Releationship between OAL and power

[Limited Custom]

I have a Limited Custom, using universal clays for power, OAL 1.195 My problem is by loading 5.3gr I got 880 FPS, when I use 5.4gr got 900 FPS If IPSC require 950FPS to meet the PF, I might need to go 5.6-5.7gr. Will that be too much power?

Can anyone tell me if that is the OAL make the difference? Should I use 1.17OAL instead and drop back to 5.4gr?

Kindly advise.

[Alan550]

You..........uh...........have a particular caliber in mind?

Alan~^~

[jimzim]

What bullet weight?

[Limited Custom]

What bullet weight?

.40 / 180 gr

Help guys.

[G-ManBart]

I have a Limited Custom, using universal clays for power, OAL 1.195 My problem is by loading 5.3gr I got 880 FPS, when I use 5.4gr got 900 FPS If IPSC require 950FPS to meet the PF, I might need to go 5.6-5.7gr. Will that be too much power?

Can anyone tell me if that is the OAL make the difference? Should I use 1.17OAL instead and drop back to 5.4gr?

Kindly advise.

Pressure is pressure. If you drop the powder charge, but decrease the OAL and get the same velocity, you're getting the same pressure as you were before, so it doesn't really help.

Adjust the OAL so that the gun functions and the rounds fit the magazine. Adjust the powder charge to meet the velocity requirements.

Sierra's data shows a load with a 180gr JHP at 1.125" going up to 6.0gr of Universal Clays as max. Sounds like you should be fine. R,

[Limited Custom]

I have a Limited Custom, using universal clays for power, OAL 1.195 My problem is by loading 5.3gr I got 880 FPS, when I use 5.4gr got 900 FPS If IPSC require 950FPS to meet the PF, I might need to go 5.6-5.7gr. Will that be too much power?

Can anyone tell me if that is the OAL make the difference? Should I use 1.17OAL instead and drop back to 5.4gr?

Kindly advise.

Pressure is pressure. If you drop the powder charge, but decrease the OAL and get the same velocity, you're getting the same pressure as you were before, so it doesn't really help.

Adjust the OAL so that the gun functions and the rounds fit the magazine. Adjust the powder charge to meet the velocity requirements.

Sierra's data shows a load with a 180gr JHP at 1.125" going up to 6.0gr of Universal Clays as max. Sounds like you should be fine. R,

But will that be more "kick" when I use more power?

What I mean is, If I use a STI for 5.2gr / 1.17 OAL to compare, the STI would feel softer (less power).

I know its different gun + the design, I'm just wounder if I should change to STI with better control.

I do like the Tanfoglio, but I am not a big guy to hold the "kick"

I can see some of you guys are using more power than suggested, (Eric use 5.2 on titegroup) is that because we need longer OAL ?

Or is it because of the way "Tanfoglio" design?

Edited January 19, 2010 by Limited Custom

[tanfogliocoe]

I would tell you to bump your powder dump until you either get the FPS that you desire or you start seeing bad pressure signs.

[jimzim]

I do like the Tanfoglio, but I am not a big guy to hold the "kick"

Have you tried Clays (not Universal Clays)? It ranks #7 on the burn rate chart and I find it to be snappy but without the "kick". 4.5 grains at 1.175 OAL yields 166.5 PF in 5200+ ft altitude.

Edited January 19, 2010 by jimzim

[twodownzero]

Clays is not really the best choice for .40 major with heavy bullets. Universal is probably a better choice.

Yes, more velocity will cause more "kick." It doesn't matter if that increased velocity comes from shorter COAL or more powder.

Recoil doesn't matter that much anyway. You'll learn to shoot it regardless.

[Limited Custom]

I would tell you to bump your powder dump until you either get the FPS that you desire or you start seeing bad pressure signs.

Tanfogliocoe - what do you mean by bad pressure signs?

jimzim - do you think a slower burn power will help (less recoil) we do not have much choice in Canada, I was thinking to switch to N320.

[G-ManBart]

I would tell you to bump your powder dump until you either get the FPS that you desire or you start seeing bad pressure signs.

Tanfogliocoe - what do you mean by bad pressure signs?

jimzim - do you think a slower burn power will help (less recoil) we do not have much choice in Canada, I was thinking to switch to N320.

Bad pressure signs are normally badly flattened or cratered primers, melted primers, or pierced primers.

Slower powders cause more recoil because you have to use more of them. The powder exiting the barrel is added to the weight of the bullet, plus the more powder you burn, the more jet effect you get pushing back into your hand.

N320 is a very soft powder for .40 Major. Depending on the exact gun, most folks are probably running between 4.5 and 5.2 or so grains of N320 with a 180gr jacketed bullet at the longer lengths (like 1.17 to 1.23") that most folks seem to use.

[jimzim]

jimzim - do you think a slower burn power will help (less recoil) we do not have much choice in Canada, I was thinking to switch to N320.

I haven't tried VV N320 with the Tanfoglio, but I do use it exclusively for my Glock 22 in Limited-10 and (to me) the recoil (for major power factor) feels similar.

