Case weight??

[muledeerarea33?]

I'm loading for a 243 Winchester, have loaded a lot before but never was concerned with case weight. I range from 158-162 grains, the majority being 161 and 160. I know to load the weight class together but how much difference would it make putting them together or let's say, a 162 grain case with a 160? Enough to notice, without a lead sled?

[PRDATR]

In a factory rifle and chamber you are not going to notice enough if a difference to amount to anything due to the inherent differences compared to a rifle with a match chamber and blueprinted action.

If your rifle is consistently capable of being able to cover 10 shots with a dime at 100 yards then you can weigh cases and bullets and sort them but it's not really necessary in a big game hunting rifle under field conditions.

[Couzer]

I noticed a big difference on my Sps factory RUM. I think it depends on how you like your groups at a 100 yards? 3-4 inch to a 1/2 inch group? And just think as you go farther out to 200 yards, 300 yards, etc, the groups will increase in size.

I bought 5 bags of factory RUM brass at Sportsmans, prep it, weighed it and kept the 50 that was more consistent in weight. Sold the rest on eBay. Now I can just buy nosler brass all weighed for cheaper than buying a bunch and sorting it. One or even a half a grain makes a huge difference in my opinion.

[muledeerarea33?]

I'm getting around 1/2 in at a hundred, 5 round groups, I haven't had a prolbem with 223 30-06 7mm or 223 wssm but all this Winchester 243 brass is different

[PRDATR]

I'm getting around 1/2 in at a hundred, 5 round groups, I haven't had a prolbem with 223 30-06 7mm or 223 wssm but all this Winchester 243 brass is different

 

Thats decent enough to shoot PD's out to 400 yrds and sorting cases and bullets by weight "should" tighten up a group. Curious, what are you doing to prep those cases and which primers are you using?

 

One thing you can do is take one case of each different weight from low to high and using bullets that all weigh exactly the same and hand weighing each charge shoot a group and see how it compares to another group using the same amount of cases that weigh exactly the same, then compare the results.

The weight difference of two grains would not be of big concern to me as it "could" be in the base which would not effect the actual case capacity and that is what decides the consistency of pressure and ultimately, velocity. Provided that OAL, case length etc are equal and thus removed from the equation.

Chronographing loads is helpful and an the information logged is useful when developing pet loads.

[rcdinaz]

I have done the case sorting, bullet sorting, meplat, trimming, neck turning, etc. If you are trying to get really small groups for competition all of them have their place I guess but I have come to the conclusion that the work yields very small if any differences in most cases. One thing I do think is a big deal is the quality of the cases. If you are going to spend all of this time then I would switch to Lapua cases or like said by matched cases from, Hornady. The Lapua stuff is far better than any of the others with machined flash holes, etc. and it is usually all very close in case weight. On the other stuff I usually make three groups from new brass and load the largest group of matched within a few grains for my hunting, final load testing, and +700 yd targets. The other stuff I use for coyotes, shorter target shooting, fouling, or other times where I know it wont make a difference.

 

After watching Shawn Carlock's reloading video, the stuff from Gunwerks, Fr. Frog's site, and some of the articles on Accurate Shooter there are a lot of long and very long range shooters who spend a lot less time on this stuff then you would think. What they all do is shoot A LOT.

[muledeerarea33?]

For case prep I always clean in media, clean the pockets and flash holes and then in a solvent tank, clean with brake cleaner, let dry, size and trim if they need trimming and then weigh them. I only do that whole process on hunting and target loads, not for pistol or bulk loading. I weigh every charge and every bullet and even primers although the federal match primers are usually right on. I try to be close in weight when it's all said and done, just wondering how much the case weight itself has to do with accuracy

[rcdinaz]

Wow! I have never weighed a primer in my life. I do all the other steps you mentioned as well but have never used solvent. Have been kicking around getting a steel media tumbler.

[muledeerarea33?]

Lol I got curious one day and found some cci's to be quite a bit different in weight. Not sure if it matters? But I figure if I'm gonna load 40 or so rounds for practice before a hunt and use during a hunt I might as well spend a little extra time for perfection, never know if its a chance of a lifetime or not. As far as the solvent and brake clean goes, I get to do that part at work for free and takes no time at all for a slightly cleaner case. Again, not sure if it helps?

[PRDATR]

Don't weigh primers it won't really get you anywhere. I have always used CCI Benchrest Primers in rifle cartridges. Don't use brake cleaner or solvents as they can make the brass brittle.

On new cases uniform and deburr the flash holes and chamfer the inside of the case mouth. Some rifles shoot everything well while others shoot bullets with a specific profile at a certain velocity best.

With a 160 gr case vs a 162 gr case the difference percentage wise is just over 1%. Not very much and unless you fill each case with water and weight it you can't be certain if that deviation is in the volume of the case ot the weight of the case itself.

I'm no math wiz but if the difference is say 1.25% and it is actually in the volumn of the case then a 243 case at an average charge weight of 45 grains we are looking at a case volumn maximum deviation of less than 1/2 a grain, to the case mouth.

If you weigh each charge using extruded powder there will be a bigger difference than using ball powder just because ball powder is finer and getting a more exact charge weight has a higher possibility.

Some cases like the 222 and 6mmPPC are inherently accurate and squeezing each cm of accuracy from them is less of a chore. Last thing you want to do is wear out the barrel and spend hundreds of dollars chasing clover leafs or one hole groups if taking snap shots at Coyotes or Coues at 200 yards on a windy day is what the rifle will spen 95% it's time doing.

[muledeerarea33?]

I'm not a bench rest competition guy, justly me shooting. I'm not worried about 1 hole groups but do love accuracy. I loaded this morning and just got done shooting, 42 grains imr4350 100 grain Sierra btsp. Weighed all components but used 2 brass of a different weight, 3 rounds touching at a hundred, the two with different case weights were off the rest of the group around 1/4 inch one left and one left low. Maybe I pulled those shots maybe its the weight difference? Like I've said before, I don't know? Lol that's the reason of the topic I started. And I'm certainly not gonna argue over a quarter inch, I just find it intriguing.

[muledeerarea33?]

Also, at 42 grains I had a max velocity difference of 36 fps. What would you guys consider acceptable?

[PRDATR]

I spent part of the afternoon at Rio with my son re-sighting in for our hunt next month. I usually pick a bullet, (Nosler Partition, Sierra Match King, etc) for a specific task, then work up the load.

Accuracy is nice but not always the destination. That, is what I expect of the terminal performance of the bullet.

Example, if I'm hunting coyot's. I want a bullet that gives me 2 MOA and dosen't exit because I know I will not be taking shots past 300 yards.

[muledeerarea33?]

I've had this gun less than a month, left to me by an uncle who passed. I might use it for my mulie hunt just to honor his memory. If I do I'm loading partitions or vld's probably. Might stick with what I'm already using. I don't really have an intended purpose for this particular rifle other than making it shoot the best it can and having a good memory.

[PRDATR]

All the standards we have for rate of twist were achieved around lead core bullets. Newer bullets of copper and ballistic tips make the bullet longer upsetting the apple cart.

Neccissating reinventing the wheel.

You're groups are great so go make some memories.