Long Range Canuck said:
I've chrono'ed a fair bit of Lapua factory ammo with the 250 gr bullets, and I've never seen velocities over 2760 fps from a 26" barrel. Quite an accurate bullet tho', at least in my TRG-S. FWIW - dan
reloading tolerances for precision shooting?
- Thread starter mbessey
- Start date
I've chrono'ed a fair bit of Lapua factory ammo with the 250 gr bullets, and I've never seen velocities over 2760 fps from a 26" barrel. Quite an accurate bullet tho', at least in my TRG-S. FWIW - dan
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
dan, that is very surprising velocity. The orig specs I saw was for 250gr bullet going 2950fps from a 26" barrel. Maybe the loads were much hotter back then??????
That's not much more zing then a 338 WM...
Jerry
That's not much more zing then a 338 WM...
Jerry
Well, I stand corrected. 
You guys have done the shooting at very long range to determine this.
I certainly would not have thought that +/- .2 gr would have made any difference at all in a load approching 100 grains.
Bad day when you don't learn something!
Ted
You guys have done the shooting at very long range to determine this.I certainly would not have thought that +/- .2 gr would have made any difference at all in a load approching 100 grains.
Bad day when you don't learn something!
Ted
Jerry, I load up to 2960-2970 in mine, with no pressure signs and reliable data, but the factory stuff that I've been able to get my hands on chrono'ed way slow. I'll see if I can get some of the Black Hills stuff and give it a whirl. As for the type and accuracy of the chronographs, yes, they're simply relative measurements, but when I get within 15fps from 3 different chronographs, I guess it's acceptable. - dan
windborne11
Regular
- Location
- SW Ontario
Weigh every load. otherwise how do you know for sure that "All of the powder" came out of the measure. A group gets pretty big when one of the cases is only half full. A pretty smart fellow that i shoot with weighs all of his finished cartridges. He must know a few tricks, Art was just inducted into the "Hall of fame".
Art weighs every loaded round to make sure he put the powder in them, trust me on this :lol: I used a cleaning rod to tap 10 bullets out of the barrel during a match :lol: That's what happens when the phone rings and you miss a whole row in the loading block
He does arrange the rounds in his box by weight. It doesn't really show a difference on his graff, but I think it is part of his mental game.
He does arrange the rounds in his box by weight. It doesn't really show a difference on his graff, but I think it is part of his mental game.
- Location
- Somewhere on the Hudson Bay Coast
Precision is about reducing variables. The guys who make money at this sort of thing strive for single digit variances in velocity. Once a rifleman has confidence in his ammo he knows that a good showing or a poor one is because of what he did behind the rifle. That is how you become confident shooter. So how do they do this?
Well lets start with the brass. When you purchase brass ensure it is all from the same lot number. Then go through the brass and cull out anything which has obvious defects - other than minor dents. You should check the neck thickness, and any cases that are way out from one side to the other should be culled as this is an indication that there could be issues with the thickness of the brass through out the entire length of the case.
Next weigh the cases and segragate them according to weight...this is far more important than weighing the powder to a tenth of a grain. You will find that most of the cases fall within a narrow margin, and this will be fine as a group. Next you will need to uniform your primer pockets and flash holes. European brass is often better than American brass because the case heads are machined and the flash holes are drilled, however the same steps should be taken with the European brass to ensure minimal variances. Next is to check neck runout, and if excessive the neck should should be turned...for maximum accuracy it should be turned anyway. Now you need to full length resize all the cases, and then trim and chamfer. The inside of the case mouth can be polished with 000 steel wool. At this point the brass you will concentrate on is very uniform.
Assuming you have a powder, primer, and bullet picked out, it's now time to start loading. I will assume that you have some ideas about seating the primer, and I concur with those who suggest powder should be weighed. Like the cases the bullets should be segragated by weight, and any abnormal bullets should be culled. Now the next part is important, and that has to do with bullet pull. The more consistant the bullet pull is from cartridge to cartridge the more accurate your ammo will be. There are two ways to do this; one is to crimp the bullet but often there is no crimping groove on match bullets and besides crimping round to round consistantly is problematic, which brings us to our second choice which is to seat the bullet firmly into the lands. I can already hear the howls of protest, but if your loads are worked up accordingly there is of coarse no safety issue. The initial firing of the new cases should show good results, but not as good as the second firing, because now the case matches the chamber.
