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The Advantages of Mild Calibres

By Jeff Brown

Sporting interests are supposed to be enjoyable. When I'm running I much prefer to be in the forest under the shelter of the trees and on a softer surface than pounding the tarmac where I find it boring and harder on my ageing body.


Likewise, with my shooting I much prefer cartridge and firearm combinations that are easy on the ears, shoulder and pocket; in essence, I like mild cartridges. I prefer combinations that don’t bark with horrendous muzzle blast, don’t inflict spine-rattling recoil and don’t cost a king’s ransom each time I squeeze the trigger!


The trouble is that my “mild cartridge” specification is entirely subjective and what may be troublesome to me might be manageable for someone else.  Let’s break it down.



Muzzle blast is noise generated by the release of hot gases from the barrel as the projectile exits and the subsequent shock wave created as the gases equalise to atmospheric pressure. The higher the muzzle pressure and larger the volume of gas the greater the blast. 


An example of this is shown in recordings taken of M855 5.56mm ammunition where measurements of muzzle pressure were collected from a barrel originally 24 inches in length reducing by 1 inch per reading down to ten inches total length.  


“...with my shooting I much prefer cartridge and firearm combinations that are easy on the ears, shoulder and pocket.


Muzzle pressure at a full 24 inches read 4800PSI whereas 10 inches of barrel produced 12,140PSI or 252% more. Short barrels are proportionally louder and larger charges of powder produce greater volumes of gas. If you have ever shot a .22lr and .22WMR you will be aware that the magnum cartridge is crisper on the ears; the greater powder charge creates greater muzzle pressure. 


In contrast my own 12g “shorty” shot-shell cartridges measure just 1.25 inches overall - loaded with 5/8oz of shot and 10 grains of powder they have a very subtle report compared to a standard factory 1oz target load. (Ed: see Jeff's shotshell reloading series in NZ Guns & Hunting issues #168/170 etc).


.22 centrefire cast reduced loads: .22 Hornet and .223 Rem.



Newton summed it up best: “For every action there is an equal and opposite reaction”. In simple shooting terms, the faster and heavier a bullet is the more a firearm will “kick” back. Whatever goes out the front reflects on how fast the firearm moves backwards against you. 


The heavier the firearm, the less felt recoil, and conversely the lighter the gun the more you will be aware of the forces at play.  


The cost of shooting, especially if volumes are large, is something to consider like it or not. The discretionary dollar only goes so far, so we need to minimise expenditure while maximising the fun factor. Cartridges that burn large amounts of powder cost more to feed - plain and simple.  


Also, the larger in diameter and weight projectiles are the more they cost. Utilising small calibre cartridges or reduced loads of powder in addition to manufacturing our own projectiles goes a long way towards keeping costs down.



Anything rimfire: Every time I take a .22lr to the range or out hunting I am reminded of what a  pleasant little round it is.  Still affordable with almost zero recoil, and even supersonic .22lr ammunition is not particularly hard on the ears especially used with a suppressor. 


Ideal for shooters of all ages and sizes the .22lr is just as effective on small game as it ever was and with new lines of youth-sized rifles on the market it will remain the most popular cartridge in the world. The .17HMR took rimfire ammo to a new level when it arrived almost 20 years ago. 


Rimfires: .22 Short, .22lr, .22LH Hyper, .22WMR, .17HM2 and .17HMR.


Introduced by Hornady in 2002 this high-stepping, long-reaching, tack-driving round, like its archaic little brother the .22, has near nil recoil and only a slightly louder bark that can be tamed with a suppressor.


I still find it astounding that bullet-makers can produce a 3-piece 17 or 20gr bullet capable of sub MOA accuracy from a rimfire cartridge in off-the-shelf rifles. Just remarkable.  

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.17-.22 Centrefire: My first centrefire rifle was a BRNO .22 Hornet. It served well for many years until I upgraded to a .223 Rem, then ironically a few years back I re-homed a Zastava .22 Hornet for my teenager daughter to use and what memories it brought back.  


I had forgotten what a sweet-shooting and mild little round the Hornet is, and with the advent of modern powders it is more potent that ever before. The initial plan was to have the late Robbie Tiffen pop a suppressor on the rifle but after shooting it I decided there was really not a great deal to be achieved.  


Much of the time our Hornet shoots cast lead alloy 40gr bullets at 2250fps over 8gr of Lil Gun powder, but even full charges of Lil Gun under jacketed bullets are still not punishing on the ears. Again near nil recoil makes the combination perfect for a younger person.


Small bore centrefire rounds: .20 Vartarg, .22 Hornet, .218 Bee, .223 Rem, .300 AAC Blackout.


The venerable .17 Rem had a pair of formerly wildcat stable-mates added in recent years in the shape of the .17 Remington Fireball in 2007 and the .17 Hornet from Hornady in 2011. All launch 20-25gr bullets and recoil is not worthy of mention. They have a sharp report but with hearing protection or a suppressor this is no concern.  


On to the .222 Rem and .223 Rem - These two consume modest charges of powder ranging from 20-28gr. They will not knock you around yet they can handle a surprising array of .224” projectiles and given their accuracy they're effective on most medium-size game animals. Again, the addition of a suppressor makes them more comfortable to shoot.  


Carbine/pistol rounds: This category includes some of the older rounds at home mostly in single-shot and lever-action rifles. Cartridges like the .25-20, .32-20, .310 Cadet, .38 Special, .38-40, .44-40, .45 Colt and any of the old English rook rounds.  


Very conducive to cast lead bullets and running on typically small charges of fast or very fast burning powder, these rounds are a joy to handload, cheap to run and fun to shoot with. 


