Range Report Realistic Velocity from 20 inch barrel

[mdesign]

Need some help with this one. I see numbers posted that are all over the place for how fast guys are running bullets coming out of shorter barrels but some of them seem pretty optimistic.

I'm looking for a consensus on what should be expected from the following cartridges and bullet weights at a average elevation.

260 Rem - 140gr
7-08 Rem - 162gr
308 Win - 175gr

Certainly apprieciate any input.

 

[Lowlight]

Re: Realistic Velocity from 20 inch barrel

I shoot a 21" 260 and load pretty conservatively.

I get 2750 with a 139gr Scenars and they are laser accurate. I am around 2850 with 130gr VLDs, which also produce good accuracy for me.

My 308 barrels are tighter but any where between 2575 and 2640fps with a 175gr, though I have seen factory barrels hover around 2495fps for a 20". I usually replace any short 308 barrels with tight bore Bartliens which get me over 2600.

No experience with 7-08.

 

[tigerfan_9]

Re: Realistic Velocity from 20 inch barrel

Lowlight what powder, brass, primer combo are you running in the 260 with the scenars?

 

[Lowlight]

Re: Realistic Velocity from 20 inch barrel

Mostly Remington brass, whatever primers, and H4350... Andrew McCourt has loaded a bunch of my match loads for this rounds so email him. But I am around 43.3gr H4350. I used the same load for the K&M Match in March and it was rock solid out of a 24" GAP. I switched rifles at the last minute, as originally I planned on shooting the AW (21") but moved over to a GAP in a AX Chassis to save a bit of weight and not need the suppressor. I would have to look up the velocity out of the 24" GAP, but it was definitely higher.

I just get the load going then have someone load it in mass to higher specs than I would... I load to shoot, not to "develop".

 

[earthquake]

Re: Realistic Velocity from 20 inch barrel

My .308 Bartlein with .299 bore at 20" gets ~2,550fps at the muzzle with SW 175 gr SMK match ammo.

 

[BoilerUP]

Re: Realistic Velocity from 20 inch barrel

Member 'RugerShooter' has a 19" 260 and reports 2700fps with a 140 SMK.

 

[RobertB]

Re: Realistic Velocity from 20 inch barrel

Im at 2850 in my 28"bbl. 260. S5horter is deff the way to go if there is much moving going on with. Im shooting the 142 smk too btw

 

[mdesign]

Re: Realistic Velocity from 20 inch barrel

Thanks Frank...some good info there.

 

[BusterB]

Re: Realistic Velocity from 20 inch barrel

I'm at 2700 in my .260 with lapua brass, h4350, and 139 scenar. 21" lilja 3 groove.

 

[hunter121]

Re: Realistic Velocity from 20 inch barrel

2770fps with my 20" 260.

Rem brass
hornady 140 bthp
Rem 9m primers
43.5gr of h4350

 

[ericthebeard]

I know this is a zombie thread, but I thought I'd add my data in here since I just went to the range yesterday to do this set of experiments with my new rifle.

Gun: AIAW with a 20" Bartlein barrel, MTU-ish contour. Unknown bore diameter.
Tools: Magneto speed. All round where shot 5x in a slow string recording individual velocities, average and SD (standard deviation).

I am interested in shooting factory 175 SMKs (with some AMAX thrown in there) and want to get over the 2600 fps barrier reliably. Shot a number of factory loads.

Data:
Black Hills 175 Match: Ave 2533 fps, SD 22 fps
SWA 175 Match (older FC brass loading not their newer SWA brass recipe): Ave 2540 fps, SD 14 fps
SWA 178 AMAX: Ave 2599 fps, SD 20 fps
FGMM 175 Match: Ave 2644 fps, SD 24 fps

Looks like there's a brick of FGMM coming my way...

 

[chrisward3]

tagged

 

[gr1ffer]

my 7mm08 with 162 amax and 44grains of rl-17 gives 2595 fps in my 20" 1 in 9 worked up using quickload, rem brass, cci br2. accuracy was so so berger vld 140 grain was much better

 

[alpha6164]

I load for a buddy with his 20" Tikka tactical with 175smk. With 44.5gr of Varget we get right at 2600ft/sec and with CFE we get 2660-2680ft/sec depending on the load. CFE is amazing for gaining speed and is still very accurate. With my 24" Bartlein 308 i was getting 2680ft/sec with varget and now get 2830 ft/sec with CFE223

 

[DCR]

308 Rem 700 aac sd

I'm getting 2550 through my factory 20 inch barrel with 178 Amaxs and varget.

 

[CapDog]

20" Factory AIAW and shooting factory Lapua 170gr Lockcbase was averaging 2600fps for the slower rifles and as high as 2650fps on the faster ones. Just finished experimenting with cutting the barrel down and adding a Jet-z suppressor and avg still at 2561fps with a 16" barrel. Will have to hook op the Magneto to the AX's to see if what they are getting out of the 20" tubes on them, but I would imagine they would be close to the same.