Testing 357 Plated Bullets Raises new Question

Today I tested Rainier 125 gr. HP bullets and some Raineir 158 gr. HP bullets.

I was feeling good that I have my cronograph running again after years of fighting with all sort of problems including muzzle blast or shock wave causing readings out of the norm. Even shooters next to me were causing readings with my cronograph. Fixed that problem with new sky screens.

I found a problem I didn't know existed with my test loads. Using a 125 gr. Rainier HP bullet and three different powders, 700X, Win. 231 and Titegroup I fired ten shot groups with varied powder charges. I noticed quite often the first round of five from my Ruger 357 Mag. Security Six would have a much lower velocity than the next four rounds. Sometimes more than 100 fps when the average velocity was only around 700 fps.. It happened with all the powders but more so with two of the three.

First I wondered if one of the chambers could be causing this. I ruled that out and started to consider variations in crimp and/or bullet retention. That could cause some problems, but not limited to first rounds fired after reloading the gun. Then I hit on what I think the problem is. I think it is a powder position problem. Think about it. Firing from a pistol rest. You load five rounds, close the cylinder and level the gun on target. The powder is mostly to the rear now, for me. Fire the first round and the other four rounds in the cylinder get jerked hard to the rear and the powder goes to the front and basicly remains there through the firing of the last four rounds.

Maybe I am just hoping I have the answer, but it will be easy to prove. I plan my next outing to be with some of the same loads, but half will be fired with powder to the rear and the other half will be fired with the powder to the front.

I have used this test with other calibers and powders so I could find the least position sensitive powder and load for that gun. It can really make a big difference in the group sizes.

I will include the results of my test on this forum.

If any of you shooters have had a similar problem I would like to hear about it. Especially if you fixed the problem.

When I tested the previous loads I tried 700X, Titegroup and Win. 231. I found all the loads to be very clean. No scorching of the brass. Actually that is why I went with the faster powders behind a 125 grain plated bullet.

One problem with plated bullets and slower powders is the fact a person can not crimp firmly enough to get a good burn without damaging or even cutting the plated shell in two. A modest taper crimp doesn't offer enough resistence so the slow powders get a good start and that results in a lot of scorching of the brass because the pressure curve is too slow and the brass doesn't seal the chamber well.

For my test, the Titegroup powder didn't group all that well, not bad but not good in my book. The 231 actually shot a couple of groups we call one ragged hole at fifty feet and seemed the least sensitive to powder position as did the Titegroup. The 700X appeared to be the most sensitive to powder position. All these loads were sparked with Winchester primers.

If anyone is wondering how I can shoot one ragged hole groups at fifty feet with seventy one year old eyes and trifocal glasses, I cheat like crazy. The gun is scoped for all my load testing and I shoot hand held with a pistol rest off a solid bench. I almost always shoot ten shot groups. On a few occasions I shoot five shot groups but that is seldom. I have always belived the more rounds fired into a group, the larger the group will be. So I don't like three shot groups because I can't tell what the real potential group size will be. I can't tell if the load is going the string out vertically or horizontally. That is my opinion and I am sure there are those that will argue the point. Lets not argue but everyone is intitled to their opinion.

Even with all the aids I use for load testing many of my revolvers, I do at times shoot a goodly number of one ragged hole groups when I am having a good day with proven loads. There are days when I can't buy a nice tight group with the same gun and load. Thats life in the real world.

To be fair I really need to try some of these loads with Remington and CCI primers. I have found my 9mm's, 45 Colts and a couple of other calibers using different powders to be powder position sensitive with one primer and not with another. Different powders do prefer one primer over another. Velocities can vary, group sizes will vary and the powder sensitivity issue can be greatly affected by the primer used. Another variable is the bullet weight. A given bullet weight, say 125 grain 357 and primer that works well may not work so good if the bullet weight is increased to say 180 grains. The heavier bullet usually requires a different powder. Changing calibers can change the choice of powder and primer again.

With reloading, success is not always easy to be had. Be willing to try other combinations and you can be rewarded with a great shooting load. Some calibers are much easier than others. I have read on this and other forums, the 45 ACP can be a lot easier than the 9mm as an example when small groups and good velocities are desired, both low velocity target loads and matching factory velocity performance loads. This has been my experience also.

I Hope I Am Not Wrong

I assume the Clays powder that has been referred to is "Hodgdon Clays".

There are two other Hodgdon Clays, Universal Clays and International Clays.

I plan to test with Hodgdon Clays and Accurate No. 2, Powders I do not have in my inventory yet.

