Slow Velocities - Tikka 7mm-08

[low2497]

Maybe my expectations were too high but something doesn’t seem right. I have a Tikka in 7mm-08 that I sent to have the barrel chopped and threaded at 18”. Im averaging 2530fps with 139gr factory Hornady ammo.

The common idea of losing 25fps for every inch of barrel that is removed had me expecting to be averaging around 2650fps with factory ammo.

Is there something Im missing?

 

[Caseknife]

Was this a new rifle or has the barrel been shot previously? Do you have experience with the velocity of the factory Hornady ammo in another rifle? If you have shot this ammo in this rifle before the chop job and knew the velocity, disregard my comments.

 

[low2497]

Was this a new rifle or has the barrel been shot previously? Do you have experience with the velocity of the factory Hornady ammo in another rifle? If you have shot this ammo in this rifle before the chop job and knew the velocity, disregard my comments.

New rifle. I had the barrel chopped right away. I don’t have any experience with this ammo in a different rifle, but I could make that happen and compare. Good idea.

Only issue is, I’ve also chrono’d 150gr factory hornady through this rifle and it also shot mid 2500s. I plan on hand loading for this rifle but those velocities just seemed extremely slow

 

[KenLee]

Was this a new rifle or has the barrel been shot previously? Do you have experience with the velocity of the factory Hornady ammo in another rifle? If you have shot this ammo in this rifle before the chop job and knew the velocity, disregard my comments.

That's what I was thinking. Slow Tikka factory barrel prior.
May have been 2750 fps with same ammo at 22 inches

 

[steelheadmike]

Could be a lot of things. I went to a 19” barrel and am getting 150fps below box velocity so your guess around 2650 wasn’t too far off.

Maybe try a different lot of ammo, check the chrono against another one, and like previously stated, let the rifle break in if it’s new.


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[low2497]

Could be a lot of things. I went to a 19” barrel and am getting 150fps below box velocity so your guess around 2650 wasn’t too far off.

Maybe try a different lot of ammo, check the chrono against another one, and like previously stated, let the rifle break in if it’s new.


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I’m using a Garmin chrono and it’s been giving expected velocities for my 7 PRC, so I don’t think it is a chrono issue.

I haven’t tried a different lot of this same ammo, but shooting 150gr Hornady factory rounds also showed way lower velocities than I expected.

Im hoping the barrel does speed up as I only have around 30-40rds through it. However, Im not holding my breath that it speeds up 100fps. I’ve read about slow tikka barrels and maybe I just got unlucky with an extra slow one

 

[NWBLKTAIL]

I bought some 7mm-08 Hornady 139gr whitetail ammo just to get some rounds down range and collect brass to load for it. Over 20 shots it averaged 2714fps with a 22” factory barrel. That was tracked with a Garmin.
These were the first 20 shots out of it, so slow was expected. I’m gonna load for it anyway so I’m not particularly worried about factory ammo velocities.
So I guess you’re not alone

This is also a tikka BTW

 

[jzeblaz]

Can you try Superformance or a lighter bullet weight? I haven't chrono'd it, but I have a 120 Hammer Hunter screaming out of the 7-08. It's not a short barrel though.

 

[nacgoat08]

Any updates on this? I also had a Tikka 7mm-08 chopped down and have been shooting Hornady 139gr whitetail ammo, suppressed. Toying around with 120gr factory Barnes loads, 120gr Hornady custom lites, and the 150gr ELD-X's. Curious which direction you ended up going.

 

[KenLee]

Any updates on this? I also had a Tikka 7mm-08 chopped down and have been shooting Hornady 139gr whitetail ammo, suppressed. Toying around with 120gr factory Barnes loads, 120gr Hornady custom lites, and the 150gr ELD-X's. Curious which direction you ended up going.

120 gr NBT is your friend

 

[steelheadmike]

Any updates on this? I also had a Tikka 7mm-08 chopped down and have been shooting Hornady 139gr whitetail ammo, suppressed. Toying around with 120gr factory Barnes loads, 120gr Hornady custom lites, and the 150gr ELD-X's. Curious which direction you ended up going.

Not much but I can give two data points:

19” tikka with can
Hornady Superformance 139 SST - 2800fps

Hornady PH 150 ELD-X - 2625fps

Both are ~150fps under box velocity


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[Pharmseller]

My T3 load for the 150 ELDX is max and I get 2780 fps, standard barrel.

Just for comparison.





P

 

[juju]

If you're having unexpected results with anything Hornady, always suspect the Hornady first. Use another manufacturer as a control.

 

[Leaf Litter]

A few things come to mind:

Aggregate velocity loss figures from around the internet seem to indicate 25-50fps/inch loss, with most settling around 35fps. My anecdotal experience is 30-35fps.

Tikkas are also notoriously slow compared to other manufacturers. Generally 50-150 fps from reports. My experience was 100fps for 243 win.

Hornady is trash. Any claims they make must be independently verified, because they lie about everything.