preliminary results with the .270x.225 DVH (.270 JDJ) barrel

[Bobby Tomek]

How do you decide on your target velocity? Which chronograph are you using, Bobby?

I simply go by past experience and interpolate from similar cartridges. For instance, with the .270x.225 DVH, I used both the .257 and the 6.5 JDJ as gauges. So if the 6.5 gets "x" velocity with a 120, it stands to reason the .270 will be able to match or potentially exceed that due to a slightly larger bore diameter, although many variables can come into play. I consider other factors, too, and all of this gets me into the ballpark as far as a target MV.

My goal for this 20.5" barrel was to reach 2600 fps with the 120 grain SST and 2850-2900 fps with the 95 grain Barnes. The round is actually capable of a bit more in the Contender, but I like to stay on the conservative side. Plus, with only 100 pieces of brass, I want to make them last as long as possible.

As to the chronograph, I currently use a Caldwell Ballistic Precision unit and always try and use it under the same type of lighting conditions. So far, it's done very well, though the "trust but verify" aspect does come into play with me. If something seems amiss, I dig out my well-worn, 8" Dan Wesson .22 LR that I've had since the late 80s. It's been tried on a number of chronographs, including the Oehler I had for about 10 years. With one particular load, you can count on it registering between 1048 and 1060 fps as long as the ambient temp is above 65. It's been remarkably consistent over the years. I actually took out the DW yesterday, and the two rounds fired across the chronograph went 1050 and 1052 fps. It may not be a scientific approach, but it's good enough for what I do and actually outed a Pro Chrony unit I had a few years ago when it began reading in the high 1100s with the DW.

[Bobby Tomek]

Forgot to say: If the terminal performance of that 95 grain TTSX doesn't impress, then my next try will be the 130 grain Ballistic Tips. I figure I could safely get them to 2500-2525 fps with ease. That would still equate to around 2000 fps at 300 yards -- well within the range of expansion for that bullet -- while providing more than 1100 ft./lbs of energy.

I wish I could have located some of the 100 or 110 grain Accubonds as I feel they'd have been optimum for this one, but my searches turned up nada.

[BT]

Keep us posted. I’m enjoying being along for the ride on this one.

[BobT]

I wish I could have located some of the 100 or 110 grain Accubonds as I feel they'd have been optimum for this one, but my searches turned up nada.

I really wish Nosler would make another big run of those bullets, I have a Wolverine barrel that dotes on them!

[Bobby Tomek]

I really wish Nosler would make another big run of those bullets, I have a Wolverine barrel that dotes on them!

If I run across any, I'll drop you a line and let you know.

[BobT]

If I run across any, I'll drop you a line and let you know.

Thanks Bobby, I'll do the same!

[Bobby Tomek]

I fireformed a bit more brass for the Van Horn .270x.225 Imp barrel today. To make it a bit more entertaining, I hauled the 10" gong out into a clearing that lasered 231 yards. Knowing that the f-f load would be quite a bit low at that range, I held on the horizontal tab (where the chains attach) atop of the gong and fired away. The first shot hit about two inches from the bottom of the gong and dead-center. Over the course of the next hour or so, I sent 19 more downrange. I did not bother to measure the spread, but you probably could cover them all with a decent-sized orange.

This one is definitely growing on me...

Now I just need a cooperative hog to let me christen it and see how those 95 grain TTSX bullets will do for me.

[BT]

Cool photo. Those short-necked cartridges are quickly coming together for you. Bring on an oinker!