ESP and Glock Conversion Barrels

[benny hill]

Never understood how you can tell a shooter to shoot all he wants & then ding him when he does[ dumping]. More of that gray area left up to the R.O. if he likes you or not. Black & white book, not gray area's.

[Jim Watson]

The true S.O. has special training by a psychic to read your mind and know if your motive for firing that extra shot was pure.

Joe and I missed that class so we will not penalize you for "dumping" on a Vickers count stage.

As to the O.P., I would consider a caliber conversion barrel an "enhancement" and grounds to move you from SSP to ESP, but disallowing it altogether is just dumb. There are many people who buy big and shoot small either because of ammunition cost or lack of recoil handling skills and I don't think they should be discriminated against. Or not much, anyhow.

[RickB]

Never understood how you can tell a shooter to shoot all he wants & then ding him when he does[ dumping]. More of that gray area left up to the R.O. if he likes you or not. Black & white book, not gray area's.

Not really sure what this has to do with changing calibers in Glock barrels?

[PLINK]

So if I can't use a 9mm conversion barrel in a factory Glock 35 .40 slide, can I swap out the complete upper to the LWD G34 (9mm) slide/barrel for ESP?

I would probably down load .40 before doing such a thing but I was wondering if it would be legal. I can't find anything in the rules about aftermarket slide replacement for ESP.

[Joe D]

I don't see why you can't shoot that in SSP as you will be changing slide and barrel. You would not have to shoot ESP although you could. You can make the .40 shoot just as softly as the 9mm. Well almost - my 200 gr 9mm load is pretty soft.

Edited March 9, 2008 by Joe D

[mpolans]

I think the reasoning behind the decision can be found in Appendix A, section 1C.

Non-IDPA-Legal modifications for all divisions: 1c - Heavy and/or cone style barrels without a barrel bushing.

A 9mm barrel that drops-in to a G35 slide will necessarily have more metal surrounding the bore than a regular 9mm barrel or even a 40 S&W barrel. It's a "heavy" barrel.

Question is: who wants to shoot 9mm in ESP anyway, when you've got a 10+1 limit at 125 PF?

With the price of ammo and bullets these days, people who want to save a lot of money by shooting cheaper 9mm instead of pricey 40 S&W, especially if the stock barrel means you have to shoot jacketed. For example:

.40 Montana Gold 180gr. FMJ = $124/1000

.355 Montana Gold 124gr. FMJ = $99/1000

Or, assuming you switch to 9mm lead since the conversion barrels don't have polygonal rifling:

.356 Kead Bullets 125gr. RN = $39/1000

.356 Kead Bullets 147gr. FP = $43.40/1000

Does anyone really think that 0.57 ounces or 249 grains would be enough difference to offer a competitive advantage? Are replacement barrels of the same caliber held to such tight tolerances? What about the difference in weight is there when switching from a plastic guide rod to a steel guide rod? Based on some the difference in dimensions between a G34 barrel and a G35 conversion barrel, here's some of the math I came up with:

">>No, the concern is that the replacement barrel for the 35 is heavier than the original 34 barrel --- because the replacement barrel needs to fill the hole left by the .40 caliber barrel in the 35 slide. Measuring my 34 barrel at the point where it exits the slide I come up with .571 inches. Measuring a G35 barrel at the same point yields a measurement of .588, a difference of 17/1000. I don't have a 9mm replacement barrel for the 35, or I could throw them both on a scale......<<

Has anyone (besides Amidon) really argued that the 0.017"x4.5" (only about 4.5" since I'd assume the thickness of the barrels around the chamber area is identical) difference in barrel thickness resulted in a competitive advantage? Doing a little math based on 0.017" difference in diameter and assuming the density of steel is 7.85g/cm3, the difference in weight should be approximately 0.57 ounces or about 249 grains. I wonder if the all the aftermarket slides that are production legal will be held to such tight tolerances as to all fit within an 0.57 ounce window."