Large calibers that do well with short barrels?

[Elite]

Hey everyone,

Currently looking to buy a new rifle over the winter and set it up. I am wondering which calibers still perform well with short barrels (20”)? I am hoping to use the gun for everything. Moose/elk/deer. I would like to be able to shoot 600 yards if needed especially for sheep hunting. I was originally looking at the 280AI but brass seems Impossible to find. Then at the 7mm mag but my reaserch says that it does not do well with a short barrel, 300 wsm looks like it might do good but the recoil looks high especially for a lightweight rifle.


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[Formidilosus]

Hey everyone,

Currently looking to buy a new rifle over the winter and set it up. I am wondering which calibers still perform well with short barrels (20”)? I am hoping to use the gun for everything. Moose/elk/deer. I would like to be able to shoot 600 yards if needed especially for sheep hunting. I was originally looking at the 280AI but brass seems Impossible to find. Then at the 7mm mag but my reaserch says that it does not do well with a short barrel, 300 wsm looks like it might do good but the recoil looks high especially for a lightweight rifle.


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All cartridges lose 20-30fps per inch. The “efficient in short barrels” is a myth.

 

[redneckbmxer24]

Once you get over 50gr of powder stuff doesn’t do as well in short barrels, there are exceptions to chamberings that do well and don’t above and below but in general magnums are going to do best with a longer barrel. 7MM rem mag does well down to 22”.

Are you going to be running a can? If not it’s a little less of a concern and I wouldn’t hesitate to run a 20” 7RM without a can. With a can though it’s going to have a lot of carbon, enough to cause issues and not just build up in the can.

Also do you load? If you do you can load with slightly faster burning powders to mitigate it as well.

The short mags are just as overview or close enough to it that’s it’s not a significant difference but it’s still a little less powder so you can get away with a little shorter.

 

[Elite]

Once you get over 50gr of powder stuff doesn’t do as well in short barrels, there are exceptions to chamberings that do well and don’t above and below but in general magnums are going to do best with a longer barrel. 7MM rem mag does well down to 22”.

Are you going to be running a can? If not it’s a little less of a concern and I wouldn’t hesitate to run a 20” 7RM without a can. With a can though it’s going to have a lot of carbon, enough to cause issues and not just build up in the can.

Also do you load? If you do you can load with slightly faster burning powders to mitigate it as well.

The short mags are just as overview or close enough to it that’s it’s not a significant difference but it’s still a little less powder so you can get away with a little shorter.

I am in Canada so unfortunately I can not run a suppressor/can. I also do hand load


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[redneckbmxer24]

I am in Canada so unfortunately I can not run a suppressor/can. I also do hand load


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I wouldn’t hesitate doing a 20” 7MM RM then. H4831 or H4831SC would be a good temp stable powder for the mid range bullet weights.

 

[awildswanger]

8.6 Blackout?

 

[Shraggs]

358 win, maybe 338 federal.

Not disagreeing with Form - my recent experience with midbores ie 35 cal snd fast-ish powders is it’s difficult to see meaningful gain in longer barrels.

 

[thinhorn_AK]

My 30-06 got cut back to 18” to shoot suppressed, im also wondering the same thing as I’m wanting to shorten my 26” 300 win mag to shoot supressed.

 

[Wapiti1]

As Form noted, you will lose velocity as the barrel gets shorter. However, it is relative to the starting point. Meaning, a 7-08 will still be slower than a 7 WSM for the same barrel length.

When going shorter, you need to decide what your velocity/bullet/ballistic criteria are, then choose a cartridge that gets you there.

That said, bore size matters and a larger bore will move the same weight bullet faster. A 130gr 6.5 will be slower than a 130gr 7mm which will be slower than a 130gr .308. This is simply pressure acting on a larger surface due to the bore.

The old school way was to bump up the bore to get the velocity back. That is why the .358 Win and .350 Rem Mag exist. They were to get 30-06 energy in a carbine length rifle. Energy being the method of comparison foisted upon an ignorant hunting population. These days, it's shifted toward velocity retention and bullet construction.

So, the answer, is pick a bullet, pick a minimum velocity, pick a max range, and then see if there are cartridges that will get you there, or swag the shortest barrel needed for a given cartridge. You'll quickly see why the 6.5 bore is so popular.

Jeremy

 

[redneckbmxer24]

358 win, maybe 338 federal.

Not disagreeing with Form - my recent experience with midbores ie 35 cal snd fast-ish powders is it’s difficult to see meaningful gain in longer barrels.

All chamberings have an optimal barrel length range where they do best and you see a standard gain per inch. Once you get to a certain point going shorter it’s going to lose substantially more FPS per inch. Same with going longer, you’re not going to see 25fps per inch going from a 26” barrel to a 36” barrel in a 308 for example. More overbore chamberings will benefit more from longer barrels and suffer more from shorter barrels.

