terminal energy and you can so use smaller pellets and more impacts.

In another hand, high speed should increase dispersion.

So, upon your experience, what is the best compromise for TSS speed ?

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[Fishh2o]

With TSS you can use much slower speeds. Keep in mind we want to achieve 1.5" penetration in ballistic gel for a clean kill on a duck. With steel being less dense than TSS we have to start ramping up speeds, going up in size, or both to get the same penetration. Now these are just examples and I'm sure there are better examples but this should give a picture.

cap1.jpg

So we would need to go up to #BB to have similar penetration at 50 yards as #9 TSS. For #2s bump up our speed to 1700FPS to get the 1.5" of Penetration.

Like you said speed increases dispersion. Lighter materials like steel at high speeds the patter results for my gun go to crap after 40 yards. I do not like shooting steel past 40 yards with my modified choke. I also like to keep my velocity under 1600FPS with steel. The denser loads will pattern much tighter for me. I have been doing most of my pattern work the last couple months with velocities of 1300 - 1400 FPS and seeing good results. Some the patterns are a little to tight at closer ranges even with Improved Cylinder. I just picked up some #9.5s to start working with at sub 40 yards. Also, not having to push the high velocities helps keep the recoil down some.



FishH2o

[Fabalis]

Thank you for the explanation.

I have made an excel sheet to calculate the ballistic of TSS and it's impressive (I have not your software).

My calculation give me for TSS#9 (1,97 mm - density 18 g/cc) @ 45 m (so around 50 yards) and with V0 = 365 m/s (1200 fps) the residual NRJ of 1,39 J. I don't know why there is such a difference... maybe you consider a lowest temperature...

However, and that's confirms my first impression, TSS doesn't need high speed and should pattern very tighty at the normal range.

I prepared 10 shells with "normal" load and waiting for my chrony to make tests.

[Dave in AZ]

You can buy the ballistics software that most of us use, KPY ballistics, from Precision Reloading for $60 if desired:

https://www.precisionreloading.com/cart.php#!l=KPY&i=SB

Pretty sure guy who wrote it is on this site now, but think this is the approved venue to purchase. The software is my #1 reloading purchase in my entire life, the data it gives and ability to study loads and populate spreadsheets is just outstanding. Highly recommended!

[Fabalis]

I cannot use the software because not available for mac.

However, if somebody can help me to compare my calculation with the KPY software

For these parameters :

• Shot : TSS #9 (1,97 mm)
• Density : 18 g/cc
• Muzzle speed : 1300 fps (396,2 m/s)
• Air : T° = 10°C - P = 1013 mb H% = 50% so air density = 1,244

I find at 50 yards (45,72 m) :

• Speed : 217,8 m/s (714,6 fps)
• NRJ : 1,73 J

[Fishh2o]

I too run a mac and have to run it like most of my other useful software in a VM.

I set the temperature of this test to 50f

test.jpg

[Fabalis]

Thanks a lot for your answer !

Are you sure of the density of the pellet (18 g/cc) ?

[Fishh2o]

Thanks a lot for your answer !

Are you sure of the density of the pellet (18 g/cc) ?

Yes sir. Here is a screen shot of the front page.

18.jpg

I know your running OS X I would boot camp it if you had to just so you can get KPY.

[Fabalis]

Many thanks.

The only difference I can see is the cross wind I don't take into consideration in my calculation. Could I ask you to put the wind to 0 mph to see the result ? If it's not close to my result, my excel sheet is not good.

Anyway, I need this software ! I will order it promptly...

[Fishh2o]

It just changed the wind drift to 0.