I am looking at putting a 16" barrel on my Savage 10. McGowen makes 44 mag barrels for the Savage ready to install; I have the tools. The question is, which twist rate is best for subsonic bullets 310 to 360 grains; the 1-10 or the 1-18? http://www.mcgowenbarrel.com/

The silencer will be made on an ATF form 1 and run most of the length of the barrel about about 8 inches past the muzzle. Thanks.

Ranb

Ownership of supressors is legal in 34 states. They are not banned. Of course I have no idea who or what a montdoug is. I would guess 1-18 is probably more than sufficient. However all things being equal I'd probably go with the 1-10 just because. When I wear out the barrel on my Browning 1885 in 454, I'll get a McGowan barrel with 1-16 twist. That should stabilize those 400 grainers I've been drooling over...

Andy B

When ever in doubt go with the faster twist. This goes double for subsonic loads.

Terry

The only reason I hesitate to go with the 1-10 twist is that I am afraid that it might be too tight and damage the bullet. I am no stranger to subsonics as I load the 300/338/510 whispers.

Drewhenrynt, you were referring to my signature, I guess I should have bolded it.

mountdoug is a person in this thread, http://forums.accuratereloadin...141055701#3141055701 . Mountdoug was ranting against silencer ownership. He also claimed they were illegal and got upset when told they were not. I live in WA, one of the 38 states that allow unlicensed civilians to own silencers. Unfortunately use is banned here and I can only enjoy my silencers when in a more gun friendly state.

Ranb

Shoot cast bullets!


Andy

I plan to as the jacketed ones are rather expensive. I think cast bullets are more prone to be damaged by excessive twist right? Or do I not know what I am talking about?

I have a Lee mold that casts a .430 310 grain gas check bullet. I am also looking at two NEI molds. It will be either the 350 or 362 grain molds listed in the .429 section here, http://www.neihandtools.com/catalog/index.html

The silencer will be made with threaded end caps so I can clean the gunk out of it occasionally.

Ranb

I'm certain that either McGowen or whomever you hire to build your silencer can advise you on the best twist rate for this application.

OTOH, look at it with the silencer removed from the equation: what you'll have is a carbine length barrel lobbing heavy, large caliber bullets at a low velocity. Now then, what twist rate makes sense for this application?

I know the silencer part of the OP is not required. I included it just in case someone was going to ask why I wanted a certain twist rate for 350 grain subsonic 44 bullets.

I'm sure McGowen be helpful, but other opinions would be useful too. Thanks.

Ranb

I have a suppressed .44 Magnum Rossi Pomba - barrel is 20" with locally made over-barrel screw-on suppressor.

I use Hornady 240 grain XTP projectiles , at about 1000 fps. One shot kills on fallow deer are the norm , usually more noise is heard from the projectile connecting with the target than comes from the barrel.

Dont know the rifling twist - its whatever Rossi use as standard. Suppressors are entirely legal on long arms here in New Zealand

Any help ? Best of luck on your project

I understand your delema. I have long thought of a 458 WM project using subsonic 400-405 gr bullets, suppressed. Cast or jacketed.

The experiment has more or less been settled by circumstance, since I have a .458 barrel with 20" twist. So, I'm gonna try that - first without a suppressor. Load development. If it works well, then I'll take it to the next level, and think about a suppressor.

On your project, I think the 18" twist ought to be good. I would avoid the 10" twist. I have never understood the thought of default to fastest twist.

Good luck on your project. I want the read more on this subject.
KB

The reason you go with a fast twist barrel is slower bullets need more rotation to stabilze. Your risk of a baffle strike greatly increases with a slower twist barrel. He is only going to be pushing the bullets 1000-1300fps. They will hold up fine in a 1-in-10" twist barrel and the extra RPM's will only help.

The only possible problem he might encounter is bullet disintegration which I seriously doubt will happen. If it does, it usually happens down range and causes no damage to the rifle or suppressor. The problem is easily fixed with a heavier or tougher bullet. Like I said before though, these bullets are only going 1000-1300fps. I doubt it's going to be a problem.

On the other hand a slow twist barrel with only aid in shooting lighter bullets faster. This is absolutely of no benefit in this particular application.

It only takes one baffle strike to ruin a good set of plans not to mention the suppessor!

Terry

When loaded with 4 grs of Bullseye, my .458 shoots 500 gr cast bullets at about 600 fps into one hole, bb gun noise. 22" barrel. At subsonic speeds, I do't think you are going to have any problems with cast bullets.

