243 rifle twist and bullet selection


March 20, 2008, 11:32 AM
I have a 243 with a 1 in 10 twist. What is the smallest grain bullet it will handle? I normally shoot 100 grain bullets, but I want to go with something smaller for varmits. Was thinking something 50 to 80 grain? Anyone had experiences with smaller grain 243 bullets? Recommendations?

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March 20, 2008, 11:57 AM
I believe 55gr is about the smallest you will find in .243. I have only used mine for deer so I stick with the 100 gr.

Maybe try something in the 65gr range? You may have to try a couple different bullets and see what shoots the best.

Art Eatman
March 20, 2008, 12:05 PM
I've had excellent results with the 85-grain Sierra HPBT on both deer and coyotes. Tight-group load. I'm using 37.5 grains of 3031; I suggest working up to that weight.

I've always gotten tight groups with the 70-grain Hornady spitzer, although I haven't loaded that one for several decades. I think I've about used up all of those that I loaded back in 1968. :) 40 grains of 3031; again, work up.

I've loaded some 55-grain VMax for prairie dogs. Ruinacious out to the 300 yards or so I've tried. I disremember the powder; not 3031...


Vern Humphrey
March 20, 2008, 12:22 PM
You will have no problems with the .243 shooting light bullets -- any barrel rifled for a heavier bullet will always shoot lighter bullets well.

The .243 was developed as a dual-purpose rifle, for both long range varmit shooting and also for hunting deer-sized game. It will do well with a wide range of bullet rates, from about 60 grains up to 117 grains.

March 20, 2008, 01:08 PM
I've got a .243 with a 1 in 9.25" twist. I've had very good luck with the Nosler 70 gr Ballistic Tips (1/4 - 3/4 MOA). I've also shot one load of the 55 gr Ballistic Tip and it shot about 1/2 MOA (a friend had some loaded and let me shoot a group). With a 1 in 10 twist, I would guess you're gun should handle lighter bullets just fine.

March 20, 2008, 04:12 PM
I just started playing with light bullets for my .243 shooting groundhogs. For factory ammo I have used Horandy 58 grain V-max moly and they shoot pretty good (less than an inch at 100 yards) and my first set of hand loads all were around 3/4" at 100 yards. I was using varget and Barnes 58 grain varminator. Both loads work really well on groundhogs.

March 20, 2008, 07:14 PM
you need a 1/9 or 1/8 twist, to fire the low boys, about the lowest yours will do is 90 grain, maybe 85.

March 20, 2008, 08:03 PM
you need a 1/9 or 1/8 twist, to fire the low boys, about the lowest yours will do is 90 grain, maybe 85.

Huh???? I shoot a 12 FV with a 1:9.25" twist, it shoots everything well from 70 Gr. Nosler BT's to the 100 gr., and loves the Sierra 85 gr. GMK.

Normally you want a faster twist to stabilize a heavier (longer) bullet, not the other way around. In fact, a 1:10" twist .243 will do best with a 55-85 gr. bullet, but may not stabilize the 105's or the VLD's (although I think it would be ok it seems marginal for the L/D).

March 20, 2008, 08:51 PM
Browningguy you are right. The one in 8 to 9 twist barrels are for heavier bullets. A remington 244, if one could be found would be great for all of the lightweight bullets now available to handloaders. They have a 1-12 twist and would handle up to 90 grain bullets.

If these light weight bullets are spun too fast they can come apart from centrifical force. Thats why the 223 normally has a 1-12 twist and the 22-250 has a 1-14 twist. The 22-250 has much higher muzzle velocity.

The 243 has loads showing close to 4000 fps with the right charge. A 1-9 twist just might tear one of these bullets up if the jacket is too thin.

November 24, 2008, 12:35 AM
So you can increase spin rate by increasing velocity right? What's the fastest heaviest bullet you can push through a standard .243 26" 1:9.25?


November 24, 2008, 04:10 AM
not so; I have a remmy 788, that is stunningly accurate, and does not shoot anything below 90 grains well. However, everything 90 g and up is fine.
Yes I know, normally you could say with all confidence, that if it has a twist rate, to stabilize a 105, it should be fine with anything lighter, but in this case, no. I have shot a lot of rifles in a lot of diff cals, and i have run across this a couple of times, and so far, it has only been with the 243 caliber, and diff rifles.
I do not know why this is; maybe because it is a high pressure round, maybe it 's internal ballistics are a bit diff than what we think, and the bullet is more molten as it moves through a 6mm tube, I don't know. But again, I have experienced this more than once, but only with the 243.

November 24, 2008, 04:14 AM
velocity and spin rate are not two sides of the same coin, don't go by that. Spin rate is used to speed up or slow down the rate of spin, depending on how long/heavy a bullet is. You generally need a faster spin rate, for a longer/heavier bullet. I would think a 1/9.25 twist would do 110's, very nicely maybe even 115's ; I think that only a few makers make 115 vld type bullets out there.

November 24, 2008, 05:11 AM
"you need a 1/9 or 1/8 twist, to fire the low boys, about the lowest yours will do is 90 grain, maybe 85."


With all due respects - that's simply wrong.


