Re: school me on the .243
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 264Charlie</div><div class="ubbcode-body">I have put a lot work into choosing a cartridge for the past few months and figured I would share the results of my findings. Please note this is for Practical Precision shooting (PPS) from 50 – 1000 yards on steel or paper.
The players:
6mm: Includes 6x47 Lapua, .243, 6superLR and other similar cartridge
6.5mm: Includes .260, 6.5x47, 6.5CM, 6.5superLR and other similar cartridge
.308: I don’t really know of another 30cal round used. You can include any similar 30cal cartridge.
.223: I don’t really know of another 22cal round. You can include any similar 22cal cartridge.
7mm: Any of the big magnums 7mm. This includes WSSM, RSUM…
Why did I lump all the similar rounds together? Well, despite how much I love to argue the .260 vs. Lapua there is not much difference in the game we shoot (PPS). Which I guess leads us to the first area of concern accuracy.
What is the level of accuracy one should strive to achieve with a PPS gun? Really we are looking for 3/8 MOA at best. Remember this is off a folding bipod with a tactical style rear bag. We don’t shoot BR and it is very unrealistic to look for BR accuracy of a bipod. If your gun is more accurate than 3/8 MOA on a rest it does not matter at all. I have seen a few Randall built guns achieve this accuracy with properly developed loads and a good shooter. I know other builder’s rifles will too; I just don’t have much experience with them.
Reloading is something I personally was hoping to “game the system” on. I thought man if I point my bullet, neck turn my cases, bla bla bla my gun would be more accurate then the next guy and I would beat him. This is simply not true. You only need to spend as much time to get you gun shooting ½ MOA and you are good to go. The real advantage is ladder testing to find the best performing load at 600+ yards.
Remember even if you do all the cool brass and bullet prep tricks on 6mmbr.com you are still gong to struggle shooting better than 3/8 MOA of the bipod. Then you will most likely lose the bass in the big matches you spent hours working on.
Before I get into the specifics of the cartridges let’s review the guns themselves. What make up a PPS comp gun? Well, we first must look at what we use them for. They are used prone, positional shooting, moved and packed in competition. We also use them for shooting both short and long distances in varying weather conditions and environments.
Lets break it down.
The Rifle including all parts should come in around 16#. You can go heavier if you are large framed guy. For the average guy this is about as heavy as you want to go.
Actions: Actions should be true and straight. Have the clearance needed to perform with some grit or water in them. Do you need a custom action to do this? NO. Will a fluted bolt help? NO. Take cosmetic upgrades for what they are, cosmetic. The cool new BR actions might be the best thing ever but it’s not the best choice for PPS.
Short actions are the preferred action for what we do. They allow most shooters to stay on the gun when cycling the bolt, they are lighter and stiffer than Long actions. Long actions could allow you to run a “middle” cartridge like a 6.5/284, a round that sits between the 6.5mm and magnum 7mms. Only go down this route if you are a shooter with a large frame, 6’2” plus.
Barrels: A few things to look at like SS vs. CM, bottom rifling vs. cut… Bottom line is you want a cut rifle barrel form a good vendor. Why is beyond this article.
Contour: Contour is one that is often over done in “tactical” shooting. What is tactical shooting anyway? I look at our sport as practical precision shooting (PPS). We are required to make the 1st & 50th round hit in competition without time to clean or prep the barrel in anyway between rounds. The rifle must be shot off hand, prone, out of a car and transported during the matches. I often see the guy building “tactical” rifles installing a MTU or other truck axels because it looks cool. If you do this that is fine but please know it is only a cosmetic upgrade will most likely hurt you in the end.
The recommend barrel contour is a standard or medium palma barrel. This will allow you to shot long strings of fire balanced with portability. If you are shooting a big 7mm round or .308 a heavy palma might work better because of the large bore of the cartridge. Only do this if your frame allows you comfortably use the rifle. Once again the larger framed shooters have an advantage here. A 6’4” 230 guy is going to be able to shoot a heavier rifle than me at 5’11 – 175lbs.
What about barrel length? 26” is the standard; you can go up to 28” if you are trying to squeeze a few extra FPS or down to 24” if it helps you shoot better. All of the short barrel, tight bore crap is BS and please don’t pay any attention to it. Every inch you remove off your barrel you will lose velocity. A tight bore barrel will not help you gain speed back all it does is raise pressure with the same powder charge. We don’t need to raise pressure with a tight bore barrel because when reloadingwe can just add more powder. Adding powder will always give more velocity than seating into the lands or tight bore barrels to get the pressure up with a lesser powder charge.
Triggers: Can’t go wrong with a Timney. They work well and are proven reliable. Jewell and others are nice, very nice but have not proven to be as reliable as the Timney. You don’t want a trigger lighter than 1.5lbs in our game. Maybe you can shoot a 2oz trigger off a bench well but try that when shooting out of the back of a car, under a time, on a 100 degree day.
