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Weatherby Nation => Around the Campfire (General Discussion) => Topic started by: ND.257fan on March 03, 2009, 07:25:51 PM

Title: Powder/Cold weather effect
Post by: ND.257fan on March 03, 2009, 07:25:51 PM
Any handloaders out there ever checked velocity from say, 0 degrees F. to say 80 degrees F.with the exact same load. I've been reloading for many years but have never used a chrono. Thinking of purchasing one to check this. Just purchased aVanguard Sub-in 257Wby and am currently working on several different bullet/powder combos. 90 and 100 grain bullets. IMR7828,RL-22,IMR4350. It seems like the chrono would be a valuable tool. Thanks for any feedback. ND.257fan
Title: Re: Powder/Cold weather effect
Post by: zonie on March 04, 2009, 05:16:27 PM
I always test my loads on the HOTTEST DAYS using a chronograph.  Here's why without going into great detail,  the hotter  the outside temp the more pressure builds in your cartridges,  As I live in Mtns of  AZ and load a very stiff load during the winter months when temp is down to 15 to 20 F, and take that same load down in the Desert in summer when it's 115 F,  I know from first hand experience I will have sticky bolts or bulged cases from a colt auto.  When I load in the summer when it's 80 F ,  I never have that problem.  According to Sierra Exterior Ballistics a 100 degree swing in temp will cause a rifle bullet to shoot approx 200 fps slower and a handgun will be 100 fps slower.  A  50 degree swing in temp will shoot approx 100 fps  slower in a rifle, and a handgun will be 50 fps slower.  Type in www.exteriorballistics.com  then go to 4 th ed,  5.6  for more info.  Chronographs are very good tools,  Hope this helps.
Title: Re: Powder/Cold weather effect
Post by: Lee on March 04, 2009, 05:55:51 PM
I load for my 257 wtby mag. I load 73 grains of IMR 7828 under a 100 grain Barnes TSX. And get great results under a .5 moa. Now I have put mine through a chorno and got 3530 fps using 5 shots. But I haven't tested in extreme temp differences. I live in FL so until recently we don't get hugh changes like what you were asking about.
Title: Re: Powder/Cold weather effect
Post by: ND.257fan on March 04, 2009, 06:52:51 PM
 Some of what I have read in tech articles on how temp. effects pressures, which to me is somewhat obvious, I just haven't used a chrono in any of my reloading in the past. I do know that when at the range in the summer here in North Dakota, 80-90 degree days any of the long guns I happen to be shooting buck a bit more than when shooting out of my tree stand when It's -10 to 20 plus degrees during deer season. Anybody have any feedback on a fair priced chronograph ? I've seen prices from 100.00 to 150.00  Thanks for any feedback. ND.257fan
Title: Re: Powder/Cold weather effect
Post by: zonie on March 05, 2009, 08:09:05 AM
That's about right on price unless you decide to buy top of the line versions.  Cabelas,  Midway, internet would be places to look.  I have used a Pact model 1 for years and find it works very well.  I think you may be suprised at how useful this tool is to handloaders.  Some rifles I have checked shot velocitys well below what I was expecting and others have shot faster,  that's what is nice about a chronograph you can switch powders, primers, etc to get the velocity back to where it should be or higher with-in reason,  as an experienced handloader I'm sure you know there is always variables to consider  i.e. temp, altitude, BBL length, tighter chambers, bullet style, different brass, primers etc. which can have an affect on velocity's.  Your chronograph doesn't lie when used correctly,  It's going to tell you for sure good or bad what your loads are doing. Call me a woos,  I don't go out when it's freezing to test loads, where I test is 7100 ft next to an east facing 7500 ft hill  snow doesn't melt for awhile,  I'm usually out Elk or some other  hunting during  that time anyway.  I already know that if I test in the summer I'm not going to run into any pressure problems.  I'm sure there are a lot of people that  don't realize just how many variables in shooting there really is, and that's OK, this forum hopefully brings out different ideas that shooters will find helpful.  I would be interested in any findings and conclusions on your test data.  It's actually a good question. 
