This has been discussed somewhat mixed in with other discussions, but I wanted to read some input from those with experience or knowledge on this specific subject. Large caliber rifle sub-sonic suppressed.

For starters, naturally I would assume that the 45 ACP in a suppressed rifle would be the quietest, and quiter yet in a bolt rifle or single shot, because of the low velocity and so little powder being burned. Simi-auto 45 ACP rifle may be acceptable since it's a natural, and cans are more common for it.

The reason for sub-sonic is to attain max quietness. The reason for going with big bore (.452 or larger) is thump. Smaller calibers may be quieter, but can't produce enough energy with sub-sonic loads.

So, I wonder just how quiet those suppressed 458 Socom sub-sonic loads really are? That should give some indicator of what to expect from suppressed 458 WM.

KB

talk to these ppl about suppressing a RRA.458 socom.... http://www.eliteiron.net/

I tried calling them once, but couldn't get through. I'll try again.

The way they present sound suppression is part of why I'm confused. They make reference to reduction in sound, but they dont say what the sound in db was before reduction or the actual db suppressed. Seems intentional evasive to me.

Another thing is the suppressors shown seem to be all extended in front of the muzzel, making for a rather long unit. There are suppressors that go back over then barrel, making for a much more compact rifle.

KB

Well my subsonic 45-70 loads sound about like a 22 out of a 18.5" barrel, so with a suppressor and longer barrel probably *click*.

The size of the can you need is proportional to the powder in the charge.

To get the can size down, use a small case with a high peak pressure.

quote:

Originally posted by tnekkcc:
The size of the can you need is proportional to the powder in the charge.

To get the can size down, use a small case with a high peak pressure.

You mean like in the 223? Why bother?
30 Whisper - well ok - but still lacking in ft lbs. And another important factor is bullet design. Those .458, 400-405 gr bullets with the wide flat nose are soft and designed to expand at the low velocity.

Does the 45 ACP meet the criteria of small case - high peak pressure?

With the 458 Socom or 458 WM - it is what it is - and they would be chosen for what they can do in ft lbs - and the can would need to be designed to fit the need. Design the can to fit the rifle, rather than the rifle to fit the can. Bigger bore, bigger can would be expected. I suppose it would not have to be so big as to block the sights? It seems they are made for the 50 BMG, so it shouldn't be difficult to make one for a 458. I'm not talking about full blast loads anyway, but greatly reduced loads, perhaps using powder like Trail Boss or the old standby 4759. (I think that's the right #)

All sticking out front doesn't seem to be a given, except maybe only if the designer decides to not consider other options. I've seen some pictures, maybe Euro, of cans that go back over the barrel, with a little extension in front.

KB

quote:

Originally posted by Kabluewy:


Does the 45 ACP meet the criteria of small case - high peak pressure?

There is no absolute criterion, just proportionality.

A 45/70 case with 1 gr Bullseye and a 45 cal lead ball in the mouth of the case will be quiet like a pellet gun, as the barrel length is enough 'can' to lower the pressure of the gas to 1 atmosphere above ambient [the threshold of super sonic gas] before escapement.
That ball will bounce off wood.
If the ball is instead seated down into the case to compress the Bullseye, the same pellet gun sound will be made, but the bullet will penetrate an inch of wood.

Here is your homework problem:
Figure out what would happen if the bullet were seated half way down into the case. What sound is expected? What penetration is expected?

I am useing the 45 acp in an ar15 and a m98 bolt gun for this purpose the 230 gr ammo is allready subsonic and you can buy it at wallmart or 7-11 functions perfectly fron a 10 in bbl and can be supressed with commonly available commercial supressors. whats not to like. I never needed the 458 barnes 2.5 in and its 500 gr bullett even though I have one.

Bullseye powder scares me, so I'll never know from personal experience. I ain't brave enough to use that powder.

I want to be sure I didn't double charge. My reloading do & don't has evolved so that now I like to use loads that mostly fill the case, with the best loads slightly compressed or close to the base of the bullet when seated. I want to be able to look inside the charged cases, under the light, and see the level of the powder charge of each case, then seat the bullet.

