Slow velocities with H4831 (.270 Win)

[Newtosavage]

Working up loads for a Tikka .270 and the velocities seem awfully low.

Bullets are 150 grain SST and 150 ABLR's over H4831 powder. I started at 54 grains and worked up in 0.3 grain increments to 55.9 grains. Highest velocity was 2720 fps. at 55.6 grains. I was expecting at least 100 fps more than that. Anyone else had this experience?

By comparison, the factory Hornady Precision Hunter 145 ELD-X were clocking 2875 out of the same rifle.

Most guides suggest H4831 is the ideal powder for the .270, so I'm surprised by these results.

My 7mm-08 clocked right where I expected it to, so I don't think it was a chrono issue.

 

[N2TRKYS]

H4831SC has proven to be the slowest powder in several different cartridges for me. Alot of folks recommend it, but it's been totally useless for me.

For your 270Win, pick up some RL26. RL16 and RL26 has been great in my 270Win.

 

[elkguide]

I always find it interesting how each rifle has it's own likes and dislikes.
H4831SC is one of my favorite powders for the .270. Consistent speeds and great accuracy.

 

[Huntin wv]

I load H4831sc in my 270 win with 130 gr Combined Technologies bullets. If I remember correctly, I think the velocity was around 3050 or so, which I was happy with out of a 24” barrel. Accuracy was also the best out of powders I tried.


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[BAKPAKR]

I use H4831SC behind 130 Accubonds and TTSXs in my Remington 700 Ti (22” barrel). My loads are accurate and appear to be close to max but, if my chronograph is on, I am only getting a little over 2900 fps.

 

[deerkiller]

Working up loads for a Tikka .270 and the velocities seem awfully low.

Bullets are 150 grain SST and 150 ABLR's over H4831 powder. I started at 54 grains and worked up in 0.3 grain increments to 55.9 grains. Highest velocity was 2720 fps. at 55.6 grains. I was expecting at least 100 fps more than that. Anyone else had this experience?

By comparison, the factory Hornady Precision Hunter 145 ELD-X were clocking 2875 out of the same rifle.

Most guides suggest H4831 is the ideal powder for the .270, so I'm surprised by these results.

My 7mm-08 clocked right where I expected it to, so I don't think it was a chrono issue.

sometimes you just end up with a "slow" barrel … doesn't necessarily mean it's a "bad" barrel, if it's accurate work with it

 

[Newtosavage]

sometimes you just end up with a "slow" barrel … doesn't necessarily mean it's a "bad" barrel, if it's accurate work with it

Yea, accuracy isn't a problem. Just strange how slow it is. A full 200 fps. behind the Nosler published velocities, although I've always had trouble reaching those from a 22-23" barrel.

When my 7mm-08 is pushing 162's at 2680 and the .270 is only driving 150's 2670 with what feels like more recoil, that doesn't bode well for the .270 (both Tikka T3's).

Son said he wants a .308 anyway, so that .270 is probably going to get rebarreled.

 

[TomM]

Have had that same experience in two different 270’s with H4831 and H4831SC. I get my best 270 speeds from RL26 and H414. 4350’s ain’t bad either...

 

[ramont]

If you check other manufacturer's reloading manuals and search the Internet I think you'll find that the evidence points to Nosler's manual being off on it's muzzle velocity for your load, it's not you or your rifle, it's them.

If you compare the load data in Hornady's manual you will see that they predict a muzzle velocity of 2700 FPS using 55.0 grains of H4831 under a 150gr bullet in a 24" barrel, that's pretty close to your results.

You mention using a 22" - 23" barrel but Nosler's book used a 24" barrel for their load development data so there will be a slight difference there.

I've got a copy of Nosler's reloading manual #6 and they don't even list the 150gr ABLR but they do show that bullet in their online load data but the data from both resources are exactly the same so it looks like they've never updated their load data when they added the ABLR bullet to the 150gr product line - that's another reason that the information that they published doesn't match your real world results.

