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222 rem bullets
fasttack
Member Posts: 81 ✭✭
again just starting out with 222. Have shot a couple boxes of different factory loads off a rest. Have found 50 gr pmc best. All of the varmit loads (MOLY Balistic tip) stuff keyholed. Any good recomend for match type bullets?
Comments
The 52 gr Amax is a good bullet also, in that weight range.
52 and 53 grain Sierra Hollowpoint Match bullets usually shoot well ( one is flat based and one is HPBT ).
The hornady moly coated 50gr vmax and rem accutip 40 gr all keyholed. PMC 50 gr best 55 gr good also.
Keyholing in this instance then would seem completely out of the norm. Did you look to see if the bullet didn't hit something in the backstop as it went through the paper? These weight bullets should not keyhole out of any .22 high power case, Especially since the 55's didn't. If the 55's shot good and didn't keyhole and the 50's did I would say something wrong with the ammo. Not to worry continue to buy better ammo and don't get keyholes.
What's the rifle and was it originally chambered in .222?
I bought a Model 54 Winchester once, .222 Rem., but it started life as a Hornet before it got rechambered for the faster .222.
It also keyholed most 50 to 55 grain bullets at normal .222 velocities. That, and the fact that the reciever rails wouldn't hold rounds in place (i.e. pull back bolt and watch your fine reloads shoot up into the air and fall to the ground) helped to make this rifle a real quick turn-around for me. In fact, as I recall, the dealer agreed to take it back several days after I first purchased it. A simpler way to respond might have been, "What's the rate of twist?"
Good luck, whatever the answer turns out to be.
If that's the problem, and since it would have to be recrowned anyway, you might want to tackle the job yourself. Not that hard, and could certainly get you out of the key-hole league, if not into the benchrest circles.
Good luck.
Are you runnning good powder at appropriate load levels?
What is the twist rate ( I have a chart)
are they seated in the case, and are they movable by hand?
is there a throat left?
Well, I'm out of ideas! With some 55 and 50's shooting fine that would rule out problems with rate of twist or crown for me.
Pick a good bullet you want to reload, maybe something in the 50 to 55 grain range at around 3,000 fps and see what happens. You may have no problems and the keyholes may remain a mystery. Otherwise we'll all have to put our thinking caps back on and see where this all leads.
Good luck.
I think JustC might have hit on it. The issue may be in your throat. The shorter bullets arent' engaging evenly into the throat. The longer ones are?
Measure, if you still have both, the overall length. If you have the tooling measure from the base to the point on the ogive of each bullet. Maybe, when you start reloading make sure to seat the 50's out a little further. I had this problem with my dad's old 340 using 40's and 45's but never troubleshot if further because 50's worked great. I always seated bullets out too far according to some of my earlier mentors though. -maybe that'll help
EDIT:
I forgot to add; that rifle, if originally chambered in .222, should be a 1-14" twist. That will stabilize up to 55 gr. when pushed near full potential of the .222. You can do the cleaning rod measuring test if you like. Take a Jag with a good ballbearing handled cleaning rod. Put a patch on and get it snug in the barrel. Take a sharpie and mark top center on your rod somewhere back at a reference point like the butt. Push the rod through watching the rotation of the rod. When your mark comes around to top center again mark the same reference you used for the first mark. Measure that and it will tell you the length it takes to make one rotation inside your barrel. -good luck with this.
There can be a multiplicity of things going on here and not traceable to any one thing in particular. This is why it's so hard to diagnose this stuff from long range without really seeing what's going on up close and personal. Take this for what it's worth.
Shooting targets at 50 yards is suitable for getting on paper and close to the middle of the target and that's about all as far as centerfire is concerned. Rimfire is a different story, of course. Get on paper and make sure that your scope is set up correctly then move out to 100 yards for testing loads. With proper boresighting, you can skip the 25 or 50 yards because you will be on paper and can start working on loads after 1 or 2 shots for sighting adjustments.
Why skip 50 yards? Mostly because the bullet hasn't had a chance to stabilize yet and you can get some KEYHOLING. This comes into play with the bullets that have boattails more than the flatbase bullets but it can be a possibility with any of the bullet shapes.
Long throats and very short bullets (40's and 45's) can cause some instability due to the longer jump to the lands allowing for the bullet to stay unstable, not rotating around it center of mass. This usually shows up as inaccuracy rather than keyholes. Rough throats can contribute to inaccuracy as well as bullets that blow up on the way to the target.
I think that the Moly coated 50's are the main problem but you haven't discussed your cleaning procedures so I can't say for sure. Using Moly bullets directly after shooting naked bullets will lead to keyholing. Using naked bullets after shooting Moly bullets can lead to higher pressures. Moly bullets usually require more velocity to perform correctly by comparison to naked bullets. Those loads need a separte work up from naked bullets. Do not mix the testing of Moly with naked bullets.
Your barrel needs to be clean and free from the copper deposits and fouling from naked bullets before shooting anything with Moly on it. The barrel also needs to be fouled with a Moly product before shooting Moly bullets. Afterwards, be sure to clean down through the levels of Moly/copper fouling when you're through shooting Moly.
I hate to buck the tide of opinion but if there was a problem with the crown it would affect all of the loads not just a couple.
You do not need Moly for varmint loads, there are lots of loads out there that will work just fine without it. The only requirements are that you keep the barrel reasonably cool and clean. Take more than one rifle and alternate, then take a break to clean and get some refreshments.
Clean your barrel now before you do any more testing and be thorough. If you insist on using moly, test only one type of bullet then clean before switching.
Best.
How severe is this keyholing? A slight "out of roundness" or a full blown "tumble"? Pending the response to that question, as far fetched as it may seem, another question would be, "Was the target secured at all corners, or subject to wind blown flapping or turning of the target which could easily mimic the bullet hole patterns of an unstable projectile?