Yeah...you can tell the difference between the guys that are retired and can shoot in the backyard compared to those of us that still work and drive 90 minutes to a range where you can set up a chronograph .

I am in the latter category unfortunately.

IC, it is a tighter chamber, but that is different that what is meant by chamber support.  A tighter chamber is different and has advantages and tradeoffs.  Easier on brass, more accurate, slightly, but not statistically significant increases in velocity.  Downside is reliability when fouled, ability to handle out of spec ammo.

I like my chambers about like your Razorback personally.  I find the Glock chambers a a little on the loose side for my taste in addition to not having a good head support.

I did a repeat on the Match using RTB 180gr and Underwood 180gr 1300. The results averaged about identical to the Hunter... .420" start and .430" when fired - .010". Next time out I will do the 1006 but it still looks like the Razorback is the tightest. 

Today I put some more through the Hunter and 1006. It was the 1006's turn for the mic of truth!

Using Underwood 1300: .420"- .428", .420"- .429", .420"- .429". Average = .00866". Given these results the 1006 is second behind the Razorback. Both Witness pieces are tied for third.

Hard to believe the Razorback is almost 2X tighter than all the others. It all makes sense in what I see though firing them.

Here are some Glock numbers with Underwood 180's. You are looking at almost .440" in some cases!  with a bulge.

http://www.handgunforum.net/range-report/32022-underwood-10mm-180grtmj-report.html#post270074

Intercooler, has learned wisely about the chambers of his guns!  Never too old to learn a new trick! 

I'd bet that the chamber on Sean's Kimber II is quite a good fit like your Razorback...

In the grand scheme of things how much does this equate to no kaboom? I will do the limited too when it gets here.

When you say; KABOOM; do you mean the point at which the barrel chamber actually splits, or just a brass case failure (where the brass case splits but the barrel chamber still contains the pressure)?

A KABOOM! is generally a case blowout.  Sometimes this correlates to other VERY BAD THINGS, but often not in modern firearms.  A 1911 with wood grips may need a new set.  Sometimes a Glock will have cracks in the frame.

Quote from: Intercooler on June 24 2013 09:55:27 AM MDT
In the grand scheme of things how much does this equate to no kaboom? I will do the limited too when it gets here.

Well if your brass doesn't get expanded like a pregnant guppie, you are less likely to stretch it out to the point of shearing with the better chamber support.  It is also why your test of the extreme ammo has served you safely over the years in your guns!

But, don't be fooled that you can just load and shoot beyond the brass case's capacity to contain the pressure.
Bongo Boy had a scary experience a short while back he shared on GT...

QuoteInterestingly, when this one lit up it didn't feel or sound any different than the previous 30 or so rds from the same box, other than the fact the action was open and wifts of smoke were emanating from every nook and cranny of the gun (EAA Witness Hunter).

Lucky me (as usual), no apparent damage to the gun or to me. I believe these loads were 10.6gr HS6 and 165 gr JHPs, although clearly there was 'an issue' with this particular one. All rounds fired felt quite modest.

Check out the stretch on that case base--whew. Very lucky for ductile brass, eh?

Why is that brass so ugly? My guess is it has been loaded several times at least.

That is gonna be the result of the kaboom.  Look at how far out that primer pocket is blown.

The black is going to be soot from the fired case being ground into the brass from the pressure.

So if it were a Glock you may have had a Kaboom?

Quote from: The_Shadow on June 26 2013 10:43:03 AM MDTWell if your brass doesn't get expanded like a pregnant guppie,.....

The_Shadow,

What firearm was that round in the picks you put up fired from?

Redline, Under the picture in the Quote...(EAA Witness Hunter) as handloaded & shot by Bongo Boy also a member here.

The brass being shown is Armscor, others also had some issues using this brass as it became very plastic like under the pressures.

     Ahh. The picture is a little clearer even more. The only splits I ever had in 10mm were with brand new Armscor cases (BVAC) ammo. Possibly double trouble there!