Title: Re: Powder/Cold weather effect
Post by: ND.257fan on March 05, 2009, 05:04:29 PM
Thanks Zonie, When you test any given combo, what do you use for a number for rounds shot. In the past I have used 10-12. I must be getting cheap in my old age because I have been thinking of going to 6-10 rounds per combo. 257 brass is a little more than 30.06 or 25.06 brass. Do you load for hand gun also? I've been looking into the Lee Pro-1000 for my .45. Any feedback on the Pro-1000? What is with the Federal primer issues with this unit? Lee says that the federal primers can go off sometimes!?? But that the CCI are OK!? I've used both primers with no problems on many other hand guns and long guns? ND.257fan   
Title: Re: Powder/Cold weather effect
Post by: zonie on March 05, 2009, 08:18:47 PM
Hi ND:  When I'm testing I usually shoot over a chronograph and for accuracy at the same time to kill 2 birds.  I always start with several  powders first with the same bullets.  I shoot 5 rd strings at 1 grain increments of each powder starting at a mid level load until I reach max or pressure signs appear.  I will try to use brass that has already been shot in that rifle, I think it is a little more accurate than new brass  i.e blown to the chamber.  Usually I can get a good bearing with just a few powders, and a couple of shots, no need to waste bullets.  I can pull them later and use them for practice.  If I don't get good groups, but good velocity,  I start over again with different bullets, then primers, and COL,  etc.  Once I get my velocity's/groups where I like I start tweeking/refining the loads.  Remember to let the BBL cool and clean as necessary,  take your time.  When starting with new loads I keep a 3-ring binder with a cheat sheet I made up and copied with all sorts of info i.e.  Rifle/Pistol,  scope, all load data,  velocity's, date, time, temp, wind, elevation, etc then I cut out and tape the target groups on the same cheat sheet to keep for reference later.  There are probably a lot of different ways to approach testing,  this is just how I do it.  I do load for handguns and usually use a Dillon 650 with all the bells and whistles, Some times I just relax and use a single stage press.  I have owned the Hornady progressive presses along with the 1050 Dillons and the High speed Ammo Loads, but to be Honest  a good single stage press and a Dillon 550B is really all anyone needs.  I don't want to ruffle anyones feathers, and have friends that use the Lee 1000 and works for them, but they don't shoot nearly the amount I do so I tend to get higher end reloading equipment.  I do like the lee pistol final crimp die and works very well on stuborn cases that won't no-go guage.   I live 180 miles from Dillon and bought a used one as a back-up, drove it down to them. they re-built it no questions asked at no charge.  In Rifles I tend to use Win and CCI primers, for Pistols.  If it's in a race gun with a light hammer drop I use Federal followed by Win.  CCI years ago had a bad rep for very hard cups and a lot of guys stayed away from them in their competition pistols as they did not go bang.   I don't know how they are now.  For rifles they work fine.  Federal pistol primers are more sensitative to firing pin impact, and Impact in general,  I suppose that's why they don't recommend them, or something in their priming design ?  I really don't know. Just a guess.  If you want to see primers go off crank up an Ammoload at 5000 rds an hour push the foot petal to the floor, only did that once,  they are great with new primed brass,  ours had scatter shields.   Retired now got rid of the Ammo Loads now back using the Dillons and RCBS.  Hope this helped
Title: Re: Powder/Cold weather effect
Post by: ahunter1989 on March 05, 2009, 08:29:06 PM
I reload the .300 in New Mexico and in the summer it always hits over 100, I take the same loads every year with me to Colorado and in November it is almost never over 0.  I have never seen a difference in my loads as far as ballistics from cold Colorado and hunting warmer New Mexico and in the summer when at the range.  Always dead on.
Title: Re: Powder/Cold weather effect
Post by: zonie on March 06, 2009, 09:14:04 AM
A little clarification :  I usually get the same field accuracy with wide temperature spreads.  Especially if you are shooting at relatively short ranges under 200 yds, with a very high velocity caliber standard hunting rifle you may or may not  see much change in your target,  and that's how it should be,  of course there are  variables and exceptions to every rule  i.e. extremely long ranges and altitude.   We are talking in general terms, for velocity ONLY  not accuracy.  Pressure and Velocity go hand in hand.  The biggest thing I am trying to get across is don't load in the dead of winter when temps are down 15 to 20 F , at  MAX  loads for that specific rifle ,  then take that same load to Phoenix in the middle of summer at 115 F , with ammo baking in the rifle or vehicle,  and not to expect some pressure issues. i.e. sticky bolts, flatter than average primers, case head expansion etc.  Every rifle is different.  If you look historically at how powder manufacturers error on the conservative side, they test their powders to shoot in all firearms as not to get anyone hurt, and rightfully so.  I have a loading book that dates in the thirtys and some of the loads in there in no way would I load today.  I load for 3 different 270 's and each has it's own load data and MAX threshold.  I don't switch brass between  rifles, each has it's own ammo boxes.  I load for an M1 garand, M1a and AR-15, and only use middle of the road recommended powders designed for those rifles, conversely when I load for my Bolt action 30-06 's and 308 's I load differently.   I  never go above MAX on any firearm,  and use only current load data for obvious reasons.  I do have friends that load way above book Maximums and don't have any problems, but these guy's are in the business of designing bullets and are extremely educated.  I just sit back and say that's pretty cool.  My Dad used a shell case with a brazed on handle 60 yrs ago to dip in the powder and fill cases, after he passed I actually checked the powder wt.  It was so far above max it was scarey.  Oh well. 