Loading reduced velocity loads in a 458 WM may be different than normal full power loads, because the powder may not mostly fill the case, but using a bulky powder is really my only acceptable option. I get real nervous if it is possible to double charge a given load, and not have the case overflow. I will use such a published load only if it appears to be my only option to achieve the objective, but I'll also consider if the goal is really that important.

Another thing, a round ball penetrating a board doesn't mean much to me since I don't have a good reference point, except maybe to compare it to one pellet from buckshot.

The 405gr .458 bullet hitting the board at 100 yards, within an inch of my aiming point, figuring some drop, at 950-1000 fps, means a lot to me. We have lots of evidence of what the old cowboy 45-70 loads do.

KB

you probably already know this, however, the reason for subsonic rounds is to eliminate the sonic crack as a bullet travels through the air. The 45acp is a perfect round for suppressing. Back in 'Nam we used the m3a1 grease gun with a suppressor to very good use

Thanks Brian and Crusher. Using the 45 ACP would certainly simplify the matter.

When I started thinking about this, I set certain criteria as the basis for messing with this or not. One of the basics is that it will be sufficient at 100 yards, starting at subsonic velocity from the muzzel. I kept messing with the formula of what fp energy is left at 100 yds, and found that the .458 is barely adequate IMO. Sure, maybe something in 50 cal would be more energy, but the use of the flat nose bullets is an enhancement IMO. .458 WM is easier brass, cheaper bullets, and most importantly much easier action/rifle platform. Also there are lots of published load data for this cartridge, and it can easily be loaded for more power with or without the can, or just use factroy loads with the thread protector only.

For example: Starting at 1050 fps, .458 - 405gr = 818 fp at 100 yds, or slightly exceeding the energy of the 44 mag at the muzzel.

.452 - 260 gr = less than half the energy at 100 yds

IMO the 45 ACP's limit is less than 50 yds.

That's why I want to step it up a bit.

KB

I have had no problem killing pigs to 100 yds with a 45 acp rifle but they dont read balistic tables. nothing is simpler than 45acp I use plain lead bullets 230 gr. good luck. if you want a rifle to try out pm me or if you need some help getting this going it is a fun project 458 or 451 .

Thanks Crusher. Will do.

I know what you mean about the ballistics tables. I just use it as a reference point. I find abstracts of little use. However, one reference point I can relate to is what the 44 mag can do with close shots at deer and hogs. So it's easy for me to relate to the capability of the same energy from a similarly constructed bullet at 100 yards. I'm very confident the 44 mag is a good hunting cartridge.

A good example of the limits of the tables, compared to actual reference point in personal experience or observation = the ft lbs of the 223 at 100 yds, full velocity, about equals the subsonic .458, but personally I would much rather hunt with the .458, having little confidence in the 223. Besides, the 223 is not subsonic to achieve that energy, and IMO bullet diameter makes a big difference.

KB

You can successfully engage 8"-12' targets at up to 100yds if you practice, at least soft skinned targets.

quote:

You can successfully engage 8"-12' targets at up to 100yds if you practice, at least soft skinned targets.

That was meant to say 8"-12" targets

Bryan,
I don't know what you mean successfully engage targets. I normally don't relate to military/police lingo. Apparantly you arent talking about hog hunting, and I don't know if you are referring to 45 ACP, 44 mag or just any firearm.

KB

quote:

Originally posted by jimatcat:
talk to these ppl about suppressing a RRA.458 socom.... http://www.eliteiron.net/

I called them. Very informative and helpful.

Thanks

quote:

Originally posted by Kabluewy:
...a suppressed rifle would be the quietest, and quiter yet in a bolt rifle or single shot, ...The only reason I can see for subsonic is to attain quietness to the max. The only reason I can see for going with big bore (.452 or larger) is thump. Smaller calibers may be quieter, but can't produce enough energy with sub-sonic loads. ...

Hey Kabluewy, A 44Spl/44Mag or 45LC in a H&R/NEF would be a relatively inexpensive way to get things going. A 300gr 0.429" Bullet in the 44Spl/44Mag would have a good bit of penetration and address the point tnekkcc brought up about Case Volume. Don't know if they make a barrel in either cartridge though.

