Has anybody done any testing of bullet velocity in a Mini 30 with a 18.5" barrel vs the Tactical with the 16.2"? I have both guns & was wondering about how much fps was lost with the shorter barrel shooting the same bullet load from both guns. Thanks for any info you may have.
grayfox2013
I've been meaning to do just that, chronograph loads out of the different length barrels.
Sunday I was up at the range eager to put some rounds through a nice old Marlin 39 Mountie I bought, sighted in the irons on the green stocked Mini, then remembered I needed to go do something, so never broke out the chronograph.
My Mini-30's are 16 1/4", 17 1/4", and 18.5" barrels. If I can get up to the range next Sunday, I'll test my SST handloads as well as PPU factory FMJ out of each gun.
Maybe pick up a few boxes of Red Army Standard Commie ammo to see what it does.
When I shot some last year it functioned 100% out of two of my Mini's and accuracy was better than other Russian ammo I've tried.
Sunday I was up at the range eager to put some rounds through a nice old Marlin 39 Mountie I bought, sighted in the irons on the green stocked Mini, then remembered I needed to go do something, so never broke out the chronograph.
My Mini-30's are 16 1/4", 17 1/4", and 18.5" barrels. If I can get up to the range next Sunday, I'll test my SST handloads as well as PPU factory FMJ out of each gun.
Maybe pick up a few boxes of Red Army Standard Commie ammo to see what it does.
When I shot some last year it functioned 100% out of two of my Mini's and accuracy was better than other Russian ammo I've tried.
I don't believe the velocity loss per inch will be as significant with the x 39 as it's not a high velocity, high pressure, slightly overbore cartridge like the 5.56mm.
Sometimes it's just easier to Google your question and see what you find. Don't be lazy, go and try to find out yourself. I Googled it and the first one that came up was perfect to answer the OP's question.
7.62×39 mm Russian: Effect of barrel length on muzzle velocity ? rifleshooter.com
7.62×39 mm Russian: Effect of barrel length on muzzle velocity ? rifleshooter.com
While not specifically definitive, I find this site useful if you don't have a chrono.
BBTI - Ballistics by the Inch :: Home
BBTI - Ballistics by the Inch :: Home
This post has been deleted
:blink: Sorry guys. Getting old!
My chrono is broke, I would love to check my 16" cut standard mini against my 22" target mini. I'm sure I posted some results in one of these threads.
I guess the question would be better stated as loss that is statistically significant. So 30rds on the 18" and 30rds on the 16. Do the stats, check your margin of error. There you go. So at the receiving end of the round, what changes. F= MA
The video in the link is interesting. Great information the have. I'm looking forward to sandog's real-world test of the Mini-30 as well because we can't have too many sources. I've seen Mini-30 barrel length tests in the past, going back to the early 1990's in gun periodicals, such as Guns & Ammo and Guns and Weapons for Law Enforcement, among others.
One test from the mid-1990's I remember concluded there was an average 80 FPS drop in velocity going from 18.5-inch barrel to 16-inch. I remember that one because there was something odd the the authors noted. They found 17-inch was a magic number for the Mini-30 of the time. With 17-inch barrel the 7.62X39 round left the Mini-30 at greater velocity than with the 18-5-inch barrel. I will dig that issue up and get the exact numbers. I'm a bit of a pack-rat when it comes to periodicals. I've kept them all.
One test from the mid-1990's I remember concluded there was an average 80 FPS drop in velocity going from 18.5-inch barrel to 16-inch. I remember that one because there was something odd the the authors noted. They found 17-inch was a magic number for the Mini-30 of the time. With 17-inch barrel the 7.62X39 round left the Mini-30 at greater velocity than with the 18-5-inch barrel. I will dig that issue up and get the exact numbers. I'm a bit of a pack-rat when it comes to periodicals. I've kept them all.
Sanddog and Grayfox, this is my 2nd post and I'd like to introduce myself, I'm Ed. And I have a question regarding the Noise factor increase of the 7.62x39mm round, when you go from an 18.5" barrel (ranch) to a tactical (16.25"). I'm on the fence as to cut the barrel down or not. All other factors aside, I am only concerned about increase in blast noise. Have you guys noticed any difference?
Regards,
Ed
Regards,
Ed
Welcome to the forum, Ed !
I have not noticed any increase in muzzle blast or noise with the shorter barrel.
It's not like shooting a high intensity cartridge like the 5.56mm out of an SBR or AR pistol.
As far as velocity loss in the shorter barrels, I tested several loads back in 2017 out of the 16.25", 17" and 18.5" barreled Mini-30s :
(47) Velocity Loss Vs. Barrel Length in the Mini-30 | Perfect Union
(47) Velocity Loss Vs. Barrel Length in the Mini-30 | Perfect Union
I have not noticed any increase in muzzle blast or noise with the shorter barrel.
