Thread: 7mm08 or .243 Subsonic round

Hey all

Has anyone looked into or developed a subsonic round for 7mm08 (24"barrel) or .243 (18" barrel)?

Any starting points would be much appreciated

Cheers

Powder charge will vary a lot depending on the projectile, cast bullets needed 8 grains of Trailboss in my 308 but the sub-x bullets needed 11 grains.
The cast bullet loads were 7.5 grains in my other 308 and the 30-30, so 7.5-8 grains of Trailboss is probably a reasonable place to start in the other 08 cases with cast bullets

if you are using 150s in the 7mm 08 it will be really similar to what Cigar's saying as thats what it was in my 308 as well
243 might be a little less but it really depends on the pill you use

start above what you need with trailboss as stuck projectiles are a real drag to get out of your barrel

You wil probably have stability problems with 150 gr bullets in the 7mmo8 the standard 1:9.5" and 1:9" twists
mat not stabilise them the 120 grain is the best option,
Same with the .243 use the lighter varmint bullets the 1:10" is barely able to stabilise the 100 grain bulles.

I've run 140gr Sierra pro hunters in a 20" Tikka 7mm08 and they shot well. I rung steel out to 300m.
145 Speers wouldn't stabilize 130's would.
I'll have to check my load out when I get home, from memory it was less than 10 hrs Trailboss.
Just remember no expansion what so ever so no good for hunting.

Yep ran some of shooternz’s cast projectiles in my 7/08. Stability no issues. Shot a couple of goats with them, not the best killers. I think because the hollow point is not as big a diameter as the .308 ones. Think I’ve still got the recipe some where. They did kill possums well though. Also great training rounds for my daughter.

Yep ran some of shooternz’s cast projectiles in my 7/08. Stability no issues. Shot a couple of goats with them, not the best killers. I think because the hollow point is not as big a diameter as the .308 ones. Think I’ve still got the recipe some where. They did kill possums well though. Also great training rounds for my daughter.

Here is my thread on them.

https://www.nzhuntingandshooting.co....-report-39740/

Originally Posted by stug

Yep ran some of shooternz’s cast projectiles in my 7/08. Stability no issues. Shot a couple of goats with them, not the best killers. I think because the hollow point is not as big a diameter as the .308 ones. Think I’ve still got the recipe some where. They did kill possums well though. Also great training rounds for my daughter.

Here is my thread on them.

https://www.nzhuntingandshooting.co....-report-39740/

Does shooting cast projectiles require alot of extra barrel cleaning? i.e. is the cast lead soft enough to leave some behind in the bore??

why do you want sub sonic 243? the appeal of 243 is shooting 100gr super fast

said it before...and will end up saying it again.... subsonics suck if you miss your mark by even a tiny amount,they are however great fun for plinking,they are much more civilised for finishing off shots up close....and awesome for pests up close,for wallabies or goats in deer country,good solid chest shot will see them fall over soon enough,spinal colume and they will drop...you can get expansion with cast,and you can have best of both worlds by cranking them up JUST A LITTLE BIT and getting some meaningful expansion.a little more energy with very little more noise....

Originally Posted by gqhoon

Does shooting cast projectiles require alot of extra barrel cleaning? i.e. is the cast lead soft enough to leave some behind in the bore??

I think it is only an issue if shooting higher velocity lead. Subs don’t seem to be an issue.

The bigger the cal and weight, the better for subs. Since they don't have the velocity they rely on weight and cross sectional area for knockdown.

Originally Posted by Allizdog

The bigger the cal and weight, the better for subs. Since they don't have the velocity they rely on weight and cross sectional area for knockdown.

Thread drift but you are 100% correct, watch the bullet go all the way and then.........................................

that video you showed Mikee does show whats possible IF you want to spend the coin,on the very best in projectiles and spend the time and projectiles to work out trajectory 100% corectly .... but other than the lack of noise it does nothing a supersonic round cant do better with less fuss.

@Strider B my 7mm08 was 9.5grs Trailboss for 1052fps. You will need a bit less for your 24inch barrel.