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Joined: Aug 2011
Posts: 182
Campfire Member
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OP
Campfire Member
Joined: Aug 2011
Posts: 182 |
I have 2 youth rifles in 243 Winchester. One is Remington 700 youth. The other is T/C Venture compact. Both have 20" barrels and are less than a year old. Accuracy with every load tried is averaging from 3/4 inch to 1 1/2 inch at 100 yards. No complaint there. In working up deer hunting loads for these rifles I am getting very low velocities compared to published data. I am loading 1/2 gr under max published data. I am working up loads for 95 sst and 100 sp Hornady bullets using H4831sc, imr4064, and imr4350. The chronograph velocities are running 200 fps to 300 fps lower than published data by Hodgdon and Lyman. The highest fps is 2705 using H4831sc with 95 SST bullet. Both rifles are giving fps readings within 25 fps of each other. I realize that I am shooting out of 20" instead of 24" bbls. What is your experience with 20 bbl velocity?
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Joined: Nov 2011
Posts: 30,908
Campfire 'Bwana
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Campfire 'Bwana
Joined: Nov 2011
Posts: 30,908 |
As a rule of thumb, the greater the bottle neck the more barrel length matters. You are giving up 4" of barrel vs. most published data, so that sounds about right.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
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Joined: Nov 2009
Posts: 6,867
Campfire Tracker
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Campfire Tracker
Joined: Nov 2009
Posts: 6,867 |
I carry a .243 Bullberry, 20" barrel a lot as a jeep gun, here on the ranch, kills everything I point it at using 85 gr. bthp, H-4895, whitetail,axis,and some big pigs,shoots under 1" at 200 yrds,want to go faster use a smaller bullet. Rio7
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Joined: Nov 2008
Posts: 8,614
Campfire Outfitter
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Campfire Outfitter
Joined: Nov 2008
Posts: 8,614 |
Youth model, 3/4 " and you are worried about velocity being off book out of 20".
Last edited by Swifty52; 07/05/15.
Swifty
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Joined: Nov 2011
Posts: 30,908
Campfire 'Bwana
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Campfire 'Bwana
Joined: Nov 2011
Posts: 30,908 |
Youth model, 3/4 " and you are worried about velocity being off book out of 20". Give him a few more years of chronographing and he will learn the books are just a guide. If the books were right for our guns, no one would buy chronographs.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
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Joined: Jun 2004
Posts: 44,805
Campfire 'Bwana
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Campfire 'Bwana
Joined: Jun 2004
Posts: 44,805 |
I'm using a barrel that was a Rem 700 take-off I had my gunsmith fit to my action and cut off at 20". Depending on which 95-100 grain bullet is being used, 41 grains of IMR4350 is giving 2830 to 2890 fps averages as reported by my Oehler 35P.
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Joined: Jul 2001
Posts: 60,054
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,054 |
antelope sniper,
And if nobody had chronographs, they'd assume their rifle got the highest velocity listed in any "book." And they'd go out and kill stuff.
This is exactly what happened before everybody could buy "personal chronographs."
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
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Joined: Feb 2006
Posts: 2,483
Campfire Regular
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Campfire Regular
Joined: Feb 2006
Posts: 2,483 |
Lots of people still out there doing that exact thing MD. I've had more than one friend that was shocked to learn how much slower his handloads were compared to book velocities after running them across a chronograph Some had been blissfully slaying game for years with slow loads
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Joined: Nov 2009
Posts: 6,867
Campfire Tracker
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Campfire Tracker
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You can have the fastest bullet in the world won't due any good unless you can hit what your shoot at were it counts. rio7
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Joined: Jul 2001
Posts: 60,054
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,054 |
PaleRider,
Yep, that happened a lot when the first chronographs appeared. I bought mine in 1979, and when at the local range other shooters would often approach me, asking if they could fire a few rounds to see what the velocity was. They were invariably disappointed, even with loads they'd been slaying deer and elk with for years.
In fact it happened to me, with that same chronograph....
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
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Joined: Feb 2006
Posts: 2,483
Campfire Regular
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Campfire Regular
Joined: Feb 2006
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MD, I have to confess to having BTDT myself back in the day
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Joined: Feb 2004
Posts: 17,094
Campfire Ranger
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Campfire Ranger
Joined: Feb 2004
Posts: 17,094 |
John, I still remember when I got my first Chrony in the early eighties. My exquisite 270 load with a 140-gr Hornady BTSP with H4831 was finally "clocked." I had shot numerous antelope and mule deer with it and it was very accurate--it was the berries!
When a five shot average showed 2700+, I was aghast and went ito a mild depression. Though the bad dreams have ended I still remember it.
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Joined: Jan 2001
Posts: 28,365
Campfire Ranger
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Campfire Ranger
Joined: Jan 2001
Posts: 28,365 |
When I first got a chronograph with skyscreens I too was a bit disappointed with some of the velocities my loads were showing.
So, I moved the screens 1" closer together and that put the velocities back where I wanted them....
Gunnery, gunnery, gunnery. Hit the target, all else is twaddle!
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Joined: Jul 2001
Posts: 60,054
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,054 |
Now THAT'S out-thinking the machine!
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
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