243,6MM or What?

[randyrat]

Is it worth getting into a 243. Having such a short neck and sloping shoulder (may or may not be a problem). Would it be better getting into a 6 MM or similar rifle cartridge?....

I can see there is not a lot of the other rifles( 6MM) falling off the shelves, is the 243 just more available. I would like to have a 243 for deer and long range shooting but I can see it's problems already.

Does anybody hand load/ cast for this 243 or is the neck just too short. Maybe the short neck is not a problem. I'm not anywhere near a ballistics expert or a rifle man so I have to ask a lot of questions when it comes to rifles before I buy.

I'm looking for a common cartridge, small enough for varmints long range, big enough for black beer and one I can cast and hand load for. I have always been impressed by the 243 (necked down 308, short action) but have no personal experience with it.

[9.3X62AL]

I've owned 4 different 243s over the years, but only began casting for the caliber about 10 years ago. This has been one of my more successful rifle calibers with castings, primarily the RCBS 95 SP. Many dozens of 1.0 to 1.25 MOA groups using 12.0 grains of 2400 under that boolit.

I think VERY highly of the 243 as a long-reach varmint caliber, and it wouldn't be bad on smaller deer with the better controlled-expansion jacketed bullets.

[rmcc]

In my experience, have had both 243 Win and 6mm Rem. 243 is a post 64 Model 70 heavy barrel flat crown. The 6mm was a 700 BDL heavy barrel. Both were stock all the way, I just adjusted the trigger pulls to my liking.
The Win 243's pet load is 37.0 BLC-2, Fed Match primer, Hornady 65 VMAX. This is not a hot load by any means but the rifle averages .269" five shot groups off a rest. It is the only load I shoot in that rifle.
The 6mm boasts a longer neck for seating long projectiles and in theory you can squeeze another 100 fps over the 243 Win in any bullet weight (I say theory because all rifles are individuals as far as how fast you can push a given bullet/ powder combination before excess pressure becomes a factor). After loading both and shooting them, I say any benefit the 6mm has over the 243 is negated by the abundance and variety of 243 Win loads over 6mm loads. My neighbor has both rifles and he prefers the 6mm.
Getting back to the neck question on the 243, I have never encountered a problem with seating depth of the longer bullets even using IMR 4350 and H4831. Granted, I don't load them to see if I can melt the bullet so if velocity was a factor seating depth could be a factor with those powders. I have shot Amaxs, Barnes, Bergers, and some others that I thought were long and just never had any problems.
I have never cast rifle bullets, so I am sorry I cannot help you in that area of the 243/6mm part of your question. Good luck in your decision!!

Rich

[Idaho Sharpshooter]

I just traded into a 700 in 260 Remington...

Rich

[41mag]

Well I have had, and shot one Win 70. since Nov. 1970. Since then I have acquired two others and have loaded or helped load for over a dozen more.

Through the years my old Mod 70 has held it's ground with any and all comers. It's a shooter plain and simple. I have used a handful of different factory rounds through it over the years and when I was in my early teens I started handloading for it. I have run the gamut of light to heavy bullets through it and with a little care she has handled everything. I don't push her hard as there is no real need. Pick a load suitable for what your going to hunt and load her up.

This said I haven't cast for, or loaded any cast bullets for any of the three. Since I could afford it I purchased my bullets in bulk and probably have enough to last the barrel lifes of all three rifles and then some. My personal favorite has been the 100gr Nosler Solid Base, or the Rem CL. The SB in weights of 85grs through 100 has done all I ever needed done whether varmint, deer, or hog. I never saw a need for the lighter bullets, but did load up some 60gr Sierra's that were pretty impressive.

Pick powders that are on the slower side of medium burn rate, starting around IMR-3031, with the lighter bullets, through IMR-4831 or Ramshot Hunter on the slow heavier end. They are not hard to find a good load for in most cases, and anything generating 2800fps or higher in a JSP will drop anything you put it to task on if you put the bullet where it needs to go. Stick to standard load data and don't try to squeeze out the last remaining fps from the load and your brass, and barrel will last a LOT longer. With cast I, as mentioned, haven't got a clue.

Good luck, and don't let the short neck fool you, they haven't been an issue with my loads other than needing a trim every once in a while.

Hope this helps.

[GabbyM]

I’ve a couple 243’s re barreled in 243 A.I. Saeco 87 grain bullet fits in the 243 neck. Haven’t tried the RCBS.

6mm REM neck is .110” longer at .351” than the 243 WIN. 6mm BR is .318” and 6XC is .305”.

