450 Corvette

[ColoradoKid]

[Texas Sheepdawg]

Dammit WC, I told you to keep the media at least five miles from our medicine show!

[wildcatter]

Dammit WC, I told you to keep the media at least five miles from our medicine show!

Lol lo lololol!!!

[MarkCO]

Hot Dang, I have some serious ideas for this.

[Texas Sheepdawg]

Hot Dang, I have some serious ideas for this.

Sorry..... I'll never dance in front of a video camera, so forget it.

[wildcatter]

I hesitate to publish the load, because you wouldn't believe it anyway or think it irresponsible. But I was trying out some 230gr FMJ 296 loads I had, on the rifle length gas system and saw speeds of well over 2800fps, with only .0005" to .001" of case head expansion, measured where the fl die lets off or about .200" north of the rim and very little flattening of the primer (normal), and no swipes.

Suffice to say these ARE NOT loads you can shoot in your Standard Factory Weapon, you'd need a 450 Corvette Conversion to even start to think you can do this..

..t

[Texas Sheepdawg]

I was wondering when that new dance would finally work.....

[wildcatter]

I was wondering when that new dance would finally work.....

I am starting to postulate a "Theorem", if you will.

Remember a Theorem is based on a Theory and what I am about to talk about is pure Theory. I only hope to get a few ideas to further my studies.

Simply stated.. The guys on this board are experiencing some pressure signs whenever they get into the neighborhood of 2500fps with say a 230gr Ball bullet, with whatever brand of powder they are using. Right?

I am about to suggest, after counseling with many of my contemporaries, that the reason I am consistently achieving much higher bullet speeds without pressure signs, is because of course the Rifle Length Gas System, specifically and the fact it allows me to use much more of slower burning powder. Let me explane.

Much has been said about how Hornady came up with their SAAMI Spec. Standards. Without rehashing all of that, I am seeing bullet speeds 20% +- (and that's allot), more than SAAMI loads without pressure problems (of course your results will be different and they wont necessarily be positive results, maybe even dangerous results), with the 450 Corvette Conversion, "ONLY"!

My "Theory" is that, with the Carbine Length Gas System (Ala 450B's), whenever the bullet approached 2500fps, the gas system is indeed, opening the bolt far too soon. Now, at that point of the extraction process, the case head is unsupported which is causing pressure signs to become visible, to say nothing of the safety concerns and the onset of short-stroking. Buuttt, with the rifle length system (Ala 450 Corvette Conversion) the bolt is opening far later, thus the case is fully supported when the case is extracting, hence no pressure signs and the elimination of safety concerns. When the case is extracting, the case has dropped in pressure to sufficiently extract without short-stroking problems as can be seen in Hypo 450b loads in the standard weapons carbine length gas system. I think??

So, my Theory is that, these maybe some of the reasons for allowing me, to achieve far better bullet performance results..

..t

[Hoot]

WC, are your test bed rifle barrels factory barrels? As in Chromed chambers? I suspect that is a factor as well. Also, I believe not all our chambers are cut the same inner diameter, nor with care given to concentricity. I get what would pass as unacceptable case head growth from standard loads, due to what I believe is a slightly looser chamber. The growth is not concentric either. Amazingly, they still excel at accuracy, but I believe it's more a result of their large caliber and bullet weight. It's harder to throw a shot put off course than a softball, even though their similar diameters. Shot put are very forgiving.

Hoot

[wildcatter]

WC, are your test bed rifle barrels factory barrels? As in Chromed chambers? I suspect that is a factor as well. Also, I believe not all our chambers are cut the same inner diameter, nor with care given to concentricity. I get what would pass as unacceptable case head growth from standard loads, due to what I believe is a slightly looser chamber. The growth is not concentric either. Amazingly, they still excel at accuracy, but I believe it's more a result of their large caliber and bullet weight. It's harder to throw a shot put off course than a softball, even though their similar diameters. Shot put are very forgiving.

Hoot

lololol..I don't know about unforgiving. I shore don't wanna get hit by no Shot-Put at 3000fps!!!!!!!!!!!!

..t