10mm 1911's and are they weak for it?

[Intercooler]

   I only have one 1911 which is my Dan Wesson in 10mm. In a recent thread where a Wilson 10mm had a couple of case failures the Wilson Rep stated they make their own line of 10mm ammo (which was suggested) which would be the max for a 1911. The ammo is rated on a 5" barrel and be about what I would term a low-mid offering.
   What differs in the 1911 where they can't take the 10mm cartridge? I haven't babied mine giving it even the most extreme and just wondered if it's one that should have a reduced loading?

    I'm still trying to learn these platforms as I'm getting educated. If it's really one that shouldn't be pushed I might be up for letting it go for a double stack that is. I like how accurate it is (best of any I own) but not married to it. In 10mm it always gives me the feel it is a little light and has more muzzle flip than my other 10's. I think it is much lighter on the front!

[pacapcop]

Originally based for the .45 ACP it also can shoot 9mm,.40.38 super,10mm and others I believe. Personally don't use but maybe a round like U/W's Delta load or even Nugents offering should be right.That's plenty for the 1911.But I always look at it in the perspective as a CCW and it's design limits. I use Nugent loads and U/W's 180's in the 1006,165's U/W's 180's in Glock.

[gandog56]

My Dan Wesson Razorback 10mm has handled ANY ammo I have put in it! And I have NEVER heard of a bad 1911 platform that regularly split cases. I would suspect he had a factory defective barrel!

[sqlbullet]

I don't think it is too weak for the 10mm, even at full power.  But....

The 1911 locking system was designed to lock the action of a 45 ACP pressure round. If you calculate the actual forces involved you will find that the 38 super, which is higher pressure similar to the 10mm, but smaller diameter, applies about the same force to the locking system as the 45 acp.  9mm is less, as are most of the other rounds.

But the 10mm is more.  About 40% more if memory serves. (area of the 45 ACP * pressure of the 45 acp vs area of the 10mm vs pressure of the 10mm)

THe 1911 design is over-engineered for 45 acp, so the 7% over design the 38 super creates is not a big deal.  But 40% is a different story.

In order to put the 10mm on similar footing, you would have to limit ammo to about 30,000 psi, which will give you the low-mid range 10mm ammo you are describing.

But, the real question is this:  What is the result of firing full-house 10mm in a 1911?

The first thing to understand is we are NOT talking about things that happen while the slide is moving.  We tend to associate wear with movement. But in this case the wear is the flexing of the slide while it is locked in battery, containing the force generated by burning gunpowder.  Altering springs, firing pin stops, etc does NOTHING to mitigate this.  It is the stress of the barrel lugs locked into the slide.

These forces are 40% more than the slide was designed to handle.  Since we know that occasionally you will see a 1911 in 45 acp with enough round through it the slide has cracked, we can reasonably expect to see more 10mm 1911's with similar cracked slides.  But you rarely hear about either a 45 acp or a 10mm 1911 with a cracked slide.

Why?

Becuase the round count needed to encounter this type of failure is insanely high.  THe general rule of thumb I have read a couple places online is that a 1911 in 45 ACP should be magnetic particle inspected for cracks after 150,000 rounds.  That is the no questions asked service life of a 1911 slide.  Also, note that unless it has measurable stretch or detectable cracks, there is no requirement to replace it at that point.

That round count works out the 100 rounds a week, every week, for 28 years. During that time you will have replaced all the springs and the extractor 30 times.

Lets assume the 10mm is going to halve that service interval to 75,000 rounds.  That is still a VERY long time.  And keep in mind that is 75,000 rounds of full-house 10mm loads.  Most of us shoot some version of a 10mm medium load for practice.  I know I burn far more Unique than Blue Dot in my 10mm's.  And I shoot more than most people I know and on a good year I burn 5K handgun rounds.  Most years I burn more like 3k-4k.

And most of us have more than one 10mm and more than 10mm handguns.  They all get some love at the range from time to time.  So, even if you do burn 5K-6K rounds a year, chances are it all won't be in one handgun, nor will it all be 260 power factor ammo.

You see where I am going with this.  Yes, a 10mm 1911 that is fed a regular diet of full power 10mm loads WILL fail before a 1911 in another caliber (unless that caliber if 45 super or 460 rowland).  But, chances are slim that even for a hardcore gunner that failure will be during their lifetime.

There are some guys here that shoot 10mm alot.  If you are one that thinks you might get there here is an idea:  Drop a dollar in a jar every time you open a new box of 50 rounds.  By the time you slide cracks, you will have plenty of cash to buy a whole new gun.

[MCQUADE]

Outstanding way to put it in perspective sqlbullet. I currently own no 1911's, just sold my last Colt a month ago. No more 45's but I am willing to throw the cash down for one in 10mm with good chamber support. I can't afford a nighthawk custom or a Wilson right now and don't think I could do it even if I had the cash, but, I may consider the Para or even a Rock Island but I prefer made in USA.