They say the 6mm Remington’s longer neck helps slow down throat erosion with full power loads. I think that’s splitting hairs and if there was more to that one you’d see far more 6mm Rem’s out there in competition.

I told myself I was going to run these new barrels at 10% reduced charge in an attempt to stretch barrel life out. Maybe their’s a twelve step program I could sign up for. Last batch I loaded was aprox 5% reduced, lol. With cast it’s been easy to find good loads. Under the 87 Saeco 18.0 grains of Rx7 shoots 1 inch at 100 and 11.0 grains Unique under the 84g Lyman Loverin shoots regular into .850” at 100. 18.0 gr Rx7 runs at average 2,140 fps which seams a bit fast for accuracy from the 1-10” twist with BHN #15 bullets. Haven’t clocked the Unique load but it books at 1,850 fps which is why I think it shoots a tad better. Like the load too. Unique actually burns clean in a 243 Ackley at 11.0 grains and has enough pressure to seal the neck for clean cases. Rounds pop instead of boom from the 26” barrel. I’m quite pleased with cast performance in the 243 AI and see no major drawback to the neck length.

I’d never given black bear hunting with a 6mm bore a passing thought. There are some good bullets sold now that may hold together and penetrate.

Stabilizing the long 6mm bullets of 87 and 100 gains takes a good barrel. In my limited personal experience as soon as the 1-10” twist barrels get a little wear on them the flat based Hornady 100 grain will not shoot but about 2 ½” at 100. My Remington M700-V 243 Win would not stabilize the 100 gr Hornady flat base or 87gr V-Max when I bought it used. My new 1-10” barrel shoots 87 V-Max just fine at under an inch at 200 yards. With a 200 yard zero on those bullets you’re .6” high at 100 and only 26.5 low at 500. I knocked over the big BPCR buffalo at 500 with one shot. Didn’t tip over it went promptly down off the rail. 243 with the big high BC bullets is a true 800 yard coyote rifle. Making an 800 yard shot off a pair of crossed sticks or Harris bi pod is another matter but if you hit them they’ll go down. So the gun is not the limiting factor. With cast they are easily minute of squirrel at 200 yards.

With bear on the menu and having gone bear hunting a total of one time and seen 30-06’s, 8mm Mauser and 375 Win big bore results I’d lean more towards a 6.5mm. The Hornady 95 grain V-max in 6.5mm has a B.C. of .365. That lags the 6mm 87 grains .400 B.C. by a little but with the 6.5mm you can shoot a 160 grain round nose bullet at the bears. Or the new Speer 140 grain Deep Curl with a B.C. of .462 if you needed a little reach out for deer or bears. It’s simply a whole bunch more gun than a 6mm.

Don’t know what you’re looking for as to weight but Savage has a new rilfe out this year called Model: 11 Lightweight Hunter. Five and a half pounds with a nice looking wood stock and 20“ barrel. In 243 it has a 1-9 ½ twist which should shoot the 100 grain bullets for you. Also your choice of two 6.5mm’s the Creedmoor or Remington. The Creedmoor is throated for 140 grain Hornady A-Max loaded to the neck base. I’ve not a clue how that would be with cast boolits. http://www.savagearms.com/firearms/finder/

[selmerfan]

I've worked with a couple of .243s over the years, a Rem. 788 and a TC Encore barrel. I've shot at least a dozen deer with the M788 and 100 gr. Nosler Partition bullets. I haven't run cast through either gun, but the 788 runs a 55 gr. Nosler BT out at just under 4000 fps with sub-MOA accuracy. It is one of my favorite chamberings, although I currently don't own one because of the fact that I have a couple of .260s and a 6PPC barrel for my Encore, which pretty heavily overlaps the .243 areas.

[quilbilly]

I started casting for the 6mm last spring. In only one trip to the range after I had tested several loads at my home range, it quickly became obvious that the 6mm is the most accurate CB shooter I have (and I have several other calibers shooting CB's with MOA accuracy). The boolit comes from an old Ideal (now Lyman) mold dropping at 89 gr including gas check. I keep the mv at a leisurely 1950 fps. The rifle is an old Rem 600 carbine.

[smoked turkey]

I have successfully used the 243 to shoot a couple of whitetails at 85 yards or so. They were both DRT. Couldn't ask for better performance from any caliber. I downloaded the 243 for my grandson and he has gotten two doe with one shot each. My son has used my handloads to shoot a couple of nice bucks at fairly close range. My reduced loads were also used by the young daughter of a friend to down two small bucks at long range. Clearly the .243 is enough caliber for whitetails if shot placement is right. I am not experienced at black bear hunting but I don't personally think a .243 is enough gun for even a small bear, but I don't have the experience others have on that issue.

