Jacket thickness and accuracy

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Jacket thickness and accuracy

Post by brisb » 07 Jul 2014, 9:50 pm

Can someone explain this to me...

I have a Sierra bullets ad talking about their Varminter and Blitzking bullets which says...

Sierra Varminter and Blitzking bullets are the world's most effective bullets for predator and varmint hunting. A thin jacket provides outstanding accuracy and the explosive expansion you need...


And on it goes...

Question is, how does the jacket thickness effect accuracy? :?:
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Re: Jacket thickness and accuracy

Post by Bills Shed » 07 Jul 2014, 10:49 pm

There are two parts to this.

Jacket thickness does control expansion but has little effect on accuracy. Accuracy comes from a jacket thickness that is very consistent.

The part about a thin jacket providing outstanding accuracy is a pretty long bow to draw. There are some very heavy game projectiles on the market with thick jackets that are very accurate.

I have made jackets from brass cases and consistency of thickness is what counts for accuracy. You would be surprised how hard it is to achieve.

It would read better if it said that, a thin jacket that is consistent in thickness provides outstanding accuracy.

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Re: Jacket thickness and accuracy

Post by Apollo » 08 Jul 2014, 2:44 am

I'll go along with Bill, actual bullet jacket thickness has nothing to do with accuracy. It's the quality of the jacket that affects accuracy.

Berger Bullets make "J4 Jackets" world recognised as probably the best available and used by most precision custom bullet makers. J4 was a seperate company to Berger but now virtually the same entity.

Berger for example make a 130gr 6.5mm VLD Bullet in Target and Hunting, the difference is the jacket thickness with the hunting being the thinner jacket. A home practical test performed here and by many others is loading both bullets with the exact same load and shot even mixed and they show absolutely no difference in any aspect of accuracy, velocity or POI from close to long range. I'm talking fired in a rifle that produces 1/8th MOA or better accuracy so if a bullet is not going to perform against another it will certainly show up.

BTW...Most Berger Bullets designated Target produce excellent results varminting / hunting. Sierra for one stipulate that some of their bullets are not suitable at all for hunting like the MatchKing, perhaps their jackets are so much harder. perhaps also they are not as accurate or is that well made.
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Re: Jacket thickness and accuracy

Post by brisb » 09 Jul 2014, 3:17 pm

Apollo wrote:Berger Bullets make "J4 Jackets" world recognised as probably the best available and used by most precision custom bullet makers. J4 was a seperate company to Berger but now virtually the same entity.


I'm a bit confused now.

I know the Berger bullets, I thought the difference between their Match bullets and hunting VLD bullets was just that the hunting bullets have the thicker jacket. Everything else is the same though.

I thought most match bullets had thin jackets, but here Sierra say thin jackets are good for hunting, and Berger suggest thick jackets are best for hunting.

:? :?:
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Re: Jacket thickness and accuracy

Post by 5Tom » 09 Jul 2014, 4:32 pm

I thought the jacket's primary goal is to engage the lands while leaving the lead core in tact.

My guess is that the jacket thickness will vary per projectile type suited for the type of game and/or distance your intending to shoot to maintain impact energy and weight retention.
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Re: Jacket thickness and accuracy

Post by Apollo » 09 Jul 2014, 6:15 pm

brisb wrote:I'm a bit confused now.

I know the Berger bullets, I thought the difference between their Match bullets and hunting VLD bullets was just that the hunting bullets have the thicker jacket. Everything else is the same though.

I thought most match bullets had thin jackets, but here Sierra say thin jackets are good for hunting, and Berger suggest thick jackets are best for hunting.

:? :?:


Okay, Berger make "Match Grade Bullets" in three lines, Target, Varmint & Hunting. All Berger Hunting Bullets are of the VLD (Very Low Drag) design, Target and Varmint can be any style from Flat Base, Boat Tail, Hybrid etc. All bullets are hollow point.

To clarify, the Berger Target Bullets have thicker J4 Jackets than do the Varmint or Hunting type. Some Berger Target Grade bullets are also suitable for Varmint and Hunting If you have the Berger Reloading Manual you will find a description on page 126 in the article Handloading Components written by Bryan Litz and here http://www.bergerbullets.com/informatio ... d-designs/

I don't see anywhere that Berger suggest thick jackets are best for hunting, quite the opposite actually.

Hope that helps.
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Re: Jacket thickness and accuracy

Post by brisb » 11 Jul 2014, 3:20 pm

Apollo wrote:I don't see anywhere that Berger suggest thick jackets are best for hunting, quite the opposite actually.

Hope that helps.


Hi Apollo,

Thanks for the information, it's all good.

About the thick jackets, I got that from a Berger video about their bullets. In the video the guy says they're often asked what the difference between their target and match bullets is, and he says the only difference is the hunting jackets are thicker.

I can't do it at the moment but will try to find the video later to you show.
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