determining max load in an auto pistol

6

6724

New member
i have a lot of unfinished projects around my bench, this one is at least a year and half old. i would like to finally finish it.

i am loading 475 wildey, obviously in a wildey auto pistol. there is not much data out there for the cartridge, even less for the 325gr speer bullet.

i use blue dot as recommended by the wildey people, i have used other powders in the past but this latest test is with blue dot.

i loaded 5 each of 17gr to 19gr in .5 gr increments. all the loads show primer cratering, so i dont think i can use that as much of an indicator.

one thought i have is to fire the remaining rounds (two each of the larger charges), single shot, and then see if i have brass flowing into the ejector.
what else could i do?
 
velocity starts at 1200 fps with 17gr. then about 1260, then 1330, then 1350, and with 19gr about 1375.

interpolating data from other bullet weights gives me a "max" charge of 19.25gr
 
To be on the safe side, I would be calling Speer and see what their Tech Support people say...That's a lot of bullet weight to be pushing at those speeds by trial and error...It wouldn't be so bad if you had some documented success factors from a reputable source, but if you are starting a fracture of the chamber by over pressure, when it lets go, you can be in a world of hurt...
 
Originally Posted By: Jack RobertsYou are looking at indications that apply to rifles, not pistols.

You need to rethink everything.

Jack

What Jack said...

Google Loading data for 475 wildey ... there is a ton of stuff out there.

 
Originally Posted By: CatShooterOriginally Posted By: Jack RobertsYou are looking at indications that apply to rifles, not pistols.

You need to rethink everything.

Jack

What Jack said...

Google Loading data for 475 wildey ... there is a ton of stuff out there.



that is precisely why i started this thread, i am trying to find out HOW to determine when i am reaching the high end of the pressure spectrum.

i have googled 475 wildey load data, and i cannot find ONE listing for a 325gr bullet. i find 300, i find 350, and lower bullet weights. i have graphed the 300 and 350 data that i have been able to find, that is how i came up with the theoretical max load of 19.25gr. if i go with using the load data for the next heavier bullet i am looking at 16.5gr if using the data from the wildey web site.

so back to my original question, how do i determine max pressure?
 
there is load data for other bullet weights. i tried some of those 15 years ago when i bought the pistol. hawk bullets were supposed to be so good, i tried a couple different weights. i was not impressed with their performance on game. the few i used came apart, lead core completely seperated from the jacket, and the lead core seemed to be very soft. so i am not interested in buying hawk bullets in 300gr or 350gr.
i bought the pistol for use on large game and backup in bear country. i have almost no issues with reliability, good enough that i trust it for backup. but i would like a bullet that will provide deep penetration, i am not worried about expansion. the 325gr speer is made for the linebaugh i believe, the linebaugh runs quite a bit faster.

i would like to find a safe, not necessarily max load. just like you guys with swifts, you don't have it to duplicate 22-250 data.
 
Originally Posted By: 6724Originally Posted By: CatShooterOriginally Posted By: Jack RobertsYou are looking at indications that apply to rifles, not pistols.

You need to rethink everything.

Jack

What Jack said...

Google Loading data for 475 wildey ... there is a ton of stuff out there.



that is precisely why i started this thread, i am trying to find out HOW to determine when i am reaching the high end of the pressure spectrum.

i have googled 475 wildey load data, and i cannot find ONE listing for a 325gr bullet. i find 300, i find 350, and lower bullet weights. i have graphed the 300 and 350 data that i have been able to find, that is how i came up with the theoretical max load of 19.25gr. if i go with using the load data for the next heavier bullet i am looking at 16.5gr if using the data from the wildey web site.

so back to my original question, how do i determine max pressure?

I'll say this up front - I know nothing about Widley pistols.

But with pistols in general, it is very difficult to determine max loads by the pressure signs that rifle people use.

With 1911, Browning P-35's, and other similar designs, loads are best determined by how far the fired case is ejected (I know that sounds dumb, but there are very good reasons for it).

With rotating bolt, gas operated pistols, it is tough, because they are not strong enough to use primers as pressure signs, and ejection is not dependent on pressures.

If it were my pistol, I would shoot known loads and keep the fired cases for a reference - than I would do as you have and plot out the slope of loads - powder weight vs bullet weight.

Then I would work up (as you are doing) and make sure that none of the cases looked worse than the cases I had from shooting known loads.

There is not much else you can do.

 
All sounds like sensible advice to me. I think one more thing you can watch as a pressure indicator is velocity. Chronographs can be very useful in this way
 
Originally Posted By: CatShooterOriginally Posted By: 6724Originally Posted By: CatShooterOriginally Posted By: Jack RobertsYou are looking at indications that apply to rifles, not pistols.

You need to rethink everything.

Jack

What Jack said...



Google Loading data for 475 wildey ... there is a ton of stuff out there.



that is precisely why i started this thread, i am trying to find out HOW to determine when i am reaching the high end of the pressure spectrum.

i have googled 475 wildey load data, and i cannot find ONE listing for a 325gr bullet. i find 300, i find 350, and lower bullet weights. i have graphed the 300 and 350 data that i have been able to find, that is how i came up with the theoretical max load of 19.25gr. if i go with using the load data for the next heavier bullet i am looking at 16.5gr if using the data from the wildey web site.

so back to my original question, how do i determine max pressure?

I'll say this up front - I know nothing about Widley pistols.

But with pistols in general, it is very difficult to determine max loads by the pressure signs that rifle people use.

With 1911, Browning P-35's, and other similar designs, loads are best determined by how far the fired case is ejected (I know that sounds dumb, but there are very good reasons for it).

With rotating bolt, gas operated pistols, it is tough, because they are not strong enough to use primers as pressure signs, and ejection is not dependent on pressures.

If it were my pistol, I would shoot known loads and keep the fired cases for a reference - than I would do as you have and plot out the slope of loads - powder weight vs bullet weight.

Then I would work up (as you are doing) and make sure that none of the cases looked worse than the cases I had from shooting known loads.

There is not much else you can do.



i was looking for a no [beeep] response like this. i realized that the normal for bolt rifle would not work. but was hoping there was some simple way to know where i was. i have never tried to achieve anything other than reliability with an auto.

time to keep researching other's efforts and hopefully speer will get back to me. i could go with the low end very safe route but then i might as well sell the gun and buy a 44 mag, and load it with factory rounds.
 
Quote:i have graphed the 300 and 350 data that i have been able to find, that is how i came up with the theoretical max load of 19.25gr. if i go with using the load data for the next heavier bullet i am looking at 16.5gr if using the data from the wildey web site....Since you have data from a lighter and heavier loading, hopefully from the factory, then I would say you are pretty close to what you are attempting to achieve...

Your first post didn't include that info, or you would have probably gotten more relevant responses...

When I was working up 200gr HP loads for my 10mm Glock, I was pretty much in the same quandary since there was no internet availability at the time and very little published information on that bullet weight...I had to take the next highest bullet weight in a factory loading (180gr) and working with a chronograph, begin some trial and error experimentation and using the ejection distance as one of the evaluation factors..Since I knew the compression weight of the recoil spring and keeping accuracy in mind, I was able to find a powder charge that I was comfortable using in that weapon...Not sure I would use it in any other 10mm though..
 
How did you use the compression weight of the recoil spring in your calculations?? The springs only job is to return the gun to battery.

Iv never thought about using the ejection distance to confirm load pressures etc. The critter gitter spits brass out about 8'
 
Originally Posted By: Widow maker 223
How did you use the compression weight of the recoil spring in your calculations?? The springs only job is to return the gun to battery.




The spring's job is to slow the slide or bolt down so it doesn't bash it's way through the back of the firearm.... it should hit the rear of the action at a speed that allows the case to be ejected 110% of tie time, and then pull another round up from a full magazine 110% of the time. The spring should NOT be stronger than is needed to meet these criteria.



Originally Posted By: Widow maker 223
I've never thought about using the ejection distance to confirm load pressures etc. The critter gitter spits brass out about 8'


When a firearm is designed to fire a standard round, the spring should be chosen so it ejects with the least amount of speed at the end of it's travel as is consistent with reliability.

When I first got into the gun business, we sold Walther PPKs, and they would not shoot well with US ammunition... the cases would smokestack. But European Geco ammo, they were fine.

The European ammo was hotter. If we cut the springs two coils, the PPKs would function with US ammo, but would toss the Geco fired cases 12 to 14 feet. IT is a balancing effort.

If you are tossing cases 8 feet, you might go with less coils, consistent with reliable magazine pick-up.
 
I was thinking about this and i see what you are saying, auto loading pistols differ a bit from strait blow back guns.

It runs great. I dont really want to shorten the spring any as it cycles fine. With the huge mass thats holding the bolt closed i actually could use a slightly stiffer spring. It doesnt slam forward the way most factory guns do. Im using a standard AR recoil spring now cut down to about 4". I need to scrounge around and see what i have.
 
what i got in return from speer:

Sam: not tested data here on loading for the 475 Wildey, you're on your
own as far as I know.
 
Most factory spec sheets provide the optimal spring weight for the recoil springs...As an example, the .40 S&W in one of my 1911s has an 18# spring and when I install the 10mm conversion, I install a 22# spring...With both calibers and my reloads (same bullet weight) the cases fall between 6 and 7 feet from my firing position...The weapon functions reliably and accurately...

One of the guys that I used to shoot with, using the same model of 1911 in .40 used to 'light load' his rounds and installed a spring that was so light you could actually see the slide function like it was in slow motion...Wasn't too great when he was in a speed shooting competition, but the light recoil allowed easier target acquisition with follow up shots on multiple targets...

Wolff Springs offers a variety of spring weights for different semi-autos and may have some info for the Wildey.....
 
the wildey is a rotating bolt gas operated auto. the gas port is adjustable as well, it can be closed off completely and fired single shot. so i can adjust the amount of gas to match the springs.
 


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