100gr .243 sellior and bellot

[Snowflakesmasher86]

Hi gents,

Reloading question.

Previously in my .243 I have used 100gr PPU to great affect. (39gr of n160) After a shortage of PPU a while ago I moved to 100grain sellior and bellot..

The problem.. I cannot get the bullets to group. 3" groups at best. I kept the same 39gr of n160 and played with the seating depth. Going from max magazine length down in say 20thou increments.

Has anyone had luck with this bullet in .243, and if so please let me know what you have settled on.

TIA

 

[Ginc]

39,2gr of VV N540 brings me sub MOA. Rifle - Savage 14, twist 1:9.25. Pressure may be high, please start somewhere lower!

 

[jonny.c]

your not even a grain off of max load ?? 0.9gr

Start min work up 0.5gr and see what you get I then Adjust once you have 2/3 good groups and adjust powder to 0.25gr (adjust finer later) would keep the bullets 20-30tho off and then once you see better groups with powder weight then stop and adjust don’t chase the lands find the sweet spot for the rifle & bullet type.

 

[.25-06]

After years of optimism I gave in and tried 95grn noslers. The old bruno .243 shoots 2-3 inch groups with 100grn but 95grns hmm groups similar to Ginc and passes through reds

 

[borbal]

Previously in my .243

What is the rate of twist in your 243?

 

[8x57]

You've just got to accept the fact that some 100 grn bullets will stabilise well in some .243win barrels and others won't. As far as I understand it it's mainly to do with bearing surface.
Drop to a slightly lighter bullet.

 

[Stevie/P]

You've just got to accept the fact that some 100 grn bullets will stabilise well in some .243win barrels and others won't. As far as I understand it it's mainly to do with bearing surface.
Drop to a slightly lighter bullet.

Try a flat base bullet sierra pro hunter 100g

 

[Heym SR20]

Traditionally the 243 Win was built with a 1 in 10” twist. Many European rifles are built on a metric lengths so so often twist rate is a touch slower.

The 243 was really designed around 80 and 90 grain bullets and it shoots these superbly. Once you get to 100gn bullets you are on the limits of stability. Short dumpy flat nosed and sharply pointed bullets will stabilise. But they are not sleet aerodynamic bullets. A 100gn boat tail or even a sleek flat base will often not stabilise as they are too long. And depending on how the bullet is built, will also affect it. My 243 shot the old pattern of RWS 100 gn T Mantle bullets very well. They then made the bullet a little longer with a sleeker point and seated them deeper. Groups opened up. Norma bullet has a tougher design with a thicker copper jacket (lighter material) so overall bullet a wee bit longer. Did not like those either.

Now that the Scottish Government have reduced min bullet weight to 80gn, there is no need to use 100gn bullets. You are better off dropping down to a lighter more aerodynamic bullet. Increased velocity more than makes up for loss of weight in terms of kinetic energy. A monolithic bullet design also sorts out all the issues of lack of penetration on bigger deer.

 

[MAH]

Previously in my .243 I have used 100gr PPU to great affect. (39gr of n160) After a shortage of PPU a while ago I moved to 100grain sellior and bellot.

Do you have any sample left of both bullet types?
If yes, measure the le ghtvof each with a micrometer.
I think you'll find thecSB are longer than PPU.
It will o ly be a small difference., but because they are longer they will not stabilise.

If you're interested in the science behind the above, Google - bullet length vs twist rate

M

Extract from AI search
A bullet's length directly impacts the required twist rate in a rifle barrel, meaning that longer bullets generally need a faster twist rate (a lower number like 1:7) to stabilize in flight, while shorter bullets can be stabilized with a slower twist rate (a higher number like 1:12) to prevent over-stabilization and potential accuracy issues; essentially, the longer the bullet, the more spin it needs to fly straight.

 

[Snowflakesmasher86]

What is the rate of twist in your 243?

Standard factory, believe 1:12?

 

[jonylandrover]

I have had very similar results with my old .243. in fact your targets look identical.

100gr PPU factory will do 1 inch or less at 100 no issues at all.

Hand loads, iv tried Hornady 100gr interlock boat tail, no luck at all.

Sierra 100gr game king boat tail, no luck at all.

Sierra 100gr pro hunter, no luck at all.

found some old 90gr Sierra FMJ I had, back to 1 inch or less.

Went down to Sierra 80gr blitz varminter, ladder tested these so far and showing promise so think I will use those if I keep up the fight with this .243

 

[borbal]

Standard factory, believe 1:12?

Standard factory is 1:10. This is very marginal when shooting 100 grain bullets, which will stabilise in some guns but not in others. The rate of twist for the 6mm Remington was 1:9 which solved this problem for 100 grain bullets. But the 243 Win is what is most popular.

So, not the bullet, but your barrel, almost certainly.

Sorry about that.

 

[hendrix's rifle]

A monolithic bullet design also sorts out all the issues of lack of penetration on bigger deer.

Never an issue with the 100g pro hunter and 90g TGK the pro hunter resulted in a couple of big stags... Never recovered one on the opposite side either

 

[Stevie/P]

I have had very similar results with my old .243. in fact your targets look identical.

100gr PPU factory will do 1 inch or less at 100 no issues at all.

Hand loads, iv tried Hornady 100gr interlock boat tail, no luck at all.

Sierra 100gr game king boat tail, no luck at all.

Sierra 100gr pro hunter, no luck at all.

found some old 90gr Sierra FMJ I had, back to 1 inch or less.

Went down to Sierra 80gr blitz varminter, ladder tested these so far and showing promise so think I will use those if I keep up the fight with this .243

A lot of people who re load consider bullet powder primer and don’t really give much thought to brass. I’ve had five 243s in the past and struggled on three of them to get a consistent group.
I was at the time using exclusively federal brass I was led to believe it’s good brass so couldn’t be that.
But that’s exactly what it was I switched to Norma and bingo result.
I’m not saying Norma is be all end all but consider brass as a potential reason for inconsistency as it was in my case I’m no expert in reloading just my experience with .243 some work others don’t.
Or just get a .270 and stop faffing around took me 20 years too realise

 

[BuckhurstBen]

Up the charge weight

 

[Snowflakesmasher86]

Update on above post:

Tried a ladder test, no luck and groups all of the same 3".

I didnt measure the length of bullet from ppu to SB but i believe the bearing surface of the SB was likely more.

I have found peace in my old 80gr sierra sbt load. The 100gr sierra prohunters seem to be working about 1" with not much effort so i will be working with these to get that even better.

Thanks for your help!