Thoughts on Barrel length (suppressor)

[SO I HUNT]

I need help building a new rifle 6.5 PRC that will be suppressed..

the can is 8.6" long and I'd like to have range out 650 yards i was thinking 20" is that too short of a barrel? Also barrel twist (140 gr.)

Thanks,

 

[Jud96]

A 20" barreled 6.5 PRC should equal the velocity and ballistics of a 24-26" 6.5 Creedmoor. So expect 140s in the 2800FPS range. This is plenty to take deer sized game out to your 650 yard goal. A standard 1-8 twist will work well with your common cup n core bullets like Hornady, Berger, Sierra, and Nosler. A monolithic bullet like a Barnes or Hammer may require a 1-7 or 1-7.5 twist barrel if you decide to shoot them in the heaviest weights.

 

[SO I HUNT]

Thanks I'm feeling better about this build..

 

[elkaholic]

Thanks I'm feeling better about this build..

If you aren't stuck on the prc, the sst will likely run near 3000' at 2.90" coal

 

[YZ-80]

LRH has told me that shorter barrels are stiffer and better suited to suppressors than longer barrels. I think Jud96 has some good advice.

 

[338 dude]

I would look at the Sherman line of cartridges myself

 

[Deleted member 103481]

Chop it

 

[lancetkenyon]

I have a 20" 1:7.5" 6.5SS to run suppressed about ready to pick up. I plan on shooting the 144 Hyb, or possibly the 150 SMK. Hoping for 2900-2950ish.

I will also be running a can on a 22" 1:8" 6.5SLR. That rifle pushes a 130 to 2900.

 

[AaronSkipDavidson]

Thats the length I run on my 6.5 PRC build with Gunwerks 6ix suppressor. Its literally perfect! We've been pushing for a long time to change the mentality of long barrel. Its hard to let go....

 

[T3ninja]

I'm planning on having one built also. Pretty much same idea. My thoughts are to have a "switch barrel." I'm thinking a 1-7 running 18". This is just what is going through my head. I am still waiting on my can atm.

 

[corsair4360]

28" barrel plus can, 30" if you can find one

 

[JAYgs8163]

I went with a 22" Proof, light sendero, 1/7.5. Build is not done yet. I've used this same proof contour barrel on my 300 PRC running suppressed but at 26" Length and have great results.

 

[Bobcape]

Good choice on 20". You'll pick up a few FPS with the suppressor (not much) but the ease of handling will be so much nicer than a longer barrel and suppressor. I have a 25" and 21" .260AI cut with the same reamer at the same time. With RL23, H4831SC and IMR4451 the 21" gives up about 80 FPS. RL17 gives up a bit more, about 120 FPS.

Bob

 

[Ronald W Schaefer]

SIH, Jud96 said what i'd have said--good words.. A couple thougths, might consider a carbon wrapped barrel for stiffness (though 20" is gonna already be pretty solid) and I went with a 22" barrel in 7mm-08 just to get the ~80 fps more velocity since BC in .284 is not what it is in .264. Just ran the twist rate calculator on some "fancy" 6.5 bullets--at 2800 fps:

1. 130 gr Barnes TSX BT (no 140) -- 1:9 twist
2. Berger 140 gr VLD Hunting -- 1:8 twist
3. 142 gr Nosler AB LR (Use this in my .260) -- 1:10
4. 137 gr Hammer Hunter (B/C folks R "eat up" with Hammer bullets on this website -- 1:7.5

So 1:7.5 would handle the extremes of bullet length and possibly slower MVs. I get 2850 out of my .260 and it handles all the bullets above...except Hammer--never tried 'em. Gonna get a test pack soon just to taste the Kool-Aid. Book says at my MV it should stabilize it. That said, all my shots with 142 NABLR have been DRT, one shot kills out to a "mere" 475 yds.

I also like the plain jane 140 Sierra game king, the Sierra game changer Tipped GK is only in 130 gr. both are 1:10.