Bottom metal: Just buy the R&D bottom metal and call it done. Others will work too; just make sure you have mags that feed ten and five rounds.
Stock: choose one that fits you well and comes in the weight limit.
Why is all this gun stuff important in a cartage thread? It all comes down to felt recoil but more on that later. Now lets jump into the performance of each round assuming the guns will have 26” barrels and average pressure loads.
The 6mm rounds can drive a 115gr bullet around 2950 or the 107’s at 3050. The 6mm’s best BC bullet available is the 115gr DTAC.
Wind drift at 1000 yards in 10 mph wind.
107SMK – 2.1 mil
115JLK – 2.0 mil
Free recoil energy in (ft/lbs) 5.2. A 243 does not require a brake but might recoil slightly more that a .260 with one.
The expected barrel life for a .243is in the range on 1500 – 1700 rounds. You might get more or less based on how hard you push it.
The 6.5mm’s (.260) can drive a 140gr bullet in the 2850 range. This is interesting because unless you shoot a custom or Burgers bullets you gain noting over the 243. The .260 recoils more, is more expensive and more complex to reload than a 243. It does have a small advantage in barrel life but that is naturalized by the bullet cost. Also, note the custom bullets can be very hard to get most of the time and may be backordered a year or more. The Berger is a good balance but is a VLD and only adds the the load dev issues of the .260.
Wind drift at 1000 yards in 10 mph wind.
142SMK – 1.9 mil
140JLK – 1.7 mil
140BerVLD – 1.8 mil
Free recoil energy in (ft/lbs) 6.7. This is a bit high for a PPS comp gun and it’s recommend 6.5 shooters install a muzzle brake.
The expected barrel life for a .260 is in the range on 1800 – 2000 rounds. You might get more or less based on how hard you push it.
You can shoot 130, or 123 in a 6.5mm but I can’t see why you would. A 6mm will beat them in the wind with less drop and recoil.
The 30cal rounds have a wide range of bullets from 155grs to 240grs. Let’s look at some of the more common ones.
Wind drift at 1000 yards in 10 mph wind.
155SMK – 2.7 mil
175SMK– 2.7 mil
190berg - 2.3 mil
Free recoil energy in (ft/lbs) of a .308 ranges from 8 -9.5. They have much more recoil then the 6/6.5 and are almost always shot with a brake.
The expected barrel life for a .308 is in the range on 4000+ rounds.
The .308 even with the heavies can’t hang with the 6/6.5mm but does have the advantage in you can find many of the shelf rifles, factory ammo and a long barrel life. This is why we recommended them for new shooters.
The 223 is often over looked but can be more competitive than the average .308 shooting 175. It offers good barrel life, little recoil, inexpensive reloading at the cost of impact signature on steel. It should not matter as hit is a hit but the spotters need to see the hit. When looking at the .223 the heavy bullets are key, seated way out to AI 223 mag length.
Wind drift at 1000 yards in 10 mph wind.
90bergerVLD – 2.2 mil
80gr SMK– 2.9 mil
Free recoil energy in (ft/lbs) 2.5. A 223 does not require a brake at all.
The expected barrel life for a .223 is in the range on 2500 -3000 rounds. You might get more or less based on how hard you push it.
Really the 223 pushing the 90gr bullets by the speed provided via R17 is a great little round. I was really surprised by the numbers. For the shooter that does not get past 600 much and cost is a concern it’s my number one choice.
The 7mm mag rounds are the kings for wind performance, recoil and cost. But what else can drive a very high BC 180gr bullet @ 2950 or better?
Wind drift at 1000 yards in 10 mph wind.
180berger – 1.6 mil
Free recoil energy in (ft/lbs) 11.7. Wow, that is over 2x the .243, you will want a brake and maybe add a few lbs to the rifle to get this down.
The expected barrel life for a 7wsw is in the range of 1000 - 1200 rounds. You might get more or less based on how hard you push it.
The 7wsm or other mags don’t make since as a primary rife. They simply cost a lot to reload, are very hard on barrels, and require a heavy rifle to get the recoil down. One would be nice to have for the windy days or for all prone shooting so the weight was not an issue.
So what did i choose to do... I am going to run a 6.5 for comps shooting the JLKs and a 223 for local matches shooting the 90gr bullets. I have some barrels to burn up setting on the shelf first so you will see a 243. and some other stuff along the way. </div></div>
Good post Charlie!
Some info.
My first 6x47L barrel lasted about 2300 and 2cnd 1500.This is with DTACS in the 3050-3100 fps range.
I have a new strategy this time around.A friend and I are sending our new barrels off to get them nitrided.I'm also changing my loads.I'm going to back down the velocity to the lowest barrel node,probably low 2900's and use a slower powder for the case,like H4831 or even H-1000.Less heat and throat erosion.Hopefully the result will be a 5000 round barrel life or so.The new DTACS with more closed hollow point should make up for some of the lost velocity because of the slightly higher BC compared to the old DTACS.All theory at this point but I'll try it anyway.