[madsenshooter]

One thing about the 243 Win vs 6mm Rem, you're much more likely to find 243 Win ammo anywhere you go. There's not a lot of cast bullets available, and some of them aren't worth messing with, to me. In particular, the Lyman 245497 isn't going to shoot worth a hoot at much over 1600fps, too much unsupported nose. The little 80gr bullets work well, I've been shooting them out of my 6x45 AR. http://castboolits.gunloads.com/showthread.php?t=121224 There are a couple 6mm group buys going right now, here's one that isn't in the group buy section as of yet: http://castboolits.gunloads.com/showthread.php?t=124042 I think it's going to work really well at high velocity and high rpm out of my AR. I personally wouldn't consider shooting at a black beer with anything smaller than 30 caliber, but that's just me. Things that bite and scratch are not to be trifled with.

[frnkeore]

Quilbilly,
What is your load in your 6mm? I have a 660 in 6mm Rem with the 20" barrel.

Regarding 243's, If you throat them to .2435 x .1 to .13 I believe that you'll have a much more versatile rifle and will be able to keep the bullet base out of the powder chamber like you can with a 6mm. They'll also still fit in the magazine with jacketed.

Frank

Frank

[Nobade]

I've been having great luck with the 243 in three different rifles, using the RCBS 95gr. boolit with Red Dot, Green Dot, and recently AA#2. Most shooting is around 1700-1900 fps and terrific accuracy. Also you can use really slow powder like WC860 and get 2600 fps with good accuracy. Just have to take it slow 'cause the barrel gets hot fast.

[6mmalldaylong]

Personally, I can't think of another caliber that has more potential than the 6mm. I've owned 243's, 6mm Rem's, 6mm PPC and BR and now I shoot a 6mm wildcat called a 6mm S.I. (Shankle Improved). It's basically a .243 that's been fire-formed in the chamber where the case and taper gets longer and a little fatter and the neck is altered to a 30 deg Bench rest type neck angle. It holds considerably more powder which allows me to load with slower powder and actually fill it up to compression loads which I believe gives it a much more consistent burn. I had a custom barrel & twist mounted on the Rem 700 clone action (26" with a 5r rifling and an 1 in 8.250 twist so I can load for the VLD's). The rifle has less than 19 MOA elevation at 1000 yards which is incredibly flat shooting. It's the best rifle I've ever loaded for, 1/4 moa all day long. Depending on your rifle's twist, you may or may not be able to load for the longer VLD bullets. The slower twists will force you into spitzer type bullets but you can still get some great loads. If you're shooting less than 300 yards then you probably wouldn't benefit from boat tail's and VLD's anyway. Most of these guns group better at short distances with the lighter and smaller bullets anyway. My 6mm's have always grouped better on the high end of load data. That may or may not be everyone's experience. I also found that a 25 thousand's jump does the trick in my gun. Other guy's jump as far out as 50 or 60. My muzzle velocity is rocking the world at more than 3400 with Vit N560 and I am moly coating my Lapua Scenar 105's. I don't like sharing my exact powder charge because I don't want someone hurting themselves over one of my loads but I arrive at my loads very carefully and it may take you some time to find your sweet spot as well. I will say though that these 6mm SI cases will comfortably hold about 10 more grains of powder than their .243 cousins. Lastly, I use only Lapua brass and I uniform the primer pockets and chamfer the flash holes and weigh each piece of brass and all my bullets and keep them in divided lots for even more uniformity. I have found that Lapua brass and bullets just seems to be way more consistent than any other brand. If anyone is interested in the "SI", I know Tony Shankle and he has the reamers and would likely share the love for a fair price. That would be up to him, of course. The gun fires the standard .243 very accurately as well which is a bonus when you are fire-forming. I literally can go groundhog hunting with the .243 rounds and fire form my cases on a hunt, then re-load my newly formed 6mm SI cases for extreme target shooting. Best of both worlds.





Is it worth getting into a 243. Having such a short neck and sloping shoulder (may or may not be a problem). Would it be better getting into a 6 MM or similar rifle cartridge?....

I can see there is not a lot of the other rifles( 6MM) falling off the shelves, is the 243 just more available. I would like to have a 243 for deer and long range shooting but I can see it's problems already.

Does anybody hand load/ cast for this 243 or is the neck just too short. Maybe the short neck is not a problem. I'm not anywhere near a ballistics expert or a rifle man so I have to ask a lot of questions when it comes to rifles before I buy.

