Gents, thoughts please. Made up some test loads for the 243 with 100gn Hornady BTSP starting at 38.5 and going up to 42gn (max load) test shot last night. The lower loads were appalling 4" for three rounds at best. Only when I got to 41gn did I start getting down 1 and bit inches. Got dark before I tried the max load. Even the 41gn was still shooting 3" lower than factory RWS 100gn which has a box velocity of 3000fps. The Heym shoots RWS very well and three rounds touching is the norm.

My thinking is that with the lower loads they were not giving anything like the velocity to get good consistent spin on the bullet, nor enough pressure to get a good clean burn. Once it's getting up to 3000 fps there is enough rotational spin to keep 100 gn bullets stabilised.

Real question is even at the high loads will there be enough spin to keep the bullet stable down range, or does spin slow down as velocity falls off down range.

I'm looking at the 100gn bullet as its the legal minimum in Scotland for he bigger deer and I want one load to do everything. I want something that's good for 200yds, but ,ost shots at 100 or so.

My default is the RWS ammo, but at £35 a box of 20 it's getting expensive.

quote:

Real question is even at the high loads will there be enough spin to keep the bullet stable down range, or does spin slow down as velocity falls off down range.

I don't have the first idea whether your spin will be enough downrange, but I can tell you that the rate of spin itself does not diminish (at least, not of any consequence - it would spin for hours before you had any significant loss of rpms).

Someone else will hopefully have some good info for you on the first part of your question! Good luck!

friar

A barrel twist of 1-10 may be to slow for a long bullet for best accuracy. Its the length of the bullet more than the weight. Try a flat base, round nose bullet to make your legal minimum. Watch for pressure signs when shooting the 42gn (max load) of IMR 4350.

Hello HEYM from South of the Border! I have had just the very same exact problems that you are having and for the very same reasons. Except in a Parker-Hale M81 Classic in 6mm Remington.

100 grain minimum weight...Deer Act...just as you need. Because as we both know that in Scotland the law says that any bullet MUST WEIGH 100 GRAINS MINUMUM.

So even a 95 grain bullet is illegal!

In my 6mm Remington that I guess is merely a standard rifle barrel blank "one size fits all" chambered by Parker-Hale to 243 Winchester or 6mm Remington as needs dictated.

My bullets were 100 grain Nosler Partition and I was using...in my 6mm Remington...42.3 grains of IMR 4350. On 19 September I noted "An increase to the powder charge in the 6mm Remington to 42.3 grains IMR 4350 behind the 100 grain Nosler Partition bullet. It seems that this greater powder charge does now show potential three inch groups at one hundred yards".

This following an entry of 25 March 2012 "A follow-up to the 2011 sessions zeroing at Epperstone and Garlands. This confirms that this rifle does not group with Nosler Partition bullets in the two powder combinations (41.0 grains IMR 4350). Also disappointing group with the Remington 100 grain Core Lokt Bonded. Indeed tumbling at two hundred and fifty yards with that bullet. The Sierra 100 grain Pro-Hunter (42.5 grains IMR 4350) gave a five to six inch group at two hundred yards however and about three to four inches at one hundred yards".

Finally by Autumn 2012 I had had enough and spent enough. "100 grain Nosler Partition with 42.0 grains IMR 4350. The end game for the 6mm Remington. This rifle has consistently failed to achieve anything better than a three inch group at one hundred yards. More often, in fact, not even that! Tried with 42.0 grains IMR 4350 and 100 grain Nosler Partition giving three to four inch groups at one hundred yards. This rifle has failed, ever, to produce acceptable accuracy. To be sold".

Not good news I fear. I think that the twist was standard Parker Hale of about 1 in 9? The whole experience was an expensive lesson in sending money up in smoke!

So whilst we may be comparing 243 Winchester to 6mm Remington at least I have been there and done it with the higher weight loads of IMR 4350 that you are approaching.

But of course being a 6mm Remington it has that extra case capacity that the 243 Winchester lacks. I was very disappointed as my "quest" was to exactly what you are now chasing. A one load for large deer and small deer throughout the United Kingdom.

Enfield,

Thanks for your comments. Thankfully with both RWS 100gn and the 105 Geco the rifle is very accurate and has been for the last fifteen years I have had it. I am going to try a 41.5 and 41.8 gn loads and see what happens.

O.K. From North America... the 6mms have been controversial since the 1960s in my experience (reading widely). Magazine writers have to have something to blabber about. Original .243 WCF was a 1 in 10 twist and would handle FLAT BASED 100 grain spire point bullets o.k. Boat tail bullets were rare and the competition was with lighter bullets. The .244 Remington (patterned after the .243 Rockchucker of Mr. Huntington / RCBS development for varmints) was 1 in 12 and would not. Remington would shoot 100 grain round nosed bullets o.k. but who wanted a round nosed bullet... (This was before the colorful plastic tips of today... that make the bullets so much more colorful, like the target, paper or flesh, really knows or cares... I keep coming back to the saying "fishing lures are designed to catch fishermen, NOT fish..." )

Bottom line, in the books and magazines, the 100 grain bullet is about the top end for the 6mms in the common 1 in 10 twist and if you "go long" with a boat tail or VLD, MAYBE not enough twist. I suspect that Hornady has a flat based bullet, comparable... you might have to paint the tip the color that suits you... that would shoot very well. Or any other 100 grain bullet with flat base and ordinary point front.

Mr. Dave Corbin of bullet swaging fame, doesn't even recommend a boat tail on bullets under .25. In his opinion, it has no useful effect on a base so small. You can read several of his books on his web site, corbins.com or swage.com or bulletswage.com ...

