Home Forums Hunting & Shooting AR and Tactical Rifles 24 Inch 8 Twist

What is the heaviest highest BC bullet that wil stabilize in this barrel?

80 JLK or I'm not sure what the wildcats were, I think they should be back in business by now, they had rebated boattails and may have had a higher BC than the JLKS.

No way you'll get a 90 to work in that tube. Assuming standard 223.

Thanks, when I bought the upper I actualy wante a 7 twist but to no avail

7 twist would not have really gained anything on the 8, except once you start to reach out there, I always had a bit better groups from the faster twists... Of course you can "overstabilize" in theory and get the tip up too high and cause more drag than there should be.... But that must happen more beyond 600 because I've shot as much 600 as anyone else.. and can never see the difference, only a plus to shooting faster twists...

In fact when working with the right twist for 90jlks, folks found the 6.5 twist shot the 80 jlks REALLY good too.....

1:8 will shoot the 80gr JLK to 1000 yards with no problem in that tube. I've done it thousands of times, literally. The claimed G1 BC of that bullet is .510.

Jeff, I'm not a bullet designer, but I'd bet my lunch that the Wildcats were far from having a higher BC than the JLK's. Long bearing surface, short ogive and big fat meplat.

Chris

You are probably right, I just know that wildcat had some really high BC bullets out.. .277 ones were high as were the .284s...I know they also did some heavier .224 ones.. but I don't have any data and never shot em. You had em didn't you?

Jeff

Jeff, where do you get your 6.5 twist barrels? In other words can you get them ready to go or do you have to have a gunsmith do the work?

Mine are pac nor 3 groove, I have John Holliger do mine up, reasonable enough for me. PN might do them too, I've never inquired but John has some reamers I like....

Also a note, 6.5 comes in Krieger but you won't get enough speed to make it worthwhile to run heavy bullets..... Don't know why there is so much difference between the two.

Also note that every so often we'd stumble into a PN that wouldn't shoot the 90s, but never seen one that wouldn't shoot the 80s. They'd be fine with 80s and 77s and such but just not better than around MOA for the 90s at distance... Just an FYI there.

Thanks

May I ask what you are planning to do with this rifle? Are you thinking of competition? If so, what kind?

There is more to this than just high claimed BC values. I've done quite well in F-class with the 8gr JLK, beating others who were using the 90gr SMK. At some point, you do need the velocity.

I agree one can shoot to heavy of a bullet and give up too much velocity

No competion just some long range shooting and Coyote busting is the plan. I am new to the small bores in this reguard and trying to learn from those that know

Learning is good. I'm happy to share whatever little bits of knowledge I may possess in LR shooting with a .223.

Let me reassure you that your 1:8 twist is perfect for what you are planning on doing. You can shoot any magazine length cartridge available and you can also single load the 80gr bullets and the 82gr Bergers.

Before you get going on spending lost of money on ammo and components, it would do you good to find out what chamber you have in the rifle. I'm thinking/hoping that with a 1:8 twist the maker was smart enough to use a Wylde or similar reamer for the chamber, or at worse a 5.56 NATO. You might want to get a Stoney Point (now Hornady) device to measure the distance to the lands and then seat the bullets accordingly. I've had good success with seating the JLKs about .010 into the lands but I keep the SMKs out of them. That's for the 80s. The other should not be able to reach the lands.

You might also look at the Hornady A-Max, 75 and 80gr bullets. They are inexpensive and they work very well. Between JLK, Berger, Sierra and Hornady you should be able to find something to your liking.

Thanks for the info. The chamber is a 5.56 NATO. I am going to try some of the 77 SMK's today if all goes well

I have some 80's, 90's and 100's. He stopped producing them and I lost interest without a sustainable supply. They may actually be shootable out of a magazine (even the 100's...the ogives are THAT short!). I didn't play with them enough to find out. I'll see if I can get some picture up.