Title: Re: Powder/Cold weather effect
Post by: ND.257fan on March 06, 2009, 08:49:04 PM
Thanks For the Info Zonie, My parents gave me a RCBS RC-2 master kit when I was 18. I do have a few misc. pcs from Lee,Lyman, and others but nobody locally has ever kept Dillon on hand. I like to read about a product then look it over, sometimes the products quality isn't always there. I do know Dillon has a good product tho. I have always shot for accuracy(i guess we all do) for hunting and never thought about velocity much, until watching a few too many very nice bucks wander off at distances further than I felt I should shoot. I guess now with the 257 I'll shoot the heck out of it out to at least 400 yards. I put a Nikon Monarch 4x16 on it, I'm still not sure I made the best choice with this scope but I'll keep it for now. The eye relief is great but there is just something missing? Maybe my eyes are getting bad? Thanks for the other replies from everybody. ND.257fan
Title: Re: Powder/Cold weather effect
Post by: zonie on March 07, 2009, 08:13:05 AM
Hi ND :  Your RCBS is a great set-up,  you will use it for life.  The Dillons are great if you load and shoot a whole lot of pistol rounds,  I don't use them for rifles although I have friends that do.  I agree accuracy is more important to me than velocity.  Down the road I would get a chrnograph.  I can't help you on the scope,  my eyes have always been bad so I try to buy something with the best clarity.  I really do like the Zeiss Conquest.  If you have any questions just post a message.  Ron
Title: Re: Powder/Cold weather effect
Post by: Salty on March 07, 2009, 08:53:10 AM
I have found significent velocity variations between summer and winter shooting in Wyoming. I use alot of Varget to moderate the swings but have heard H4895 is also coated with temp control chemicals. I usually try to find a load 5% ish uncer maximum as I also like to take it easy on brass and barrel. You will see your 257 Weatherby shoots lighter bullets quite fast. I keep my 257 and 25:06 loads in the low 3000's to keep barrel wear down as I shoot them over 100 rounds annually. However if your rifle is a low volume use then crank it up as it is not a big deal as it will take several decades to hit 500 ish rounds which is where throat/ barrel wear will becomes an accuracy factor in the Weatherby Mags running full bore loads - excluding the 30-378.  A Lee Classic turret is a good choice for your single stage type unit and a Dillon 550 if you shoot higher volume are a good pair.
Title: Re: Powder/Cold weather effect
Post by: dubyam on March 07, 2009, 09:00:06 AM
I don't know what your experience has been, Salty, but 500rds is pretty early to see throat erosion affecting accuracy in the standard Weatherby calibers, even the 257.  If you shoot it hot, sure, it can happen quickly.  But properly cared for, even loaded at max, I suspect useful life prior to accuracy deterioration is more in the 1500-2000rd range.  I've several hundred rounds through my 270Wby, most all of them running at or near max velocity, and accuracy is first rate, the bore looks brand new, and I expect it to remain so for many more rounds to come.
Title: Re: Powder/Cold weather effect
Post by: ND.257fan on March 07, 2009, 01:02:25 PM
Zonie, I looked at the Ziess Conquest it came down to the price factor. I may use it for a few years then look at the Conquest harder. Salty, I put at least 500-800 rounds through several of my long guns each year and 250-500 rounds thru each of my 357 and 45 ACP hand guns also. Just got my 257Wby a month ago and already got 60 rounds thru it. As Dubyam said don't shoot it hot and don't shoot it hot. My 1903-A1 has some erosion but I wasn't alive when the gun was built and I don't know the whole history of the gun. Thanks all. ND.257fan
Title: Re: Powder/Cold weather effect
Post by: NDTerminator on March 10, 2009, 11:26:41 AM
I've had very good result with Hodgdon's Extreme Powders with consistent velocity & pressure across a wide range of temps.  H1000 is an excellent choice for the 257 Wby...