If it was a Contender Carbine, you can always get a barrel from TC or from a Custom shop.

But if I was serious about it, I might go with a Bolt Action Ruger 77/44(or whatever the description is) and either download the 44Mag Cases to what I wanted while Seating the 300gr Bullet deeper. And/or try a 44Spl Case in it and see if it would feed. If it didn't feed, it could always be used as a Single Shot.

The Rimed Case of the 4Spl/44Mag or 45LC makes a project like this much easier in my mind than a Rimless. And I'd expect Hog Killing accuracy at 100yds sould be easy enough.

Of course, there is always "The Beast" if you like closer shots. It seems to make a good bit more noise than what you have in mind though. Notice the dogs reaction to the shot. And if you do go with The Beast, I'd also recommend a good Insurance Policy.

If I was to go with a single shot, I think it would be the Encore. I talked to a guy who had a short barrel in 50 Alaska - suppressed, for his Encore.

I had a NEF once, didn't like it. Extractor problems. Never again.

I had a Ruger bolt action rifle in 44 mag once. It took the prize as the most inaccurate rifle I ever shot. Never again. That thing was junk - no way a serious rifle, very bad design, no recoil lug, designed like the 22, springy/flexing action, no way to make it shoot accurately.

I have little use for pistol cartridges in rifles, although sometimes I still think about it, yet I always snap out of it, remembering the damn Ruger 44.

Your link was interesting, but it goes to an air rifle site.

Subsonic at the muzzel, the 458 has the energy left at 100 yards as the 44 mag at the muzzel, 1200 fps.

KB

quote:

Originally posted by Kabluewy:
...Your link was interesting, but it goes to an air rifle site. ...

Yes it does. Check the "movie" in the middle of the page. That fool is Hunting Hogs with a Pellet Rifle.

I had a Contender Carbine with one of the barrels in 44Mag for a few years. Killed some nice Deer with it, but it wasn't the most accurate rifle either. Did fine inside the woods/swamps at short range.

Never tried a Reduced Load in it.

I can understand why you do not want to go with the others as I see you have had problems with them.

Best of luck to you on your project.

I have made some mistakes in the past and wasted money on experiments that I thought was a good idea at the time. At least I learned maybe a little from those mistakes. I have a few base line rules for myself now, that will hopefully minimize dissappointment. One rule for sure is to not do the same thing again expecting different results.

KB

how about an HR in 45 LC or 45/70? now, if it was offered in 480 ..

could get subsonic loads pretty easy, and if you decided to buy a can license/tax stamp, well, there it is

Jeffe,
I have had pistols for the 45 LC, and 480, and an Encore in 45-70, and really liked them all. The 45-70 was one of the short barreled versions, and I made the mistake of shooting some buffalo bore ammo in it without hearing protection. Wow - that was terrible. I have shot the Marlin lever gun in 45-70 lots of times and liked it too.

I really liked the Ruger in 480, and why I sold it beats me. Accurate too. I really liked the cartridge.

45 LC is a good plinker, and has little use to me for hunting.

Honestly, I don't like the HR break open rifle. It's a toy to me. Although it seems generally well made and is a good value, I had one that constantly gave me problems with extraction. I figured the extractor is the weak link with that gun. I just don't want to mess with another one. I have two Encore frames and three barrels, and once I got past the initial break in and adjustments I have had no problems it them. I really like shooting the Encore. I have one barrel that I like especially in 9.3x74R. It's a dandy, and I like it much much more than the 45-70 barrel, which I sold.

On a suppressed rifle, I just don't want to deal with a single shot, and especially a break-open single shot. Maybe a falling block. But if I don't use a bolt action, then simi-auto for sure.

So, Saturday I sent the Ruger 77 MK II 338 WM barreled action to my gunsmith. He said it arrived today. For an unknown reason, that 338 isn't accurate. Oh well - good donar action for the 458. He has the PacNor .458 barrel there that I used on the 450 Marlin experiment, which just would not feed properly. He says he can set it back a little and ream it out to .458 WM, no problem. So, I should be able to work up some good subsonic loads before winter sets in here. If I draw a moose tag, I can use it with some stiff loads pushing 400 gr Swifts.

