At the DSC George Caswell was kind enough to share with me with a load to try in my Searcy .577. The load is 112 grains of IMR3031, 2-3 grains of polyfill, F215M primer and a 750 grain bullet. The bullet I chose to use was a Woodleigh Hydrostatically Stabilized solid. I loaded up six rounds and headed to the range this morning. As shown in the picture the load was very accurate in my rifle. Velocity was a little hot, average 2122 fps, right barrel average 2113 fps, left barrel average 2131 fps. There was no sign of pressure on the primers but the rifle was a little hard to open. It would open half way and then you had to push it open the rest of the way. My head tells me to reduce the charge to something like 110 grains and try it to see what the velocity is and whether the stiff opening goes away. My heart tells me, damn that is an accurate load, leave well enough alone. Suggestions?

Mike,

Do this:
Drop the load down substantially - like to 105 grains of 3031. Load 4 of these and fire them. If the action is not stiff it tells you everything you need to know and you simply can not use that load.

If its just as stiff, something else is going on.

You're known for your quick reload and fire times. That may save your life or may have done so already. Can you risk a slower reload due to a stiff action from an over-pressure load?

You asked and there is my advice.

Good luck and stay well,

Paul

Mike,

It might also be worth remembering that pressures may be a lot higher in the hot African sun.

465H&H

Mike, one question I would have with the 2100+ velocity is, are the barrels crossing? Your target isn't marked L and R so that is the first thing I would want to know.

If they are, then even though it is printing well at that range, crossing will degrade the group at a longer range.

Obviously, this would tie in with too much pressure. What I'm driving at, and I'm sure you already know this, is that by reducing a couple of grains, if they are currently crossing, you may end up with just as good a grouping without the crossing, at which point you would have solved multiple issues including pressure as well as longer range accuracy.

I bring this up because as I mentioned to you at DSC, with my 577 and the CEB's generating right at 2115fps, mine are crossing a bit. I have no pressure issues at all but I need to reduce the load a bit to correct it.

All that said, Paul's advice is spot on in that you need to determine if the stiff opening is pressure related. If it is, the accuracy of that load doesn't matter. Furthermore, I doubt backing off just a bit would cause much opening of the group if they are not crossing now. So I would suggest, as did Paul, to go back to 105 grains, and see what you get, then work back up to a load that satisfies both accuracy and pressure concerns.

No, the barrels are not crossing although it is sort of hard to tell after the first two shots when everything is going into one ragged hole! I have been using a load with RL15 that was giving me around 1950 fps and the rifle opens fine, so I am sure it is the load and not the rifle. I know that the right thing to do is to drop the load a little and I do worry about temperatures being hotter in Zim (today when I was shooting it was only about 65 degrees). In the end my head will win, but every time I look at the target my heart says leave it be. I am going to drop down to 108-110 and see what I get. Thanks for the input and reinforcing what I need to do.

It is a fine looking target!!

Just make sure that the filler is COMPRESSING the powder charge between the bullet and the primer.

After shaking a loaded round HARD you should still not hear or feel any powder in the case.

Also that sounds like a lot of IMR 3031, especially in a new made rifle, ie tighter chambers, tighter barrels, I would have started with 100 grains and worked up.

Original ballistics call for a 750gr bullet at 2050fps in a 28" barrel.

quote:

Originally posted by MJines:
... the rifle was a little hard to open. It would open half way and then you had to push it open the rest of the way.

Mike - I would say the rifle being hard to open is a sign of excessive pressure.

The "primer rules" don't really apply (IMO) to a double, becasue you wouldn't notice primer signs until you get above @ 60K... then you're 20K over where you want to be.

Mike,

Did you notice a difference in the perceived recoil from the RL-15 loads?

I appreciate everyone's input.

Tony, the polyfill was well compressed against the powder so I think we can check that issue off the list.

Tony and Chris, I am convinced the charge is too much. The velocity is well above "target" and the fact that I have shot a lot of RL15 loads with no problems suggests to me that 112 grains is too much. I am going to load up four rounds with 104 grains and four rounds with 108 grains and see what I get. I will start with the 104 grain rounds.

Todd, sort of hard to say. Since these loads were ~150 fps faster it is sort of like an apples-to-oranges comparison. As I get the velocity closer to 2000-2050 fps I will have a better sense.

Mike, what was your RL 15 load?

Another thing to think about with the over pressure load(which it sounds like you have) is it is hard on ejectors pushing tight cases out of the barrels. It is annoying to break one at the range but how about out in the field?

I had a similar issue(over pressure) with mine and RL15. 2 grains reduced and the group stayed the same but the cases ejected flawlesly everytime even at 100 degrees.


Matthew

quote:

Originally posted by N E 450 No2:
Mike, what was your RL 15 load?

119 - 120 grains of RL15, F215M, Kynoch Wad, and a 750 grain bullet. With that load I was getting 1910 - 1930 fps with the Woodleigh Hydro Stabilized bullets.