[Limited Custom]

So, is that mean you are suggested to use faster power so that I can use less power, then less recoil?

Beside titegroup, what kind ? (we cannot get tigegroup here)

Edited January 19, 2010 by Limited Custom

[CHA-LEE]

Standard Clays, 4.7gr drop, 180gr FMJ Montana Gold, 1.225 OAL is what I use for USPSA Major (165 PF) in my EAA Witness Limited. It shoots fairly soft but if you are really recoil sensitive just shoot minor. You can make some super weak sauce .40 minor loads that have virtually no recoil. Or you can simply learn to manage the recoil of major loads.

In the end, just pick a load and shoot it until you are use to it. Too many people forever chase the "Magical" load that is super soft shooting and, bla, bla, bla. Every load recoils a little differently and it changes your timing which changes the grip pressure you need. So its better just to pick a load and shoot it so you give yourself a chance to learn and tune YOUR shooting to it.

[Limited Custom]

Standard Clays, 4.7gr drop, 180gr FMJ Montana Gold, 1.225 OAL is what I use for USPSA Major (165 PF) in my EAA Witness Limited. It shoots fairly soft but if you are really recoil sensitive just shoot minor. You can make some super weak sauce .40 minor loads that have virtually no recoil. Or you can simply learn to manage the recoil of major loads.

In the end, just pick a load and shoot it until you are use to it. Too many people forever chase the "Magical" load that is super soft shooting and, bla, bla, bla. Every load recoils a little differently and it changes your timing which changes the grip pressure you need. So its better just to pick a load and shoot it so you give yourself a chance to learn and tune YOUR shooting to it.

Cha-Lee This is another thing I don't understand, Spec on Clay max should be about 3.8 1.12OAL. But your's are a lot higher. How can we make it "soft" by using more power?

Longer OAL = need more power = more "bang"???????

[twodownzero]

Pressure = force / area

Increase numerator or decrease denominator = more pressure.

[Jim Norman]

LC, get a really good manual and read it, then read it again. Then talk to the successful shooters and reloaders at your club, get them to show you hands on what to look for. Pictures are good, real life is better. The information as to what to look for given here appears to be good. Just remember " just because it is on the internet doesn't make it so."

Then start low and slow and build up to PF. Do however watch that you don't load too light. That in some powders can have as bad an effect as loading too hot.

Once you get your basics down, you can start to play around a bit. Note that some people like snappy loads, others like pushy loads, some guns feel better with this or that. YMMV. The important thing to remember is that you will be shooting your gun with your loads and how YOU feel and how YOU shoot is the ultimate criteria (After the safety aspects are properly dealt with)

Jim

[Mo Hepworth]

FYI,...In Canada you compete in Standard division, so making major requires 170pf. I use ammo that makes approx. 175pf +/-. I use remanufactured ammunition 180gr .40 Combat master ammo. (I sell it as well, so that is why I use it.)

[Limited Custom]

FYI,...In Canada you compete in Standard division, so making major requires 170pf. I use ammo that makes approx. 175pf +/-. I use remanufactured ammunition 180gr .40 Combat master ammo. (I sell it as well, so that is why I use it.)

You ar right, 175 PF for me in a Tanfoglio is very tough to handle, thats why I was hopping to find a special receipe to match or might need to change gun....

[askomiko]

Really? My feelings are quite the opposite, Tanfoglio feels the softest recoiling gun to me. 180gr bullets, around 5.3gr of Vihtavuori N320, PF 173. (40SW HC Custom, with regular slide, eg. not lightned. Whatever it is called in USA, the top standard class model.)

STI has heavier and a lot higher slide, and lighter frame. Also I've never gotten to like the ergonomics of the grip, safety, and trigger guard. I also had a CZ Tactical sports in .40, and it just plain kicked harded than Tanfoglio with the same ammo.

Edited January 20, 2010 by askomiko

[Limited Custom]

Really? My feelings are quite the opposite, Tanfoglio feels the softest recoiling gun to me. 180gr bullets, around 5.3gr of Vihtavuori N320, PF 173. (40SW HC Custom, with regular slide, eg. not lightned. Whatever it is called in USA, the top standard class model.)

STI has heavier and a lot higher slide, and lighter frame. Also I've never gotten to like the ergonomics of the grip, safety, and trigger guard. I also had a CZ Tactical sports in .40, and it just plain kicked harded than Tanfoglio with the same ammo.

Askomiko - whats your OAL on the N320 ammo? that's the powder I would like to try. 5.3gr enough?

[askomiko]

30.45mm = 1.2". But pressure and speed-wise, that's an useless figure unless you use the same bullet. I use copper plated lead bullets, so I suppose they're softer than regular jacketed bullets. But in general, this gun runs better with longer ammo. Factory is too short. I chrono my ammo almost every time I visit the range, and I like to keep it quite close to the PF170, the needed powder amount varies a bit with different powder cans and weather, 5.25-5.4.

Edited January 20, 2010 by askomiko