Six different .32-20 loads; even a heavy subsonic bullet is still mild to shoot.


More importantly they operate at modest pressure levels that when combined with small powder charges minimises muzzle blast (which is why I elected not to include the .357 and .44 Magnum rounds in this list as both run at higher pressure, although they can be downloaded).  


At the lower end I run my Martini .32-20 on as  little as 4.2gr of Green Dot shotgun powder producing 1030fps with a 125gr flat-nose cast bullet, superbly quiet through the suppressor and deadly on small game, not to mention that they are a hoot on gong targets.  


A South Canterbury wallaby taken with Jeff's .310 Cadet


The .310 Cadet is fond of 5gr of Unique propelling 125gr bullets at just shy of 1400fps. When these very soft lead bullets are hollow-pointed they are effective on South Canterbury wallabies.  


James Passmore has previously written in NZ Guns & Hunting about hunting with his .44-40 and demonstrated what our forefathers knew already - that a soft lead bullet at a modest velocity is more than capable of taking deer-size game. 


Vintage cartridges: Cartridges from the early years of smokeless powder, the late 1800s, operate at what are today considered conservative pressures and velocities. This is due to (1) the reduced strength of the actions of these older firearms, (2) early smokeless powder efficiency, and (3) iron sights prevailed so long-legged rounds were just not needed.  


No less effective today, these old cartridges still have a lot to offer with the advantage of being pleasant to use. The likes of .25-35, .250/3000, .30/30, .32 Special, .35 Rem, .38/55 and .45/70 cover a wide range of applications.


All are still available today, although it may be hard to find .25-35 (it can be made from .30/30 brass). They are all suitable for handloading with cast bullets for economy and with the possible exception of the big thumper .45-70, will not stand you up from prone due to recoil. 


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Reduced cast loads for both 6.5x52mm Carcano and .303 British.


Interestingly, the formerly almost obsolete .35 Rem has had a resurgence in the last few years with Hornady loading it with modern powders and FTX “Flex Tip Expanding” bullets for better ballistics.


The .35 Rem is quite possibly the perfect cast bullet rifle cartridge being a medium bore with mild pressures and velocities. There's a wide range of .358” calibre projectiles available too (you can even shoot 9mm/.38 pistol bullets in it) for a range of applications.   


Intermediate rounds: With the popularity of AR platforms (y’all remember ARs…) some nice little niche cartridges have been developed, shortened down to fit into AR15 magazines. Based on the 7.62x39, the 6.5mm Grendel is a sweet-shooting cartridge burning less than 30gr of powder and capable of clocking 2400fps with 120gr bullets. 


I had the pleasure of shooting my friend’s rifle in the USA two years ago and it was a joy to use. Similarly, there is the 6.8SPC shooting .277” diameter bullets, and the .300AAC Blackout. These are tidy little packages capable of surprising performance thanks to modern developments in powder technology.


Loading down: There is no reason to run heavier cartridges at full throttle if the performance is not acceptable to the user or required for an application. There are a lot of shooters out there who would shoot more accurately, comfortably and confidently if they were not filled with trepidation every time they squeezed the trigger.  


Having the extra range of a 7mm Rem. Mag. is of no practical use if you have a flinch that causes you to miss or place bullets poorly. The good folk at Hodgdon and ADI have load data for Cowboy Action and reduced rifle and shotgun loads for those inclined to back off a shade.  


A pair of “shorty” 12g rounds flanking two .310 Cadets.


H4895/AR2206H is a brilliant powder most suitable for loads down to 60% of full charge. This allows you to tailor loads to suit your confidence and/or capability levels. Likewise, IMR/ADI Trail Boss, a bulky, fast-burning powder originally designed for 40mm grenade application, allows you to fill a case with powder while producing modest terminal ballistics.


I have written extensively over the years about cast bullet loads developed for cartridges that allow for economical, comfortable shooting, eg; the .30/30, .303 British and 8x57mm. With some informed loading procedures it is not difficult to get cast bullets shooting very accurately in these rounds.


Where our overseas cousins have strict hunting seasons, many shooters use their big game rifles with reduced loads for hunting small game in order to keep their eye in.


Specialised loads can also be developed - I have a subsonic load for my .303s using 120gr bullets at 1050fps, and a 220gr load at 2000fps which duplicates the ballistics of the factory Mk VI round.Where our overseas cousins have strict hunting seasons, many shooters use their big game rifles with reduced loads for hunting small game in order to keep their eye in. 


Running a standard weight .270 bullet at 1500fps is perfectly adequate for small game for example, and the man who can cleanly take a head shot on smaller animals will be well served come deer season. Cast bullets need not be used for reduced loads however as matching selected jacketed bullets to velocity ranges can work well.


50m Green Dot mild rounds can really shoot too; here are some cast bullet .32-20 groups shot at 50 metres.


Backing off your .300 Win Mag to more sedate velocities might be best served by loading bullets intended for the .30/30 as these projectiles are manufactured to expand at lower speeds.


You can use FMJs where no expansion is required.It is not always possible to strike a balance of all three factors of noise, recoil and cost but looking at how you react to each is a worthwhile exercise. 


I personally consider cost to be the least of the three considerations. This article is not intended to be comprehensive on the subject of mild cartridges and firearm combinations but merely my thoughts on experiences over the last 30 odd years.  


Being a long-term bean-pole weighing in at 76kg I know what I like to shoot. I have also witnessed people using firearms they didn’t shoot confidently due to the noise, recoil or poor fit of the gun. Sometimes it is worth remembering that less is actually more.  




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