November 24, 2008, 06:09 AM
I meant spin rate like rpm.

November 24, 2008, 06:35 AM
You generally need a faster spin rate, for a longer/heavier bullet. I would think a 1/9.25 twist would do 110's, very nicely maybe even 115's ; I think that only a few makers make 115 vld type bullets out there.

You will need a 1-8" twist to stabilize a 6mm 115 grain bullet.... all of which I currently know of are VLD's.

Trust me.... see my tagline.

BTW, I started out shooting way back when with a .243.... two of them actually. I never had any problems getting 60-65 grain bullets to shoot in the factory standard 1-10" twist barrels.

Best to all,

Garands forever

February 27, 2010, 11:18 PM
I shoot a .243 Rem 700 26" SPS Varmint. 1:9 1/4. I use IMR4064 for everything below 85g and IMR4350 for 100g. Shot a 10 shot / 3/4" group @ 200yds today on 100g Sierra GameKings. I've also shot as close with Hornady 100g BTSP of the shelf. I've shot 1" @ 200yd with 55g Blitzkings on IMR4064. I shoot in the lower to mid range of Hodgden Reloading data. To be honest, I used H4895 for everything for years, and don't know why I changed. Maybe just got bored with good results. Other calibers moved me to IMR4350, which seems to be really good in .270 and .30-06 Mid and heavy loads.

Point is some experimentation with powders and charges can add real accuracy. Start with some web survey of options. The twist may be less a factor than some methodical and patient matching to your particular barrel. Take you time, shoot every windless day you can, and log your results. Personal load + your personal rifle.

February 27, 2010, 11:25 PM
You can go a small as you want... I had great luck with 70 gr. Nosler Ballistic Tips. RL 15 is a great powder for that weight.

March 1, 2010, 09:10 AM
I have successfully shot the 55 gr Sierra Blitzkings in my 10 twist rifle, but the sweetest bullet in this barrel is an 87 gr. Hornady Vmax. I tried a 95 gr Berger VLD and it will not stabilize it, went with the 87 Vmax and fell in love.

March 3, 2010, 08:08 AM

I've tried many loads in my 243 and have found Sierra's 80 grain to be quite accurate and deadly.

95 grain Nosler Ballisitc Tip bullet is our family's favorite for pronghorn antelope.


March 3, 2010, 10:34 AM
Now that I think about it; it could seriously be related to the powder used; I know that as i go to a lighter bullet , my groups start opening up. Normally i would say , you just have to try diff bullets out there, to see if lighter works for you, but i have only found 3 diff makers, who offer factory loads lighter than 90 grains; so if you try them, and they are not so accurate for you, you may have to go to handloads, if you want light and accurate.
But normally , a 1/10 twist would do the job, in 99% of the rifles in other calibers you could think of- just something a bit strange about the 243 i have found, they seem to not likey lighter bullets so much.

March 3, 2010, 12:41 PM
I have tried the Federal 55 grain Nosler factory loads in my model 70 winchester and it is as accurate with them as with 100 grains. Tried a Tikka and it opened up as I got lighter. Got a CZ on the way....:D

Will try it with 100, 80 and 55 factory loads and see how it does. Then go from there on what to do with reloads.

March 3, 2010, 03:09 PM
First off, I think a 1 in 10 twist rate is fine for all practical shooting. My particular experience is mostly with an off the shelf unmodified Rem 700 varminter purchased around 1977 with a 1 in 10 twist. If I remember correctly the lightest bullet I could find was the 60 gr. Sierra FB. I also used the 70 gr. Sierra HPBT match bullet. Accuracy between those two was slightly better in the 70 gr. I also used the Sierra 85 gr. HPBT. There was very little difference in accuracy.
Some of these targets are at 200 yards.


Now, the rest of the story. When I bought my rifle my shooting partner bought the exact same rifle only in 6 m/m. At the time he believed the 6 m/m had the same twist rate as the older 244 which was 1 in 12. He wanted the slower twist to shoot lighter bullets. What he got was a 1 in 9 twist and the results were a rifle that shot 87 gr. bullets better than 60 or 70. And when I say better, it was noticeably better.

I think that when you get into the competitive shooting game where the goal and necessity is very small groups shot from custom built rifles you are obviously better off with a twist tailored for your specific bullet.

- 8" Special for VLD bullets over 100 gr.
- 8"* Ratchet rifled 4 groove
- 10" For bullets up to 120 gr. and VLD under 100 gr.
- 12" for bullets up to 85gr.
- 13"* for bullets up to 75gr.
- 13.5"* for bullets up to 70gr.
- 14"* for bullets up to 70gr.
- 14"* Ratchet rifled 4 groove
- 15"* Special for bullets up to 70gr.

March 4, 2010, 12:48 AM
... to Viking... whewww!!! glad I am not crazy, and this also happens to some other peeps with a 243...

March 4, 2010, 12:01 PM
I also have an older (pre Garcia ) Sako L579 sporter in 243. It shoots factory 100 gr. spitzers fairly well. The only hand load I've come up with that shoots really good is one with 100 gr. round nose bullets. It makes a good Black tail load and that's mostly what is here.