I'm not saying you're wrong because it's your gun, but it certainly is surprising to me that you can get 4 gr of Bullseye to push a 500 gr bullet out of a 22 inch barrel at 600fps. 2 gr bullseye in a .38 special with 158gr WC will get you 750fps or so out of a 6 inch barrel, and that case has probably 15% or less (this is a guess without looking it up) of the volume of a .458 win which means you get higher pressures. So you're doubling the charge, and tripling the bullet wt and having a longer barrel which has to slow it down using Bullseye and getting nearly the same velocity.......like I said, seems odd to me.

I had not planned on using bullseye, or any of the low volume pistol powder.

As I remember, there are some suitable loads using a powder I think named Trail Boss, which I think is a high volume fast powder.

Terry,
I had no idea that a twist rate as fast as 10" was made for the .429. I was thinking the fastest twist available is 16" twist. Who makes 10" twist .429 barrels? Well, I looked at McGowen and answered my own question. I still think it's odd and question why?

As I remember, 1 in 38" twist is considered slow for the 44 mag, 1 in 16" is fast.

KB

Because the the bullets are flying slower and the extra RPM's help stablize them.

It's pretty much the same with .22LR subsonic barrels. The normal twist for a .22LR is 1-in-16" but if you're setting up for subsonics the ideal twist is 1-in-9".

More stabile = Mo' better when using suppressor's.

Terry

the ruger 77/44 has a 1/14" bbl, which is probaly set for 240 grain bullets, i'd go to the 10"

oh yeah and i'd think twice about cast bullets. supressors need to be cleaned and with all those baffles inside that isn't necessarily a nice job. i'd hate to think about cleaning the lead out of one

I shoot lead through my 300/338/510 whispers, 458 socom, 9mm and 22lr silencers. All of them are take apart and the gunk wipes off easy. I do not clean all the way down to the metal though, just wipe it all with a cloth or scrub pad.

I do not shoot cast bullets through my welded 5.56 and 308 silencers though.

Ranb

Edited to add; I contacted McGowen for their recommendation on twist rate. Thanks for the advice guys.

Edited to add; McGowen recommended a 1-10 twist.

This post helped me decide to go ahead with the 458 project. Since I already have a barrel, I think I'll try it to see how well it works out. It's a PacNor 20" twist rate .458 barrel.

The reason I am still comfortable with continuing with it, rather than just getting a faster twist barrel is bacause I looked at some of the velocities of the cowboy action 45-70 loads, and other low pressure SAAMI loads, and the velocity ranges from 1100 -1300 fps. As I recall the twist for the 45-70 is 1 in 20".

I don't know - maybe it would be better with a faster twist, but I'll use what I have first. Should be pretty evident whether it works or not when I test it without a suppressor. Worked for the 45-70 all thest years, so I can't figure why it wouldn't work now.

KB

Well, nobody ever said you couldn't. The question was which is best and the answer was given. Best of luck with your project.

Terry

Terry,
I wasn't arguing whether I could or couldn't, and I remember the discussion wasn't about my project.

I was just giving info relative to the discussion on twist rate. It just doesn't add up somehow - especially using a formula like greenhill. The original twist rate for the 44 was 1 in 38". Except for McGowen as far as I know the fastest offered is Douglas 1/14" - PacNor 1/18", Shilen 1/16", Kreiger 1/20". Now suddenly the absolute best is 1/10" for a pistol cartridge. I don't think so.

Similar logic seems applicable to the 45/70 & 458. Why would a 1/20" twist be so suitable for such a long time in 45-70, and not suitable for the 458 shooting the same bullet at approximately the same velocity?

Does sub-sonic make a difference?

KB

I've answered the question times already.

You win.

Terry

You're way too easy Terry.

Looking at the McGowen site, listing of barrels and twists:
41 caliber 1-14" twist for heavy bullets
44-40 1-24" twist for cast bullets
45-70 1-18" twist for heavy bullets

I'm saying that 1-10" twist in .429 is an anomaly that I haven't heard a sufficient an logical explanation for, other than default to the fastest twist available, which is something I hear often, and it annoys me.

Best regards,
KB

I explained it in detail in my 2nd post on this thread. You obviously didn't read or comprehend it. Still annoyed?

