Reloading book data... ie 22-250 heavy bulleta

[mike22250]

I have a question on the reloading book data. Let me open with, i have a 22-250 with a 9 twist barrel. It loves the 70 gr VLDs, but due to the cost i went looking for a less expensive projectile.
I bought some 68 gr BTHP Match from hornady. The book shows that they were tested in a 1:9 twist barrel. So i figured my gun would be ok to shoot. So i loaded up 13 rounds, starting at 2 gr below max and went upto max in .2 gr increments. Shot all but the last 2 and realized that they were keyhole. So my question is Hornady tested them in a 9 twist were they stabilized in their gun? Or are they just shooting for pressure/velocity? Side note, the tested the range of 68 gr up to the 80 gr in the same rifle.

 

[Homerange]

Projectile stability is the product of caliber, projectile weight, length and velocity.
Step just one of those out of the happy zone for your caliber and you can have issues.
Use a twist rate calculator and use the velocity and bullet info to stay within the happy zone.

 

[Texas10]

That bullet shoots just fine out of my 9 twist 223, can't imagine why it wouldn't stabilize out of a 9 twist 22-250. What barrel are you shooting and what kink of velocity are you seeing with your load work up when they just become stable?

 

[mike22250]

I was thinking last night so i pulled out my cleaning rod. I pulled out a piece of tape on one end. I then added a patch and positioned the tape vertical. I then pushed the rod till i got one rev. I then marked the spot, and pulled it back till i was back at 12 o'clock. Then marked it again with tape and removed the rod. I measured the distance and realized i am actually a 1:9.9 twist. So after that i relaized thats the reason why they didnt stabilize. Thanks for the comments. Guess i should double check the barrels actual twist.

I have a Mcgowen re-age barrel. I put it on a Rem. 700 LA.

 

[Dusty Stevens]

I was thinking last night so i pulled out my cleaning rod. I pulled out a piece of tape on one end. I then added a patch and positioned the tape vertical. I then pushed the rod till i got one rev. I then marked the spot, and pulled it back till i was back at 12 o'clock. Then marked it again with tape and removed the rod. I measured the distance and realized i am actually a 1:9.9 twist. So after that i relaized thats the reason why they didnt stabilize. Thanks for the comments. Guess i should double check the barrels actual twist.

I have a Mcgowen re-age barrel. I put it on a Rem. 700 LA.

Id call em if you got a 10twist by mistake

 

[mike22250]

Im looking at my paper work. I was going to call and verify. Thanks

 

[Ned Ludd]

Regardless of what they tell you, take a cleaning rod with a jag and a dry patch, push it slightly into the bore, mark the rod at a specific/reproducible spot with some tape and put an additional pen mark at 12:00, then push the rod into the bore until it goes through one full turn (i.e. pen mark at 12:00 comes back up), mark the rod again using your chosen landmark with another piece of tape, then pull it out of the bore and measure the distance between the two pieces of tape in inches. Repeat as necessary. It should give you a pretty good idea of your twist rate.

 

[Dusty Stevens]

Regardless of what they tell you, take a cleaning rod with a jag and a dry patch, push it slightly into the bore, mark the rod at a specific/reproducible spot with some tape and put an additional pen mark at 12:00, then push the rod into the bore until it goes through one full turn (i.e. pen mark at 12:00 comes back up), mark the rod again using your chosen landmark with another piece of tape, then pull it out of the bore and measure the distance between the two pieces of tape in inches. Repeat as necessary. It should give you a pretty good idea of your twist rate.

He did exactly that

 

[Ned Ludd]

He did exactly that

Sorry, I missed that. I've used that approach with a known 11.25-twist and gotten spot on 11.25" in successive repetitive measurements. I'm guessing he somehow got a 10-twist as you suggested. It will be interesting to hear what the company has in the record book.

 

[Dusty Stevens]

Sorry, I missed that. I've used that approach with a known 11.25-twist and gotten spot on 11.25" in successive repetitive measurements. I'm guessing he somehow got a 10-twist as you suggested. It will be interesting to hear what the company has in the record book.

I bet as many barrels as they have go thru there they either missed it or didnt have what he wanted and hoped he wouldnt catch it (how many of their customers actually discover an issue?)

 

[Lefty Trigger]

Always good to check as sometimes they are not stamped or worse yet stamped wrong.

 

[Ned Ludd]

I bet as many barrels as they have go thru there they either missed it or didnt have what he wanted and hoped he wouldnt catch it (how many of their customers actually discover an issue?)

Yes. I received an 11.25-twist instead of a 9-twist 30 cal barrel the only time I've ever had one not be the right thing. The entire rifle was built around the barrel for shooting monolithic solids. As you might imagine, the 11.25-twist didn't work out so well LOL.

 

[Homerange]

Yes. I received an 11.25-twist instead of a 9-twist 30 cal barrel the only time I've ever had one not be the right thing. The entire rifle was built around the barrel for shooting monolithic solids. As you might imagine, the 11.25-twist didn't work out so well LOL.

For deep penetration requirements ?
A buddy couldn't get reliable results from any of the smaller caliber hunting projectiles and had to do this to for humane euthanizing of stranded large marine mammals.
Dangerous game round nose solids is what performed best.

 

[Ned Ludd]

For deep penetration requirements ?
A buddy couldn't get reliable results from any of the smaller caliber hunting projectiles and had to do this to for humane euthanizing of stranded large marine mammals.
Dangerous game round nose solids is what performed best.

This was a number of years ago. At the time, there was a 30 cal monolithic available, known as the 176 gr Predator. Like many of the newer designs, the BC was off the charts relative to similar weight traditional lead core bullet offerings available at the time. I thought it would be a great bullet for F-TR, which may or may not have been a correct assumption. So I had a new rifle built with (what I thought was) a 9-twist barrel. Believing the rifle to have a 9-twist barrel (I ordinarily always check and for some reason I didn't with this one, go figure), I tried some preliminary load development. The bullets did not keyhole at 100 yd, but gave 4" to 5" groups at 100 yd. I spent some time messing around with it and finally gave up they shot so poorly. I figured at the time that it must be the bullet design. I didn't even consider the barrel twist rate because they weren't going through the paper sideways.

That particular rifle became a practice gun because it happened to shoot FGMM175 factory ammo extremely well, which I had a lot of laying around. I still have that barrel. It wasn't until a couple years later I went back and looked at the target images with those bullets and notices that the holes were, in fact, ever so slightly oblong/oval. At that point I whipped out the cleaning rod and measured spot on 11.25-twist barrel over several replicates to convince myself. Needless to say I wasn't too happy, although the mystery of why that monolithic bullet had shot so poorly was solved at last LOL.