IMR4227 supersonic BLK

[sub-sonic]

so I am loading 130 grain bullets in the BLK and I have lots of 4227. I searched for load data and get conflicting information.
IMR site says start load is 18 and max is 19.2 so I load up 18.5 and go see what happens and its a good load. primers look good and all is ok. velocity is 1945fps from a 10" barrel. BUT the load almost totally fills the case to the top so I was doing some more load checking and everything I can find gives around 17.5 as max load. so what gives? is IMR wrong or is the published data from several major bullet manufacturers wrong and the internet load guru's have just gone with 17.5 as max?

[Kanook]

I'm using 18grains for my Barnes 130 with no pressure signs in my H&R and Thompson Encore.

[quiettime]

...IMR site says start load is 18 and max is 19.2 so I load up 18.5 and go see what happens and its a good load. primers look good and all is ok. velocity is 1945fps from a 10" barrel. BUT the load almost totally fills the case to the top so I was doing some more load checking and everything I can find gives around 17.5 as max load. ...

Does IMR list the same brass you are using?

Compressed loads are not that uncommon with stick powder but there are slight variations in brass capacity also. What's more, powder varies slightly from lot to lot.

IF your velocity is in line with the mfg velocity and you are not seeing pressure signs or anything odd about operation (excess blowback, excess action noise etc) then you can probably stick with IMR's data

[quiettime]

OK went to the Hodgdon/IMR site. That data is also listed for "130 gr SPR HP". If you're using a different bullet than that, you may need to back down.

I also noticed their test barrel was 16". You're on par with what their velocity would be from a 16" barrel and you're shooting a 10" barrel. Id say you are above recommended in your case.

Primers are not always a great indicator of pressure. Certainly a good thing to look at but they don't always tell the whole story.

What bullet are you actually shooting? Is it listed in the other data you mentioned?

[sub-sonic]

my load is
speer 130 hollow point #2005
18.5 grains of IMR 4227
1x fired winchester 223 brass cut down to 1.360 sized in lee dies
cci primer
OAL 2.020
barrel 10.5" 1:8 twist pistol gas

velocity test
1240 feet 60f
1) 1953
2) 1917
3) 1921
4) 1967
5) 1944
6) 1966
average velocity 1945

[quiettime]

Load up some at 17.5 and see if the accuracy is good and what the velocity is. My guess is you'll see about 100 fps slower.

[sub-sonic]

Load up some at 17.5 and see if the accuracy is good and what the velocity is. My guess is you'll see about 100 fps slower.

you are thinking opposite to me. I am thinking no pressure signs and still room in the case add more powder

[quiettime]

...BUT the load almost totally fills the case to the top so I was doing some more load checking and everything I can find gives around 17.5 as max load. ...

That didn't make me think of adding more powder for some reason...

"Pressure signs" are only something for us hobbyists to look for as partial clues. Velocity usually tells more of the story and you're exceeding the factory velocity by a good margin, which usually handloaders can expect not to reach factory velocity because they use pressure barrels cut to tight specs under ideal conditions.

Proceed with caution, to say the least

[sub-sonic]

update.

I am back to loading this again. I asked the same question on a few sites and got no actual answers other than posts quoting internet guru's who were quoting other internet guru's.
searching today I have found some original posts (not people quoting) using 18 to 18.7 grains of 4227 with a 130 grain bullet but all are from 16" barrels.
I have fired 400 rounds of this load with out 1 single issue but now am out of ammo so its time to load again. So I figure I will load 18.5 again.