Loading Powder Position Test Loads

I now have the Accurate No. 2 and Clays powder in addition to the 700X, 231 and Titegroup that I have been using with the 125 grain Rainier HP bullet fired in my Ruger Security Six, 6" barrel. The barrel cylinder gap is more than desirable, .007" and that accounts for some velocity loss.

I plan to load ten rounds with each of the five powders and with three different primers. Remington 1-1/2, Winchester spp and CCI 500. I will fire each ten round test with five powder forward and five powder to the rear. All these tests will be fired over the cronograph for a record of the results.

I hope to put together a chart that I can post here for everyone to see. I hope to fire this test this coming week.

Test Results Are In

357 Magnum – Powder Position Firing Test

Finally the weather has been good and personal business out of the way.

The test gun is a Ruger Security Six, scoped, with a 6” barrel and a barrel cylinder gap of .007” to .008”. All firing was hand held off a pistol rest on a solid shooting bench. The chronograph is a Pact with sky screens at 15 feet in front of the muzzle.

I used a 125 grain HP Rainier bullet, Winchester Nickel brass and five powders sparked by three different primers. The powders chosen are AA 2, Titegroup, Clays, 700X and Win. 231. The primers used were Rem. 1-1/2, Win. SPP and CCI 500. Some powders do prefer one primer over another for consistent ignition.

I am looking for a powder and primer combination that will provide the least Powder Position Sensitivity, fast enough burning to avoid scorched brass and is accurate. I decided to go with the faster powders to avoid the scorched brass. This may not have been the best choice for what I was looking for.

I used the velocities, extreme spread, group size and group position on the target as indicators of performance changes due to a powder position problem. I should indicate here, a powder position problem is aggravated by low volume powder charges relative to the case capacity, the nature of the powder and primer combination and my powders of choice were probably going to give me trouble.

I loaded 4.3 grains of Clays, 4.5 grains of AA 2, 4.3 grains of Titegroup, 4.1 grains of 700X and 4.3 grains of Win. 231. My target was for a load that would provide a minimum velocity of 800 fps as a starting load. I used the same five chambers throughout the test and fired ten rounds with each load combination. Five with the powder forward and five with the powder to the rear.

With all the loads tested, all of them indicated the powder forward rounds shot lower on the target and with lower velocities. The extreme spread varied from least with powder forward to powder to the rear. No consistency there.

Clays powder was best using Win. SPP. The average velocity change from 814.5 fps powder forward to 921.2 fps powder to rear and the groups shifted only 0.10” up with powder to the rear. Using Rem. 1-1/2 primers the group shifted up 1.10” with powder to the rear and CCI 500 primers the group shifted up 0.60”. Average velocities varied from 107.3, 106.7 and 193.9 up when powder was to the rear. The worst being 193.9 with CCI 500 primers.

AA 2 powder was worst with Win. SPP with a group shift up of 1.40” and a velocity spread of 199.6.

Tightgroup was had the greatest group shift up of 1.49” with Rem. 1-1/2 primers and worst velocity spread of 166.1fps using Win. SPP.

700X was a bit better than Tightgroup with Rem. 1-1/2 primers the group shift was 0.45” up and velocity spread was 80.4 fps.

Win. 231 was probably the worst powder in this test. Group shifts up were 1,00”, 1.10” and 1.50”. The velocity spreads were 226.8, 244.8 and 277.3. Not a good choice.

Group sizes varied like crazy from tiny 0.40” and 0.50” center to center clusters to groups as large as 2.15”. Some of the smallest groups were with powder forward and some with powder to the rear. The larger groups were with both powder positions also. When groups shift up or down due the varied powder position, those loads will usually shoot groups that are strung out vertically and larger than desired.

Bottom line is, I am not really happy with any of these loads I used. Most likely due to the small powder volumes with these powders. So much for the powders reported to be less position sensitive. I find this to be not so with a 357 magnum case and light powder charges.

I will probably have to go to the mid range burn rate powders and look for the most bulky ones. Hopefully I can find a powder that will provide better results.

rsrocket1,

I did try some Trail Boss in one of my 357 magnums but at this moment I don't remember what bullet I was using. Seems to me I wasn't happy with the load.

I do plan to try the Trail Boss with this 125 grain Rainier HP. It may work, but I am not sure what the high end for velocity may be. I want to be able to run from 800 fps to around 1100 fps.

I am using 357 Mag. brass. One problem with the plated bullets and using the slower powders is the crimp. Plated bullets can not be crimped heavily and especially with a roll crimp. That limits the bullet pull that slower powders like for good ignition.