Yesterday while testing a new load on my 264 win. mag. I ran into some trouble. I have a nice load worked up using a 130 gr. accubond running at 3100 fps. I wanted to try a lighter bullet for coyote hunting so I was working on an 85 gr. sierra hp. I made up 10 rounds, set up the chrono. and shot 1 round through it. 3400 fps. just about what I was expecting. Cold bore shot went right where I expected. Next shot 3350 fps. again pretty close to where it should hit. Next shot 3400 fps. didn't hit the target. This is a 4' x 4' piece of steel and I'm 100 yds away. Next shot no reading on the chrono and no hit on the target. I see dust about half way between me and the target. I walk down and take a look at the steel. Just 2 hits. I'm wondering what the heck is going on so I go back to my bench and throw in a 130 gr. accubond and give that a try. bulls eye. I know my scope is still on, nothing wromg with the rifle. Is the 85 gr. Sierra coming apart on me.

I don't know the twist rate of the rifle, but it is tight. It has always shot heavier bullets well. I have never had this problem before but I'm pretty new at shooting and reloading. I had never shot a light bullet from this rifle before. Any ideas as to whats is going wrong with the 85 gr. rounds??

Mike, If you have a piece of cardboard or paper that you can set up at say 50 or 75 yrs it will tell you for sure if the bullets are frags.

Dave

quote:

Posted 12 September 2011 16:30

Great idea! I can do that this afternoon.

If that's a 1:8" twist barrel, those bullets would be turning about 306,000 rpms. That's pretty fast for a varmint bullet. So yes, they may be coming apart. Hivelosity's idea is excellent. Let us know what you find.

LWD

quote:

I see dust about half way between me and the target.

From your description sounds to me like they're coming apart on you.

Not sure in your case but I had an issue with Hornady SX's out of a .22-250 and a .223. Butcher paper at about 50 feet proved it.
The same bullet was fine with the same load out of a slower twist .223 but I only have one .22-250 so I just pulled those bullets.
FWIW I can push a Nosler BT the same way as tose SX's were without the bullet coming apart. Nate

Yes I would say you have bullets comming apart before hitting the target.

You have two choices, go to a tougher bullet, or the same bullet at lower velocity.

Once upon a time I had a 264 Win Mag. I might go to a tougher 100gr bullet.

Dave, is that pic you or Earl Scruggs ?

Yea, thats Earl. One of the greatest banjo pickers ever. close thought I have the same gap in my teeth

Yep, they're coming apart on me. This was just an idea I was exploring,trying to get a lighter bullet for coyote hunting. I have a good round using 130 gr. accubonds. I think I'll just stay with them. I guess the twist is just too tight. Thanks for all the help. I was scratchin my head over this untill I got your advice.

Try Sierra 85gr. HP's at around 3000f/s I loaded some using H414 and didnt have an issue with them other than accuracy at higher velocities. 53 grains gave me 3/4" groups @ 100 yrds. my rifle is a winchester pr 64 1:9 twist. pretty close to what you got?
Dave

ok, I'll try loading down to 3000 fps. and see if they will work. That should put me in the 260 relhem, which is ok with me. May be just the ticket for coyotes.

I'm not sure if they still come labeled that way, but the Sierra 6.5/85 HP's used to be labeled for some limited velocity, implying that they would fail if fired at higher velocities. I'm sure this is what is happening with yours.

There are several good 100 grain 6.5 varmint-style bullets on the market which can be pushed to 3500 fps (using the right powder in a .264WM chamber with a reasonable leade -- not the zero leade of SAMMI specs). Try one of those instead of the highly frangible 85 HPs.

I agree with Stonecreek. Recently I had a problem with 62 grain 6mm Barnes Varmint Grenades coming apart upon leaving the barrel. Happened twice, one of which took apart my chronograph screen with jacket fragments. The barrel is a Brux 6mm 1:8" twist chambered for the .243 WSSM on a Savage Precision Target Action. The load I was using has been shot several years at ground squirrels, with no problems. Bolt lift was a little sticky, with the fragments developing over 5,000 fps before the screen was destroyed.

What caused these high velocity rated bullets to come apart? Too much twist? No. I traced it down to a bit of Styrofoam seal from a powder can that lodged in my powder measure - it held back a bit of a dropped charge, under-loading one case and then shifted dropping the charge over-loading another. High pressure blew the bullet apart, not velocity or twist rate. Weird situation that happened only once in 50 years of loading.

There are some bullets, I recall the Sierra Blitz King being one, that would self-destruct on the way to the target if driven too fast. The box was marked not to be used over a certain velocity. Other Sierra bullets on the day were labeled for medium or high velocities. You knew it was happening because the bullet left a "vapor trail" that looked a bit like a tracer.

So, I would suspect that either that particular bullet is not suitable for your rifle and load, or you were unlucky to get a bad lot. I have been doing a lot of experimenting with fast twist barrels, so far not one bullet has failed due to too much twist, but accuracy has increased to astounding levels with some combinations. I cite a 26 grain .204 Varmint Grenade shot in a 1:8.5" twist at 4,110 fps that groups right at .250" for 10 shots or more at 100 yards, as one example.

each of these loads was hand measured. I'm sure that isn't the problem. Please give me some ideas of a bullet that will handle the 1 in 8 twist and 3400 fps that is in 6.5 and around 100 gr. or less. I have only used Sierra and Nosler bullets in this rifle.