[AKM]

Unfortunately the same load won't always give the same velocity in 2 different pistols, even with the same barrel length. If you have access to a chrono (and it sounds like you do) then try bumping the charge up 0.2 grains and see if that makes it. One of my manuals says it will take 5.9 to make 850 even with a 5" barrel.

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No Second Place Winner

 

[KLN]

While velocity can vary considerably from one pistol to the next, your velocity sounds a bit low for the load. One would expect to see at least 800 fps even with the short barrel.

Is it possible you were getting erroneous readings from the chronograph due to the shock wave from muzzle blast? That can happen, and give significantly low readings. If that is happening, it is usually inconsistent, with a few higher readings every now and then. Moving farther away from the chrono will solve that problem.

Overall loaded length can also affect velocity quite a bit. If your loads are unusually long, that can reduce velocity.

 

[scarman]

I'm using 5.6 grns of W231 with a 200 grn LSWC from Precision Bullets. Case length is 1.245 and Winchester primers. With my Pro Carry I get around 825.

It seems to be a very comfortable and accurate round to shoot for me.

 

[Hobbes]

Hmmm. I recently found that 5.7 grains of W231 behind a D&J 200 grain LSWC, Win LLP, mixed brass w/OAL of 1.250" and .467" crimp at the case mouth goes about 925 FPS out of my 5" Springfield. Take care.

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"Quid hoc ad aeternitatem?"

[This message has been edited by Hobbes (edited 08-28-2001).]

 

[fremont]

You're loading jacketed flat points ("fpj")? I'd do what alot of us do: buy cast lead 200 SWCs and load them over about 5.6 grains of WW231, overall length of 1.250". Cheaper and they should make the required power factor (165). Maybe even take them up to 5.7 grains to be sure.

 

[nwgunman]

I've also been trying to work up a load for my Kimber compact that will meet the IDPA power factor. My loads use 185gr jhp bullets because that's what I carry. Using 9.7gr of AA#5 I'm getting about 910fps. This is a mid-range load for that powder and bullet weight, and, as you can see, just barely makes that power factor. But it shoots great. Using V-V N340 I really had to increase the charge to get the velocity. At 7.8grs I am again getting around a little over 900fps. Both powders burn cleanly and have fairly low muzzle flash. I'm currently loading Remington bullets at an OAL of 1.215". I'm thinking about trying Montana Gold bullets when I re-supply. Stay safe.

 

[JoeMc]

What you are looking for is right in front of you. You are looking for power factor in a 4" barrel. IDPA chronos loads for CDP in a 5" barrel. In other words chrono your loads in a 5" barrel, if they meet power factor you can shoot them in a 4" gun in competition. The same with a revolver, they use a 4" to test. If it meets PW in a 4"{ you can shoot it in your snub.

 

[BillD]

Originally posted by JoeMc:
What you are looking for is right in front of you. You are looking for power factor in a 4" barrel. IDPA chronos loads for CDP in a 5" barrel. In other words chrono your loads in a 5" barrel, if they meet power factor you can shoot them in a 4" gun in competition. The same with a revolver, they use a 4" to test. If it meets PW in a 4"{ you can shoot it in your snub.

In my understanding, they dropped the power factor to 165 so that officers models would still qualify with ball ammo. I believe you have to chrono your load in your own gun not a longer barreled gun.



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"What most of these people need is a good slap upside the head. What I don't need is any more lawsuits." John "The Tooz" Matusak

 

[nwgunman]

Yeah, that's what I understand too. You step up to the chrono and fire three(?) rounds. The average velocity of the three times the bullet weight divided by 1000. Actually, I fire 5 round strings.

 

[JoeMc]

I quote from the rule book page 16"Official chronographing procedure is as follows: Chronograph three(3) rounds at a distance of 10 feet using a weapon of maximum barrel lenth for the division" "Prior to each shot the muzzle of the weaponshould be elevated to move the powder charge to the rear of the case,thus giving the competitor every chance to achieve maximum velocity"

In a Revolver it's a 5" barrel until October. In CDP,SSP & ESP it's 5".

 

[fremont]

I think Bill, Ken, Walt and the Gang had brain fade when they came up with the chrono'ing rule. Are IDPA clubs supposed to keep guns with the "maximum barrel length" around for each division? DumbDumbDumb

(Almost as bad as making IPSC match directors--or clubs--keep a 9mm around loaded with 121PF ammo to calibrate poppers.)

 

[Joe D]

I just chronographed a load today. 200 lead SWC OAL of 1.260" with 4.5 grs of Titegroup. Average fps out of a 5" Kimber was 866. Should be enough in a 4" gun.

 

[Joe D]

I forgot to mention that I had to go up to either 4.8 or 5.0 grs with a 200 gr plated bullet to make the 165 pf. Seems like the 4.8 load was right on the borderline in a 5" gun.