Loads for subsonic .308

timbeech

Well-Known Member
Has anyone got any experience of reloading subsonic rounds for a .308 . I've read online about using 180 gr FN bullets, about 10gr of IMR Trail Boss, and large pistol primers.

I want these for fox control in an equestrian yard where I need to be quiet so I don't spook the horses or wake up the locals.

Before I get the usual barrage of useless comments lets clear up a few things :

  • Haven't got a 22LR and don't want one
  • I have got a spare slot on my FAC for a .223REM and eventually when funds allow will get one (or 20TAC) and I have
  • Already got the 308 and all the reloading stuff, so will only need the bullets, powder and primers
  • Don't quite trust my 17HMR for foxes



Thanks,

Tim
 
a shotgun load is probably easier to download,

I used to load a 7/8ths load with half the normal powder/power for a 1 1/8ths load.

low power rifle loads can be more dangerous to the shooter than the quarry.
 
I would imagine a 308 sub load would ricochet worse than 22lr, ive shot a lot of foxes with my 22lr, out to 70yd headshots, I had one a few weeks ago
 
Your on the money with the load discussed but remember they penetrate very well so you will kill a fox with a 308 hole in its heart but there is no expansion braining it would be better !

In my load I use large rifle primers but apart from that its the same as above

a lot of he scaremongering about subsonic loads was pre trail boss !

i don't know the range your thinking of but you will need to know the range to the target very accurately(the drop is shocking) , and in honesty I think subsonic 308 for fox is a 150m round max as a good sub load should group 2-3 inches at this range.

​Good luck
 
Muir suggested Trail boss for sub sonic loads I want to try out.
If you do find any please let me know because I have been searching the UK for some

As a by the way ,don't expect too much range from your round
I used some Swiss military 145g FMJ, factory produced 308 sub (just on 1100fps) and after 75ish metres the bullet started to run out of ooomph so serious hold over may well be needed
 
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9.5gr n320 with cci magnum rifle primer and Lapua 200gr fmjbt sub-sonic projectile. As has already been said, serious ricochet risk, no expansion and loopy. Also be VERY careful with your load as double loads can easily happen and are bad news for you and your rifle! This load is safe, accurate and sub-sonic in my rifle but the load was developed especially for it and it has polygonal twist rifling in an 18" barrel. It will do the job just fine and I have nutted a few Charlie's with mine.
 
4.9g of Viht N310 with a 115g cast boolit, either "soupcan" or roundnose and standard primer. We shoot these in both my 308s indoors at 25M.

With my 20" Howa 1500 I get a velocity of 978fps with a muzzle energy of 244ft/lb.

This is a well proven load used by most of my clubs members in Lee Enfields, Moisin Nagants and more modern 308s etc.
 
Lapua B416 200gr. A few grains of Trail Boss or similar. When I say a few, I mean work up from 6.

I have never been so cautious with any load but there are very good reasons.

On the other hand, I have merrily played with .303 Brit with a squib load of Tubal 3000 pushing a cast 125G bullet with reasonable accuracy and dead foxes.

Since I have no intention of moderating my ancient No1 Mk3 I only know its subsonic by the "lack of crack".
 
Use a round nose bullet over a spire point, they are more stable at subsonic velocities. Normal primers are fine and Trail Boss is probably the best choice give its density.

Instead of working the load up, you should work down. Do not initially test loads with your moderator on just in case the bulets tumble, not good for obvious reasons. You should find a subsonic load around 10 - 11 grains.

​However for vermin /fox be aware of the problems with the first cold shot, this is a problem in some standard factory rifles and subsonic loads.
 
Very solid advice from Jagged77.

I have experience only in Vihtavuori powders, N310 and N320 are good, start from 9 grains and work your way down. Chronograph recommended.

Please be aware that muzzle velocity could vary quite much. This is due to the low load density, even tipping the barrel up or down can have a drastic effect. I've never used filler (Dacron or similar) since I'm concerned whether it would build up in moderator.

Up to something like 50m, the muzzle velocity variation won't play a big role in accuracy. From there on the drop's quite bad (1MRAD/7.5cm at 75m and 2.5MRAD/25cm at 100m are good rulees of thumb for any projectile at around 300m/s) and muzzle velocity variation can ruin the accuracy. Also bullet flight time is significant.

I've had good results with H&N (H&N air gun pellets and bullets) plated bullets, very low muzzle velocity variation. Round nose isn't optimal for terminal ballistics so I cut the tip flat (can be done with a metal file but I use mill). If this is not possible due to legislation etc. you could try and find some flat tip bullets like 150gr manufactured for 30-30 (flat tip required for tubular magazine). Beware though, jacketed bullets may be quite erratic regarding muzzle velocity.

In 1-10" barrel twist any flat base (no boat tail) bullets up to 200gr should be fine, if you have 1-12" the 150gr would be safe bet and 180gr may be on the edge. Longer bullets (boat tail and hollow point) require faster twist to stabilize. For terminal ballistics every bullet you can find would be fine and the trajectory is virtually the same (no gain from heavier bullets). In fact you could use 7.65mm pistol bullets which would even expand at subsonic velocities, but the muzzle velocity tends to be very erratic in 308 sized case.
 
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