Suppressors Do I really need to use an 18" rather than 24" barrel with a .308 suppressor?

[Psychopathetic]

So I have decided that I am going to bite the bullet and get a Kel-Tec RFB .308 after years of drooling over them. The only problem that I have is which barrel length to get, 18" or 24". I plan on using a Yankee Hill Machine .308 stainless can and I would really like the ability to have the range of more than 500m that the 24" would give. I have heard from many places that it is better to have a shorter barrel when running a suppressor due to fowling. The RFB uses a short stroke adjustable gas system. The 18" rifles are harder to come by since all of them leaving the factory are currently 24" but both are still around if you look hard enough.

How big of a deal would it be to run a 24" rather than an 18"?

Should I use a stainless or titanium suppressor with the longer barrel length?

Thanks.

 

[msflyer]

Read this post. http://www.snipershide.com/shooting/showthread.php?t=4716&highlight=barrel+1000
There is a video here http://www.youtube.com/watch?v=15qj032UJ1I
of him shooting his "short barrel" to a thousand.

 

[msflyer]

I have a 24" GAP Hospitaller and with a suppressor mounted and it's a handful to maneuver around quickly. I like it and it shoots 1000 yds well, but it is a long rifle with a suppressor attached.
On this site, search is your friend. Some members will frag you a bit for not searching answers out yourself. YMMV

 

[Chanonry]

How big of a deal would it be to run a 24" rather than an 18"?



Thanks.

None.

If you use a reflex type then you are adding 4 " max. The short barrel stuff is very trendy and the video of lowlight shooting out to 1000 is oft shown as 'proving' that 18" is "all you need".

I don't think that was ever the point. It is possible to shoot long ranges with an 18" barrel and normal ammo. However if anyone wants to make the argument that an 18" barrel is as good as a 24" I think they are onto a loser as 6" of barrel means quite a bit of velocity and higher velocity will always give better ballistic performance. Whether you need that is another question.

Personally I get the compact package story but would rather have a folding stock and a long barrel.

There is a thread on here listing what the top practical shooters are using in competition. It was very interesting on a number of points. No-one was using a short barrel, yet they seemed to be able to lug it around ok.

It is personal preference...

 

[Killswitch Engage]

[QUOTEPersonally I get the compact package story but would rather have a folding stock and a long barrel.][/QUOTE]

+1 same here

 

[Psychopathetic]

None.

If you use a reflex type then you are adding 4 " max. The short barrel stuff is very trendy and the video of lowlight shooting out to 1000 is oft shown as 'proving' that 18" is "all you need".

I don't think that was ever the point. It is possible to shoot long ranges with an 18" barrel and normal ammo. However if anyone wants to make the argument that an 18" barrel is as good as a 24" I think they are onto a loser as 6" of barrel means quite a bit of velocity and higher velocity will always give better ballistic performance. Whether you need that is another question.

Personally I get the compact package story but would rather have a folding stock and a long barrel.

There is a thread on here listing what the top practical shooters are using in competition. It was very interesting on a number of points. No-one was using a short barrel, yet they seemed to be able to lug it around ok.

It is personal preference...

Well as far as the weight and length go... The Kel-Tec RFB (http://www.keltecweapons.com/our-guns/rifles/rfb/) is 26" at 8.1 pounds for the 18" and 31" at 9.8 pounds for the 24" so neither one are going to be near the weight and length that conventional .308 rifles are going to run. The RFB gas system is adjustable so I guess it is possible that it can be "tuned" to run suppressed regardless of barrel length. I just wanted to hear if anyone else has experience with this before I chose which model to go with. I looked through this forum but was unable to find anything except for ballistic and accuracy related barrel length questions.

I knew that it was possible to get 1000yd range out of a 18" bolt gun, but how feasible is it to get that range out of an 18" suppressed semi-auto short-stroke gas gun?

How does a 24" barrel run compared to an 18" with regard to function rather than ballistically when suppressed?

 

[poison123]

The keltec if i'm not mistaken also is not a free floated barrel. Thats going to mean more to accuracy than a short or longer barrel.

 

[Arbiter]

The keltec if i'm not mistaken also is not a free floated barrel. Thats going to mean more to accuracy than a short or longer barrel.

Bingo. Plus, it's an autoloader using FAL magazines - also a big negative.

IMO, the overall length of the RFB with the 24" barrel and a suppressor probably isn't as bad as you think, simply because it's already a very short rifle (comparable in length to a folded AICS 2.0, for instance).

The real issue is that the RFB simply isn't a precision rifle platform. Can it be shot to MOA or better? Probably so, with the right handloads and lots of experimentation. Is it likely to do so out of the box, using factory ammo? Definitely a crapshoot when compared with an OBR or similar precision semi-auto. The barrel length and muzzle velocity factors are going to be far less important than the inherent accuracy potential of the platform. If you desire to plink at longer distances, then go for it. If you're expecting it to be able to run and gun against TRGs, GAPs, AIs, LaRues, etc in tactical matches, you're liable to be disappointed on the longer stages where inherent accuracy of the rifle system starts to really matter.

