Key hole with 22-250

[lendar]

I have a 22-250 barrel that with a 55 grain bullet shoots about an inch at 100 yards.  That part of the story is great.  It also shots about the same with 45 grain bullets.  The problem is with 62 grain bullets.  I tried 2 kinds of powder, 4350 and 4064.  With both of these at or about the starting load the bullet key holes.  The bullet is a 62 grain boat tail hollow point.  The same bullet in a 223 AR with shoot under one inch.  The AR has a 1 in 9 twist and the 22-250 has a 1 in 14 twist.  I thought that might be what the problem is but after looking at my loading book I am not so sure.  When I looked in the book under test specifications, it showed the barrel they used (universal receiver) to have a 1 in 14 twist.  Now, if a 62 grain bullet worked with the barrel they used, why does it not work with the 22-250 barrel I have?

[trotterlg]

The problem is the physical length of the bullet.  A BTHP is about as long as a bullet can get for a given weight.  The length of the bullet is the limiting factor in how high a twist rate you need, the recomended twist rates for a gerenic bullet weight are what will be stable if it is a flat base FMJ type of bullet.  Also remember it is the RPM (spin rate) that determines if the bullet is stable, not how fast it is going (as long as it is above sonic), so yours may be stable if you load it up to max and get the RPM up some.  Larry

[wtroger]

Bottom line is if your handi is anything slower than 1-10 twist it probably won't shoot bullets heavier than 55 grain very well. I have had the same problem with a 788 remington in 223 it will shoot 55 grainers into a clover leaf group but will key hole the 60 and above bullets.

[trotterlg]

Your 22-250 with a 1 in 14 twist will shoot the 55 gr bullets fine, and if you use a round nose flat base 60 to 65 gr bullet they will shoot just fine also.  The twist rate to make a bullet stable is mostly over calculated, too much twist will cause a loss of BC at long ranges and generally hurt your cause as much as it may help.  The reason the .223 has a faster twist rate is party because it does not shoot the bullets as fast as a 22-250 does, so the get the same rotational speed the twist rate has to be higher.  Larry

[Lone Star]

With both of these at or about the starting load the bullet key holes.

Apparently no one read these words.  Your .22-250 might shoot the 62s just fine - with maximum loads.  Starting loads have too low a velocity - and thus the bullets have too low a rotational speed.  Heat the loads up a few hundred fps and the bullet stability problem may go away.


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[lendar]

If all of you read my original  post.  My loading manual shows them to be using a barrel with a 1 in 14 inch twist.  The starting load of 4895 is one of the loads I used and it key holed.  This is also noted in my reloading book as the accuracy load.  It does not key hole in the universal receiver, why would it key hole in my 1 in 14 inch barrel.  I may try to up the powder just a little, faster may make it spin more and stop the key hole.  In the reloading book, with the starting loads I've got it going about 3,000 fps, and the max is about 3,500 fps.  Please understand that with lighter bullets this barrel is as nice a shooting rifle as I have seen in a while, Its no big deal that it won't shoot the heavy bullets.  I just do not understand why this is going on. 

[trotterlg]

You don't understand?  You have picked the most difficult type of bullet to make stable and are shooting it at the low end of the velocity range in a barrel with a slow twist rate, it is the classic setup for failure.  Boat tail Hollow Point bullets are very long for their weigth, even though bullet weigth is listed in the load tables the stability part is based on the length of the bullet, and you are using a very long one, (this is one of the only things in life where short is better).  A boat tail bullet is also more prone to muzzel crown problems, the base of the bullet is exposed to the excaping gasses longer than a flat base bullet is, so crown problems affect a BT bullet more than they do a flat base one.  If you want to shoot a heavy bullet get a flat base round nosed one and have at it.  Larry

[quickdtoo]

FWIW, I have a fluted 22-250, my best load so far is the 50gr Vmax and a near start load of H4895, groups are a riight at 1".

Tim

[billy_56081]

The faster you push a bullet down a barrel the faster it spins. The longer the bullet is the faster it needs to spin to be stabilize. Now for the starting load and accuracy in the test gun verses yours. The test rifle may have been acheiving higher velocities than your gun thus a higher roational velocity. Most times what the data says for a particular load and what the actual velocity is is much different. I chrono alot of loads and very rarley have one that acheive as high of velocity as the data says. And what load is accurate in one gun is not in another. Start bumping up your charge and I will bet you dollars to dognuts that the keyholing will stop.

[lendar]

I just got done loading 5 more at a little over mid way between minimum and max.  I will try them in the morning and let you know how it works. 

[lendar]

The new ones I loaded only took one try to see they key holed just like the first ones.  These are about 200 FPS under max,  so that's the end of the more powder idea. I will just use this bullet in the 223 and the lighter bullets in my 22-250.

[Dave Allen]

hello..when i had a two "fiddy" handi...i only loaded 55 grain sierra & hornady soft point's..it grouped well using w-760..&..h-380..38 grain's of each worked well...i never experimented with other bullet weight's..so i can't comment on the heavy's...i'm not a handi rifle reloading pro..in the three handi's i have reloaded for...mild load's have worked best for me..

[Lone Star]

...The starting load of 4895 is one of the loads I used and it key holed.  This is also noted in my reloading book as the accuracy load.  It does not key hole in the universal receiver, why would it key hole in my 1 in 14 inch barrel....

You are assuming far too much here.  Why do you believe it did not keyhole in the Universal receiver?   Developing data for a manual is a very costly endevour, and few loads published in manuals are ever fired for accuracy, just velocity (heck, in some manuals the maximum listed loads are often not even tested).  It is very doubtful that your lower velocity load was ever targeted to 200 yards to confirm accuracy or stability.  Many manuals list "accuracy loads" based upon ballistic uniformity only - not grouping on a target.  IIRC, Nosler's is one such manual.

These are about 200 FPS under max,  so that's the end of the more powder idea....

This is an odd comment.  First, how do you know the velocity in your rifle with your components?  And, how does this 'prove' more powder does not work?  The bullets may be perfectly stable at maximum velocity.     Good luck with your shooting.

.

[lendar]

I think I will continue to believe and assume the information in my loading books is true, and continue to believe and assume that you are a person who does not know what they are talking about.   

[quickdtoo]

You're entitled to your opinion here, but there's no need to respond that way Lendar, Lone Star is a very knowledgeable and reliable contributor here, I would give his thoughts consideration with your accuracy issue.

Tim

[Dee]

I have a 22-250 barrel that with a 55 grain bullet shoots about an inch at 100 yards.  That part of the story is great.  It also shots about the same with 45 grain bullets.  The problem is with 62 grain bullets.  I tried 2 kinds of powder, 4350 and 4064.  With both of these at or about the starting load the bullet key holes.  The bullet is a 62 grain boat tail hollow point.  The same bullet in a 223 AR with shoot under one inch.  The AR has a 1 in 9 twist and the 22-250 has a 1 in 14 twist.  I thought that might be what the problem is but after looking at my loading book I am not so sure.  When I looked in the book under test specifications, it showed the barrel they used (universal receiver) to have a 1 in 14 twist.  Now, if a 62 grain bullet worked with the barrel they used, why does it not work with the 22-250 barrel I have?

Here is the question you SHOULD BE ASKING. Did the TEST SPECIFICATIONS in the book, list velocity, pressure ect. ALONG WITH ACCURACY? I have been reloading this round off and on since the seventies, and BARREL twist is ALMOST ALWAYS the issue in key holeing. IF the the book said it was an accurate bullet in that barrel twist then and only then would I look else where for the problem of key holeing. jmo