 

[Formidilosus]

All chamberings have an optimal barrel length range where they do best and you see a standard gain per inch. Once you get to a certain point going shorter it’s going to lose substantially more FPS per inch. Same with going longer, you’re not going to see 25fps per inch going from a 26” barrel to a 36” barrel in a 308 for example. More overbore chamberings will benefit more from longer barrels and suffer more from shorter barrels.

In common rounds, that hasn’t been the case- from 223 to 300 NM. When loaded for 26” and measured for velocity, and then the same for 18”, none of them have shown to be “more efficient” than any others on average. Yes, sometimes a change is powder is warranted when shortening, but I haven’t seen this magical round that loses 5fps per inch when optimized, nor the one that loses 100fps per inch when optimized either.

I’ve got/had 300RUM’s at 34” to 20”, 300 and 338NM’s from 26” to 18”. 7mm mags from 26” to 17”, etc.

 

[Wrench]

Everything I've shortened was somewhere between 25 and 50fps per inch. Do realize that we're not shooting data sized strings to get too accurate on velocity. Muzzle blast and flash unsupressed is a legitimate concern and short barrels are a diminishing return, once you head south of the 16-18" area things get less predictable.

 

[redneckbmxer24]

In common rounds, that hasn’t been the case- from 223 to 300 NM. When loaded for 26” and measured for velocity, and then the same for 18”, none of them have shown to be “more efficient” than any others on average. Yes, sometimes a change is powder is warranted when shortening, but I haven’t seen this magical round that loses 5fps per inch when optimized, nor the one that loses 100fps per inch when optimized either.

I’ve got/had 300RUM’s at 34” to 20”, 300 and 338NM’s from 26” to 18”. 7mm mags from 26” to 17”, etc.

So you think you can take a 26” 308 barrel, fire it with FGMM for example and only lose 400 FPS cutting it to 10”? Nope, it’s more like 1000fps. There’s also a ton of data on 556 barrels at different length that shows this isn’t the case

Yes, barrels get to the point of dinished return as they get longer and there’s a point as they get shorter that the velocity loss per inch increases significantly.

300RUM also isn’t a good comparison for longer barrels because it’s so overbore that you can put a 36” barrel on it and still get solid gains. Years ago I cut back a 300RUM barrel 2” at a time and the velocity loss increased significantly below 24”. It was near 50fps per in 20-24”, more below 20”. That was measured on the same barrel which is the only way to get a truly accurate comparison. You can take two identical barrels made at the same time from the same barrel steel and run them the same length and see 30-50fps difference between them with the same charge weight or ammo. So comparing velocity data from one rifle at 20” with one barrel and another rifle with another barrel at 34” isn’t scientific at all.

Here’s a good data sheet of a 223 bolt gun barrel that was cut back:

https://i0.wp.com/rifleshooter.com/wp-content/uploads/2015/12/223-rem-heavy-match-68-grain-barrel-length-velocity-26-to-6-inches.png?ssl=1

 

[Formidilosus]

So you think you can take a 26” 308 barrel, fire it with FGMM for example and only lose 400 FPS cutting it to 10”? Nope, it’s more like 1000fps.

Well, I/we shoot 13.5” 7.62’s a bunch and they average between 25-30fps per inch less than 20” barrels. Haven’t shot enough 10” 308’s to say, but you are now grasping at straws as a 10” 308 is an extremely niche item. A 18” 7mm RM or 300mag isn’t a niche item, they are used heavily in different parts of the world.

There’s also a ton of data on 556 barrels at different length that shows this isn’t the case

I shoot and see shot hundreds of thousands of rounds a year of 5.56 from barrels as short as 5.75” to 24”- I know exactly what they do.

Yes, barrels get to the point of dinished return as they get longer and there’s a point as they get shorter that the velocity loss per inch increases significantly.

Not in usable lengths from 17” on up from what I’ve seen- they all average 20-30fps per inch with loads made for them.

300RUM also isn’t a good comparison for longer barrels because it’s so overbore that you can put a 36” barrel on it and still get solid gains. Years ago I cut back a 300RUM barrel 2” at a time and the velocity loss increased significantly below 24”. It was near 50fps per in 20-24”, more below 20”.

(Bolted part). Using the same load, correct?

I’ve shot a lot of big 30cal mags in short and long barrels, I can happily cut a barrel back and show it. When you get in touch with Ryan about the scope range day, we can do a barrel/load as well.

That was measured on the same barrel which is the only way to get a truly accurate comparison.

Correct, but you need to work up a different load as the barrel is shortened- different powders.