 

[KYS]

None.

If you use a reflex type then you are adding 4 " max. The short barrel stuff is very trendy and the video of lowlight shooting out to 1000 is oft shown as 'proving' that 18" is "all you need".

I don't think that was ever the point. It is possible to shoot long ranges with an 18" barrel and normal ammo. However if anyone wants to make the argument that an 18" barrel is as good as a 24" I think they are onto a loser as 6" of barrel means quite a bit of velocity and higher velocity will always give better ballistic performance. Whether you need that is another question.

Personally I get the compact package story but would rather have a folding stock and a long barrel.

There is a thread on here listing what the top practical shooters are using in competition. It was very interesting on a number of points. No-one was using a short barrel, yet they seemed to be able to lug it around ok.

It is personal preference...

That's not true of all manufacturers. I would not be trying to lump all the suppressors into one group especially when you don't have access to the ones we do.

 

[mike in pa]

Personally, if I was sending in my rifle that was 24" for threading, I would have them shorten it to 20".

 

[panzerr]

The shorter the barrel, the faster the round exits the muzzle. It follows that the less time a round has in the barrel the less time there is for the shooter (or in the case of a semi-auto the shooter and the action of the bolt) to deviate the round from the original point of aim when the trigger was squeezed.

This nonsense about longer barrels being more accurate is just that -nonsense.

The only effect barrel length has is on velocity, if you adjust twist rate accordingly. What you need to determine is if the velocity of the round will have enough energy to make the desired effect on target at the desired range. And, of course, you want the round to remain supersonic at the desired maximal intended use range. Take all of this into account before making a choice.

 

[biffj]

You may find that as far as fowling is concerned you are better off with a shotgun. Birds are mighty tough to hit with a rifle. If you mean fouling than it really makes no difference anyway. The suppressor may cause a bit more fouling than the rifle normally has unsuppressed but this is mainly a concern in semi-autos (like the RFB) and even then its normally not a problem. The barrel length won't make much difference there. In reality the shorter barrel may be more accurate because its stiffer and won't flex as much. If you reload your own you can work up a load for shooting longer ranges. If you really want good long range accuracy suppressed you are probably better off with a bolt action. Most of the semi's are not built for pinpoint accuracy but rather for higher rates of fire. You just have to choose what makes you happy.

Frank

 

[fast freddy]

you may want to actually shoot a rfb suppressed before jumping in. i had the chance to play with one when they first came out and while neat as a suppressed weapon it sucked. shot fine just had to wash my face after i was done 5 shots was all i cared to put through it and even then the whole right side of my face was black.

 

[RRA_45]

I never had issues with blow back on mine. I just took the gas regulator off. It was loud as shit though. One shot and my ears started ringing pretty good if no ear protection was used.

 

[300WSM]

all comes down to size you want to have and amount of elevation windage you want to use. 16" will get it there but you'll use more dope than a 24" simple as that.

 

[tctlrld]

18" on a semi. Although since it's a bullpup you might be able to get away with a 24" without it getting too unbalanced.

 

[bdotley]

I would get the 24" and cut it back if I found it didn't work for me. My 308 is a 20" and I exclusively run suppressed and it makes for a well balanced package...

 

[Tevis]

I like velocity. The bullpup design makes it an easy choice get the long barrel with more velocity and with a can attached to will still have a rifle about the same size as the non-bullpup rifles without a suppressor.

People get jealous when you start talking about 2900 fps from 175 smks and it is all from barrel length. But that's a bolt gun also

 

[ggmanning]

I shoot the same can on a POF 16". 600 yds is not a problem and 800 is plenty doable with the short barrel. It dies quickly towards subsonic after that for me. I will say the shorter barrel in a small profile like that is going to be better than the long unless you change suppressors. The YHM SS Phantom is a cinder block and its a lot to hang on a sporter like profile.

 

[TXTransplant]

At 500-800 yards you are going to still be supersonic AT SEA LEVEL with most factory 175 gr match ammo out of an 18" barrel. If you are in Colorado at 5,000 feet, you are going to stay supersonic maybe to 1000 with that barrel length, again with something like FGMM.

If that's all your shooting, yeah dial in a tiny bit more elevation and there will be no difference. If you are trying to hit that 1,000 yard magic number, well, things change:

This is generalizing a bit, but to keep it simple, a rule of thumb is that to keep a 175 grain SMK from going transsonic at 1000 yards it has to start out going 2600 at sea level. That is what Federal Gold Medal Match 175 gr starts out at out of a 24" barrel. Again, at sea level, from a 24" barrel, that load is barely staying supersonic at 1000.

Note--again, if you are shooting at altitude, don't even worry about this shit. You can start the bullets out maybe 100fps slower and they will still say supersonic at 1,000.

