keyhole

[sako2]

I loaded some tbbc for my buddy's 22-250. They where suppose to be 62gn bullets i weighed some and they where 67gn. I started at min charge of 33gn of w760 and they keyholed very little. If i push them harder will it help from keyholing?

 

[jimbires]

yes , more velocity will help . here is a calculator to play with . you should be able to get an idea of how much more velocity is needed to stabilize the bullet . the next question will be , can that velocity be reached .

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

 

[truck driver]

No ballistic expert but rate of twist has a lot to do with it bullets key holing. My 257 Roberts with a 1-12" twist will not stabilize anything over 115gr and then it has to be a round nose bullet in 115gr.
I believe the older 22-250s barrels were twisted 1-12" to shoot light bullets very fast.

 

[JD338]

I had a Remington 700 VLS 22-250 with a 1:14 twist that shot bug holes with the 50 gr BT. With the 55 gr BT, I struggled to find a load that shot. I finally did but it took time and top end velocity to get there.

JD338

 

[sako2]

Yes it's 1:14 twist. It shoots 55gn pills just fine.

 

[truck driver]

Gee I'm getting old forgetting the Rem 700 22-250 barrel was twisted 1-14".

 

[DrMike]

Me? I'm just glad to be on this side of the snow! It's stunning to suddenly recall what I've "mis-remembered."

 

[jimbires]

if you play with the twist rate calculator , you will see everything comes into play .

 

[RL338]

When I rebarreled my Savage Striker to 25 Creed I went with 1:9 twist to sablize 110-115 grain bullets. With the shorter barrel that twist works just fine.
With 22-250’s with 1:14 the best I could do with tipped bullets was 50gr.

 

[filmjunkie4ever]

My Ruger M77 1-14” twist .22-250 shoots the 55 grain Sierra Gameking very well but the 55 grain Nosler BT won’t shoot worth a darn.

My Dad’s Remington 700 1-14” twist .22-250 shoots the 55 grain NBT extremely well.

 

[sako2]

Finally got around to shooting the higher charges. Pushing them faster stabilized them. 36.5 gn of w760 shot the best group. I'll work on seating depth.

 

[TackDriver284]

Finally got around to shooting the higher charges. Pushing them faster stabilized them. 36.5 gn of w760 shot the best group. I'll work on seating depth.

That is a promising start, how much more speed did it take to get them stabilized, if I may ask?

 

[sako2]

That is a promising start, how much more speed did it take to get them stabilized, if I may ask?

200 fps

 

[TackDriver284]

200 fps

Good stuff, let us know how she shoots after seating depth adjustments.