It's not like shooting a high intensity cartridge like the 5.56mm out of an SBR or AR pistol.
As far as velocity loss in the shorter barrels, I tested several loads back in 2017 out of the 16.25", 17" and 18.5" barreled Mini-30s :
(47) Velocity Loss Vs. Barrel Length in the Mini-30 | Perfect Union
(47) Velocity Loss Vs. Barrel Length in the Mini-30 | Perfect Union
No expert, but cutting barrel length always results in loss of velocity to bullet, all other things being equal.
Most say that shorter barrels display more muzzle flash, absent suitable flash suppressors. I agree.
YMMV, but I would not cut down a barrel unless the muzzle/bore was severely damaged.
I want the greater effective range a longer barrel provides. This is probably much more important with the 5.56 ctg, as the bullet requires a certain minimum velocity in order to reliably fragment. Reducing barrel length also reduces bullet velocity, and so reduces the effective (fragmenting) range of the 5.56 bullet. Not an issue with the 7.62X39, apparently.
Most say that shorter barrels display more muzzle flash, absent suitable flash suppressors. I agree.
YMMV, but I would not cut down a barrel unless the muzzle/bore was severely damaged.
I want the greater effective range a longer barrel provides. This is probably much more important with the 5.56 ctg, as the bullet requires a certain minimum velocity in order to reliably fragment. Reducing barrel length also reduces bullet velocity, and so reduces the effective (fragmenting) range of the 5.56 bullet. Not an issue with the 7.62X39, apparently.
That would be true with a 5.56mm, Bob. But not with the 7.62 x 39.
Seems Russian ammo has powder formulated for the 16" barrel of an AK.
In some instances, I got MORE velocity out of my shortest barrel than I did with the long one.
See my tests in the links above.
Seems Russian ammo has powder formulated for the 16" barrel of an AK.
In some instances, I got MORE velocity out of my shortest barrel than I did with the long one.
See my tests in the links above.
I'm no expert on the Mini-30, that's for sure.
But all that notwithstanding, and given my general experience, the longer the barrel, the greater the velocity of the bullet. That has been my personal experience with many different rifles. Generally confirmed from many sources.
FWIW, I had to re-zero my Mini-14 after reducing the size of the gas vent, because the bullet was leaving the barrel at a slightly higher velocity.
It seems that users of 7.62X39 ctg tend use longer barrels to reach out further.
Certainly not saying you are wrong with respect to 7.62X39; your results speak for themselves..
But all that notwithstanding, and given my general experience, the longer the barrel, the greater the velocity of the bullet. That has been my personal experience with many different rifles. Generally confirmed from many sources.
FWIW, I had to re-zero my Mini-14 after reducing the size of the gas vent, because the bullet was leaving the barrel at a slightly higher velocity.
It seems that users of 7.62X39 ctg tend use longer barrels to reach out further.
Certainly not saying you are wrong with respect to 7.62X39; your results speak for themselves..
I will also offer for your consideration that the overall length of the two rifles in terms of Ruger's specifications is 37.5 inches with the synthetic stock and 18 inch barrel and is 36.75 inches for the synthetic stock and the 16 inch barrel with a flash suppressor. So overall difference in length is just .75 inches. Really no increase in close quarters usability IMHO. So by my thinking it really comes down to what you value more...velocity or flash suppression. YMMV
In my experience, two inches difference in barrel length is not gonna make enough difference to get excited about.
If it does my 24-inch barreled Model 700 must be a supergun.
If it does my 24-inch barreled Model 700 must be a supergun.
It depends on a lot of variables.
If you have two of the same series Mini-30s with same bore diameter then you can compare.
Then it depends on the brand of ammo or hand loads. Some faster burning powders can give you a bit more velocity from a 16.25-inch barrel than from an 18.5-inch or longer barrel.
The conventional wisdom of gaining velocity per inch of barrel still applies to 7.62x39, and again it depends on the round used. Gains or losses in velocity per inch of barrel are generally between 10 to 20 fps, with 15 fps being a long recognized reference for guesswork in the world of x39.
By comparison, 30-30 Win looses a lot more velocity per loss of inch than does 7.62x39.
If you have two of the same series Mini-30s with same bore diameter then you can compare.
Then it depends on the brand of ammo or hand loads. Some faster burning powders can give you a bit more velocity from a 16.25-inch barrel than from an 18.5-inch or longer barrel.
The conventional wisdom of gaining velocity per inch of barrel still applies to 7.62x39, and again it depends on the round used. Gains or losses in velocity per inch of barrel are generally between 10 to 20 fps, with 15 fps being a long recognized reference for guesswork in the world of x39.
By comparison, 30-30 Win looses a lot more velocity per loss of inch than does 7.62x39.
Mini-14/30, users as well as M1/M1A users have various devices which will allow bullets and powders not originally intended for their rifles to be used without damage to the user, or rifle. Even so, there are limits, and in ignorant hands such devices can be a curse.