In Mr. Ackley's books, he makes the point that there is very little resistance to the rotational spin of a bullet and so it slows little or not at all. As a rule the bullet hits something long before the spins slows. Sometimes this shows up at 1,000 yards, but how often does a hunter shoot that far?

And in the .308 case (parent to the .243) 4350 is on the real slow side. Bullet is heavy enough to burn it as you get to full loads, but with lighter loads, might not be getting good pressure and thereby, good performance. Faster powders, 4320, 4064, and 3031 might be better as available... Government/military standard runs H335 or WW748 or Ball C2, like that.

Sympathize on price of ammo. Doesn't go down. '06, .270, .243, .308, etc. had a great advantage with a military cases readily available here and CHEAP to free. At one time, with the purchase of a surplus springfield rifle the surplus '06 ammo as $0.01 per round and cases got left on the ground. Good old days. Luck with your efforts. Suspect top 4350 loads will be much more satisfactory. Happy trails.

PS One option is to ream out the chamber to something larger, say 6mm/.284 to get more velocity and spin the bullet faster... Older options were the .240 Weatherby or 6mm/'06. Gives up some barrel life...

243winxb has your answer. A flat based, round nosed bullet will work. And work well. Out to 250-300 yards, the round nosed bullets give nothing away to the BTSP and, IMO, does a better job of killing.

1. It is pure fantasy to believe that a 100 grain factory load in your 243 rifle with standard length barrel will chronograph 3000 fps. No apologies to the ammo marketeers.

2. Partition bullets, solid base bullets and boat tails are all longer than flat base cup and core bullets and require more spin to stabilize. I normally avoid boat tails if I can. They are nice to load and some times shoot well but I generally get better results with flat base bullets.

3. The only Parker Hale barrel I ever owned was bought from a AR member and it was a 6mm Rem barrel. This barrel had a terrible rough spot about half way through and about 2 inches long. I sent that piece of crap barrel back. No telling who got stuck with it because I am sure the owner did not believe it was bad.

4. I have personally shot 44 grains of Accurate 4350 with the Hornady 100 grain flat base through a chronograph for an uncorrected 3003 fps. This was using 6mm 22 inch factory barrel 700 Rem. The factory twist is one turn in 9 inches. The groups were in the 5/8" to 3/4" range.

Re 2. Partition Bullets. I did indeed suspect that I might have problems with stabilisation because of their length. Having some 150 grain 270 Partition and even longer 150 grain 270 Partition Gold I get it exactly. And the 100 grain 243/6mm Partition were also over long.

Re 3. There's some in UK would hang you for what they'd consider heresy! Whilst I am no apologist for Parker-Hale they did get some things right...and others very wrong.

My son's .243 is a Parker Hale '98 with 1 in 10" Lothar Walther barrel. Load is 40 grains of 2209 (almost identical burn rate to 4350) under a Sierra 100 SptBt. Oal is 2.650. Chronographed velocity is 2,712 fps in the 23" barrel.

This groups under 1" at 100 yards and he has made shots out to 270 yards with it on 30kg Australian ferals.

Here is the largest animal neck shot with it and that combo, at 150 yards. Shot by his mate, pictured.



I don't see you having a problem apart from possibly cost.

Spin is the last motion to stop.
Rifling twist vs velocity may be your problem.

With the standard 1 in 10 twist, a 243 should stabilize just about 100 gr. bullet just fine. Mine shoots the Hornady BTSP like a dream and kills antelope as well as anything I've ever observed. For best velocity and accuracy in the 243 I've had success with both 4831s, RL-22, and H-450 (no longer produced, but I have a stash). Out of a 22" barrel I get chronograph readings of 3150 fps and no pressure signs. I think I do have a "fast" barrel on that rifle.

I got better grouping using RL19 @ 40.6gr with the 100 gr hornady. I wasn't looking for speed as much as accuracy though. Confident enough with the way it shoots to do 300 yards on deer/antelope. 4350 just wouldn't bring my group size tight enough. Using just a model 78 sportsman so no big money in the rifle, but she's a shooter.

I think you fellows are discovering what the gripe is that I have had with the .243 for as long as I have known about it: it just doesn't group heavy bullets like it does the lighter...

The .243 was originally designed as a wildcat, for shooting varmints. Several of the hotrod riflemen back in the day decided that the rifle with the right twist and heavier bullets would be a decent deer gun, and here we went.

In my estimation and experience, you will never get a .243 to shoot anything much over the now discontinued Nosler 85-grain Partition very well; the twist isn't fast enough, and the bullets are just too long.

If an inch or so satisfies you, so be it. It doesn't satisfy me...

It has become fashionable lately to blame any kind of accuracy problem on "rate of twist". Baloney.

One-in-ten inches is fully adequate for 100 grain bullets in a .243 -- which doesn't necessarily mean that every 100 grain bullet will group well with any powder charge. Individual rifles "like" certain bullet/powder combinations, regardless of what twist their barrels may be made with.

IMR 4350 is the very fastest powder that I would load in a .243 with 100 grain bullets. H4831 would be somewhat better, and if you can get RL-22 (Norma MRP spec powder), that should also do well for you.

If your heavier loads of 4350 are more accurate, then use them -- after all, more velocity when hunting Red Deer can't hurt. Until and unless you reach the point of excessive case head expansion your pressure is irrelevant.

Current Rem 700 in 243win caliber, has a twist rate of 1-9 1/8" This rate handles the longer bullets better than the 1-10 that i shoot.