Length of Sierra .270 175gn Game King?

[ww111]

Length of Sierra .270 175gn Game King? Several threads on this bullet but I can't find the actual length of the bullet. Does anyone have a caliper they can throw on one? Many thanks

 

[Darkker]

Sierra .270 175gn Tipped Game King

I was perusing the Sierra website when I came across these. Anyone seen or tried these? It said they need a 1-8" twist. Now we're getting somewhere!

www.longrangehunting.com

 

[Poor_choices]

I just measured 7of them and got an average of 1.645"

 

[Muddyboots]

The Sierra 175 is not in here but many other bullets are from JBM. Handy to have around.

JBM - Bullet Length List

www.jbmballistics.com

 

[ARlife4me]

I think a 9 is supposed to stabilize it? Nothing wrong with doing an 8 or 8.5t. Call or email Sierra about it as they ARE good at answering and giving load data! I'll check my #6 book for info.

 

[ARlife4me]

according to sierra it needs an 8t and their site doesn't give any other info like berger does.

 

[FEENIX]

according to sierra it needs an 8t and their site doesn't give any other info like berger does.

Matrix was the first to develop the 175g .277 cal, which requires 1:8' or faster. I built my .270 AI in 2012 with a 30" Lilja 3G barrel primarily to propel the 165/175 Matrix VLDs.

 

[Darkker]

according to sierra it needs an 8t and their site doesn't give any other info like berger does.

Remember that bullet weight is mostly irrelevant to stability, it's length that needs stabilization through RPM.

Use the JBM link given above, they have a stability calculator on the left. Plug in the length given to you by poor choices, and you'll have an idea of there's any hope of stability.

Remember that JBM's calc isn't perfect, so RPM dependant, yellow might work. This is because while velocity decay happens rather quickly, rotational decay happens quite slowly. So relative to the linear velocity, RPM increases as the bullet travels down range.

 

[ARlife4me]

Remember that bullet weight is mostly irrelevant to stability, it's length that needs stabilization through RPM.

Use the JBM link given above, they have a stability calculator on the left. Plug in the length given to you by poor choices, and you'll have an idea of there's any hope of stability.

Remember that JBM's calc isn't perfect, so RPM dependant, yellow might work. This is because while velocity decay happens rather quickly, rotational decay happens quite slowly. So relative to the linear velocity, RPM increases as the bullet travels down range.

not necessarily, but in most cases length does matter more on stability. velocity can matter also. twist gets to stability faster than upping velocity. i run numbers thru berger and jbm. if you think that length is the GREATEST factor, drop velocity by 500, 1,000 or to half.

 

[lancetkenyon]

Remember that bullet weight is mostly irrelevant to stability, it's length that needs stabilization through RPM.

While this is technically true, bullet length is directly related to bullet weight in any given caliber as long as we are talking same bullet design (cup and core HPBT for example).
With a fixed diameter, higher weight can only be had with longer bullets.

There are some variable factors that come into play with ogive shape, and base shape. When you want higher BC boattails and long ogives, these only exaggerate the lengths.
A 175 flat base round nose will be much shorter than a 175 boattail high BC match bullets.