The FAL has an adjustable gas system, but it has its's limits, being intended to adjust within fairly narrow margins of various 7.62 NATO ctgs. Not at all sure if the FAL adjustable gas system is valid for ctgs much outside NATO ctg specs.
I look forward to the day when such a device is made for the SKS. If I have missed such, please inform me!
For the most part, and IMHO, using ammo not originally intended for one's semi-auto rifle is NOT advised. Doing so moves into "Expert" territory.
The aforementioned devices can be useful items for some folks, including folks operating in a SHTF scenario, where reliable, factory-made ammo is in scant supply. Unfortunately, it takes a few rds to "dial-in" the devices, so small numbers of pick-up rds are not easily configured to most semi-auto rifles. In addition to adjusting the gas device, there is also the Sighting-in process which takes at least a few more rds. All of this assumes identical "pickup" rds of identical composition, and a substantial number of them. Folks using "pickup" ammo will have some problems, unless such rds are factory-made.
The .30-30 has always been defined by the blunt nose of the bullet, required by the usual tube-fed rifles, and which bullet shape inhibits the velocity of the bullet. I understand there is modern (expensive) ammo which attempts to alleviate this factor. There is also the rimmed Ctg case to consider. Not an issue in tube-fed lever actions, but a hassle in mag-fed bolters and semi-autos. That's where the REAL problem lies; the ctg is generally not suitable for modern, mass-produced semi-auto or bolt-action rifles. No doubt expensive exceptions, but...
Love your .30-30 lever action rifle. Mod it into a Scout rifle, and have an excellent short-range rifle.
I might buy a Ruger "Remlin" when they become available.; Preferably in 7.62, but that's a dream. Given proposed Fed/State bans, such a rifle might be what we are "allowed" to own. Probably not for long, since such a rifle is a very good short-range rifle. Too good...
The FAL has an adjustable gas system, but it has its's limits, being intended to adjust within fairly narrow margins of various 7.62 NATO ctgs. Not at all sure if the FAL adjustable gas system is valid for ctgs much outside NATO ctg specs.
I look forward to the day when such a device is made for the SKS. If I have missed such, please inform me!
For the most part, and IMHO, using ammo not originally intended for one's semi-auto rifle is NOT advised. Doing so moves into "Expert" territory.
The aforementioned devices can be useful items for some folks, including folks operating in a SHTF scenario, where reliable, factory-made ammo is in scant supply. Unfortunately, it takes a few rds to "dial-in" the devices, so small numbers of pick-up rds are not easily configured to most semi-auto rifles. In addition to adjusting the gas device, there is also the Sighting-in process which takes at least a few more rds. All of this assumes identical "pickup" rds of identical composition, and a substantial number of them. Folks using "pickup" ammo will have some problems, unless such rds are factory-made.
The .30-30 has always been defined by the blunt nose of the bullet, required by the usual tube-fed rifles, and which bullet shape inhibits the velocity of the bullet. I understand there is modern (expensive) ammo which attempts to alleviate this factor. There is also the rimmed Ctg case to consider. Not an issue in tube-fed lever actions, but a hassle in mag-fed bolters and semi-autos. That's where the REAL problem lies; the ctg is generally not suitable for modern, mass-produced semi-auto or bolt-action rifles. No doubt expensive exceptions, but...
Love your .30-30 lever action rifle. Mod it into a Scout rifle, and have an excellent short-range rifle.
I might buy a Ruger "Remlin" when they become available.; Preferably in 7.62, but that's a dream. Given proposed Fed/State bans, such a rifle might be what we are "allowed" to own. Probably not for long, since such a rifle is a very good short-range rifle. Too good...
Some posters here love to argue their points, while never admitting they might be wrong, ever.
The above exchange is one of them.
Frankly, I favor Beck's point of view. IMHO the .30-30 is an outmoded ctg, and the rifles which shoot it are also outmoded.
EXCEPT that such rifles and ammo are what will be allowed, in the short-term, by the Antis.
Unfortunately, the Antis will devolve us all to single-shot rifles just prior to banning all firearms-- except tor the police and the military, of course.
The above exchange is one of them.
Frankly, I favor Beck's point of view. IMHO the .30-30 is an outmoded ctg, and the rifles which shoot it are also outmoded.
EXCEPT that such rifles and ammo are what will be allowed, in the short-term, by the Antis.
Unfortunately, the Antis will devolve us all to single-shot rifles just prior to banning all firearms-- except tor the police and the military, of course.
As I pretty much only shoot steel case, "Soviet" bloc type ammo, the 16" barrel Mini 30 is perfect in my opinion. It's a nicer rifle than the SKS or AK, American made that matters to me, and it does not "look" like an evil rifle unless I have a large capacity magazine hanging out the underside of it. Not a huge consideration, but it does have a certain "sleeper" effect v/s MSR's that are very popular in this world.
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