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FALPhil Super Member
Joined: Aug 18, 2007 Posts: 377 Location: Dixie
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Posted: Fri May 30, 2008 12:19 pm Post subject: Re: 308 Win. reloading |
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wncchester wrote: |
It's a common fallicy to say that "best accuracy" comes from seating into the lands and many people agonize over how to accomplish that with long factory chambers. |
I am not sure how true that statement is. I never met a non-competitor that was worried about seating bullets out to the lands, and I never met a serious competitor would was using a factory issued barrel with a long leade.
wncchester wrote: |
Touching the lands tends to be true for BR rifles, they often seat bullets shallow and soft. That's not the way of ours, we usually seat so the bullets are firmly held in the cases, about a full caliber deep. We get better accuracy with our bullets seated back off the lands. That does give our bullets a running start before striking the lands and it holds pressure down a little. |
Where the ogive sits in relation to the lands and how it affects accuracy varies from rifle to rifle based on a variety of factors and there is no one rule that applies to all rifles, or even one particular model of rifle. Each rifle is its own unique platform, so that your Remington 700 in 308 may be most accurate with the ogive of your Hornady A-Max 0.020 off the lands, while my Remington 700 in 308 just two serial numbers behind yours may be most accurate with the A-max ogive just kissing the lands.
_________________ The Wicked Witch of the West is alive and well and serving as the Speaker of the House. |
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wncchester Member
Joined: Apr 08, 2006 Posts: 160
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Posted: Fri May 30, 2008 3:56 pm Post subject: Re: 308 Win. reloading |
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Phil, we are in otal agreement. You said it better that I.
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shadowdrak Rookie Member
Joined: May 18, 2008 Posts: 13
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Posted: Sun Jun 01, 2008 7:06 pm Post subject: Re: 308 Win. reloading |
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I finally got my Lyman 48th edition (no easy feat since alot of people were sold out on them). Just got a RCBS Rock Chucker Supreme reloading kit and some other odds and ends it say I will need.
I'm thinking of first trying out Seirra 165 grain spitzer boattail rounds. Will these work out real good for a 700 with a 26" barrel with 1:12 grooves? I heard that the 5R barrel with it's 1:11.25 grooves is better suited for 180-200 grain bullets, so I figure a slightly lighter bullet will work better for the longer grooves.
Also after reading the manual, it stated that some rifles do perform differently with variations in length to the grooves and to try using different round lengths to determine the best accuracy for that particular bullet being used. How do I make a dummy round that will give me the length I need to determine the distance (i.e. distance from neck to landings with bullet ogive touch)? I wasn't able to find anything in the manual to show me how to accomplish that (just states using a dummy round and working from there).
Thanks for all the help guys. I don't really feel to nervous getting started in this like I thought I would. I'm looking forward to start my reloading (haven't been able to start because I'm waiting on my brass getting here and they were on back order, I guess you have to order ahead of time if you want to get the good brass. I order Lupau brass.)
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11395 Location: Ava, Missouri
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Posted: Mon Jun 02, 2008 8:39 am Post subject: Re: 308 Win. reloading |
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If you use the "sliding bullet" method. Seat the bullet of your choice in a case. Using a "error eraser" (enertia hammer) pull the bullet. Now reseat the bullet long and insert it in the chamber and close the bolt slowly and lock it. Now carefully extract it and measure it for OAL. Remember that the soft nose bullets will not give you an accurate measurment for each bullet. You will also need special gauges that measures from the same point on the ogive to be consistent. The same is true using the "lamp black" method. The soft pointed bullets are not the same length because of damage that may have occured during packaging and shipping...Full metal jacketed bullets will be closer, but if you plan to see how close you can get to the leed rifling you will need the gauges...
After all this and you still wish to try one of these methods...Remember if you experience hard closing of the bolt at the end of the stroke as you lock it up. You are jamming the bullet into the rifling or the case length is too long and you are jamming the case mouth into the barrel mouth or the shoulder is too long for the chamber...Just a few of the things you need to be aware of when reloading bottle neck cases...
By The Way...When using an "error eraser" to pull delicate nosed bullets. Put an ear plug in the bottom of the hammer. This will protect the soft point from damage.
_________________ I have one nerve left and yer standin' on it...
DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote... |
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11395 Location: Ava, Missouri
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Posted: Mon Jun 02, 2008 8:59 am Post subject: Re: 308 Win. reloading |
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Couple more notes about adjusting the OAL of a rifle cartridge. The more you push a bullet close to or into the rifling the higher the chamber pressure will be. Some rifles don't care and some do. Not all rifles require the bullet to be as close to the rifling as you can get it to be more accurate. I have had rifles that liked a .030" bullet jump. On the other hand my Browning A-bolt .30-06 using Sierra 165 grain HPBT prefers to have a .005" jump...
I know some people that jam the bullet into the rifling by closing the bolt on a too long cartridge. I sometimes think they have been lucky that their rifle is forgiving...
_________________ I have one nerve left and yer standin' on it...
DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote... |
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Vince Site Admin
Joined: May 25, 2005 Posts: 15725 Location: Brisbane AUSTRALIA
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Posted: Mon Jun 02, 2008 6:38 pm Post subject: Re: 308 Win. reloading |
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As Busy says shadowdrak...check your seating depth of the bullet. Also, have a look at the articles found on the Home page. Below are links to a couple of them.
