.243 Ruger American, 1/9 twist, 22" barrel, suitable bullet weights?

Chris Baker

Member
Afternoon SD its been a while...

Can anyone advise as I currently shoot a Ruger American .243 (22" barrel and 1/9 twist) and use Honrady SST 95 grain, I'm considering a change to a slightly heavier bullet weight (100 or 105g) so I can happily shoot Roe, Red or Sika without having to change my ammunition and zero my scope in as certain shoots (BASC Isle or Arran etc) require a minimum of 100g.


What are the limits or acceptable range of bullet weights for my setup and does anyone have any recommendations of suitable factory loaded ammunition?

Cheers
Chris
 
Twist/Stability is more related to bullet length than weight but I would think that 1-9 would stabilize 105's. All Hodgdon's data was derived with a 1-10" twist up to 107 grains. Hornady recommends 1-9" twist for their 105 grn A-Max and Match HP bullets which are pretty long: You should be good to go with a 1-9" twist. How do you like the American? ~Muir
 
Hi Chris,

Give a box of 105gn GECO (RWS) ammo a go. It worked fine in my Tikka 590 243 on red deer (stags and hinds) and was amongst the cheapest factory ammo at that time.

I noticed in another thread that Bushwear in Perth might have some, clearly you'll need to go by boat at the minute.................

Best of luck,

hh
 
Ha funny you should mention the Geco 105's Haggis Hunter as somebody recommended them to me, which sparked off my interest in changing my ammo to the heavier grain bullet, ive been quoted £115 for 100 which is no too bad. I'll contact bushwear and see what there asking for them.

Muir thanks for the advice, I'm quite liking the American the more I use it, particularly its weight and simple layout, no frills just does the job, I got the trigger pull reduced to around 3.5 lbs and i've been happy with it since.

Cheers
C
 
Last edited:
It uses a flat-base bullet which has the effect of reducing the bullet's overall length (and therefore the necessary rotational speed for full gyroscopic stability) compared to an equivalent boat-tail design, and also FB bullets don't need as much spin anyway as BT types even when everything else is the same. Berger quotes special twist rates for its few flat-base 6mm models, the rule of thumb being a full 1 in 1-inch slower pitch needed than the same length boat-tail design.

So 1 in 9 will likely be ideal for this particular model, and there are magazine reviews around (Google the cartridge and you'll find a couple of archived copies available free) at least one of which obtained satisfactory results in a standard 1-10" twist rate barrel.

If it'd been any of the 105gn HPBT match or Berger Hunting VLD models, that would change things - most need an 8-inch rate optimally given their considerable length and 9-inch would either produce unstable results, or so marginally stabilised that performance would be poor.
 
Muir thanks for the advice, I'm quite liking the American the more I use it, particularly its weight and simple layout, no frills just does the job, I got the trigger pull reduced to around 3.5 lbs and i've been happy with it since.

Cheers
C
Timney, man! Timney! I put one on my 300 Blackout Ranch Rifle and love it. It completed the project.~Muir
PS: There are some on line articles about reducing the trigger pull.
 
Most .243 Win rifles are 1:10, but most 6mm Remington ( .244 Remington / 6x57mm ) are 1:9, 1:9.25, around there. I had a Browning B-78 in it, and it shot 100-gr and 105-gr ammo into tiny groups ( mostly what came with the rifle. I sold it to a friend fairly soon.)
 
My 1:10" .243 will shoot 100gn SP beautifully, but 105gn vlds go sideways at 60m. A 1:9" MAY stabilise a hunting projectile but it'll be touch and go for the match VLDs.
 
As MUIR correctly says it isn't weight, per se, but length. OK length is obviously longer with heavier bullets but then you get the "exotocs" where they are in fact longer than their weight would suggest. And also the round nose type .243"/6mm bullet where their length is shorter than their weight would suggest.

LAURIE's response interests me..

Do they, I don't know so that's why I ask, because they have a shorter surface in contact with the bore stabilise as if they were a shorter bullet...like the flat base round nose type seem to do? Certainly I never tried them so don't know.

View attachment 64115

I had a Parker-Hale in 6mm Remington and that would not shoot at all with Nosler Partition 100 grains and not very well, either, with Remington Core Lokt Ultra Bonded 100 grains. What I never tried and perhaps others will help is boat tail pointed soft point 100 grain bullets in 100 grain.

But what I do predict...I spoke to someone at BASC and hey appeared dis-interested...is that mandatory non-lead bullets will (for deer where 100 grain is required) effectively render most .243"/6mm rifles unusable...
 
As long as the bullet doesn't lose contact with the rifling (stripping) it's bearing length won't be of consequence. When driven at like speeds, bullets will rotate a the same rate: It has no choice. It can rotate neither faster nor slower while traveling down the barrel. How well it is stabilized once it leaves the barrel is another story.~Muir
 
because they have a shorter surface in contact with the bore stabilise as if they were a shorter bullet...like the flat base round nose type seem to do?

Not necessarily. A flat based bullet, with more bearing surface, tends to line up in the bore and get a smooth start. A boattail with a hollow or plastic tip, which shifts the center of mass to the rear, will tend to stabilize quickly, even with a bit of an off-center launch.

You just have to try.
 
Last night I ran into a guy who loads an American in 243 for his wife. We didn't have much time to talk in front of the bullet and powder display in the store, but he indicated his rifle shot "all" the 100 grain bullets he's tried, so far at least, very well. He looked like he'd had enough of the Christmas rush so i didn't press him when his powder arrived.~Muir
 
I had a Rem 700 6mm with the 1-9" twist it shot the Speer 105 gr semi pointed brilliantly and all the 100 gr bullets I tried shot well ,my current 6mm built on a Parker Hale 1200 has a 1-10" barrel and shoots best
with 87-90 gr bullets 100 gr not too bad the 105 gr RN pretty good, Hornady make a 100 gr BT and a 100 gr FB I would look at those for all round use, the 105-107 gr bullets may stabilise if you shoot them fast enough they work best in a 1-8" barrel I use them in a couple of 1-8" 6mmBR's for target shooting
 
Back
Top