[Kermit]

I'm trying to work up some .357 Magnum handloads for long range (100 yds.) shooting at targets. I'm shooting a 4 inch Ruger GP100 revolver. I'm trying to work up the load using 158 cast LSWC bullets manufactured by Bushwhacker Bullet Co. in MO. I'm sorry but I don't know that the Brinnel hardness rating is for these bullets. They are bevel base bullets. I've used these bullets for light and medium .38 special loads for practice and qualification with acceptable results.

These bullets have given fair results so far in the .357 loads, but I feel accuracy isn't what it should be when I compare it to my .41 magnum. I've tried several powders. I've tried up to 14.3 grains of 2400, and up to 5.0 grains of Titegroup. Today I tried 5.4, 5.8, and 6.2 grains of Universal with only fair results. I've only been shooting at 25 yards. A buddy of mine suggests that the accuracy isn't good due to the bullets having a bevel base. My buddy says if I use cast .357 bullets with a flat base the accuracy will improve. In my .41 magnum all I've ever used are flat based cast bullets or JHP bullets and accuracy is great.

Any thoughts or advice on this problem? All opinions and advice will be appreciated. Thank you.

 

[bulletmaker]

No the bases have nothing to do with it...I doubt you will get much accuracy from that short barrel at the distance your trying for..Your really pushing your luck on this one...So keep banging away you may get lucky on one of your shots....

 

[Rocky Raab]

I DO think it has to do with the bevel base. I use a gas-checked 158 SWC and can hit a football-sized target at 100 yards five of six shots at 100 yards using my 4 5/8 Blackhawk. The load is 15.0 4227, a mag primer and a firm crimp.

Bevel bases allow the escaping gas to "jet" at unpredictable angles just as the bullet clears the muzzle, blowing the bullet a bit off course. The bevel is there so the bullet releases easier from the commercial mould - that's all.

 

[wildhobbybobby]

I have never tried commercially cast bullets with heavy loads, but have had good results with both plain flat base and gas check cast bullets (and commercial jacketed bullets too) with max loads in the .357. I agree you might want to try something other than a bevel base bullet for your long range shooting. Also, I have had excellent results in several calibers including .357 with 4 inch barreled guns, so as long as you don't have issues with timing, chamber throats or forcing cone vs. bore size, you should be able to find a load that works for your purposes.

If you are still experimenting with powders, give H110/WW296 a try (they are the same powder in different cans).

 

[gschwertley]

A couple of things that haven't yet been mentioned here. One is, you haven't mentioned if there has been a measurement of the bullet diameter compared to the known diameter of the revolver bore. It's important that these two numbers are compatible to achieve accuracy, for example a .358 bullet in a true .357 bore.

The other thing is, with a plain base bullet, your quest for higher velocity to shoot at great distance is limited by the design of the bullet. You may drive a gas checked bullet faster than a plain based bullet, given the same hardness. Driving any plain base bullet too fast may lead to barrel leading problems.

"Store-bought" cast bullets are sometimes not the most accurate you can obtain. Compromises in design (like the bevel base) and manufacture (bullets made overly-hard in order to stand up better in shipping) occur to satisfy commercial purposes. Lots of these bullets get blasted down-range at distances much shorter than 100 yards without much thought being given to accuracy.

 

[Kermit]

I checked a few of the commercial cast bullets with my calipers and they show .357 diameter. I'm sorry but I can't provide the measurement for the bore. I'm getting suspicious based on what I'm reading that the .357 bullets may be contributing to the problem. My buddy is going to cast some bullets and size them .358 with a flat base. We're going to test these and I'm thinking we'll see an improvement. Could be wrong but we'll see...

 

[ironhead7544]

For long range, Id try one of the silhouette bullets. Thats what they are made for. The Keith 173 grain bullet is also designed for long range. For 100 yards Ive had good results from IMR 4227 with 125 grain jacketed hollow points. Use the start load and work up. Some of the groups with this load in a scoped revolver were surprising to say the least. Also, with iron sights you need to have the right target for 100 yards. I found that a black square thats just the width that the front sight at that range makes it easier to index the shot. Just leave float the square with a little light under it. When I had the old 1.5x TC scope on my M19 S&W I put up 4 bulleyes spaced a little apart. Then indexed the crosshairs between them. Cut my group sizes in half.

 

[Throckmorton]

I"m betting that going to a bullet sized .358 will give better results.
Were the .357's showing any keyholing?
what kinds of velocities are you thinking of going for in your .357 loads?

 

[unclenick]

As Rocky said, the bevel base can affect accuracy. Some molds don't cast it perfectly symetrically, and if it isn't perfectly symetrical below the sized portion of the bullet, the bullet will tend to be tipped by muzzle blast deflecting unevenly off of it. Ease of machine feed and of setting it straight in a neck flare are the only values the bevel base offers reloaders. Get a Lyman M type expander to keep bullets seating straight, not the bevel base.

A lot of revolvers shoot better with lead bullets 0.002" oversize. That would be .359" if your friend has a sizing die that size? If so, perhaps you could get him to make some of each size for you to compare? You need to slug the bore to be sure you have what you need?

Also note that revolvers can be a bit picky with lead bullets. If you slug the bore you should also slug the cylinder throats. They should be a thousandth or more over groove diameter in the bore. If not, you can take it off the gun and get them reamed to maximum by cylindersmith.com. That's quick. Or you can send it to Ruger with an accuracy complaint and they will do it free if it isn't right, except the overnight postage will cost more than have cylindersmith do it.

The other reason to slug the bore is to feel for constrictions. It is not uncommon for revolvers to have a constriction where the barrel screws into the frame. That is very detrimental to lead bullet accuracy, though jacketed bullets aren't bothered a lot by it. Firelapping will remove the constriction.