Gunsmithing How much cartridge case to chamber clearance?

[greentimber]

How much case body to chamber clearance is suggested for a tactical (going to get dirty) rifle? How much case neck to chamber clearance? How loose should it be for reliability? How tight should it be for accuracy?

0.008"?
0.005"?
0.003"?

other???

Thanks in advance,

Kyle

 

[our gang]

Re: How much cartridge case to chamber clearance?

That is why Holland & Holland invented belted cartridges. Case bodies could be undersized, shoulders set back and it mattered not a whit as headspacing was off the belt. It worked in Africa & India since the 1900s and still does. If I wanted a 30 cal Magnum sniper that would feed and extract under conditions that would tie up a push feeder with a "modern" cartridge, I'd be building a 300 H&H on a Magnum Mauser controlled feed action. You never will break off a bolt handle, lots of muscle to chamber a less than perfect round that will always feed (look at the shape of the 300 H&H) and an extractor that will rip off a case head before it ever fails. If you cant get it done with a 168 @3100 fps, it's time to call in the artillery. Here's a good start. All you need is a synthetic stock and a change in optics (maybe).
And 3000 pounds sterling!

 

[Jerry m]

Re: How much cartridge case to chamber clearance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mr. Humble</div><div class="ubbcode-body">That is why Holland & Holland invented belted cartridges. Case bodies could be undersized, shoulders set back and it mattered not a whit as headspacing was off the belt. It worked in Africa & India since the 1900s and still does. If I wanted a 30 cal Magnum sniper that would feed and extract under conditions that would tie up a push feeder with a "modern" cartridge, I'd be building a 300 H&H on a Magnum Mauser controlled feed action. You never will break off a bolt handle, lots of muscle to chamber a less than perfect round that will always feed (look at the shape of the 300 H&H) and an extractor that will rip off a case head before it ever fails. If you cant get it done with a 168 @3100 fps, it's time to call in the artillery. Here's a good start. All you need is a synthetic stock and a change in optics (maybe).
And 3000 pounds sterling!

</div></div>

The need for the belt was as a result of the tapered cartridge needed for reliable feeding and extraction in bolt action rifles used in the tropics. The original load was cordite which was very temperature sensitive. Certainly not needed today with the advances in powder and case designs. Also, where are you going to get a magnum (H&H) length Mauser action, your a couple decades behind the curve. And you did not answer the original question either.

 

[Outsydlooknin75]

Re: How much cartridge case to chamber clearance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jerry M</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mr. Humble</div><div class="ubbcode-body">That is why Holland & Holland invented belted cartridges. Case bodies could be undersized, shoulders set back and it mattered not a whit as headspacing was off the belt. It worked in Africa & India since the 1900s and still does. If I wanted a 30 cal Magnum sniper that would feed and extract under conditions that would tie up a push feeder with a "modern" cartridge, I'd be building a 300 H&H on a Magnum Mauser controlled feed action. You never will break off a bolt handle, lots of muscle to chamber a less than perfect round that will always feed (look at the shape of the 300 H&H) and an extractor that will rip off a case head before it ever fails. If you cant get it done with a 168 @3100 fps, it's time to call in the artillery. Here's a good start. All you need is a synthetic stock and a change in optics (maybe).
And 3000 pounds sterling!

</div></div>

The need for the belt was as a result of the tapered cartridge needed for reliable feeding and extraction in bolt action rifles used in the tropics. The original load was cordite which was very temperature sensitive. Certainly not needed today with the advances in powder and case designs. Also, where are you going to get a magnum (H&H) length Mauser action, your a couple decades behind the curve. And you did not answer the original question either. </div></div>

Did you actually expect him to answer a question with a propper answer?

 

[GLShooter]

Re: How much cartridge case to chamber clearance?

I believe in using 0.003 to 0.005. Dirty is a relative term to some guys but 0.005 will cover all your bases and degradation of accuracy will not be that noticeable in my experience.

Greg L.