After you have cleaned the fired brass, check the runout of the cases. If you have a good chamber it should be close to zero. Resize a case and see if the runout is still true, if not you may have to adjust your sizing die or replace it. This is where bushing style hand dies and bullet seaters really shine.
Some folks think that this is the time to start neck sizing and I don't have a good argument against that, except to say that many of the top long range shooters prefer to set the shoulder back very slightly...so that's what I do.
Not everyone follows all of these steps, and of course you will have to do what works for you, but this should help get you up on step.
Well lets start with the brass. When you purchase brass ensure it is all from the same lot number. Then go through the brass and cull out anything which has obvious defects - other than minor dents. You should check the neck thickness, and any cases that are way out from one side to the other should be culled as this is an indication that there could be issues with the thickness of the brass through out the entire length of the case.
Next weigh the cases and segragate them according to weight...this is far more important than weighing the powder to a tenth of a grain. You will find that most of the cases fall within a narrow margin, and this will be fine as a group. Next you will need to uniform your primer pockets and flash holes. European brass is often better than American brass because the case heads are machined and the flash holes are drilled, however the same steps should be taken with the European brass to ensure minimal variances. Next is to check neck runout, and if excessive the neck should should be turned...for maximum accuracy it should be turned anyway. Now you need to full length resize all the cases, and then trim and chamfer. The inside of the case mouth can be polished with 000 steel wool. At this point the brass you will concentrate on is very uniform.
Assuming you have a powder, primer, and bullet picked out, it's now time to start loading. I will assume that you have some ideas about seating the primer, and I concur with those who suggest powder should be weighed. Like the cases the bullets should be segragated by weight, and any abnormal bullets should be culled. Now the next part is important, and that has to do with bullet pull. The more consistant the bullet pull is from cartridge to cartridge the more accurate your ammo will be. There are two ways to do this; one is to crimp the bullet but often there is no crimping groove on match bullets and besides crimping round to round consistantly is problematic, which brings us to our second choice which is to seat the bullet firmly into the lands. I can already hear the howls of protest, but if your loads are worked up accordingly there is of coarse no safety issue. The initial firing of the new cases should show good results, but not as good as the second firing, because now the case matches the chamber.
After you have cleaned the fired brass, check the runout of the cases. If you have a good chamber it should be close to zero. Resize a case and see if the runout is still true, if not you may have to adjust your sizing die or replace it. This is where bushing style hand dies and bullet seaters really shine.
Some folks think that this is the time to start neck sizing and I don't have a good argument against that, except to say that many of the top long range shooters prefer to set the shoulder back very slightly...so that's what I do.
Not everyone follows all of these steps, and of course you will have to do what works for you, but this should help get you up on step.
Terry Perkins
CGN frequent flyer
- Location
- Bruce County
35 fps and .4 grains variance over 96 grains won't matter at 100 to 200 yards. As a matter of fact, 100/200 yard benchrest shooters could care less about velocity changes, as long they make itty bitty 5 shot holes. However, in precision shooting the distance stretches to possibly 800 meters...35 fps and .4 grain variances will suck, period. Another point...if you can't make small groups at 100 yards (ES has to be low also), you won't group well at 800. Change your primers, monitor your neck tension, etc. Consistency in reloading will cure a lot of problems.
Terry Perkins
Terry Perkins
Here is my two cents weighing individual charges matters for long range shooting. As most have already started the short range guys have different requirements then F class or F/TR shooter. For them a difference of +_ .2 grains at 100 or 200 yards in minimal but for folks that shoot at greater ranges 700, 800, 900 meters a higher extreme velocity spread will have noticeable effect. Instead of hitting the V bull with your load you are now in the 10 ring because the increased velocity of that one round was able to use one click less then your other shots. All of the top shooters weight each charge and go through pretty elaborate steps to get there.