I've used QuickLoad for years and it predicts:
Assuming total case capacity, to the mouth of the case, is 71.27gr of water
COAL of 3.340"
Trim-to-Length of 2.540"
55.9gr of H4831
22" barrel
Muzzle velocity will be about 2723 FPS

I have no idea what the true water capacity of your case is, most often I'm seeing references list the case capacity for a .270 winchester to be 68 grains of water so I could be wrong but if you can get a little over 71 grains of water in to your fired/ unsized cases then I don't think that your rifle is doing anything unusual.

 

[Wrench]

My 270 shoves a 150 LRAB at 3050 with rl26. I was only pushing my 130's that fast with 4831. 26 and 150's are made for each other.

 

[jorgensen.travis]

My 270 shoves a 150 LRAB at 3050 with rl26. I was only pushing my 130's that fast with 4831. 26 and 150's are made for each other.

Wow!
What length barrel?

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[Newtosavage]

Thanks for all the great advice and information. I'd like to get these 150's up to at least 2800. Until then, it's not doing anything my 7mm-08 isn't already doing.

So if I end up keeping this barrel, I'll experiment with some RL26. I got good results from H4350 under 130 TSX's but I think that's too fast for the 150's.

Again, thanks for all the great info.

 

[N2TRKYS]

My 150 grain Partitions are going 2900+ in my 22" barreled 270Win with RL26.

 

[.270]

I was getting 3150 with 129 lrx and 130 SST with around 62 grains of H4831sc out of a 24" barrel. I recently rebarreled my .270 with proof 24" and I have gotten good accuracy with 145 eldx and RL26. Just havent been back out to confirm the velocity yet.

 

[tyeager2964]

I'll second the Nosler data being off. I am not saying it is always inaccurate but in my 7 mm mag the Nosler data was roughly 150 to 200 fps faster than myagneto speed

 

[bhylton]

I maxed out at 2820 in a tikka 270 using h4831sc and 150gr partitions. ablr and eld-x are much longer and would intrude on case capacity more than a partition. are you hitting pressure before running out of case capacity? if so, try a faster burn powder like r16, Hybrid100V or a 4350

 

[Wrench]

Wow!
What length barrel?

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22" rem ti.

 

[deerkiller]

If you check other manufacturer's reloading manuals and search the Internet I think you'll find that the evidence points to Nosler's manual being off on it's muzzle velocity for your load, it's not you or your rifle, it's them.

If you compare the load data in Hornady's manual you will see that they predict a muzzle velocity of 2700 FPS using 55.0 grains of H4831 under a 150gr bullet in a 24" barrel, that's pretty close to your results.

You mention using a 22" - 23" barrel but Nosler's book used a 24" barrel for their load development data so there will be a slight difference there.

I've got a copy of Nosler's reloading manual #6 and they don't even list the 150gr ABLR but they do show that bullet in their online load data but the data from both resources are exactly the same so it looks like they've never updated their load data when they added the ABLR bullet to the 150gr product line - that's another reason that the information that they published doesn't match your real world results.

I've used QuickLoad for years and it predicts:
Assuming total case capacity, to the mouth of the case, is 71.27gr of water
COAL of 3.340"
Trim-to-Length of 2.540"
55.9gr of H4831
22" barrel
Muzzle velocity will be about 2723 FPS

I have no idea what the true water capacity of your case is, most often I'm seeing references list the case capacity for a .270 winchester to be 68 grains of water so I could be wrong but if you can get a little over 71 grains of water in to your fired/ unsized cases then I don't think that your rifle is doing anything unusual.

NOSLER also uses "pressure barrels" a lot for their testing making "real world rifle" comparisons more of an "apples to oranges" comparison - there ARE some "tricks" one can use in the process of chasing velocities but as I've become more "wise" I've realized that velocity ALONE is only part of the useful equation

 

[deerkiller]

I maxed out at 2820 in a tikka 270 using h4831sc and 150gr partitions. ablr and eld-x are much longer and would intrude on case capacity more than a partition. are you hitting pressure before running out of case capacity? if so, try a faster burn powder like r16, Hybrid100V or a 4350

OR a shorter bullet - a 270 "anything" coupled with a good 130 gr is a very formidable combo (and commonly thought to be the sweet spot with a 270 bore)

 

[N2TRKYS]

I’ve found Nosler’s data to be pretty close in several different rifles and cartridges, except for H4831SC.