Barrel Shortening Analysis

[YRUpunting?]

I was about to post a question about barrel shortening and increased report and muzzle blast when google gave me the link below.  It's not a Handi but it is interesting when report and blast become noticeably increased.  Also shows drop in FPS as barrel is shortened. 

Wish I would have been smart enough to think of a project like this in college.


http://brassstacker.com/skin/common_files/images/BrandonClarkReport.pdf

[petemi]

Thanks for posting it.  I reads like a typical thesis....sorta akin to Pentagonese.  It only confirms what any serious shooter already knows.  The new fact, to me, is that the Mosin/ammo combo he used wasn't very accurate    I have found that loss of velocity due to shortening a barrel can usually be compensated for by simply using a faster powder.  I see no difference in accuracy in most calibers between a long and short barrel.  Here, the 22 inch and 32 inch .45-70s are a good example.  And yes, increased flash and bang are to be expected from the short barrel.  I guess they had a lot of fun coming up with the equipment and doing the testing, but the subject matter was about as original as proving the Earth isn't flat.  To my way of thinking, the barrel used should have been a shooter to begin with.  Then he could have determined any change in accuracy......but, who wants to cut up a good shooter??

Pete.

[hoytcanon]

I like it... a kid figured out a way to go shooting and get credit for it... I would have done the same at that age (actually did a few times)... good for him. But as Pete says, nothing new in the report... I hope ten thousand other students try to refine the data at their own ranges, all over North America! 

[jeepmann1948]

Actually there are a lot of college age "kids" doing lots of firearm "usage tests" and instead of getting an "A" they  get room and board in a country far away from home and get paid too.
 My hat goes off for them for their service
 Here is a site that does a lot of testing for different cartridges:
http://www.ballisticsbytheinch.com/
Interesting data
George


 

[cwlongshot]

Pete is correct... its been a while since reading such a paper... 

One thing to remember and its something Pete touched upon. This is an anaelogy of this caliber... It will not stand for all calibers. Some loose little form shorter tubes, partially from the powders and allot to do with expansion ratio...

AS for noise, thats also a direct result of the pressure the cartridage is operating at. I have long recomended limiting this pruning to pistol calibers. I have had a 30-30, 35 Rem and 45-70 calibers on 12-16'' barrels... they damn sure do ring your ears if you let them... Let alone rifle calibers...wow!!

Stick with the pistol and shotgun calibers and you will be rewarded with INCREASED vel over the handgun velocities and NOT overly ring those ears.

CW

[YRUpunting?]

I agree it more or less just documents what we all know about shortening a barrel. What I thought was interesting was report and muzzle blast really increased when they go below 20".  Seemed this may be some explanation to why Handi's are no shorter than 20"?

This was the first year for me hunting with my 357 Maxi, and the biggest surprise to me was how low the report and muzzle blast was.  Sitting here looking at pictures of shorties posted here I keep telling my self I should chop down my 44 Mag, but I'm not convinced I will be able to live with the report and muzzle blast.

[Doublebass73]

This was the first year for me hunting with my 357 Maxi, and the biggest surprise to me was how low the report and muzzle blast was.

I like that feature about the Maxi also. I shoot a max load of Lil'Gun under a 180 grain SSP and it's still much more quiet than a 30-30. My barrel is 22 inches.

[petemi]

I think the Talo Trappers were a great idea.  As CW said about the pistol caliber shorties, they're still about as efficient as you can get.  Two of my shorties, ballistically speaking, should probably be longer...the .356/358 and the .38-55.  However, I haven't experienced any great loss or change in any area and the lightness and speedy control is well worth the hypothetical loss.

Pete

[Shu]

The 45-70 is perfect shortie. Even subsonic those big 400 grain + bullets still have alot of smash. I shoot subsonic 45-70s alot, it takes some getting used to. There is no muzzle blast etc so this is a good fit forme anyway.
 
You just have to realize bullet drop is a huge factor.

[petemi]

Somehow I know about
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                                                                           T

                                                                                       drop in the .45-70

Pete

[rdlange]

OK, extrapolate... say 30-30 or 35 Remington in a Contender 14".  Typically use faster powder to compensate for shorter barrel.  Do we get reduced noise? 

[Shu]

No, unless you are going subsonic. Part of the noise you get is from the expanding gases from burning powder breaking the sound barrier. (well you might get less sound but your ear won't be able to tell the difference). The faster powder is burned and not ejected out the barrel.
 
Switching to a faster powder to maintain velocity will still result in noise. You have to minimize bullet speed and gas speed to reduce sound.

[nanuk-O-dah-Nort]

....the subject matter was about as original as proving the Earth isn't flat.  ...
Pete.

Huh?

you mean the Earth ISN'T flat??

[petemi]

....the subject matter was about as original as proving the Earth isn't flat.  ...
Pete.

Huh?

you mean the Earth ISN'T flat??

No, Silly.  You're probably too far north to see this, but that's why flowers lean into the sun

[ibgp3]

OK, extrapolate... say 30-30 or 35 Remington in a Contender 14".  Typically use faster powder to compensate for shorter barrel.  Do we get reduced noise?

...or, say 308 in a 15" XP.
Factory loads produced a ball of fire described by others as "bigger than you".
...each round was like a concussion grenade, and everyone else left the range.
Loads taylored to the XP were not quiet, but there was a difference.

[GrassLakeRon]

You should try a mosin with a 17 inch barrel.  You talk about a fire breathing dragon.  Oh I forgot the shock wave.  See when you shot at something living the shock wave kills them and the fire grills them.  All you need is a fork.

Ron

[gcrank1]

Reminds me of the first time I experienced someone letting loose some 125(?)gr. 357Mags out of a snubbie next to me on the range........thought my nose was gonna bleed.
I wonder if I could get a Gov. Grant to study how long a barrel needs to be to get quieter?

[ibgp3]

If you get the right grant writer and send the application to the right place you can get a grant to compare and contrast toilet paper.