One piece of equipment they go out and buy is very sensitive scale such as the one made by Denver. These scales and similar ones are so sensitive they can measure a single powder kernel. Then they throw a charge that they know is less then the desired charge and trickle each charge until they get the desired weight Check out 6mmbr.com and the article 284 and wind reading by Jerry Tierney. Jerry uses an electronic scale and powder trickler all in one called the Prometheus. I would have posted the link put it is currently down. He has a lot of great information on distance shooting.
If paying $255 US for an electronic scale seem a little extreme. (it does to me but I hope Santa is good to me this year..) You could concentrate on the bullets instead.
These next steps are more time consuming then money but will give you confidence that your bullets are consistent and you can start worrying about other aspects of the reloading process. Once thing you can look at is checking the Ogvie. Go out and buy TWO seating comparators either Stoney point or Davidson and attach them to your calipers. Take each bullet and measure the ogive and sort them into different piles. (You can buy a David Tubbs Ogive checker but there rather pricey unless you shoot a lot or have a few friends that shoot the same caliber.) Then reload each group so when you’re shooting you will have consistent jump from batch to batch.
Secondly get a melplate trimmer either from Dave Tooley or other reputable guys, and trim the melpate of each bullet. This will uniform the nose of the rounds and it has been shown to reduce the average group size.
All this work is on Match bullets using Game king or other hunting bullets have other variables that can not be accounted for.
Good luck
One piece of equipment they go out and buy is very sensitive scale such as the one made by Denver. These scales and similar ones are so sensitive they can measure a single powder kernel. Then they throw a charge that they know is less then the desired charge and trickle each charge until they get the desired weight Check out 6mmbr.com and the article 284 and wind reading by Jerry Tierney. Jerry uses an electronic scale and powder trickler all in one called the Prometheus. I would have posted the link put it is currently down. He has a lot of great information on distance shooting.
If paying $255 US for an electronic scale seem a little extreme. (it does to me but I hope Santa is good to me this year..) You could concentrate on the bullets instead.
These next steps are more time consuming then money but will give you confidence that your bullets are consistent and you can start worrying about other aspects of the reloading process. Once thing you can look at is checking the Ogvie. Go out and buy TWO seating comparators either Stoney point or Davidson and attach them to your calipers. Take each bullet and measure the ogive and sort them into different piles. (You can buy a David Tubbs Ogive checker but there rather pricey unless you shoot a lot or have a few friends that shoot the same caliber.) Then reload each group so when you’re shooting you will have consistent jump from batch to batch.
Secondly get a melplate trimmer either from Dave Tooley or other reputable guys, and trim the melpate of each bullet. This will uniform the nose of the rounds and it has been shown to reduce the average group size.
All this work is on Match bullets using Game king or other hunting bullets have other variables that can not be accounted for.
Good luck
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Another point; in short range BR, shooters also reload at the range because it is much easier to maintain 10-15 perfect (identical) brass and reload each brass 15-20 times over the course of a weekend shoot, than to even consider having 200 prepped brass. Throwing charges in exactly the same manner for every charge will eliminate the need to weigh provided a repeatable powder measure is used, and a powder that flows half decently. In many cases I doubt a lot of BR shooters even know off hand what the exact weight of their powder charges are, but they know the setting on the powder measure. 1000 yard guys will have different needs.
Rick Pollock
Rick Pollock
Why not? said:Actually, a variation of plus or minus .2 grain in a 96 gr charge is meaningless.
As well, weighing charges instead of throwing them with a good powder measure, is a lot of extra work that really won't make any difference on the target, especially in a case the size you are using.
If you speak with a dozen or so bench rest shooters, you will find that most of them use a good powder measure rather than a scale to charge the case, and they are concerned with shooting groups much smaller than 0.4 inch.
Ted
X1
+-.2gr is plenty for accurate powder charges. Match bullets are usually +-0.1gr IIRC. For long range shooting, the weather conditions impose a far greater variation that the powder charge
