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243 Win sporting 1:9.25 twist - 107gr MatchKing
Cubslover
Member Posts: 18,601 ✭✭
Do you think it could stabilize the 107gr Sierra Matchking?
Lilja's site shows 90-100gr bullets for a 1:10 twist and 105-107 for a 1:8 twist. Any chance the 1:9.25 would handle them or would the 100 grain pills be just about tops?
Also, would 80 or 87 grainers perform OK?
I'm looking to start loading a potent Varmint round, but there aren't many varmint bullets available in 90+ grain sizes.
Thanks in advance.
Lilja's site shows 90-100gr bullets for a 1:10 twist and 105-107 for a 1:8 twist. Any chance the 1:9.25 would handle them or would the 100 grain pills be just about tops?
Also, would 80 or 87 grainers perform OK?
I'm looking to start loading a potent Varmint round, but there aren't many varmint bullets available in 90+ grain sizes.
Thanks in advance.
Half of the lives they tell about me aren't true.
Comments
"Do you think it could stabilize the 107gr Sierra Matchking?"
Most likely, no. I hate to be the bearer of that news but even if you run the velocity right up to the top end of the pressure scale, you will still be a tad short and the bullet might not stabilize every time, or any time for that matter. The Sierras have the older tangent ogive which provides greater surface area of contact for engagement of the rifling but even that probably won't be enough to get you the stability that you need.
"Also, would 80 or 87 grainers perform OK?"
Absolutely. They perform great!
http://www.6mmbr.com/bullets.html
Best.
No chance a Moly bullet ran at the max would stabilize?
Everything I've read has shown a 10 or 12 twist for weights in the 80's or less. I'd like to light off some smokin hot 55 grainers but there's no way they'd stay intact.[:p]
I've been shooting 100 grainers and having good luck, but I don't big game hunt with it and would like to try some different loads. We can only hunt varmints/Coyote with a hi-po and I can't find any heavier Varmint bullets.
BTW, what is your opinion on those Lapua 90gr Scencar's or Berger's 80gr or 88gr Low Drag pills?
I really do appreciate the help and patience you've shown.
The moly bullets will just cost you more and not accomplish what you want.
I went back through some notes from a couple of years ago and I see where I got some good performance from the 105 AMAX and a .243 Win. with standard barrel. The numbers seem to indicate that you could use an upper end load around 3000 fps. to get this one to stabilize. The AMAX will wreak havoc on the coyote population and should bring some good accuracy to the combination.
I like all of the midrange 6mm bullets since I shoot the 6BRs in 1:10" twist barrels. The 87's, 88's and 90's work like a charm and the 95's will work but you need all the velocity you can get from the smaller case coupled with the right atmospheric conditions. The 88 gr. Bergers were a pleasant surprise to me so I have them in stock on the bench all time now. Don't forget about the 95 gr. Nosler Ballistic Tips.
Best.
The 80 grain Fowler is also a dandy for varmints in the 6mm's.....
While I hate to disagree with nn...because usually you aren't right when you do, I think the 1-9:25 will stabilize a Sierra 107. I don't have any handy to get the length but I do load a lot of Sierra 100's and those run at .995" So I used 2850 as your velocity and a 1.115" as your length and mathematically it comes out to a 9.05" twist you need.
That being said we used to load Speer round nose 105's and they stabilized okay from a 1-10" twist. Add the length of the spitzer and you should need to go 1" tighter twist. All this being said, you will still be marginal for stabilizing these. You need to be right at the top of the velocity chart.
If you are looking for a varmint round though I don't think this is it. I would personally look from 75 gr. up to 90 gr. with the occasional trial of the 95's. My two favorites are 80 gr.s and Sierra 90 gr. bullets. You will get better velocity and better trajectory out to as far as you will be shooting varmints. The 107 is more of a 600 yd. to 1000 yd. bullet. -good luck
I run those 55 grainers in a Ruger 77MKII stainless sporter. They are superbly accurate, and they do hang together. I am using top end loads of H414, and they are leaving better than 4000 fps. They are truly evrything a 22-250, 22-250AI, or a swift would like to be, but are not. On a calm day, bottle tops on pop bottles are a regular thing at 200 yards.
If you can get them, also try the Barnes 85 gr XLC, or the new TSX. I use them for deer, and they are really awesome, and they hang together, and retain almost all of their weight. They can be started out at 3200-3300 also, and have a higher BC than any lead core their weight.
You can get about 3100 fps out of a 95 gr. bullet. But that is about max. with a long barrel (24") and a full charge of slower burning powder. I like the longer barrel on them so as to get the extra velocity. Something to consider though is as you get higher up in weight for 6mm the BC's start getting a lot better and you don't have to have all that velocity.
If comparing to a .220 Swift, you should get a little better barrel life if you shoot a fair amount. Although you can take out a .243 barrel quick enough if you don't cool it down between shots as well. In general the .243 will have better range than the Swift. Which will help on those singular long shots you may come across. The Swift in it's own right though is like a laser out to most varminting ranges and really isn't bothered by the wind until it gets out a ways.