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mehavey · October 10, 2011, 07:31 PM

The thing I hate about this forum is that every once in a while I gotta put my money where my mouth is (e.g., demonstrating the futility of trying to chase advertised velocities, and defending the honor of QuickLoad

)

Wingspan was concerned that he wasn't getting full velocity with his 243 loadouts, and I countered "...don't worry about it." Others came at it from a concern that moly did evil things and/or powder manufacturers had to be regarded as the holy bearers of the sacred relics of the true Cross where the latest hot-lick powder was concerned. <big smile>

Case in point: The Hogdon/IMR site lists a 55gr Nosler over 43gr of IMR8208 going out at 3931fps. Being both the eternal skeptic and a fan of QuickLoad, I ran some numbers that said expected velocities should be much lower than advertised. So today I pulled Gertrude (my M77V 243 from back in`73) out of the closet and hied to Clark Bro's who had both some IMR8208 and Nosler 55's

The results are below:

and

The good news/bad news is that the brass showed no pressure signs (I don't know where the knee-in-the-curve is yet.)
The bad news is QuickLoad's velocity pessimism is borne out.

The good news is that groups averaged < 3/4", with one at 1/2", which runs totally counter to
my expereince with most really short bullets sitting waaay off the lands.

postscript: Many thanks to UncleNick who posted the cross-references showing IMR8208-XBR is plain old Aussie ADI AR-2210
See http://www.adi-powders.com.au/handlo...uide/rifle.asp

October 10, 2011, 07:31 PM	#25
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,894	The thing I hate about this forum is that every once in a while I gotta put my money where my mouth is (e.g., demonstrating the futility of trying to chase advertised velocities, and defending the honor of QuickLoad ) Wingspan was concerned that he wasn't getting full velocity with his 243 loadouts, and I countered "...don't worry about it." Others came at it from a concern that moly did evil things and/or powder manufacturers had to be regarded as the holy bearers of the sacred relics of the true Cross where the latest hot-lick powder was concerned. <big smile> Case in point: The Hogdon/IMR site lists a 55gr Nosler over 43gr of IMR8208 going out at 3931fps. Being both the eternal skeptic and a fan of QuickLoad, I ran some numbers that said expected velocities should be much lower than advertised. So today I pulled Gertrude (my M77V 243 from back in`73) out of the closet and hied to Clark Bro's who had both some IMR8208 and Nosler 55's The results are below: and The good news/bad news is that the brass showed no pressure signs (I don't know where the knee-in-the-curve is yet.) The bad news is QuickLoad's velocity pessimism is borne out. The good news is that groups averaged < 3/4", with one at 1/2", which runs totally counter to my expereince with most really short bullets sitting waaay off the lands. postscript: Many thanks to UncleNick who posted the cross-references showing IMR8208-XBR is plain old Aussie ADI AR-2210 See http://www.adi-powders.com.au/handlo...uide/rifle.asp Last edited by mehavey; October 10, 2011 at 11:16 PM.