New 220 Nosler BT' Range Report... Problems.

Moderators: gds, bakerjw, renegade, bamachem

Klem
Silent But Deadly
Posts: 199
Joined: Fri Aug 10, 2012 9:07 pm

New 220 Nosler BT' Range Report... Problems.

Post by Klem » Tue Mar 20, 2018 4:12 am

Anyone have any idea as to why these new bullets are tumbling?

Image

Bought a box and was load testing at 100yards. Result are that most tumble sideways through the target. Took the suppressor off after the first round and continued without it (too expensive to risk damage).
Image

Results are as you would expect, except for the stability of the bullet.
Image

Barrel, 1:7, 12.5"
Speed of sound, 1140fps on the day.

Anyone else have any experience with this bullet?

BulletFlight for Android
User avatar
pruhdlr
Silent But Deadly
Posts: 350
Joined: Sat Jul 13, 2013 3:31 pm
Location: Cantonment,Florida

Re: New 220 Nosler BT' Range Report... Problems.

Post by pruhdlr » Tue Mar 20, 2018 7:36 am

My guess would be. - - -> bullets rotational velocity . . . ?
No . . . Really . . . It could be that the nose profile is slowing them down more than anticipated out past the chrono. What is the B.C. of these bullets ?? Rough and/or dirty bore could be another thing I suppose. --- pruhdlr
Why just dance when you can "rock and roll".
STONER 63A / XM177E2

Klem
Silent But Deadly
Posts: 199
Joined: Fri Aug 10, 2012 9:07 pm

Re: New 220 Nosler BT' Range Report... Problems.

Post by Klem » Tue Mar 20, 2018 10:19 am

pruhdlr wrote:My guess would be. - - -> bullets rotational velocity . . . ?
No . . . Really . . . It could be that the nose profile is slowing them down more than anticipated out past the chrono. What is the B.C. of these bullets ?? Rough and/or dirty bore could be another thing I suppose. --- pruhdlr
The bullets are impacting the target at 100yards at between 940 and 970fps depending on the load. I am using a Lab Radar which records the velocity at various increments downrange.

The barrel is not 'rough' or overly 'dirty'. I fired about 40 220gn Sierra Match Kings during the same session without issue. They pencilled the target a usual. The barrel is a Ranier Ultramatch.

I have contacted Nosler but they have yet to respond. Just wondering if anyone out there has used these. I'm thinking they might be spinning too fast with the 1:7 twist, or just defective.

User avatar
dellet
Silent But Deadly
Posts: 6384
Joined: Fri Nov 30, 2012 1:25 pm

Re: New 220 Nosler BT' Range Report... Problems.

Post by dellet » Tue Mar 20, 2018 10:37 am

A lot of people have had trouble with them. First thing I would do is physically check twist rate of the barrel. Then start at 10 yards to check stability, then you will know if it's ever stable.

viewtopic.php?f=141&t=101041
300 Blackout, not just for sub-sonics.

User avatar
pruhdlr
Silent But Deadly
Posts: 350
Joined: Sat Jul 13, 2013 3:31 pm
Location: Cantonment,Florida

Re: New 220 Nosler BT' Range Report... Problems.

Post by pruhdlr » Tue Mar 20, 2018 12:33 pm

The rotational velocity of your load is <100,000 RPM. That is super slow for any bullet.
Got a 308Win ?? See what happens if you push them at 2000fps or even max vel from a 1:10 twist bbl. They would be at 144,000. --- pruhdlr
Why just dance when you can "rock and roll".
STONER 63A / XM177E2

User avatar
dellet
Silent But Deadly
Posts: 6384
Joined: Fri Nov 30, 2012 1:25 pm

Re: New 220 Nosler BT' Range Report... Problems.

Post by dellet » Tue Mar 20, 2018 12:55 pm

pruhdlr wrote:The rotational velocity of your load is <100,000 RPM. That is super slow for any bullet.
Got a 308Win ?? See what happens if you push them at 2000fps or even max vel from a 1:10 twist bbl. They would be at 144,000. --- pruhdlr
That bullet should be more than stable at 100,000 rpm, or 900 fps in a 1/9. It's very short bullet for weight.

I haven't loaded any, but I'm beginning to think that people are having trouble either seating them straight because of the nose shape, or are damaging the tip.

Checking runout would be a good next step.
300 Blackout, not just for sub-sonics.

User avatar
pruhdlr
Silent But Deadly
Posts: 350
Joined: Sat Jul 13, 2013 3:31 pm
Location: Cantonment,Florida

Re: New 220 Nosler BT' Range Report... Problems.

Post by pruhdlr » Tue Mar 20, 2018 5:28 pm

Might try - - -> lock back BCG . . gently drop round into chamber . . close action . . fire.
Keyhole ??
The mag could possibly be tearing up/distorting the bullets nose. --- pruhdlr
Why just dance when you can "rock and roll".
STONER 63A / XM177E2

bearcatrp
Silent But Deadly
Posts: 380
Joined: Tue Jul 25, 2017 9:31 am

Re: New 220 Nosler BT' Range Report... Problems.

Post by bearcatrp » Tue Mar 20, 2018 7:05 pm

Are these bullets rated for the 300BO? Box states 308. Glad I decided on the Hornady 190 sub. Works very well with no key holing.

User avatar
dellet
Silent But Deadly
Posts: 6384
Joined: Fri Nov 30, 2012 1:25 pm

Re: New 220 Nosler BT' Range Report... Problems.

Post by dellet » Tue Mar 20, 2018 8:43 pm

bearcatrp wrote:Are these bullets rated for the 300BO? Box states 308. Glad I decided on the Hornady 190 sub. Works very well with no key holing.
They are a .308” 30 calber bullet designed for subsonic use. Doesn’t really matter what brass is behind them.

It would be good to see your 100 yard targets with the Hornady bullet. If it has less stability issues it would be great.
300 Blackout, not just for sub-sonics.

User avatar
pruhdlr
Silent But Deadly
Posts: 350
Joined: Sat Jul 13, 2013 3:31 pm
Location: Cantonment,Florida

Re: New 220 Nosler BT' Range Report... Problems.

Post by pruhdlr » Wed Mar 21, 2018 7:26 am

There is something about all of this that I do not understand.
The above states that these bullets are "designed for subsonic use". How do you know that ?? And if they are,why do they have a boat tail ??
Back to my above . . . someone please fire some of these in a 10 twist 308 at 2500. I would really like to know why these bullets are tumbleing IF NOT for the extremely slow forward and rotational velocity. --- pruhdlr
Why just dance when you can "rock and roll".
STONER 63A / XM177E2

Post Reply