Matthewx, that is my hope too, reduce the load a little, retain the accuracy and regain effortless extraction.

Go to 160 grains Curtis and Harvey Diamond Grade No. 6, well compressed, and a lead bullet hardened with mercury, and you will be fine, says Sir Samuel Baker ...

Mike,
Your rifle was regulated with Woodleigh bullets which creates higher presures. Thus 119 to 120 grains of RL-15 works fine. But with the Woodleigh Hydro Stabilized bullet you need to encrease the RL-15 powder charger to get 2050 FPS. I do not recommend 3031( 90 Grs. of 3031 gives in most rifles a velcity of 2000 FPS), RL-15 is the most forgiving as to presures with a proper wad.

Butch,

If I was getting 1920 fps with 120 grains of RL15 (with the 750 grain Woodleigh Hydro. Stabilized bullet), what would you suggest upping the RL15 charge to get approximately 2025-2050 fps?

Mike it makes no difference how accurate the rifle is with those loads, if the rifle opens properly with the loads you normally and the rifle is sticky on opening with the load you just fired then I would either back off on the load, or change the bullet!

A double rifle will rarely show normal sign of pressure indicative of being fired in a bolt rifle. The first sign of OVER PRESSURE in a double rifle is being hard to open after firing a new load in it. By the time pressure sign shows up in a double rifle the damage is often already done. Over pressure is a ghost in many cases, not showing the classic sign of pressure one finds in bolt rifles.

........................................................................

Understood. At Butch's suggestion I have bumped up my RL15 load to account for the banded bullets. I am headed to the range in the morning to see how the new RL15 rounds shoot. I have put the experimentation with IMR3031 on the shelf for the time being.

Mike,
You were asking for suggestions. Well think how you would answer this if I was posting and you were reading it, just a thought.
Bill

I think I would have answered just as Mac and others did. Regardless of the accuracy if you are having extraction issues, you need to explore other options. Period, end of story. Like I said, my head knew the answer, but it was being led astray by my no good heart. We will see, but I bet boosting the velocity a little with the bumped up RL15 load (~2000-2025 fps versus 1925 fps) will produce groups that are still pretty darn good.

That is an good way to think about it though. What advice would you give someone else that posed the same question . . . it certainly ought to work both ways.

Mike,

In my 577s I have used 119 to 122 grains of RL-15 behind Woodleigh softs and CEB BBW#13s with no problems. If you remember the Woodleigh Hydro in Michael's and my tests showed higher pressures than other bullets with the same powder charges. Also if your gun has 24 inch barrels you probably won't get much over 2000 fps at normal pressures. Most of the older velocities listed were from much longer barrels.

Sam

quote:

Originally posted by srose:
Mike,

In my 577s I have used 119 to 122 grains of RL-15 behind Woodleigh softs and CEB BBW#13s with no problems. If you remember the Woodleigh Hydro in Michael's and my tests showed higher pressures than other bullets with the same powder charges. Also if your gun has 24 inch barrels you probably won't get much over 2000 fps at normal pressures. Most of the older velocities listed were from much longer barrels.

Sam

Hello Sam,

I think Mike told me his Searcy has 26" barrels. But your statement brings up a question.

I'm getting 2115fps with the 750gr CEB #13 bullet ahead of your load of 119grs of RL-15 in my VC 577NE with 24" barrels. I'm not seeing any pressure signs such as stiff opening, however, that load is crossing just a bit in my rifle. I'm thinking it wasn't regulated for that speed so I'm going to back down a couple of grains, trying to get it to 2050fps. But the question I have is about the CEB #13 bullet.

I was getting right at 100fps faster with it in my 500NE as compared to the Barnes Banded Solid with an identical powder charge. It seems I'm getting about 100fps faster with that bullet in the 577 as well compared to your Woodleigh load. Any ideas why?

Todd,

Yes you may be getting more velocity with the CEB with less pressure. This is why we designed the bullet the way it is. We found in most cases the CEBs produced higher velocity with lower pressure. If your gun is crossing it is because most 577 factory loads are in the 1975 fps range in 24 inch barrels. Every barrel is different so there can be some differences from gun to gun.

Sam

Another trip to the range today. Back to RL15 loads. I tried going up to 123 grains, with only a modest boost in velocity. The 120 grain loads are getting around 1950 fps, extraction is easy, accuracy is fine and recoil is manageable. I think I am going to call the process done and load up the ammo for my trip with this load.

No Flies on this load, I think you got a winner here, is it a 50 yard group?

Best regards

Malek
Good shooting/hunting and God's best

quote:

Originally posted by malek:
No Flies on this load, I think you got a winner here, is it a 50 yard group?

I consider the .577 a "close quarters" weapon. I do not think I have ever shot it at more than 25 yards.

Still a very nice group even at 25 yard, them elephants will have no chance.


Best regards

Malek
Good shooting/hunting and God's best