How do I "tune" a load to be more accurate?
Accuracy Tips
Cheers, Vince
_________________ Cheers, Vince
Illegitimi non carborundum
(Never let the bastards grind you down)
Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God.
"Nulla Si Fa Senza Volonta."
(Without Commitment, Nothing Gets Done) |
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shadowdrak Rookie Member
Joined: May 18, 2008 Posts: 13
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Posted: Fri Jul 04, 2008 7:51 pm Post subject: Re: 308 Win. reloading |
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I was wondering if I just neck size my brass, do they still need to be lubed? I figure the FL sizes the whole case, thus the lube, but the neck only die contacts just the shoulder and neck which doesn't get lubed when I roll them.
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PaulS Super Member
Joined: Feb 18, 2006 Posts: 4330 Location: South-Eastern Washington - the State
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Posted: Fri Jul 04, 2008 9:28 pm Post subject: Re: 308 Win. reloading |
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If you get a carbide neck sizer you don't need to lube at all.
If you are going to use your FL dies to partial size then you need to lube the necks, inside and out.
_________________ Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads |
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Vince Site Admin
Joined: May 25, 2005 Posts: 15725 Location: Brisbane AUSTRALIA
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twofifty Member
Joined: Feb 07, 2007 Posts: 158 Location: BC Rockies
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Posted: Fri Jul 04, 2008 10:35 pm Post subject: Re: 308 Win. reloading |
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shadowdrak, if I may clarify something that is important to your choice of bullet weights..... You speak of "a 700 with a 26" barrel with 1:12 grooves", then of a "5R barrel with it's 1:11.25 grooves".
Figures like 1:12 describe a barrel's twist rate. In your Rem 700, the twist rate is 1:12, which means that as a bullet travels 12 inches down your barrel, it will be forced by the rifling to undergo a single complete revolution - regardless of its weight. Note that differences in barrel length neither change the twist rate, nor the number of forced revolutions per distance travelled that the bullet undergoes.
A lot of .308 hunting rifles have twist rates of 1:10 or 1:12. You are correct that heavier for caliber bullets (i.e. longer bullets) will perform (stabilize) better in lower ratio twist rates, as they stabilize optimally at higher RPMs.
To see what the rifling does to a bullet, simply retrieve a fired bullet out of an animal or a backstop. Look for very lightly spiraled (and lightly engraved) grooves in the bullet's jacket; the groves were cut by the high portion of the rifling, called the "lands" (not landings).
Finally, when measuring a round's length, you will find that the overall length varies by several thou amongst bullets from the same box - apparently these small variations are not significant. It is more relevant to measure bullet length from the base to the ogive, using a bullet comparator device. Others here have explained that process to you. Heavier bullets are necessarily longer from base to ogive, so they experience more friction (resistance) in the barrel. The lower twist rate ratio also increases this friction. That may or may not be the reason why powder loads are lighter for the heavier bullets....which is counter-intuitive and came as a big surprise to me. Others here might chime in on this aspect ?
Speaking of feeling nervous, that describes my state of mind before touching off my very first reload, about 1.5 years ago. I am sure you will enjoy learning about the process as much as you will sending them downrange.
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Pumpkinslinger Super Member
Joined: Sep 22, 2007 Posts: 5002 Location: NC foothills
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Posted: Sat Jul 05, 2008 11:23 am Post subject: Re: 308 Win. reloading |
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Twofifty, the powder charges are lower for heavier bullets because you have to stay under the maximum pressure while pushing more weight and having more friction (longer bullet generally has more bearing surface).
To take the idea to extremes as a simplified example imagine a blank cartridge with no projectile. The pressure in the chamber would hardly build up at all. Then take a cartridge fired in a blocked barrel. The pressure would build until something gave way to release it.
_________________ Mike
"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle |
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shadowdrak Rookie Member
Joined: May 18, 2008 Posts: 13
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Posted: Mon Jul 07, 2008 2:12 pm Post subject: Re: 308 Win. reloading |
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Reloaded my first batch of bullets. Got another question now.... I noticed some of the bullets have a slight mark running about half down the bullet and all around. I believe it's from the RCBS seating die marking the bullets, is this normal? If not, is their a way to remedy it (i.e. different brand of seating die)? I'm just worried that this might affect long range accuracy by affecting the areodynamics of the bullet. Thanks for all the help so far.
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PaulS Super Member
Joined: Feb 18, 2006 Posts: 4330 Location: South-Eastern Washington - the State
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Posted: Mon Jul 07, 2008 2:15 pm Post subject: Re: 308 Win. reloading |
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Clean the seating plug and the bore of the die with solvent and then use some 000 steel wool on a wooden dowel, in a drill, to polish both.
_________________ Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads |
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shadowdrak Rookie Member
Joined: May 18, 2008 Posts: 13
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Posted: Mon Jul 07, 2008 5:44 pm Post subject: Re: 308 Win. reloading |
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Thanks for the tip PaulS
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PaulS Super Member
Joined: Feb 18, 2006 Posts: 4330 Location: South-Eastern Washington - the State
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Posted: Mon Jul 07, 2008 11:34 pm Post subject: Re: 308 Win. reloading |
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Shadowdrak,
We share what we know - no bother at all, you're welcome.
_________________ Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads |
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