[gandog56]

I don't think it is too weak for the 10mm, even at full power.  But....

The 1911 locking system was designed to lock the action of a 45 ACP pressure round. If you calculate the actual forces involved you will find that the 38 super, which is higher pressure similar to the 10mm, but smaller diameter, applies about the same force to the locking system as the 45 acp.  9mm is less, as are most of the other rounds.

But the 10mm is more.  About 40% more if memory serves. (area of the 45 ACP * pressure of the 45 acp vs area of the 10mm vs pressure of the 10mm)

THe 1911 design is over-engineered for 45 acp, so the 7% over design the 38 super creates is not a big deal.  But 40% is a different story.

In order to put the 10mm on similar footing, you would have to limit ammo to about 30,000 psi, which will give you the low-mid range 10mm ammo you are describing.

But, the real question is this:  What is the result of firing full-house 10mm in a 1911?

The first thing to understand is we are NOT talking about things that happen while the slide is moving.  We tend to associate wear with movement. But in this case the wear is the flexing of the slide while it is locked in battery, containing the force generated by burning gunpowder.  Altering springs, firing pin stops, etc does NOTHING to mitigate this.  It is the stress of the barrel lugs locked into the slide.

These forces are 40% more than the slide was designed to handle.  Since we know that occasionally you will see a 1911 in 45 acp with enough round through it the slide has cracked, we can reasonably expect to see more 10mm 1911's with similar cracked slides.  But you rarely hear about either a 45 acp or a 10mm 1911 with a cracked slide.

Why?

Becuase the round count needed to encounter this type of failure is insanely high.  THe general rule of thumb I have read a couple places online is that a 1911 in 45 ACP should be magnetic particle inspected for cracks after 150,000 rounds.  That is the no questions asked service life of a 1911 slide.  Also, note that unless it has measurable stretch or detectable cracks, there is no requirement to replace it at that point.

That round count works out the 100 rounds a week, every week, for 28 years. During that time you will have replaced all the springs and the extractor 30 times.

Lets assume the 10mm is going to halve that service interval to 75,000 rounds.  That is still a VERY long time.  And keep in mind that is 75,000 rounds of full-house 10mm loads.  Most of us shoot some version of a 10mm medium load for practice.  I know I burn far more Unique than Blue Dot in my 10mm's.  And I shoot more than most people I know and on a good year I burn 5K handgun rounds.  Most years I burn more like 3k-4k.

And most of us have more than one 10mm and more than 10mm handguns.  They all get some love at the range from time to time.  So, even if you do burn 5K-6K rounds a year, chances are it all won't be in one handgun, nor will it all be 260 power factor ammo.

You see where I am going with this.  Yes, a 10mm 1911 that is fed a regular diet of full power 10mm loads WILL fail before a 1911 in another caliber (unless that caliber if 45 super or 460 rowland).  But, chances are slim that even for a hardcore gunner that failure will be during their lifetime.

There are some guys here that shoot 10mm alot.  If you are one that thinks you might get there here is an idea:  Drop a dollar in a jar every time you open a new box of 50 rounds.  By the time you slide cracks, you will have plenty of cash to buy a whole new gun.

My Dan Wesson Razorback was only ever issued in 10mm. It was never a .45! Come to think of it, I don't think Fusion Firearms makes my custom built long slide Hunter 10mm in a .45.

[Intercooler]

Yes very good!

           As Shadow guessed and my most recent test to confirm my Razorback has the tightest chamber support. I get little round shavings of brass where I think the top part of the brass catches something on the way in. I should have taken a picture last time out! Any fixes for this?

[gandog56]

Yes very good!

           As Shadow guessed and my most recent test to confirm my Razorback has the tightest chamber support. I get little round shavings of brass where I think the top part of the brass catches something on the way in. I should have taken a picture last time out! Any fixes for this?

My Fusion also looks tight. Fully supported ramp.

[Intercooler]

  Measure some new rounds and fire them. Take another measurement right after and see where it's at. I'm doing the 1006 and Match next time out with Underwood 1300.

[harrygunner]

'sqlbullet' explained things in a way that places the whole issue in perspective.   
   
There are well known steps to take to lengthen the life of a 10mm 1911: Use a well made, steel slide; install a flat firing pin stop; custom fit the barrel to the slide and frame. The last one is less frequently stated. The action really smooths out with a properly fitted barrel.

This question has been asked a few times. http://pistolsmith.com/10mm/ holds a decade of posts on the 10mm.  One post by Bill Caldwell, states: "A 1911 built to the CORRECT SPECS from QUALITY PARTS will take a lot more than 10MM pressures." 

I'm thinking a slide manufacturer, like STI for example, probably isn't building them to "just squeeze by" .45 ACP pressures. They just may be capable of handling the 10mm.

