Thread: 7x57 subsonic

Hi all
A work mate has had a couple of sub optimal scenarios with home kill cattle using .22rf
I have offered to help him with some subsonic rounds for his centrefire (7x57)

I have managed to get hold of just over 20 7mm 175gr projectiles, this will be plenty enough if I don’t have to do much load development. To that end has anyone got any good recipes for trail boss and 175gr projectiles in a 7mm barrel?
Thanks in advance.

I can't help with 7mm, but the load will vary a huge amount depending on the projectile, so you need help from someone using the same one.

In my 308, the 151gr cast bullet uses 8gr of Trailboss, while the 190gr Sub-X projectile needed 11gr. That's nearly 40% more powder! At the same 8gr load the Sub-X was 390fps slower than the cast bullet.

Yes at best there is about a 50% chance I will get it right first time, I have managed that with making subs for a couple of other calibers, but I would prefer to start in known territory here and not have to shell out for 100 projectiles which is the next step if first attempts aren’t successful.

Given that it’s trail boss I would also be interested to know any recipes people may have used for 175s in 7mm08
(Note I wouldn’t swap other powder data between calibers)

Yeah, data from other 7mm cartridges may work well, my 308 and 30-30 both use the same load of Trailboss despite quite different case capacities.

I hope you are using cast bullets because they will work best at that speed. 8 to 10 grains of unique or similar pistol powders would work. Before trailboss that was the standard recipie for cast bullets and it still works just fine.
Your not talking about a long range number here 25 yards max I guess so subsonic it will have plenty grunt but placement is still the key.

Robert has a 120 grn hp cast that looks very similar to the awesome 151s in .308 that so many fellas swear by...that would be my starting point and using trailboss IM GUESSING somewhere between 10-12grns.....because 6-9 seems to be right in smaller cases...std primers,not magmum. and just let mate know to be cautious of bullet bounce it he misses and hits likes of rocks/concrete.....one thing for sure if one does go wrong he in much better position to end it without issue by putting noisy load in and whacking one in neck...not ideal but hell of a lot safer than trying it with .22lr.

depends a lot on what shape the bullet is

it will likely be around 9 grains but i would work my way down from 11 at .5gr increments

if a bullet gets stuck from too low charge its a real pain

if the sides of the bullet are flat and have heaps of bearing surface it will take more powder to get it moving

I wouldnt bother building a load for 20 projectiles none will be left by the time load dev is done

I used ballistic tips for a long time at sub speed and they work great as skull crackers but they were pretty expensive for essentially FMJ performance as you could damn near reuse any bullets you recover

he will basically have to site his rifle in for these bullets otherwise the guess work will cause him even more issues as the differences in POI are huge

you dont have a 22mag or a 12ga to lend him those work well for people having problems
they both work great
as does my 300blk and a lot less noise

he probably already knows this but the skull is thickest in the center of the forehead in a line running vertically (tip of the nose to forehead) so if hes using something gutless like a 22lr you always shoot half an inch to the side of that line if you want to punch thru

ear to opposing eye to get the cross then a little bit to the side of that point

heres my last one and I apparently didn't follow my off to the side thing(not needed with a 190gr subx)
one to put it down and one to make sure it doesn't get up

Originally Posted by Bill999

depends a lot on what shape the bullet is

it will likely be around 9 grains but i would work my way down from 11 at .5gr increments

if a bullet gets stuck from too low charge its a real pain

if the sides of the bullet are flat and have heaps of bearing surface it will take more powder to get it moving

I wouldnt bother building a load for 20 projectiles none will be left by the time load dev is done

I used ballistic tips for a long time at sub speed and they work great as skull crackers but they were pretty expensive for essentially FMJ performance as you could damn near reuse any bullets you recover

Yep hoping to roll the dice on load dev and get double sixes first roll, if not then we get some more projectiles and do it the traditional way.

These are for the annual homekill of a tame steer on a lifestyle block. The problem the last two years is that the cattle have somehow had an awareness of what is about to occur and gone from tame to gate wreckers as soon as a stranger with a rifle gets within half a kilometre of the property.
The load only needs to be accurate enough for 15m shot. If I get it right I just need three to prove stability and subsonic velocity and then three more to check POI with suppressor in place. That will leave enough for >a decade of homekill.

if you were going to just guess (which is always a great idea when creating explosives for use close to your face) id guess 9 gr trailboss maybe a little less if the first one went bang instead of woosh
I think 6 grain got a bullet stuck in my 45BM

i did notice the 165gr noslers took more to push than the lubed lead cast 151gr bullets

you could just make one at a time and walk outside to pull the trigger
it is exactly how I got a bullet stuck as 45cal never gets quiet like the smaller ones so i kept reducing the load till it was so quiet the bullet didnt even come out

I do it with a chroni now (went and got one because of the previous fuck up)

Originally Posted by longshot

Yep hoping to roll the dice on load dev and get double sixes first roll, if not then we get some more projectiles and do it the traditional way.

These are for the annual homekill of a tame steer on a lifestyle block. The problem the last two years is that the cattle have somehow had an awareness of what is about to occur and gone from tame to gate wreckers as soon as a stranger with a rifle gets within half a kilometre of the property.
The load only needs to be accurate enough for 15m shot. If I get it right I just need three to prove stability and subsonic velocity and then three more to check POI with suppressor in place. That will leave enough for >a decade of homekill.

if the week before you kill you get a sack of cow food and feed them at the same time every day that problem will dissopear
I read on here taking an apple each time you visit does the same
mine come to the call but thats because they are more pet than stock

you cant shoot any further with the 7x57 sub than you could with the 22lr it just breaks the forehead better
15m is perfect, 30 max sort of thing

seriously recomend you hit Robert up for some of his cast pills.... they SHOULD be slightly safer as less likely to exit and will do some expansion at subsonic speeds....speaking of which,if you go just above subsonic,eg case semi full of TB,same volume,or bit less than your normal supersonic loading,, they will expand quite a lot and the energy will be a lot higher and give you slightly more margin for error...the noise through suppressor will still be similar to 22lr if not slightly less.

Check out the ADI handloaders guide. I'm not sure if they suggest a load for Trailboss in 7-08 but I like my 7-08.

Another thought, old timers used to use a .310 cadet or .310 rounds in a Humane Cattle Killer assembly.

I destroyed a few yarded cattle with a .38special round from a .357mag lever action for work.
Worked a treat.

Originally Posted by Micky Duck

seriously recomend you hit Robert up for some of his cast pills.... they SHOULD be slightly safer as less likely to exit and will do some expansion at subsonic speeds....speaking of which,if you go just above subsonic,eg case semi full of TB,same volume,or bit less than your normal supersonic loading,, they will expand quite a lot and the energy will be a lot higher and give you slightly more margin for error...the noise through suppressor will still be similar to 22lr if not slightly less.

That is a good idea
even if just to save spending north of 80 dollars on a 100 count packet of projectiles of which maybe 30 get used.
Robert will probably have some TB recipes too which is what the original hope of this thread was for.