You can take two identical barrels made at the same time from the same barrel steel and run them the same length and see 30-50fps difference between them with the same charge weight or ammo. So comparing velocity data from one rifle at 20” with one barrel and another rifle with another barrel at 34” isn’t scientific at all.

Ok. How many barrels, in what cartridges have you personally- not some third party, worked up a load at 26” or whatever, then cut the barrel back and reworked loads for that shorter length?

Here’s a good data sheet of a 223 bolt gun barrel that was cut back:

https://i0.wp.com/rifleshooter.com/wp-content/uploads/2015/12/223-rem-heavy-match-68-grain-barrel-length-velocity-26-to-6-inches.png?ssl=1

Why would you use a load designed for 24” plus barrels in a 12” barrel? If you’re going to use factory ammo that is designed for long barrels, in a short barrel, well…. It’ll suck.

 

[Formidilosus]

@redneckbmxer24

To be clear, I’m not saying you are wrong, I’m saying that in a lot (a lot) of short and long barrels of various cartridges everything we have seen is that they can all be made to work in all usable barrels lengths, and all are around 20-30fps loss per inch. I/we were shooting 18”-20” barreled 300wm and 300NM’s, as well as short barreled 338L’s and 338nm’s before it was popular and the common “knowledge” was and is completely wrong.

 

[Fitzwho]

Second for 338 Federal. 200grain bullet running 2700ft/s still has over 2000 ft-lbs of energy at 600 yards (9 MOA drop at that distance, so not a flat shooter, but it is maintaining more than enough energy).

 

[plentycoupe]

Love how all these question threads turn into a pissing match between people that know a lot about the subjects.

I would like to find the same info. Let’s say a
20” barrel
.30 caliber 200grn Terminal Ascent(.608 bc) or similar round.

Minimum 1800fps at 600 yards

Or maybe someone can mention another caliber that would be at or above the same velocity at 600 yards and shoot well in a 20” barrel.

Factory ammo.
Let’s assume that we want it to be accurate, want to be able to shoot a muzzle break or a silencer(and not ruin one or the other or cause facial damage with muzzle blast).

I don’t have near the expertise on the subject as most yet follow these questions as I know others on here do have that expertise! Will look at the .338 Federal

 

[thinhorn_AK]

@redneckbmxer24

To be clear, I’m not saying you are wrong, I’m saying that in a lot (a lot) of short and long barrels of various cartridges everything we have seen is that they can all be made to work in all usable barrels lengths, and all are around 20-30fps loss per inch. I/we were shooting 18”-20” barreled 300wm and 300NM’s, as well as short barreled 338L’s and 338nm’s before it was popular and the common “knowledge” was and is completely wrong.

What length would you reccomend for a 300wim intended to be suppressed and used for hunting?

 

[Formidilosus]

What length would you reccomend for a 300wim intended to be suppressed and used for hunting?

I don’t go longer than 20” anymore for suppressed. Using the same barrels, my current 20” 300WM’s are right at 90fps and 115fps less than they were at 24”.

If that doesn’t get me the impact velocity range that I want/need, I go larger cartridge.

 

[Formidilosus]

Love how all these question threads turn into a pissing match between people that know a lot about the subjects.

I don’t think it’s a pissing match, at least not for me. But you are dealing with a subject that very few people have personal experience in, and almost no one has multiples of personal experiences in. Rifles and shooting have more “daddy said so” myths and outright BS in it than any other subject. Most things in shooting and guns, when actually tested and evaluated in large sample sizes, generally proves out that grandpappy was wrong.

I would like to find the same info. Let’s say a
20” barrel
.30 caliber 200grn Terminal Ascent(.608 bc) or similar round.

Minimum 1800fps at 600 yards

Loading a 300WM with 200gr TA’s (though I would and do want more than 1,800fps with them), it is easy to get well beyond 600 yards of terminal range in a 20”.

Or maybe someone can mention another caliber that would be at or above the same velocity at 600 yards and shoot well in a 20” barrel.

They’ll all work. Hell, 6cm and 6.5cm’s kill like gang busters past 600 yards with 20” barrels.

Factory ammo.
Let’s assume that we want it to be accurate, want to be able to shoot a muzzle break or a silencer(and not ruin one or the other or cause facial damage with muzzle blast).

Factory Federal 200gr TA from the 300WM and a 20” barrel gets a bit over 2,700fps MV. At 5k DA, that’s 785 yards to 1,800fps. Again, having used TA’s at range on animals, I would not be choosing to do so at 1,800fps.

I don’t have near the expertise on the subject as most yet follow these questions as I know others on here do have that expertise! Will look at the .338 Federal

The 338 Fed is a poor choice for 600 yard use on animals.