13.5in barrel .308?

[Creature]

I have a 20" bbl'd FNH PBR and a YHM 7.62 can but the rifle is not very handy in position shooting. I was thinking about chopping it to 13.5in and then having a my QD mounted permanently.

What kind of velocity should I expect with full house loads? My current load is 44grs var, 178gr Amax at 2600. Should I consider a different bullet? I would rather have a rifle/can I can hoof around for miles and shoot offhand than a rifle I only shoot prone. YHM had to come out with the Ti can a few months after i got my SS one.

 

[Longshot38]

Re: 13.5in barrel .308?

My suggestion is get a lighter suppressor. SBR have their place but it is not engaging target at distance.

 

[Creature]

Re: 13.5in barrel .308?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Longshot38</div><div class="ubbcode-body">My suggestion is get a lighter suppressor. SBR have their place but it is not engaging target at distance. </div></div>

Thats not gonna happen anytime soon. I don't expect to be shooting to 700yds with the thing. This is really just a spastic idea I had that would eleviate my problem. Just wanted to bounce the idea of others.

Should I not go under a certain length? If so, what? I'm sure someone around here has gathered data on this before. Barrel length to velocity ratio?

 

[Pusher591]

Re: 13.5in barrel .308?

Way too short IMHO.

I wouldn't go less then 16.5 on a bolt gun.

 

[Creature]

Re: 13.5in barrel .308?

I know Lowlight had done some work with a 16in bbl .308 bolt. I wonder what effective range a setup like that would have?

 

[gstaylorg]

Re: 13.5in barrel .308?

Not exactly the same as your proposed 13.5", but you might get some general idea from the MV values obtained using a POF .308 with 12.0" or 14.5" barrels:

http://www.pof-usa.net/technical/chronoresults.htm

 

[Graham]

Re: 13.5in barrel .308?

Have a look at Stacey's AE Covert Thread. I would be surprised if there was more than 14" of rifling on the Covert conversion barrel.

 

[tlg308]

Re: 13.5in barrel .308?

Ha go for it. My guess is that the powder wont even be burned all the way with the 13.5" barrel. I think for every inch you take off you loose 100 or 50 fps from where the origanal lenght was. What twist is your barrel?
Edit...

Disregard the fps's from above, I took this from the AI Covert thread that Stacey from mile high shooting said,

1. when you drop from a 24" bbl down to 20", average velocity loss runs about 10 fps per inch = 40 fps loss overall (average).

2. when you drop from a 24" bbl down to 16", average velocity loss runs about 15 fps per inch = 120 fps loss overall (average)

Hope this hepls!

 

[gstaylorg]

Re: 13.5in barrel .308?

You may be surprised to find you might not lose nearly that much MV. For a DTA SRS Covert with 22" and 16" barrels, the total loss in MV was between 50 and 100 fps, depending on the ammo, which was for 8" of barrel length difference (http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1597047&page=16; ~1/3 down the page). Of course, this was out of a bolt gun and YMMV with a different rifle/barrel.

 

[Lowlight]

Re: 13.5in barrel .308?

I have shot a 12.5" POF 308 out to distance.

It worked to 600 yards, after that it fell off, I don't recall the MV or the MOA necessary to reach 600 yards, but it worked fine. There was no issue with accuracy.

It really depends on the barrel. My 16" GAP AR10Type only needs 39MOA to 1000 yards at sea level with factory ammo. But it is a very fast tight bore Bartlien not a stock factory barrel, that is the main difference.

If you're gonna go short, do it with the right barrel, which means, as tight as they make and either Bartlien or I have found Rock Creeks to be very fast. Factory barrels cut back need not apply. (The POF was a Rock) I also have 14.5" POF rifles here that are effective but never left CO where our elevation gives me an advantage.

 

[pappy83]

Re: 13.5in barrel .308?

Factory Savage Precision Carbine, barrel cut down to 14.5 inch needs 4 mil to get to 600yds with 200yd zero with a 155smk loaded hot. Shoots well at 600yds.

 

[bm11]

Re: 13.5in barrel .308?

I think a suppressed 13.5 inch 308 bolt gun for 0-500 or 0-600 yards would be pretty sweet.

Or even better, buy a DTA Covert. 16" barrel but WAY shorter than your proposed 13.5 inch conventional build.

 

[Creature]

Re: 13.5in barrel .308?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bm11</div><div class="ubbcode-body">I think a suppressed 13.5 inch 308 bolt gun for 0-500 or 0-600 yards would be pretty sweet.

Or even better, buy a DTA Covert. 16" barrel but WAY shorter than your proposed 13.5 inch conventional build. </div></div>

I've been coveting the covert for some time now. Unfortunately I'm at a place where I must make due with what I have. The wheels are turning guys, thank a bunch for the ideas.

 

[jp0319]

Re: 13.5in barrel .308?

I was actually just contemplating doing something like this today. Having a Rem 700 SPS cut down to 14.5" and a sure fire break pinned to legal lenth at 16". Mounted in a an AI folding stock. That would be really portable.

JP

 

[Creature]

Re: 13.5in barrel .308?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jp0319</div><div class="ubbcode-body">I was actually just contemplating doing something like this today. Having a Rem 700 SPS cut down to 14.5" and a sure fire break pinned to legal lenth at 16". Mounted in a an AI folding stock. That would be really portable.

JP </div></div>

Mine is a FNH PBR in a McM A3. I've got probably 4000rds through this barrel and figured I could try this new setup for another few thousand if it works. If not I'll just spin it off and try something else.

 

[jp0319]

Re: 13.5in barrel .308?

Mines going to be new but its a $600 SPS so if it doesn't work out the way I am planning I'll put another barrel on too. I just think a short compact precision type rifle would be pretty cool out to 500 ish yds.

JP

 

[Creature]

Re: 13.5in barrel .308?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jp0319</div><div class="ubbcode-body">Mines going to be new but its a $600 SPS so if it doesn't work out the way I am planning I'll put another barrel on too. I just think a short compact precision type rifle would be pretty cool out to 500 ish yds.

JP </div></div>

I got one of the FNH PBR barreled actions from CDNN for $420 a few years ago. I got the McMillan A3 for $400.

I agree. 500yds is a long ways away to shoot something moving. This rifle will be something I can shoot standing, sitting, and kneeling while hunting.

 

[JD42]

Re: 13.5in barrel .308?

Post some pictures if you can. Thinking along the same lines myself.