75gr V-max 4056 fps for Varminting

[Land Rover]

HI Guys

As per my last thread I have a P17 Enfield (M1917 Enfield) chambered in 25-06 Rem.
It is shooting a book max load for the 75 gr V-max projectile and is not showing pressure signs, maybe just starting to flatten the edge of the pimers. Not sticky bolt lift or extraction issues. Book max says 3700 fps but my rifle does have a 25" very heavy barrel.
My rig weights 11.5 lbs. The thing is over the chrony it is showing 4056 fps ave.
This seems very quick from what info I can find for a 25 06. I would like to know a bit more about these higher velocities and if I need to back it off a bit? Will this damaged my barrel way quicker than a slower load? What velocities do other shooters get with the 75gr V-Max. Looking at the charts it is super flat shooting and should be good for varmints.
My Tikka T3 shoots the exact same load at 3720 fps (shorter barrel).
Look forward to your replies.

 

[ShootnMathews]

Are you sure that the chronograph isn't sitting too close and measuring the speed of the gas being expelled from the barrel?? That seems impossibly fast to me.

 

[Land Rover]

Are you sure that the chronograph isn't sitting too close and measuring the speed of the gas being expelled from the barrel?? That seems impossibly fast to me.

Yeah my thoughts exaxtly, but the factory rounds were bang on as stated shooting from my Tikka 25 06@ 3700fps. And over 4000 fps from my P17, with a 3" longer barrel.
No the chrony was fully extended on its cable to the screen, probably 4 m away. And I use a suppressor that might help disperse the gas? (not sure about that though, just a guess)

 

[ShootnMathews]

The extra 3" barrel should get you another 75 Fps or so. I can't seee an extra 300 fps gain. I don't know. I'd shoot at some distance and calculate velocity by drop data. I bet it won't work out to 4000 +

 

[Land Rover]

yep 4000fps + does sound extreme. That's why I'm hoping others will chip in with
their actual velocities chronographed for a 25 06 75gr Vmax.
Maybe my chrony is faulty?

Does anyone have a load program that can estimate the velocity?

25" Barrel, 58.5gr AR2209 Book Max, 75 gr Vmax, 215M Primer.


Powder Equivalents AR2209 H414/ H4350 IMR4350 W760 Tu 7000 N204 AA4350 N150 / N550

 

[Rich Coyle]

I know in two of my rifles, which are not .25-06, there was 295 feet per second difference from the same box of ammo. One rifle was a factory 26" rifle and the other was a 30" Pac-Nor.

 

[Land Rover]

I know in two of my rifles, which are not .25-06, there was 295 feet per second difference from the same box of ammo. One rifle was a factory 26" rifle and the other was a 30" Pac-Nor.

wow, o.k so maybe it is legit. I had better measure the Tikka to see what actual length the barrel is. I am thinking 22" vs 25" for the P17.

 

[orch]

Have you shot the load out to distance yet? That'd be the best way to verify your speed/drops if you have a place you can stretch things out..
4000 fps is possible.... I've pushed 70gr blitz kings outta my 2506ai to 3950 with no pressure signs on a 27" barrel... Had lots of case capacity left.... Pretty sure I could have made over 4000 with it before pressure.... Not sure the bullets would hold together though... They were flying apart outta my old 2506ai barrel at 3900 (new barrel they make it out to 900 yards accurately in one piece)...

As far as higher speed damaging the barrel....well, I'm on my second 25-06ai barrel....
More speed requires more pressure and makes more heat, barrel life will definetly be shorter than a reduced load... But what fun would that be?
They make new barrels everyday, keep a gunsmith employed and have fun!

Orch

 

[Land Rover]

O.K I smacked my dominant eye accidentally with a cricket ball, so all shooting has been on hold for a short while. I am leaning towards bad readings in my chronograph for the over 4000 fps readings. Maybe I need to shoot it again on a cloudy day. Again I will do a drop check once my eye is o.k.
Does any one else have an opinion on the 75 gr Vmax in the 25 06?.
Any tried and tested velocity data?

 

[Land Rover]

O.k I have been at my hunting block and completed some drop tests that I need help working out the velocities.

I only did drop tests for the P17 25 06 as that seemed to have a fast barrel.
I shot both loads 117 gr Pro hunters and 75 gr V-max.
They were shot at 100 yards and 337 yards (337 yards because that was a clear shooting platform at my hunting block).

117gr Prohunters shot at 100 yards and then at 337 yards.
Three shot groups of both. The drop was 105mm. 40mm group at 337 yards.

75 gr V-max the drop was 39mm. Similar group at 337 yards.

What velocities does this give me when worked from the drop test?
I don't know how to work it out.

When chronographed 3200 fps for the 117gr Prohunters and 4056 fps for the 75 gr V-max. (but thinking the chrony is not reading correctly).

 

[WildRose]

Just for grins I ran it for you on Hornady's ballistic calculator. At 4000fps it shows a drop of 14.6" at 400yds using a 100yds zero.

At 300yds I get a drop of 5.8"

The maximum velocity for the calculator is 4600fps which shows a drop of 9.8" at 400yds and 3.6" at 300.

Your chrony may not be too far off and if that's the case I'd back off a grain or two or try a different powder because your barrel life is going to be extremely short.

I can tell you from personal experience that running anything at over 4000fps makes for lots of fun for a few hundred shots and after that you're going down hill rapidly due to throat erosion.

You can cheat that a bit by seating bullets farther out but not for long especially since you're shooting a pretty short bullet already.

http://www.hornady.com/ballistics-resource/ballistics-calculator

 

[WildRose]

Rover I may have missed it, did you give a velocity for the 117's?

I ran it for Hornady's 117gr interlock with a BC of .391 using a velocity of 3700 and came up with drops of 6.5 and 15.7" at 300 and 400yds.

It's a pretty handy calculator so you may want to save it to your favorites.

 

[Land Rover]

Rover I may have missed it, did you give a velocity for the 117's?

I ran it for Hornady's 117gr interlock with a BC of .391 using a velocity of 3700 and came up with drops of 6.5 and 15.7" at 300 and 400yds.

It's a pretty handy calculator so you may want to save it to your favorites.

Hi WildRose. I had 3200 fps for the 117 gr Prohunters. 105mm drop between 100 and 337 yards.

 

[WildRose]

Hi WildRose. I had 3200 fps for the 117 gr Prohunters. 105mm drop between 100 and 337 yards.

That sounds then as though your velicity numbers may very well be quite close to accurate.