6.5 PRC Barrel Length and Twist

[ramrod79]

Good day all looking for some Input on a custom rifle I'm interested in purchasing.
Rifle is a custom built off Tikka long action with a 22 inch barrel and a 1-7 twist.
Do you think with the shorter pipe I'll give up to much velocity?
Will the 1-7 work well with 140s if I decide to shoot them? My plan is to try 147 Factory ammo first then try reloading 150 SMK or if we ever get 156 EOL in Canada try them.
Any thoughts or input.

 

[JTB]

Have a PRC running a 22" barrel, 1:7.5, Tikka action. Just looking quickly at where the nodes ended up: 147@3000, 142 ABLR@2985, 150 SMK@2980, 156 EOL@2920(still working-up). I normally use Retumbo but had to go with H-1000 for velocity consistency with the 142 and the 22" barrel. The other heavies had no problem with Retumbo. At the velocities you will be running, I think the 7" twist will be fine but no personal experience.

 

[Another Casual]

Still working up loads for mine and the barrel is still speeding up, but I have a 26 inch tube and haven't been impressed with the numbers on my chrono so far. Everything so far seems to be well under the published hornady data with IMR4831. Only have been able to find one pound of H1000 and have been saving it. Loaded up some accubonds with that yesterday. To me, the round wouldnt be worth it for a 22 inch barrel. I'd probably just go 6.5 creedmoor at that point and run RL26 as some here have reported excellent results.

 

[Rprecision]

I am considering a similar build, when I called proof they suggested 7.5 twist which should stabilize up to a 155ish bullet depending on length

 

[ramrod79]

Thanks for input I see most are running the 1-7.5 vs the 1-7 and yes 22 is a bit short. I have a CM does well with 4350 130s but the hornady 129 AW shot so accurate I quit hand loAding for it.

 

[BrentM]

I have a 22" 1:7.5 proof. Only 30 rounds down the barrel but minor testing shows 2900 should be a safe load with 147's and expect 3000 with 140's. I am testing retumbo, H1000, RL26. If you compare Hornady max loads with all 3, retumbo was fastest in my initial test. However, I also noticed some bolt lift below max on h1k and retumbo. I didn't see that with RL26 and am testing a little higher to see how it plays out. For comparison my 20" proof creed is running a 140 at 2800. I expect there to be about 200 fps between the 2.

 

[Dry Heat?]

I always smile when someone wants a fast Cartridge but then wants to handicap it with a short tube. Just be like everyone else and get a CM.

 

[CA48]

I always smile when someone wants a fast Cartridge but then wants to handicap it with a short tube. Just be like everyone else and get a CM.

You might ask why the OP is wanting a shorter barrel then give a recommendation off his answer if you actually wanted to contribute. If you read his posts you would see that he owned a Creedmoor already.

Most people are cutting down PRC barrels to 20-22" to add add a suppressor and have the same overall length rifle as a 26" barreled rifle with a break and they can still outrun the Creedmoor by 150-200 fps. Not many ppl want to pack around or have a Comp rifle with a 26" Bbl and a can hanging off the end.

 

[BrentM]

I always smile when someone wants a fast Cartridge but then wants to handicap it with a short tube. Just be like everyone else and get a CM.

Usually that's called a smirk. Smirks can be from someone's preconceived idea they understand another persons needs, desires, or preferences. Instead of understanding those things, they smirk and make comments that provide little value and to antagonize. Now, on the other hand some people choose short barrels, tubes in your mind, to be combined with suppressors. My suppressor is 7" long which makes a 28 plus 7, 35" barrel, a real turd to handle and pack even with folding stocks. So to each there own, but a short barrel may be for use with a can or could be for the handling, or a host of other reasons. In the end, yes, it might be better to just go the route of the creed, but without asking the question of those who are playing the game, one may never know.

 

[Aoudad shooter1975]

I always smile when someone wants a fast Cartridge but then wants to handicap it with a short tube. Just be like everyone else and get a CM.

well...dont agree with you..i agree you can handicap a fast cartridge with a short tube but with the right choice a efficient fast cartridge can do well in a short tube...I built my 7 mm SAUM on a 22 in barrel because I find it very nice to hunt with a shorter barrel. I get adv 2722 with EOL 175s out of a Wyatt short action mag--and it probably has a bit more--but it is a good node..I struggled to get much over 2600 fps with 168s out of a 7-08...handicap....i don't know---but I'll take it

I think a PRC will do great with a 22 in tube and a 143-150 grain bullet...

 

[Litehiker]

My 6.5 PRC Browning X-Bolt Pro has a 24" barrel with a 1:7 twist for heavier bullets. The X-Bolt Pro Long Range model has a 26" barrel for maximum velocity. Your choice on barrel lengths.

I'd get the 1:7 twist for stabilizing 140+ grain bullets. This is because B/C you have a "magnum Creedmoor" in the 6.5 PRC and can utilize those heavier bullets. Heavier (i.e. longer) bullets don't shoot quite as flat as lighter bullets but they remain supersonic quite a bit longer with more energy as well.

Eric B.

 

[BrentM]

My 6.5 PRC Browning X-Bolt Pro has a 24" barrel with a 1:7 twist for heavier bullets. The X-Bolt Pro Long Range model has a 26" barrel for maximum velocity. Your choice on barrel lengths.

I'd get the 1:7 twist for stabilizing 140+ grain bullets. This is because B/C you have a "magnum Creedmoor" in the 6.5 PRC and can utilize those heavier bullets. Heavier (i.e. longer) bullets don't shoot quite as flat as lighter bullets but they remain supersonic quite a bit longer with more energy as well.

Eric B.

A 1:7 thru 1:8 twist will work fine for any 6.5 caliber bullet, even the 160 matrix and 156 EOL, unless a person is seeing pretty low velocity. The formula for calculating stability can be studied or a person can look at the berger calculator and plug and play.

 

[ramrod79]

I've looked a Berger and it says stability is a full with 1-7 even with 140 eol. First thing I though of was Matrix 152 or 160 but I don't think he's in business any longer as web page couldn't be found. I would just hate to buy outfit and get low velocity. May be worth just a re barrel on my 338ss in spring. Go 24 inch pipe 1-7.5 twist on my long action call it good.

 

[Litehiker]

ramrod,
You can improve barrel velocity almost immediately if your barrel is lapped, either hand lapped or, after you get it, by "fire lapping" with hand loaded bullets rolled in coarse, medium and fine grits. NECO and David Tubb sell these kits. If you don't and load Tubb sells pre-loaded ammo with the grits in the bullets.
But once lapped the barrel will settle into standard velocities with a specific load and barrel length.

Fire lapping is a slow process but yields very good results and makes cleaning easier B/C copper build up is much slower.

Eric B.