Reply With QuotePiggys lOOk out Bobby's is going to play
Well, after getting some brass fireformed, I tried some hunting loads today -- and so far, I am impressed with the potential of this 20.5" Van Horn barrel. The load that got my attention in a hurry features the 95 grain Barnes TTSX driven by SW Precision powder. The first three-shot, 100 yard group went into less than 3/8th of an inch. Group #2 went 0.48. Two groups prove nothing, but it is confidence-inspiring to see such results.
I only verified zero at 200 and did not shoot any groups at that range since I don't have all that much brass ready to go just yet. But I did put one of those 95 grain Barnes bullets into a blend of semi-damp newsprint and bundled cotton fabric at 200. I did not use water or fully-soaked newsprint. Those tend to create more hydraulic effect and generally result in wider mushrooms. But I have no complaints from what I saw. The widest part of the mushroom measure 0.597" while the narrowest is .536".
I did not clock it at that range. But the program I use indicates impact speed should have been around 2350 fps. One day, I'll run the load over the chronograph at that range to get an actual figure.
The Hornady 120 grain SST also did well, though I hate the cannelure being so far out of the case. It just looks odd to me. Nonetheless, the one group I fired with this bullet and SW Precision measured 0.69 for three shots at 100 yards, and the velocity at 15 feet averaged just a bit over 2600 fps.
Here's the recovered Barnes bullet. Pardon the poor quality phone image.
Piggys lOOk out Bobby's is going to play
I hope that's right, Sunny. Haven't seen a pig here in a long while, though there is fresh rooting just two pastures over.
Forgot to mention: for fireforming, I am using IMR-4320 and Nosler 140 grain BTs (blems from SPS). That load shoots very well and would even do for modest-range hunting in a pinch.
Impressive groups. Were these your first attempts? You’re definitely going in the right direction. Great bullet performance too.
Those were the first groups in fireformed brass. To conserve expensive components, I started lower in the powder charges, would fire one over the chronograph, examine the brass and then continue to work up until I got into my target velocity range. Then I fired a group.
In burning up fireforming loads, at one point I fired six at 200 yards and got a group that went about 1.8".
How do you decide on your target velocity? Which chronograph are you using, Bobby?
I don't know Bobby that's pretty bad 1.8 at 200......that would be a stopping point for me
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.Originally Posted by BT
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.
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.
Keep us posted. I’m enjoying being along for the ride on this one.
I really wish Nosler would make another big run of those bullets, I have a Wolverine barrel that dotes on them!
It's better to shoot for the moon and hit the fencepost than to shoot for the fencepost and hit the ground!
If I run across any, I'll drop you a line and let you know.
Thanks Bobby, I'll do the same!
It's better to shoot for the moon and hit the fencepost than to shoot for the fencepost and hit the ground!
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.
Cool photo. Those short-necked cartridges are quickly coming together for you. Bring on an oinker!
Bobby...was nosing around looking for some other data i had saved some time ago, and stumbled onto i had stashed back at some point...just noticed it had a wee bit of 270jdj data:
Thanks! I appreciate it! I was actually shooting it at 200 yards today after tweaking my primary load just a bit.
Both groups were impressive. The point-of-impact was about 3/4" high, but I will leave it that way as there was a bit of a tailwind this morning. I suspect on a calm day -- if we ever have one of those lol -- it will be dead-on.
This is my 5th Van Horn barrel, and each one has shown exceptional accuracy. Some of you may remember the full-bull Encore barrel I had in 6.5x55 as I used to post about it during the early days of SP. I routinely shot that DVH work of art at 300 yards, and it would keep three shots in an inch or less with monotonous regularity. It shot everything well, but Re-22 and the 140 grain Sierra GK was simply magical in that barrel.
Here's one of the 200 yard groups from today:
Nice!! I can usually count on 100 yard groups looking like that with the proper loads through a few different Contender set-ups but I don't think I've ever managed that nice a group at 200. :)
Got a few loaded this evening. The sight of these makes me smile. But I'd smile more if I could send one into the direction of a big hog.
Posting Permissions
Bookmarks