But at sea level, an 18" or 20" barrel using your most common factory match ammo, FGMM 175 grain, is NOT going to keep the bullet supersonic at 1000. It will prob be supersonic out to 900 yards. Yeah the bullet will land and yeah you'll hit the target some but your hits will be noticeably less reliable than at say 900 yards.

Again, if you handload them hotter, this isn't a problem. And I've heard that the new Corbon 175 SMK load is running 2740 FPS out of a 24" (ie way hotter than FGMM) so if you are running that ammo, you should be fine at sea level out to 1000 with a 20". Maybe an 18".

This is based on my own experience running my 20" bbl shorty at 1,000 vs my 26" bbl rifle (both 308) at 1000. Hits with the shorty at 1,000 yards are noticeably less consistent than they are at 900 yards. You can tell the bullet is starting to act goofy. Whereas the 26" bbl stay consistent to and past 1,000. Again, this is at sea level.

Hope that makes sense. Maybe you already knew it.

 

[fnbrowning]

The shorter the barrel, the faster the round exits the muzzle. It follows that the less time a round has in the barrel the less time there is for the shooter (or in the case of a semi-auto the shooter and the action of the bolt) to deviate the round from the original point of aim when the trigger was squeezed.

This nonsense about longer barrels being more accurate is just that -nonsense.

The only effect barrel length has is on velocity, if you adjust twist rate accordingly. What you need to determine is if the velocity of the round will have enough energy to make the desired effect on target at the desired range. And, of course, you want the round to remain supersonic at the desired maximal intended use range. Take all of this into account before making a choice.

With respect, if you're going to label something nonsense, it would be your first paragraph.
The laws of inertia guarantee that the faster, smaller mass has left the barrel, even a 30" barrel, before the inertia of the much more massive rifle has been overcome. You have to remember the projectile is only in the barrel for milliseconds. Any movement of the barrel; it was already in motion caused by the operator pulling his shot.

 

[fnbrowning]

At 500-800 yards you are going to still be supersonic AT SEA LEVEL with most factory 175 gr match ammo out of an 18" barrel. If you are in Colorado at 5,000 feet, you are going to stay supersonic maybe to 1000 with that barrel length, again with something like FGMM.

If that's all your shooting, yeah dial in a tiny bit more elevation and there will be no difference. If you are trying to hit that 1,000 yard magic number, well, things change:

This is generalizing a bit, but to keep it simple, a rule of thumb is that to keep a 175 grain SMK from going transsonic at 1000 yards it has to start out going 2600 at sea level. That is what Federal Gold Medal Match 175 gr starts out at out of a 24" barrel. Again, at sea level, from a 24" barrel, that load is barely staying supersonic at 1000.

Note--again, if you are shooting at altitude, don't even worry about this shit. You can start the bullets out maybe 100fps slower and they will still say supersonic at 1,000.

But at sea level, an 18" or 20" barrel using your most common factory match ammo, FGMM 175 grain, is NOT going to keep the bullet supersonic at 1000. It will prob be supersonic out to 900 yards. Yeah the bullet will land and yeah you'll hit the target some but your hits will be noticeably less reliable than at say 900 yards.

Again, if you handload them hotter, this isn't a problem. And I've heard that the new Corbon 175 SMK load is running 2740 FPS out of a 24" (ie way hotter than FGMM) so if you are running that ammo, you should be fine at sea level out to 1000 with a 20". Maybe an 18".

This is based on my own experience running my 20" bbl shorty at 1,000 vs my 26" bbl rifle (both 308) at 1000. Hits with the shorty at 1,000 yards are noticeably less consistent than they are at 900 yards. You can tell the bullet is starting to act goofy. Whereas the 26" bbl stay consistent to and past 1,000. Again, this is at sea level.

Hope that makes sense. Maybe you already knew it.

That's a good write.
The alert reader will notice that TXTransplant calls a "shorty" a 20-inch barrel. In my view, in .308, 20" is as shorty as I would ever go. I paid for the damn powder, and I want the damn velocity not a powder flare at the muzzle.

I think anything shorter than 20" belongs on a CQC 5.56mm assault rifle or MP5. The .308 belongs with the Squad Designated Marksman, and a 20" barrel.

 

[Charger442]

i always used the rule of thumb of two twists of the bullet before leaving the barrel to determine barrel length, with a 308, regardless of suppressor being used or not.

1-10" TWist - 20" tube
1-12" twist - 24" tube
1-11.25" twist - 22.5" tube

obviously, some people like shooting their 18" barrel 308s but, as was pointed out before, your going to lose something the further out you go.


for me, i shoot a 1-10 twist barrel, at 22" long with a TBAC 30BA brake and can. i could go to 20" but it honestly doesn't bother me at all. i can always take barrel length off, but I cant put it back on.

 

[pinkhair]

I used to use a 24" barrelled .308 with suppressor. As some others have said it can be rather long and front heavy with a suppressor attached, doesn't balance well. I'd go shorter for sure if i were you. I'm a fan of 18.5" now.