Do you have any suppressors now? Do you know what a baffle strike is and that it can turn an extremely expensive toy into nothing more than a paper weight with a tax stamp? It can and does happen. Fast twist barrels help eliminate this problem.

Do what you want. If you want slow twist barrel, use one.

Terry

I have a suppressed AR-15 in 458 socom. I have not had a baffle strike, yet. I have not shot the larger 535 cast bullets through the can because I have stability issues that I do not want causing any problems in the silencer. The twist is 1-14 on the 458, I wish it was a bit faster.

I am going with the 1-10 for the 44 mag rifle project. It seems to be the safest way as long as I am paying a $200 tax on each silencer that only costs me about $40 to make.

Ranb

quote:

Originally posted by TC1:
I explained it in detail in my 2nd post on this thread. You obviously didn't read or comprehend it. Still annoyed?

Do you have any suppressors now? Do you know what a baffle strike is and that it can turn an extremely expensive toy into nothing more than a paper weight with a tax stamp? It can and does happen. Fast twist barrels help eliminate this problem.

Do what you want. If you want slow twist barrel, use one.

Terry

OK, who is annoyed now? I'm not only stating my point, but I'm trying to learn something, so obviously I'm far more interested in listening than arguing.

No, I do not have suppressors now, but I want to. No, I do not know what a baffle strike is, and from what I can imagine I do not want to find out the hard way.

I can only assume what would be the cause of a baffle strike. I figure you are saying a bullet that leaves the muzzel unstable and has wobbel, due to insufficient rotation. I also figure that if the bullet is unstable at the muzzel, it is unstable at all ranges, and will key hole on target.

Before, I go on with this DISCUSSION, I want to see if we are on the same page.

Please continue if you don't mind.

KB

Yes KB, you are correct.

The main cause of baffle strikes is ocillatting (not tumbling) bullets. Even if a bullet flies true there is no gauranty (sp?) it won't ocillate when it leaves the barrel but a faster twist barrel helps eliminate it. There is only a few thousanths between the baffle and the bullet, we want it flying as true as possible.

Look at like this. Like me you'll be buying not building your can. By the time you've bought the can and payed all the taxes you're gonna be out around $850-$950. Why not do everything possible to ensure a safe, trouble free experience with your new toy?

Sorry about being so gruff. I just felt like I was repeating myself too much.


Terry

Thanks Terry. Sorry about wording in such a way that seemed argumentative. Sometimes choices of words isn't that easy in an electronic media.

Since I'm very inclined to use the barrel I have, for reasons stated, are there ways of gaining assurance that stability is good to go before attaching the suppressor, without just selling the barrel and going with a faster twist to start with?

Here's what I was thinking: I would go ahead and have the barrel installed properly on the action. Then get busy shooting it a lot, especially with load development to get the subsonic load of choice. When satisfied with accuracy, then send it off for the threading and installation of the suppressor.

As I remember, the only experience I've ever had with subsonic loads was actually with a 44 mag rifle, many years ago. It was one of the Remington 788s, which was offered initially in 44 mag and 30-30. I realy liked the rifle, and I have no idea why I got rid of it. Also as I remember, it had a very slow twist rate - I think it was 1 in 38". I shot lots of different loads through it, but that was before the days of bullets heavier than 240 gr in common use.

One of my favorite loads was 240 gr cast - gas check bullets at about 900 fps. Very mild and very accurate. I mean almost one hole groups at 50-75 yards.

So that experience caused me to believe the bullet was stablized. That's because I've also been of the impression that unstablized bullets for lack of spin will also be inaccurate first, and actually key-hole if bad enough.

So, that's the background. But for now the issue is avoiding baffel strike. I suppose to boil it down, do you think that if I get great accuracy with a 400 gr .458 bullet, is that a pretty good indicator that the bullet is not wobbeling or ocillating?

KB

Well, since you are dead set on using that barrel start out with a light for caliber bullet. If it was mine I would resale it and move on. If it's still new you'll be able to get most if not all of your money back and then you can start out with a more versitile setup.

Some other advice, get the barrel threaded when you get it installed. This will save time and maybe a little money. No need to send it back latter. Even if you never buy a suppressor you won't be out that much money and a threaded barrel is always a good selling point if you decide to get rid of it.

