subsonic 450 bushmaster reloading data

[whitetail regulator]

i like it ...keep spinning... i did the switchblock gas block on sevral 300 blkout builds with great results very quiet like a bolt gun....however all the 45acp ar style carbines i have seen are direct blow back so no gas block to shut off....unless im missing one? i like the idea of 45acp easy to find cheap subsonic expanders...

 

[J E Custom]

There may be another option for sub sonic bullets. There is a bunch of cast bullets that are around 400 grains and In one of my sharps, (A 45 120) I use a 620 grain cast .458 bullet. But with a .452 bullet swage die, They could be swaged down or if you can find a bullet mold for .452 dia. bullet you can size them for yous sub sonic 450 Bushmaster loads.

A 600+ grain bullet should get pass through s on most game at sub sonic velocities. Lead bullets should not be a problem at these low velocities And the alloy could be adjusted for good performance.

Just another possibility.

J E CUSTOM

 

[Gord0]

The only problem with 45acp is penetration. A 230gr slug that expands double diameter and is only going 850ish fps isn't going to penetrate very far if it hits a shoulder bone. I like JE Custom's idea.

 

[LoneTraveler]

There is a kit sold by Rhineland that can be used on a 98 Mauser, That shoots 45 ACP shell with a pistol type magazine that holds about 8 rounds.
A friend got one of these conversion kits, I have talked to him about it, But I have never seen the finished project.
During World WWII some 45 ACP shell casing was made using US ARMY 30 rifle shell cases by cutting them off and reaming them for load with .452. Scrap brass was recycled.
About 1972-74 a gunsmith friend Chuck Wilcox, Who was a wild cat nut, Chambered a barrel and fit it to a Mauser rifle. The shell used a 30-06 base case cut to 1.250. He made a long expander rod and reamed the case for a .452 bullet. He used a 250 gr. 45 Long Colt cast bullet in it. If I remember right, He talked about using Hercules 2400, Herco and DuPont 4198 when he worked up the loads for it.

 

[whitetail regulator]

There may be another option for sub sonic bullets. There is a bunch of cast bullets that are around 400 grains and In one of my sharps, (A 45 120) I use a 620 grain cast .458 bullet. But with a .452 bullet swage die, They could be swaged down or if you can find a bullet mold for .452 dia. bullet you can size them for yous sub sonic 450 Bushmaster loads.

A 600+ grain bullet should get pass through s on most game at sub sonic velocities. Lead bullets should not be a problem at these low velocities And the alloy could be adjusted for good performance.

Just another possibility.

J E CUSTOM

ok i seen a .458 405gr jhp subsonic expander by outlaw state bullets. i heard they will swedge down to .452. i like this however im not shure how fast i can get it going with trail boss. im getting 990fps with 300gr xtp over 12 gr of trailboss gunna try 12.2-12.5gr and see if i can get up to 1050 fps avg...a 400 gr maybe way to slow...but there's plenty of room in the mag to seat bullets long...giving me more room in case for powder so i guess the only way to know is to try...lol unless someone else has tried 400 gr projectiles in 450bm over trail boss or maybe a different powder. anyone? lol...ps i really am trying to avoid case fillers

 

[whitetail regulator]

either way i still think the 300gr xtp regular is gunna be a subsonic jackhammer....im hoping for good expansion

 

[Bravo 4]

Just be careful of not getting enough velocity. You get a bullet stuck in the barrel and you will have a heck of a time getting it out!

 

[whitetail regulator]

but... i would like to try heavier if i can keep the 1000fps mark and get expansion

 

[J E Custom]

ok i seen a .458 405gr jhp subsonic expander by outlaw state bullets. i heard they will swedge down to .452. i like this however im not shure how fast i can get it going with trail boss. im getting 990fps with 300gr xtp over 12 gr of trailboss gunna try 12.2-12.5gr and see if i can get up to 1050 fps avg...a 400 gr maybe way to slow...but there's plenty of room in the mag to seat bullets long...giving me more room in case for powder so i guess the only way to know is to try...lol unless someone else has tried 400 gr projectiles in 450bm over trail boss or maybe a different powder. anyone? lol...ps i really am trying to avoid case fillers

You are wise to avoid fillers. I tried them on the 45/70 and the 45/110 using smokeless powder and found them erratic in both velocity and SDs.