I'm looking for a common cartridge, small enough for varmints long range, big enough for black beer and one I can cast and hand load for. I have always been impressed by the 243 (necked down 308, short action) but have no personal experience with it.

[MT Gianni]

I made a decision last year to get down to 4 bore sizes in rifles. That meant selling a 243 among others. Mine had a E R Shaw bbl and was it very easy to get good groups with cast from it.

[Love Life]

I like the 243.

[dk17hmr]

One thing about the 243 Win vs 6mm Rem, you're much more likely to find 243 Win ammo anywhere you go.....

I don't know if I would go that far. The local gunshops here in SW Wyoming stock almost as much 6mm Remington as they do 243win.

Go 243 to start with than when you shoot out the throat run a 6mm AI reamer in and start over.

[uscra112]

My 2nd CF rifle was a .243 - Rem 700 BDL. Shot hundreds if not thousands of rounds learning to load for a high pressure rifle. Very accurate with j-warts, but the short neck and large powder space didn't recommend it to me for boolits, so I never tried. Haven't even fired it in many years. I agree that it's a great do-it-all cartridge for someone who is going to have just one rifle and shoot only factory ammunition, but for an all-around rifle to cast for, I'll take the .30-30 or .30-40 any day. Exposed loob grooves just makes me shiver. My 700 is still in the safe, and when my son-in-law finally decides to relocate to the West it will go to him for antelope and varmints. Meanwhile I have tooling, brass, dies, barrel blank and intent to build a 6x47 for boolits, just because.....

[wv109323]

Remington first introduced the cartridge as the .244 Remington. It had an extremely slow twist (1 in 14"). With that twist it would not stabilize the longer and heavier bullets so the .243 Winchester ate the .244 Remington's lunch. Remington changed the rate of twist to 1 in 9" and renamed the cartridge as the 6mm Remington. The .243 Win. in my area is much more popular and the new rifles chambered in .243 far outnumber those in 6mm.
I would lean toward the 6mm if the heavier bullets were necessary. I would also think the fast rate of twist in the 6mm would be less desirable with cast bullets if driven hard. There is no right or wrong answer here. I would get the best bargain I could find in either caliber. I would stay away from the older .244 Remington rifles.

[dtknowles]

My .243 is not a bolt action, it is a single shot so your mileage may vary. I like .243, mine will shoot cast with gc with good accuracy up to a velocity limit so bear or deer with cast is a short range deal and cast for long range varmints is not even in the plan. I seat boolits with lube grooves exposed (throat is plenty long, but magazine in bolt gun may not allow) and can't get groups down when velocity is over 2400 fps. For long shots I use jacketed bullets and for punching paper or game at shorter distances I use Boolits.

Tim

[.22-10-45]

I have a fast twist 6mm that takes to the old Ideal 245498 100gr. bullet like a duck to water..it's one you won't see on the range too often...a Winchester 1895 straight-pull sporting rifle in .236 (6mm) Lee-Navy. This one left the factory Jan. 1898 & it's near mint bore has Metford rifling with a 1- 71/2" twist. This one nearly gave me fits just trying to get it to even chamber a cast bullet load. The throat is LONG! even with that long 245498 only held by gas-check..it still didin't reach rifling. And the chamber throat is as close as I can measure .0005" under groove dia! No matter how tight a fit of bullet in neck..bullets were being pushed back into case as action was closed. I finally had to size bullet to groove dia. & then size 1st. band .001 under groove dia. in order to chamber. The G.C. does spring back .001 over groove dia. so I was hoping that would seal. That fast twist had me plenty worried..so I cast up some extra-hard as well as my more or less std. range-scrap tin alloy. I did initial testing at 50yds. on account of rocky mountain open rear & german silver blade front. 10.0grs. H4227 shot to point of aim & grouped in 3/4". I then tried TrailBoss..interestingly, 10grs also prooved most accurate with a 3/4" grouping as well. One thing I noticed right off..with the Hodgdon powder..even the heaviest loads...where groups became patterns..there would be powder soot down to case shoulder. With TrailBoss..even start loads left cases clean..and with noticably less muzzle blast as well. I did back up to 100yds and same 10gr. loads shot into 1 1/4"..I didn't think that too bad for open irons and 50+ peepers! I never did get around to using the hard stuff..wasn't needed..not a speck of leading. Perhaps someday I might try a modern rifle chambered for this old..."too far ahead of it's time"..and available powders. One thing for sure it has to have one of the longest necks of the 6mm clan.