Now here's one way out in left field. Have thought about starting out with a different can to see if this is even for you? They really aren't that useful for hunting. I mean I can come up with 10 reasons to own one but it honestly won't help me harvest game. Face it this is a toy, nothing amatter with that but it is what it is. That said I have more fun with my .22LR can than any I've owned or shot. It's the quitest and the cheapest to shoot, hence the most fun. I would start out with a rimfire can first and see it it was something I thought was worth the investment.

Terry

Threading the muzzel already could be a good idea. I don't know if the suppressor threads are all the same or not, and I'll have to get a thread protector cap. I doubt the gunsmith I am working with on the 458 knows much about suppressors, but he might. I've never discussed it with him.

Besides, the suppressor is merely a thought now, and I surely could change my mind about it. But I can still use the 458 and have fun with it, using all range of loads.

I never thought of the suppressor as a toy, but now that I think about it, I suppose all my guns are toys.

As a side note, as I remember the 22 LR has a 1/16" twist, and low velocity.

I'm wondering, since you mentioned it, have you ever had baffel strike?

KB

I just had my .22lr can rebuilt. I went from a cone and spacer system to a monolithic baffle system. Dave said you could see a few contact spots but nothing serious.

On my other can (.223 Gemtech M4) I've never had any mishaps. All of the guns I run it on have a 1-in-7" or 1-in-8" twist barrels though.

Terry

I've had baffles strikes on my 22lr, 9mm and 510 whisper silencers. I neglected to check tightness on the pistol silencers after each mag and they drooped a bit. When the bullets started missing the target, I checked the end caps and saw a slight bulge. Hammering the end caps back into shape and checking the silencer secure each time eliminated the problems

The 510 whisper was worse. I decided to use cast bullets without gas checks to improve velocity without a higher powder charge. I checked velocity but nothing else. After several rounds failed to hit anything but dirt, the end cap and last two baffles had dings in them. Shooting at a target at 25 yards without the can on resulted in the bullets turning 90 degrees, making 2.5 inch long holes in the target. Using gas checks and sizing to .510 instead of .512 eliminated this problem as well.

Ranb

quote:

Suppressors are entirely legal on long arms here in New Zealand.

I wish they were here, as well. We can get them; it's just that you have to go through the crap to license one just as if it were a machine gun. At least the idiots who ended the sales of new manufacture full-autos to civilians back in 1986 didn't end the sales of suppressors, too...

quote:

Originally posted by ranb40:
I've had baffles strikes on my 22lr, 9mm and 510 whisper silencers. I neglected to check tightness on the pistol silencers after each mag and they drooped a bit. When the bullets started missing the target, I checked the end caps and saw a slight bulge. Hammering the end caps back into shape and checking the silencer secure each time eliminated the problems

The 510 whisper was worse. I decided to use cast bullets without gas checks to improve velocity without a higher powder charge. I checked velocity but nothing else. After several rounds failed to hit anything but dirt, the end cap and last two baffles had dings in them. Shooting at a target at 25 yards without the can on resulted in the bullets turning 90 degrees, making 2.5 inch long holes in the target. Using gas checks and sizing to .510 instead of .512 eliminated this problem as well.

Ranb

Seems that your baffel strike issues had nothing to do with insufficient twist rate. It's good to learn from your experiences, hopefully to avoid having to learn the hard way myself.

On my project I'm just going to avoid lead bullets and gas checks. I'll use jacketed soft nose bullets only, and make sure the can is screwed on tight. One thing I would be concerned with using cast or swaged lead bullets with or without gas checks would be some of the lubricant or a piece of the bullet striking a baffel, regardless of whether the bullet wobbeled or not. Easiest solution is to use jacketed bullets only with the suppressor.

Even though I have no experience with suppressors, I don't believe stability of the bullet will be an issue. I'll be thoroughly testing the handloads without the suppressor. The 45-70 has been shooting round holes with stable bullets through 20" twist barrels for over a century. Stable is stable, and faster twist ain't gonna make it more stable IMO except in the mind of some shooters.

If I planned on using bullets heavier than 405 gr, that might be different. For the set up I'm putting together, I see no need for heavier bullets.

The more I think about the 458 project, the better I like the idea. Hopefully I can start testing by August. I already ordered some Remington 405 gr .458 bullets, and some SR 4759 powder, and I have the rest of the componants, dies, etc. The gunsmith said he could get to it within two or three weeks. Promises - promises. I think I'll push him a little on this one, since I really want to try it out. If things go well, maybe I can get the suppressor before the end of the year, but I know that's optomistic thinking.

KB