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Internal ballistics program

#1
Has anyone got an internal ballistics program? It any good? Are they worth buying? Do they even exist?

If somebody has got one of these potentially mythical beasts handy, could they please plug the following data into it for me?

Bullet: 135 grain Sierra Match King
Case: 7.62 x 39 mm
barrel length: 18 inches
powder: 23.5 grains Vit N130

I would like to know what it thinks the muzzle velocity should be.

If it does turn out that these things are entirely mythical, the product of vicious rumour and wishful thinking, forget I raised my head above the parapet...
 

ugly

LE
Moderator
#3
stoatman said:
Has anyone got an internal ballistics program? It any good? Are they worth buying? Do they even exist?

If somebody has got one of these potentially mythical beasts handy, could they please plug the following data into it for me?

Bullet: 135 grain Sierra Match King
Case: 7.62 x 39 mm
barrel length: 18 inches
powder: 23.5 grains Vit N130

I would like to know what it thinks the muzzle velocity should be.

If it does turn out that these things are entirely mythical, the product of vicious rumour and wishful thinking, forget I raised my head above the parapet...

7.62 x 39mm
Primer: Remington 9 1/2 Test Firearm: Ruger Mini-Thirty
Case: Winchester BBL Length: 18 1/2"
Twist: 1 x 10" Trim-to Length: 1.515"
Bullets:
#7350 .30 Caliber/7.62mm (.308) 135 gr. SPT - Single Shot Pistol OAL 2.185

Powder/Velocity 2000 2050 2100 2150 2200


Viht N130 24.0 24.5 25.0 25.5 26.0



Energy/ft.lbs. 1199 1260 1322 1385 1451
Accuracy Load: Viht N130/ 25.5grs. 2150fps/ 1385ft. lbs.
Hunting Load: IMR-4198/ 24.3grs. 2150fps/ 1385ft. lbs.
Copyright 2003 Sierra Bullets, LLC.

According to that there is bags of room for improvement. I push my 125 Gn .311 at 2550 fps and 1750 foot pounds.
 

ugly

LE
Moderator
#4
If you have the BC etc I can create a custom load as the bullet you describe is new isnt it, I can do a custom one with bullet drop etc.
 
#5
Interesting, thank you very much.

The accuracy with the match King definitely peaked at 23.3 grains for me -- 24.5 was pushing the 1 MOA, and 25.0 was definitely above it.

I have done exterior ballistics through the JBM online calculator, and it will be interesting to compare with your programme.

BC is: .390 @ 3250 fps and above; .370 between 1900 and 3250 fps; .345 between 1500 and 1900 fps; .300 @ 1500 fps and below

what I'm also wondering is whether I can push this bullet to 2400 fps, which would give me a chance of using the rifle at the Civilian Service Rifle competitions next summer. Using the JBM calculator suggests that this would be a better option than the heavier 150 or 155 grain bullets at 2250 fps.
 

ugly

LE
Moderator
#6
I cant get the Sierra programme to offer me a .308 bullet lighter than 150 grains for even the custom load and ballistic pages despite it offering the bullet in 100 grains and upward for its standard published loads, I suspect the 135 grain match king is a new bullet?
As an aside I one tried game kings in 150 grain as they were allegedly as well made if not better than the FMJs for accuracy (this was when they werent sect 5) and I found them dramatically sensitive to tiny differences in loads. I am planning to develop a load for the 7.5 x 55 french in a Game king and now I have the electronic scale and powder throw I suspect my loads should be more consistent.
 
#7
Yes, it is a new bullet this year, and actually performs almost the same as the 150 grain MK in terms of exterior ballistics. Plus, it is cheaper...

Shame the program won't let you go any lighter than 150.

Would the 135 not be a good option for your 7.5 French? It's as close to 139 grains as you are going to get.
 
#8
Sorry, it is new from last year:

30 Caliber (.308 diameter) 135 gr. HPBT MatchKing

Sierra is pleased to introduce the newest member of our 30 caliber MatchKing line; the 30 caliber 135 grain HPBT. This bullet was designed to fill the need for a lighter-weight / low recoil 30 caliber bullet for smaller capacity cartridges. Sierra expects this bullet to be a popular choice for our across the course, handgun silhouette and 100-200 yard benchrest customers.

These bullets will be available in boxes of 100 bullets (stock #2123) with a 2008 suggested retail of $35.30 per box or in boxes of 500 bullets (stock #2123C) with a suggested 2008 retail of $164.49 per box.
 

ugly

LE
Moderator
#9
I was feeding it 146 gn fmjbt basic nato mg fodder in .308 (nominal .307) and it was good enough. I have kept the slot as a .30 wildcat calling it 7.62 x 55. Just in case I decide to go to france with a good deer/boar combo!
In theory it gets around the rules as its a wildcat based on necking up the 6.5 swede case by 1 mm and not trimming it. Thats basically how I started handloading for the rifle before Indep made ammo and brass!
 
#12
Hi Uggs,

I have real-world data now. All is based on 5 (or sometimes 6) round groups. 18" bbl.

The 23.5gn MK load does 1983fps loaded long & 2021fps @ mag length, with no detectable accuracy difference in practical terms. Today I was mostly shooting these loads just over 1/2MOA.

I then did a few tests:

Lapua 123gn 311 spitzer with a mil load of Czech mil powder did 2388fps, but blew 1 of 10 primers! :shock: Not doing that again...

Then, experiments for a "service" load which makes IPSC Major (power factor >320). I did this as I would for a competition, so loaded to mag length & with thrown charges. Bullet is 150gn Prvi flat base .308, powder is N130.

LOAD -- ave velocity -- power factor

25.5 -- 2123 -- 318
26.0 -- 2160 -- 324
26.5 -- 2165 -- 325 (there's some statistics going on here, extreme spreads were 55-65fps for the 26.0 & 26.5 loads. This load shot around 1.1MOA discounting 1 flyer I pulled though, which put the whole group @ 1.9MOA)
27.0 -- 2210 -- 331

So, the 150 Prvi flat base is my major IPSC load.

You can all wake up again at the back now!
 

Alsacien

MIA
Moderator
#13
Gun_Nut said:
From what I have read Quickload is considered to be pretty impressive. JMS Arms imports it into the UK.
I use Quickload now (and Sierra 6). It has proper internal ballistics and every nerdy thing imaginable. It also has separate files for every powder/bullet/primer/case manufacturer with all their offerings.
The Sierra 6 is great - but if you want to run a Nosler bullet with Vectan powder the reality in Quickload differs from the conversions and equivalents in Sierra.
 

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