Rosco P
April 4, 2010, 10:29 PM
Well, I am firing 107's out of a 20 inch 1:9 and am not seeing any luck

here is what I have been trying

105 Nos Match
47gr Winchester Sup780
Winchester LRP
New Win brass, FL sized

I got a couple groups under 1moa but I was hoping for better.

Is my barrel too short for 105s?

April 4, 2010, 11:13 PM
I wanted to do some long range bunny busting with my PH 243 so I tried 55gn Nosler Ballistic Silvertips @ 3500ft/sec, and the slightest wind spoils a good group, they were all over the place. However, under the same conditions 80gn Sierra Spitzers did the job much better tight group and headless bunnies was the result. Twist unknown. ;)

April 4, 2010, 11:25 PM
I found 55gn Nosler Silver Ballistic Tips in my PH would not puch any wind @ 3500ft/sec they were all over the place, even at 100yds. However, Sierra Spitzers solid base 80gn does the job under the same conditions. Twist unknown. I'm beginning to learn light bullets are not the way to go. Same results in mt 25-06.

April 4, 2010, 11:44 PM
Rosco P, your pretty much maxed out with the Win 780 and I'm guessing you're getting maybe 2850fps. Your 20" barrel is not helping with the velocity and Sierra recommends a 1in8 twist or faster to stabilize the 107gr.
I'm not sure what twist Nosler recommends for the 105, but you're probably on the edge.
Perhaps if you try the new Rel-17 powder, you can gain a little velocity.


April 5, 2010, 12:35 AM
... hmm bbl lenght shouldn't have anything to do with it, and the twist rate seems fine. At this point, we need some 243 handloaders to chime in on some different recipes, and possibly seating depths, brass recommends, etc., because so far, it seems like you should be better than that. Can we assume you have a pretty nice trigger, the bbl is either freefloated, pressure padded or it is bedded, and that you have a nicely done muzzle?

my 788 is a 1/10 twist, and loves the vld/softpoints by hsm ammunition, but in truth , it actually shoots the jacketed softpoints better than the vld's, which weigh 5 grains less.
The heaviest I am shooting through this is 105 grainers.
But then again, shooting is all subjective, and maybe your bbl, even though you would think a 1 /9 twist is allright, just simply ain't haven anything over 100 or 105 grainers... you never know.

April 5, 2010, 05:20 PM
Your 1:10 twist will handle the lightest loads of 55gr. It may have a hard time handling loads of 100 gr or higher. Some rifles will handle the 100 gr others need a 1:9.25 twist. For the Heavier loads you will need a 1:7 to handle the 115 DTAC.

Ky Larry
April 6, 2010, 12:09 AM
I have a Savage Model 12BVSS in .243 Win. IB the twist rate is 1:9.25. Haven't got my instructional manual with me. It loves 55gr Sierra B.K.s and 58gr Hornady V-Maxs. It seems to like bullets undr 85gr best. Don't know if this is helpful or not. Also, I use one of the 4350 powders.

April 6, 2010, 10:59 AM
I thought this argument was settled, decades ago, in 1955, when Remington came out with the .244 Remington cartridge, to counter the Winchester .243, but offered it with a slow twist (1 in 12)barrel. The slower twist just wouldn't stabilize heavier bullets, so the .244 was never offered with bullets heavier than 90 grains.
Remington corrected their mistake by offering a 1 to 9 twist barrel, which allowed bullet weights up to 100 grains, and renamed it the 6MM Remington.
That's the only real difference between the two cartridges/rifles.
Their conclusion was that smaller bullets will stabilize nicely with slower twists, but heavier ones will not.
I believe a little research would find that Mauser came to the same conclusion around the beginning of the twentieth (not twenty-first)century.
We just seem to keep trying to re-invent the wheel and re-learn the same, hard-won lessons.
Thanks for your time.

April 7, 2010, 03:11 AM
paducahrider; normally 99% of the time, I would agree with every word you just said-- that being said, we are talking about the 243 here. And just as there are ballistic anomalies that go on with the 22lr round, that happen with absolutely no other bullet, and that goes for other 22 cal bullets as well, there is a few strange things that happen with the 243/6mm bullets. I am not sure what it is, or even how to correctly describe what is happening, but for some reason, you will find a lot, A WHOLE LOT, of 243 shooters, with very good rifles, with 1/10 twist or faster, who when shooting light bullets all the way up to 80 grains, they group ... very .... mmeh, to say the least, then start throwing in anything from 85's up to 105's, which you would think is too heavy at the upper end, and suddenly they are a one hole punch.
If I were to take a stupid guess at this, I would say that the lands/grooves aren't being made correctly, for a 6mm bullet, that is traveling over 3000 fps from a bbl, and because of this and the molten action of a bullet during it's internal flight, there is a certain amount of slippage, or on and off traction, that the bullet is getting from the bbl. And that speed and grip inside the bbl, is not consistent because of this, so the lighter bullets get ' thrown around' a bit as they go down the tube, at differing speeds, causing weird accuracy or groupings downrange.
Then again, I may not have a clue to what i am talking about, and am just
totally full of it...

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