Hello fine people,
So I was sitting at home, minding my own business, when a tidal wave of desire for a 10 mm carbine struck me. Unfortunately, I live in an unfree European country where hunting regulations would make the 10 mm carbine practically useful only if it could pump out an impact energy of 600 ft lbs at 100 yards distance. (that's the minimum requirement for hunting smaller deer and some other animals, if the 10 mm can't muster 600 ft lbs at 100 yards I could just as well get a 9 mm, which isn't legal on small deer but way more practical and a lot cheaper).
I've read a bunch of chronograph tests of handguns and some comparisons of handgun and carbine velocities, but I've never really found info on what you can do with purpose loaded carbine ammo. I'd think this is the place to find such info.
So please, share your tips on how to squeeze out the maximum performance from a 10 mm case in a 16-20" barrel.
Start here for sample muzzle velocities at varying lengths (muzzle energy chart is in a link at the top): http://ballisticsbytheinch.com/10mm.html
Next is the part I couldn't quickly find: a ballistic calculator to determine the rate of velocity/energy drop off over distance for your particular cartridge choice
...
Profit.
Others on the site can sanity check my meme, but I get the impression from bbti that 600 ft lbs at 100 yds is going to be a stretch unless you're loading it really hot.
In this video, you can see the results out of a hi-point carbine at 100 yards. He was using 150 gr bullets and got 1478 fps. Which is over 700 ft/lbs. With better bullets and powder, better ballistics can be achieved.
A 155 gr bullet at 1,325fps at 100 yards is easily obtained out of a carbine. That would be just over 600 ft/lbs.
https://youtu.be/LTcbDfTd4yA
I really like this website for calculations and trajectories
http://www.shooterscalculator.com/bullet-kinetic-energy.php (http://www.shooterscalculator.com/bullet-kinetic-energy.php)
According to ALASKAN BALLISTICS, you can get UNDERWOOD EXTREME PENETRATOR to do 1500 fps from a G29. I'd think that a carbine length would fit the bill.
Quote from: Patriot on November 29 2020 08:13:12 AM MST
In this video, you can see the results out of a hi-point carbine at 100 yards. He was using 150 gr bullets and got 1478 fps. Which is over 700 ft/lbs. With better bullets and powder, better ballistics can be achieved.
I took the G1 BC from a random big name bullet manufacturer and put these numbers through Hornadys Ballistic calculator. I got something like 550 ft lbs. With the 155 gr Barnes bullet I got closer, but I doubt you could get the 155 gr copper bullet up to 1478 fps. It's both heavier and a lot bigger than the 150 gr copper/lead bullet.
Quote from: Patriot on November 29 2020 08:13:12 AM MSTA 155 gr bullet at 1,325fps at 100 yards is easily obtained out of a carbine. That would be just over 600 ft/lbs.
https://youtu.be/LTcbDfTd4yA
I can't really find a lot of examples of it though.
I was getting an average of 1619fps with 155gr XTPs out of my AR carbine with a 16" barrel. The load was 10.0gr of 800X. The chronograph was about 10' from the muzzle.
According to the calculator at gun data.org, muzzle energy was 901ft/lbs. 50yd energy 672ft/lbs and 1397fps and 100yd energy 509ft/lbs @ 1216fps. They list the ballistic coefficient as 0.138 for that specific bullet. http://gundata.org/ballistic-calculator/
Hodgdon lists a max load at 9.8gr of 800X at a meager 30,000psi for 155gr bullets. Hornady lists a max load of 11.5gr of 800X for the 155gr XTP, with no pressure data.
So my thoughts are you probably can drive a 155gr XTP fast enough to get to 600ft/lbs at 100yds. But is that a good choice for the hunting applications that you mentioned? If a small deer happens to present itself at 50yds, or less, you are overdriving that bullet (XTP). Perhaps the better choice would be a solid copper, like the LeHigh. Or prove the muzzle energy with the 155s and hunt with 180s or heavier, if that's possible.
Quote from: Graybeard on November 30 2020 02:24:38 PM MST
I was getting an average of 1619fps with 155gr XTPs out of my AR carbine with a 16" barrel. The load was 10.0gr of 800X. The chronograph was about 10' from the muzzle.
According to the calculator at gun data.org, muzzle energy was 901ft/lbs. 50yd energy 672ft/lbs and 1397fps and 100yd energy 509ft/lbs @ 1216fps. They list the ballistic coefficient as 0.138 for that specific bullet. http://gundata.org/ballistic-calculator/
Hodgdon lists a max load at 9.8gr of 800X at a meager 30,000psi for 155gr bullets. Hornady lists a max load of 11.5gr of 800X for the 155gr XTP, with no pressure data.
So my thoughts are you probably can drive a 155gr XTP fast enough to get to 600ft/lbs at 100yds. But is that a good choice for the hunting applications that you mentioned? If a small deer happens to present itself at 50yds, or less, you are overdriving that bullet (XTP). Perhaps the better choice would be a solid copper, like the LeHigh. Or prove the muzzle energy with the 155s and hunt with 180s or heavier, if that's possible.
Thank you for your real world data!
I have been running bullets and velocities through the calculator and I'm getting the same results over and over again. You could probably find a legal load, but it's going to be pushing the cartridge to it's limit. A .357 lever or a .223 semi is probably the right way to do what I want to do.
First ... apologies. I thought I had results that could confirm your target out in the cloud. I looked but I've only uploaded data through 50 yards. Good news is that the string of Federal 180gr soft point Trophy Bonded I measured delivered Ke at 800 from a 16" barrel at 50 yards.
You can find raw, unformatted data for the entire 11 shot string here:
https://docs.google.com/spreadsheets/d/1Q9QryFLJ0Zy1yMsBcWol4oytStypnmaYzM7hch2O5eI/edit?usp=drivesdk (https://docs.google.com/spreadsheets/d/1Q9QryFLJ0Zy1yMsBcWol4oytStypnmaYzM7hch2O5eI/edit?usp=drivesdk)
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Looking at the BBTI data, a Buffalos' Bore 180 gr bullet will reach 1573 out of an 18" barrel. Running that muzzle velocity thru jbmballistics.com using a Hornady 180gr XTP, yields 599 FP-KE. So the 600 FP level is within realistic limits. Loading ammo with some of the slower powders like AA#9 or Alliant 2400 will probably see a tad more velocity and a realistic 600+FP . This without staring the gussets and gaskets.