Hodgdon numbers way off!

[BBerguson]

This is from the Hodgdon website.
cartridge is 350 Legend
165gr Hornady plastic tipped bullet
IMR 4227
Max load is 25.2
Velocity 2040
CCI Small Rifle primer

Rifle is a CVA Cascade

I generally start loads in the middle of the listed data but this time I didn’t, I loaded 10 at 25 grains. I’ve been burning a lot of this powder in my 44 magnum and 350 Legend and think I’d have a hard time putting enough in to cause a pressure problem. And I wasn’t showing any signs of pressure. Bolt movement was normal, extraction was easy, primers not flattened at all. Everything felt fine. It is the chronograph numbers that are surprising me with an average velocity of 2366, SD = 57 (not a typo) 326 higher than listed and I wasn’t at their published max. .2 grains shy of it to be exact.

As a point of reference, I was also shooting a 200gr cast with gas check. No published data, making it up as I go along…
4227
CCI Small PISTOL primer

powder charge - average velocity SD
13.5 1310 21.9
14 1354 15.5
14.5 1391 7.2

I have shot this bullet with 16 grains but the groups were opening up and so far 14 grains is shooting the tightest groups.

 

[fiver]

the 350 is kind of sketchy anyway.
i'm assuming your using a 358 diameter bullet, that could splain the extra, normally it wouldn't even come close to that much extra [shrug] but?

 

[BBerguson]

My cast are sized to .358. I had to go measure the jacketed, they are .354. Accuracy isn’t terrible but it’s not great.

 

[Ian]

Hornady may be advertising their velocity for a 16" semi-auto, or a 16" pressure barrel. How long is your CVA?

 

[RBHarter]

I had a rifle that consistently posted 200 fps faster than data with 2" less barrel . It had a long shallow leade kind of a Weatherby deal .

 

[Tomme boy]

All of the 350 data is suspect.

25.5gr imr4227 170gr hornady out of a ruger 16" American was 2096fps for 5 shots. 13fps SD.

Ran it up to 27gr with a 27.4gr max workable. 2246fps 15fps SD.

Here is Lymans data for the 165ftx below.

Also I have found that the 165ftx is a lower set of loads than the 170gr SP Hornady. At first the loads were the same. Not so much anymore. Hodgdon even changed it as they were the first to have data.

My AR15 in 350 ran on avg almost 100fps faster with h110 and lilgun. Both guns were 16". But got rid of the AR barrel as it was larger in the chamber and brass would not go into the Ruger bolt gun even after FL sizing. The webs were stretching down past were the dies would size. It is from the coned breech the AR barrels have to have to feed.

 

[CWLONGSHOT]

I have a 24" & a 16" 350 Legend barrel. Neither one will apretuably exceed factory published velocities before pressure signs.

Also same load for a 165 ftx W/h110 is just over 2200 in 16 but not even 2300 from 24".

Its a strange critter.

Maybe you just have a "fast" barrel? My Ruger American 20" 358 is a fast barrel. Shooting a top load of TAC under a 225 Sierra just over 2500 fps.

CW

 

[Bret4207]

Agree with CW. There are always those barrels out there that shoot markedly faster, or slower, than the norm. Chamber dimensions, throat, rifling, barrel internal dimensions, length, "choke"...it can all make one barrel faster than another. It can be a blessing.

 

[BBerguson]

Hornady may be advertising their velocity for a 16" semi-auto, or a 16" pressure barrel. How long is your CVA?

22”. These numbers came from the Hodgdon Reloading Center. Yes, it does say 16” barrel on the page, that makes a little more sense.

 

[RBHarter]

Barrels , cases , powder ,lots , .........

 

[BBerguson]

Just checking my targets again. These are grouping better than I thought, just a little over an inch at 100 yards.