To me, a 10mm 1911 is a great combination. And an added safety feature comes with that platform, it won't fire out of battery.

[DM1906]

There's a lot more to consider than just combustion pressure, from one caliber to another.  All else being equal, it's the surface area of the case head that applies force to the breach.  The chamber isn't the problem, but a 78% head surface area, and a 100% increase in pressure will increase breach force, significantly.  Case wall and web support relies on timing and chamber design, while the pressure limit of the brass is consistent, regardless of what you fire it in.  If the mean failure threshold is a 150% standard, the .45 will fail at some point, theoretically, firing full pressure 10mm.  Not to say that it will fail, but it is designed to fail, under that specific condition.

[REDLINE]

I don't think it is too weak for the 10mm, even at full power.  But....

The 1911 locking system was designed to lock the action of a 45 ACP pressure round. If you calculate the actual forces involved you will find that the 38 super, which is higher pressure similar to the 10mm, but smaller diameter, applies about the same force to the locking system as the 45 acp.  9mm is less, as are most of the other rounds.

But the 10mm is more.  About 40% more if memory serves. (area of the 45 ACP * pressure of the 45 acp vs area of the 10mm vs pressure of the 10mm)

THe 1911 design is over-engineered for 45 acp, so the 7% over design the 38 super creates is not a big deal.  But 40% is a different story.

In order to put the 10mm on similar footing, you would have to limit ammo to about 30,000 psi, which will give you the low-mid range 10mm ammo you are describing.

But, the real question is this:  What is the result of firing full-house 10mm in a 1911?

The first thing to understand is we are NOT talking about things that happen while the slide is moving.  We tend to associate wear with movement. But in this case the wear is the flexing of the slide while it is locked in battery, containing the force generated by burning gunpowder.  Altering springs, firing pin stops, etc does NOTHING to mitigate this.  It is the stress of the barrel lugs locked into the slide.

These forces are 40% more than the slide was designed to handle.  Since we know that occasionally you will see a 1911 in 45 acp with enough round through it the slide has cracked, we can reasonably expect to see more 10mm 1911's with similar cracked slides.  But you rarely hear about either a 45 acp or a 10mm 1911 with a cracked slide.

Why?

Becuase the round count needed to encounter this type of failure is insanely high.  THe general rule of thumb I have read a couple places online is that a 1911 in 45 ACP should be magnetic particle inspected for cracks after 150,000 rounds.  That is the no questions asked service life of a 1911 slide.  Also, note that unless it has measurable stretch or detectable cracks, there is no requirement to replace it at that point.

That round count works out the 100 rounds a week, every week, for 28 years. During that time you will have replaced all the springs and the extractor 30 times.

Lets assume the 10mm is going to halve that service interval to 75,000 rounds.  That is still a VERY long time.  And keep in mind that is 75,000 rounds of full-house 10mm loads.  Most of us shoot some version of a 10mm medium load for practice.  I know I burn far more Unique than Blue Dot in my 10mm's.  And I shoot more than most people I know and on a good year I burn 5K handgun rounds.  Most years I burn more like 3k-4k.

And most of us have more than one 10mm and more than 10mm handguns.  They all get some love at the range from time to time.  So, even if you do burn 5K-6K rounds a year, chances are it all won't be in one handgun, nor will it all be 260 power factor ammo.

You see where I am going with this.  Yes, a 10mm 1911 that is fed a regular diet of full power 10mm loads WILL fail before a 1911 in another caliber (unless that caliber if 45 super or 460 rowland).  But, chances are slim that even for a hardcore gunner that failure will be during their lifetime.

There are some guys here that shoot 10mm alot.  If you are one that thinks you might get there here is an idea:  Drop a dollar in a jar every time you open a new box of 50 rounds.  By the time you slide cracks, you will have plenty of cash to buy a whole new gun.

IMO this post alone qualifies as a stickie.

[REDLINE]

Outstanding way to put it in perspective sqlbullet. I currently own no 1911's, just sold my last Colt a month ago. No more 45's but I am willing to throw the cash down for one in 10mm with good chamber support. I can't afford a nighthawk custom or a Wilson right now and don't think I could do it even if I had the cash, but, I may consider the Para or even a Rock Island but I prefer made in USA.

In terms of chamber support I have yet to see any manufacturers gun barrel (1911 or any other) have more chamber support than Kimber's does, on top of it having more barrel steel surrounding the chamber in 10mm.  I realize they do cost more than RIA and Para, but are still waaaaaay less than Wilson.  Just throwing it out there knowing there's a chance you've already considered it, but just in case.

[Intercooler]

I would like to see someone do the brass test like I did mine on Kimber. Would be interesting to see if it could be any tighter than my Razorback  It would need to give no more expansion than .004".

[REDLINE]

I'ld like to see the same done with a Kimber too.