I did lots of research on fillers and the consensus was that the filler had to much air space in it and this could change the burn rate. Even though it could be compressed, being fibrous It was contributing more oxygen to the powder effectively causing the powder to act more like a squib load.

I even went as far as weighting the filler, and still found that the same weight of filler material took up different amounts of space and measuring compression force found differences.

A long time commercial re loader advised me not to use fibrous fillers and to switch to compressed and treated (Normally wax) wads. This worked, but it was difficult to find wads the right thickness so I abandoned the whole process and found a powder that could fill the case and achieve the velocity and pressure i wanted.

I know that there are some people using fillers to fill cases, But my experiences with them was not to my liking. I never had any thing bad happen but the results were Questionable so I elected to be on the safe side.

Mike Venturino has written lots of information about the use of fillers and warnings. I will try to fine some of them and post them.

My only comment is to be careful if you do use fillers.

J E CUSTOM

 

[Bravo 4]

You are wise to avoid fillers. I tried them on the 45/70 and the 45/110 using smokeless powder and found them erratic in both velocity and SDs.

I did lots of research on fillers and the consensus was that the filler had to much air space in it and this could change the burn rate. Even though it could be compressed, being fibrous It was contributing more oxygen to the powder effectively causing the powder to act more like a squib load.

I even went as far as weighting the filler, and still found that the same weight of filler material took up different amounts of space and measuring compression force found differences.

A long time commercial re loader advised me not to use fibrous fillers and to switch to compressed and treated (Normally wax) wads. This worked, but it was difficult to find wads the right thickness so I abandoned the whole process and found a powder that could fill the case and achieve the velocity and pressure i wanted.

I know that there are some people using fillers to fill cases, But my experiences with them was not to my liking. I never had any thing bad happen but the results were Questionable so I elected to be on the safe side.

Mike Venturino has written lots of information about the use of fillers and warnings. I will try to fine some of them and post them.

My only comment is to be careful if you do use fillers.

J E CUSTOM

I guess everybody's experiences are different. I cannot get trailboss to shoot worth a flip and had big velocity swings from shot to shot. However lil'gun or RL-7 and a filler shrank groups a very large amount and made more consistent velocity.

 

[whitetail regulator]

ok...so i loaded a new batch of 450bm
hornady xtp 300gr regular
starline brass cut to 1.693
cci #400 small rifle primer
12.3 gr trailboss
no crimp
avg 1030fps
from ruger ranch rifle .
much closer sd and es than 12gr. not shure if that is a result of filling up the case better...
will try for accuracy soon hoping for good results...may try 12.4-12.5 if i don't like what i get

 

[whitetail regulator]

after firing the 12.3 load the case shrank .005 from 1.693 to 1.687...
i was concerned because spec is 1.7-1.69. after resizing the case it grew back to 1.693...so i guess were good to go ...i would like to get some 1.699-1.7 brass but everything ive seen is closer to 1.693

 

[whitetail regulator]

any body knows 450bm brass that is 1.70 or longer to start? or should i go the 284 win case route?

 

[Bravo 4]

ok...so i loaded a new batch of 450bm
hornady xtp 300gr regular
starline brass cut to 1.693
cci #400 small rifle primer
12.3 gr trailboss
no crimp
avg 1030fps
from ruger ranch rifle .
much closer sd and es than 12gr. not shure if that is a result of filling up the case better...
will try for accuracy soon hoping for good results...may try 12.4-12.5 if i don't like what i get

If you can keep the velocity consistent then you should be fine, depending on the temperatures you intend on shooting. As the temp gets lower the speed of sound gets slower. I usually try to keep velocity around 1,000 fps, because if you are pushing the velocity envelope all it takes is a slight increase in velocity or decrease in temp and it is no longer subsonic.
Also, with a push feed rifle the case length is important for one that headspaces on the case mouth. I go through this with my .510 based on a shortened ultra mag case and a Savage 112 action. If your empty cases will extract on their own then I wouldn't worry about it. If not then they may not go off due to the firing pin not make good enough contact with the primer.