Triple 7 fffg and Blackhorn 209 range info

[klundin2000]

Just posting a "FYI" of some of my range results in the last couple days using the power stem breech plug with Triple 7 fffg powder and the standard breech plug with Blackhorn 209 powder.

8/30/09
Knight Long Range Hunter
Power Stem Breech Plug
89.1 Triple 7 fffg powder (weighed)
250 MZ EZ Harvester Sabot
Triple 7 primers

Group #1
0.912" c-t-c Average Velocity 2058fps

Group #2
0.767" c-t-c Average Velocity 2068 fps

9/1/09
Knight Long Range Hunter
Standard Breech Plug
Barnes 250 MZ EZ Harvester Sabots

Group#1
Blackhorn 209...78.1 grains (measured)1.121" c-t-c avg vel 1920fps with CCI M primers

Group #2
Blackhorn 209...78.1 grains (measured) 0.983" c-t-c avg. vel 1930fps
with Federal 209A primers.

Group #3
Blackhorn 209...81.5grains(measured) 1.721" c-t-c avg vel 1970fps
Federal 209A primers

Group #4
Blackhorn 209....86.1 grains (measured) 1.509" c-t-c avg vel 2035fps
Federal 209A primers.

The 89.1 grains of Triple 7 fffg is equal to approximately 110 volume measured.

78.1 grains weighed of Blackhorn is about 110 volume measured.
81.5 grains weighed of Blackhorn is about 115 volume measured.
86.1 grains weithed of Blackhorn is about 120 volume measured.

I have always been a Blackhorn fan...but I must say that Triple 7 powder isn't too bad. I may buy a pound of Triple 7 ffg powder and give it a try with the power stem breech plug.

[sabotloader]

klundin2000

Thanks for sharing... looks like you have really shrank your groups down mighty nice little package...

Remember the 'Power Stem' is suppose to add 100/150 fps when shooting T7...

Got this information from a reliable source....

You can google "frontal ignition"; it is used on artillary shells and it improves the combustion efficiency and reduces velocity variation

This was a part of a discussion about the extended flash hole out into the powder....

I have shot a few pounds of BH through many different rifles - I remain a T7 shooter myself.

[txhunter58]

Great post.

Did you mean to say that you weighed the BH 209?

Also, which breechplug where you using with the Blackhorn? The plastic jacket or nonplastic jacket. I was having hangfires with the plastic, but haven't had any with the bare primer breech.

[lemoyne]

There have been two people that have complained about the power stem burning a ring in there barrel. I have to admit I don't know what to think about that.
Nice shooting you are holding them right in there. Lee

[sabotloader]

txhunter58

I shoot BH with the FPJ and I think Grouse does also - never had a problem with hang fires or non-ignition. So for some Knights with the FPJ it seems to work fine.

The NFPJ with a domed BP is suppose to be somewhat of a problem with BH because of the reduced size of the flash hole. BUT, I really have never tried that one myself.

[sabotloader]

Lee

I 'wonder' about the thought of burning a ring in the bore with a 'Power Stem' but I would not wonder about creating a 'Crud Ring' at that point and I guess there are people that really stuggle with a hard 'burnt on' crud ring. That might be more of what they are finding.

just a thought....

[klundin2000]

Hi Lee

When using the standard breech plug FPJ with T7, I experienced a crud ring. However, when I shoot the power stem breech plug, the CR isn't there.

I know a guy that drilled two additional holes in the end of the power stem...like porting a barrel. He called Knight and told them he was having great success with higher velocities. Knight wrote him back and advised him against doing that because of the increased chamber pressure.

I'm very interested the new "Blackhorn Breech plug" that Grouse will be testing.

[lemoyne]

Mike there was a guy on an other forum that was complaining said it eliminated the crud ring and added to the velocity, but that after he shot it for a couple years you could see and feel in the barrel where it was burning away the metal. Lee

[sabotloader]

Lee

Next time I am talking to Gordy - i will ask him about that - seems odd as at the end of the power stem would be the place I would expect the least heat and pressure...

anyway i will see if Knight knows anything about it....