Keyhole strike?

[i8asquirrel]

So I'm at the range shooting some new loads. I have a 16" 1x10 barrel. I have been using 190 smk's and 180 sst bullets with great luck. I loaded some 200 gr Nosler BT to be subsonic...when I fired them I saw a sparkle through the scope, I checked My buzzle break, No strike or anything else wrong for that matter. I fired four more rounds, each one sparkled down range. walked down to inspect target at 100yds. Five full keyhole bullet strikes! so my ? is should I be able to stabilize a 200 gr projectile in that twist at subsonic vel. or should I just stick with 180 and 190 gr projectiles...i would be thankfull for anyhelp.

[Scalce]

I have a 1x8 so I don't have first hand experiences with a 1x10 but I would say that stabilizing a 200 grain BTHP in a 1x10 twist at SS velocities is not guranteed or even expected.

You obviously proved that point with that barrel and bullet combo at least.

I would double check those 190 SMKs to make sure they are definately stabalized before running more through a can.

[i8asquirrel]

Yep ,,,190 are fine grouping < 1moa 180's doing well 165's shoot fine I think 200 at least in that bullet length are not gonna make it.

[Titleiiredneck]

i had a 1-10 ar 16" barrel, i tried some 200smk's and no luck so i stuck with 175smk. 180 speer round nose and 190 smk's. That was a long time ago though, may find a better 190+ pill now

[Alleycat]

Stabilization is a length vs twist issue. Length of the bullet and twist of the barrel. Your 200 gr bullets will not stabilize, but a 200gr Lapua or a 220 round nose will. I've been working with a 225 round nose hollow point that shoots great out of a 1 in 10




http://www.midwayusa.com/viewProduct...tNumber=381996

[dick]

Originally Posted by Alleycat

Stabilization is a length vs twist issue. Length of the bullet and twist of the barrel. Your 200 gr bullets will not stabilize, but a 200gr Lapua or a 220 round nose will. I've been working with a 225 round nose hollow point that shoots great out of a 1 in 10




http://www.midwayusa.com/viewProduct...tNumber=381996

Whats this 225 round nose hollow point you speek of? What gun and load are you using?

[JFettig]

Originally Posted by Alleycat

Stabilization is a length vs twist issue. Length of the bullet and twist of the barrel. Your 200 gr bullets will not stabilize, but a 200gr Lapua or a 220 round nose will. I've been working with a 225 round nose hollow point that shoots great out of a 1 in 10




http://www.midwayusa.com/viewProduct...tNumber=381996

I haven't proven this but I'm pretty sure velocity also plays a roll in this.

One way you could test it is shoot that bullet at 1250fps and see if it stabilizes, this would give the bullet an equal RPM to a 8 twist at 1000fps.


Jon

[Alleycat]

Originally Posted by dick

Whats this 225 round nose hollow point you speek of? What gun and load are you using?

I'm working on a Savage precision carbine that has been threaded for a cyclone and a 4.5x14 MK4. The load is 10.4 grs of Trail boss WLRM primers, and a 225 Outlaw state bullet. I have to chronograph the load, but its definitely subsonic. I've been shooting some 180 Sierra GameKings with 10.2 grs of Trail boss with good results. I suggest getting some 220 rounds to test and see if your setup generates enough RPMs to stabilize them. What is your intended purpose for the subsonic loads? If you are just pinking, 190s or the 200 Lapua will work fine. The 180s are just cheap fun for me. The 225s have only one job, Killin Deer

[Alleycat]

Originally Posted by JFettig

I haven't proven this but I'm pretty sure velocity also plays a roll in this.

One way you could test it is shoot that bullet at 1250fps and see if it stabilizes, this would give the bullet an equal RPM to a 8 twist at 1000fps.


Jon

Technically It's length vs RPM, but you get into some long explanations on that one.

[Alleycat]

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi