Powder question.

[DBnoise]

It's actually better to have a case that is full to the base of the bullet. I was just recently re-reading some info on how light charges can cause a much higher pressure spike,, due to powder position & the way it ignites.

Many, many years ago,, I spent a lot of time studying what Rick Jamison would write in his "Reloading" column for Shooting times. One thing that always stood out was how the most uniform & consistent loads were from using a powder that would allow a safe charge,, to where it just touched the base or was slightly compressed.

A very light charge,, where there is a bit of "air space" inside the case,, when loaded in the gun,, the powder lays in the bottom of the case. The primer flashes across the powder. That causes erratic ignition and can create a larger pressure spike. In the case of what you are showing above,, I'd go with the 4198 powder instead of the Unique.

And I use a lot of Unique in a lot of handgun loads. But in general,, it is used in an amount to where the primer can ignite the powder while the powder is still against the base of the case internally.

I followed alot of Rick's articles. Pretty scientific in my estimation. Did some of the same stuff. A chronograph is the tell all on loads for me. I try to use a powder that gives the best accuracy, highest velocity and near 100% load density.

 

[308 Scout]

I followed alot of Rick's articles. Pretty scientific in my estimation. Did some of the same stuff. A chronograph is the tell all on loads for me. I try to use a powder that gives the best accuracy, highest velocity and near 100% load density.

If I remember correctly, most if not all of Rick Jamison's load development was for rifle cartridges. In those cases and with rifle powders, a full case is very much beneficial. However with straight-wall handgun cartridges there is nothing at all wrong with light charges. I've personally never seen the point of filling a case with a slow burning powder to achieve X velocity when half as much of a faster burning powder will provide the same velocity. I load for extensively for .357, .41 Magnum, .44 Special, .44 Magnum and .45 Colt. I typically stick with powders that burn between Bullseye and Unique and lately have burned quite a lot of Titegroup in my .41 Magnums running 210-220 gr. bullets right at 1100 fps. With any of these type powders in the aforementioned cartridges, extreme spreads stay around 30-45 fps and accuracy is really good all the way out to 300 yds.

 

[Pál_K]

In general, the powder that is slowest burning (from the charts) is my choice for any given load as it developes the lower pressures. Not a 100% guide, as loads need to be proved by the shooting of them.

Bob Wright

One exception would be if the slower powder is too slow for the barrel length.

But, I agree, the slowest of the powders listed in the manual's reloading data will offer a lower pressure and a high loading density (filling the case the most).

I have a 10" .30-30 Contender and first chose W748. Way too slow. Powder burning out the barrel caused turbulence and poor accuracy. But a beautiful muzzle flash, blast, and ground shock wave when shooting Silhouette. The faster IMR-4198 was the sweet spot.

heres a dumb question.
Burn rate charts? Do they have a numercal rating or is it just fastest on top of list progressing down the list to the slowest.

Just a relative rate. This is the chart I use, but there are many others.

 

[Pál_K]

If I remember correctly, most if not all of Rick Jamison's load development was for rifle cartridges. In those cases and with rifle powders, a full case is very much beneficial. However with straight-wall handgun cartridges there is nothing at all wrong with light charges. ...

A friend and I were talking about this because my favorite .38 Special load with W231 is almost like dust in the bottom of the case - and it's not even the lightest load listed! With one pound of powder, I can load well over 1500 rounds.

My friend mentioned that some of the more popular other caliber loadings use even faster powders like Green Dot, Bullseye, and Red Dot, where there may be less than two grains in the case.

 

[DBnoise]

I

If I remember correctly, most if not all of Rick Jamison's load development was for rifle cartridges. In those cases and with rifle powders, a full case is very much beneficial. However with straight-wall handgun cartridges there is nothing at all wrong with light charges. I've personally never seen the point of filling a case with a slow burning powder to achieve X velocity when half as much of a faster burning powder will provide the same velocity. I load for extensively for .357, .41 Magnum, .44 Special, .44 Magnum and .45 Colt. I typically stick with powders that burn between Bullseye and Unique and lately have burned quite a lot of Titegroup in my .41 Magnums running 210-220 gr. bullets right at 1100 fps. With any of these type powders in the aforementioned cartridges, extreme spreads stay around 30-45 fps and accuracy is really good all the way out to 300 yds.

I dont push my hand guns but my rifles are a different story.. Am going to share with you what I did with a straight wall 350 Legend. First thing I did was buy new longest barrel rifle, 23 1/4 inch. Shot a few factory loads to break it in. Then started load development on Starline brass. My goal was to have an effective 275 yard rifle. Tried a couple of bullets and settle on a 165gr flextip. I like the 140s in my 357 GP100. I tried H110, W296, IMR4227, XMR5744, AA1680, and Lil'Gun. Took 150 rds to get the the top 2 highest velocity that wasn't too shaby on accuracy, w296 and Lil'Gun. Then I started accuracizing. Put a flash suppressor on, bedded the action and weight the butt, lead shot and epoxy, and full length bedded the barrel. Floated it from muzzle back until best group with the load below. I use moly coated bullets. The brass, all prep'd and treated like a bottle neck with small base 357 dies, made an adapter to my press and only sizing the neck to base of bullet. Trimmed fired cases to .005 shorter than my chamber. Final loads, 165gr Flextip moly coated, Rem 7 1/2, 29.0gr Lil'Gun, .040 off the lands at 2.335 oal, .003 neck tension, 2625fps. Groups 5 rounds at 1 inch at 200 yards.. Fits a modified magazine in my bolt.
I have room to go on powder as I went up to 30 grains but best group was at 29.0. Room to go on oal too that I could to the lands and still function in the magazine. It's a Franchi Momentum. That barrel was very very good through a bore scope. So good so bought another for my daughter. That one the barrel was pretty shitty. Sent it back, they didn't even look in the barrel, shot a 3 rounds just barely inside an inch and sent back. I should be getting it back in a week or so from a gunsmith with a 26 to 27 inch barrel. My goal is to hit close to 2800fps velocities and have solid 300 to 325 yard rifle with 1000 ft lbs left on that 165 gr bullet. It's for Buckeye straight wall country this deer season.
Next project is total custom cartridge with a .358 bullet, straight wall, with enough length to give a 180 gr bullet 2750+ fps velocity. Waiting to win the lottery on that one!! Lol