I called the company recommended for suppressors, and had a good chat with the knowledgable fellow there. He says that they are developing a new style suppressor, which protrudes less out front, and goes back over the barrel, reducing the overall length of the assembly. Anyway, he quoted me a price, and said that he could do the job. He said that subsonic loads in the rifle would be very quiet, less that that of a 22 short. That's amazing to me - if it can really happen.

He recommended a 17" barrel, but I'm waiting until later to have it cut that short. I'll leave it at 20" for now, and test loads. Once I'm satisfied with accuracy, and all other aspects of the rifle, then I'll consider going forward with the suppressor. He said that if the bullets cut round holes at 25 yards, they are stable. That's Ok, but they better cut round holes at 100 yards too, in an inch or less group to make me happy. He didn't have a problem with the 20" twist and 400 gr bullets. Said it ought to work well.

So, the debate is over, I'm committed to the 458 WM - up to the point of testing it to see if I want to go on with it. If not, well certainly it will function as a 458 should - well more like a slick feeding bolt action 45-70, and I'll enjoy it anyway, and I can use light or hot loads, or even full blast factory loads if I really want to.

My intentions with the suppressor is to use only subsonic loads, and only jacketed soft flat nose bullets like the Speer or Remington. That's all I need for the hunting situation I'll use it for. It will have a cap or thread protector, so if I take it moose hunting, it will be without the suppressor. So what if it's only 17" or 18" of barrel. 400 gr Swift at 2000 fps = good moose or bear thumper.

KB

hell if you want a slick feeding 45-70 bolt gun send me $2500 and you got it.

You have one? Fact is that I've inspected several, especially on the Siamese Mauser, and I have yet to see one that fed anywhere close to worth a sheet. Frankly I don't believe one exists that feeds properly. If one does exist, $2500 is about what I figure it would take to get it right.

Fact is, I don't want a 45-70 bolt action rifle. Another fact is that the Ruger cost about $450 for the original used Stainless 338 mag, sell the stock for ($75), 458 stainless barrel installed $400, sell 338 barrel ($75), trigger tweaking $50, Hogue stock full aluminum block $200. So, I'll have about $950 in it, not counting the scope or the suppressor, or shipping to gunsmith, or reloading stuff.

If available from factory, I would buy one ready made, but it is fun to put one together.

KB

Hey KB, If a guy had a small Lathe, some Brass bar stock and a bit of time on his hands, he might be able to make some special Cases for the 458Win that would help with the Down Loads. 458Win on the outside, small diameter hole down close to the Primer and then a normal size opening at the Case Mouth. The "thin" Case Mouth area would be a bit tedious, but the rest would go real quick.

There used to be a company that made Chamber Inserts for shooting various revolver cartridges in rifles, but I do not know if they made anything that would work in a 458Win. Don't remember their name either, but they had a web site at one time.

That sure is a lot of Case Volume to Down Load below 1050fps in the 458Win Case. What do you plan to use in it?

Seems to me downloading the 458 is no big deal. Practically every manual I look in has suitable reduced loads. Some cast bullet loads, and some jacketed loads. Hogdon shows cast bullet loads using Trail Boss. Speer shows SR 4759.

I remember using light loads in the last 458 I had, and enjoyed it.

I think SR 4759 and Speer 400gr bullets is the combo I'll start with.

There are many factors involved in something like this, none of which can be ignored or the project will be dissappointing. From many sources, I find that the 458 downloads well.

Having to make special cases on a lathe would definately defeat one of the critical factors of this project, namely cheap and easily available componants. Other critical factors are published load data. Wildcat is not acceptable. It has to feed perfectly from the right platform/action. I like the Ruger action because no modifications are required. The 458 was chosen because it produces the sub-sonic energy at 100 yds needed. Of course the 45-70 or 450 Marlin would too, but they don't mate up with the receiver for proper feeding. Finding the right cartridge is only part of the equasion. There are numerous cartridges that would basically duplicate what I intend to do with the 458 WM, but it all has to work together. The cartridge alone doesn't make the deal.

KB