Subsonic Loads 450 Bushmaster

[randyf]

I want to make some subsonic loads for my 450B. AR

What bullets and powders do you use ?

Also, do any of the loads cycle the bolt ?

[Texas Sheepdawg]

Seek out the cast lead posts. There’s some stuff in there. I’ve heard Trail Boss mentioned quite often for sub Sonics.

[rob cullen]

New Factory HDY SS Ammo
Hi all, good news, guns shops in west oz can now sell guns and ammo , went in today and got some stuff and they had the new 450 Bushy Factory Sub loads available - probably old news to you guys but i pulled one to see what was in it.
See pics attached
I weighed the slug at 395 grains and the powder at 16.8gr ( may have lost a couple of grains but very little ) I cant make out the powder and hoping you guys can enlighten me - it looks like a mix of 2 different ones, also the slug is massive in comparison to XTP 300 , interesting anyhow.
Cheers
Rob

[Hoot]

Looks like Lil Gun and models like it in QuickLoad. If you use 18gr. it predicts ~1065fps depending upon bullet length. BTW, how long is it?

Hoot

[rob cullen]

Thanks Hoot
I measured the bullet at 1.115'' and COAL at 2.215'' ( i did measure last night and got a slightly different measurement , probably operator but i triple checked this morning and measurements here are good)
We are very limited to powder choice here and difficult to get anything other than ADI 2205 ( IMR 4227, H4227 ) ADI 2207 ( IMR 4198, H4198 ) and trail boss for BM loads so i have never seen LIL gun.
My gun is a bolt so i have no idea if these would cycle in a semi ? I imagine they must do for a factory round.
Pretty sure it stated 1050 fps on cartridge box
cheers
Rob

[Al in Mi]

Wonder if they'll offer that bullet as a component??

[Hoot]

Thanks Hoot
I measured the bullet at 1.115'' and COAL at 2.215'' ( i did measure last night and got a slightly different measurement , probably operator but i triple checked this morning and measurements here are good)
We are very limited to powder choice here and difficult to get anything other than ADI 2205 ( IMR 4227, H4227 ) ADI 2207 ( IMR 4198, H4198 ) and trail boss for BM loads so i have never seen LIL gun.
My gun is a bolt so i have no idea if these would cycle in a semi ? I imagine they must do for a factory round.
Pretty sure it stated 1050 fps on cartridge box
cheers
Rob

Plugging in those two dimensions yields a predicted 1048fps @ 16.8gr of Lil Gun. Life mimics art!

Hoot

[rob cullen]

Wow
That pretty much nails it.
Hopefully that solves a few riddles for all the guys doing sub loads
Big question is - will they cycle reliably in semis i guess?
Would be good to hear any feedback from guys/girls that have used this round.
Cheers
Rob

[Hoot]

Taking a second look at the modeling result, the above load only shows a 49% case fill and as such gives me the "willies". I personally would never advise anybody loading up such a short load. Given the fact that it only yields in theory, a chamber pressure of 10.4k psi, may be a saving grace. All that having been said. The fact that the powder in the image looks like Lil Gun to my eye doesn't mean it is Lil Gun. I'm not a professional powder spotter, just someone who's used his share of Lil Gun over the past 10 years reloading for the 450b. Identifying a powder by its appearance is at best a weight or age guessing effort at a carnival. IE highly unscientific and consequently unreliable.

If they work, be happy and don't look under the hood.

Hoot

[rob cullen]

Thanks Hoot
Yea i ran it on Gordens reloading tool ( test version ) and i got about 56% load ratio with Vihtavuori N110 which is the closest i could find to lilgun , i think i got around 1150 fps ( theoretical )so still too fast for sub
I remember you telling me best not to mess with loads below 70% ( i think) so interesting.
Anyhow doing a bush job tomorrow and may have time for a couple shots on way home to test FTX200 hotloads so will pop a couple of subs as well and see what happens.
Cheers
Rob