I am doing some load development for my 375. Working with 250 TTSX's. At 75.5 grains of RL 15, I hit an average of 2887. At 76, about 1 grain below max, velocity averaged 2872. So either I messed something up there with those loads, maybe swapped labels or whatever, or?

The reason why it's important is the 2872 load was the most accurate TTSX load of the day, by a significant margin. It's actually the best group I have shot with this rifle. My goal was actually 2800 fps, but the accuracy there was significantly worse.

So has anyone seen where an additional amount of powder actually lowers velocity? I am thinking maybe I swapped labels or something, so need to load up 75.5's and 76's again, but at the cost of powder and bullets, I'd like to avoid that if possible.

And how would you go about finding the 'sweetest' spot around the load...up and down in 1/10 grain increments?

I can't do much with seating depth due to the limitations of my box...might get a couple hundredths longer, but I doubt it (can go shorter, of course).

Any other suggestions would be helpful, as I am getting a sinking feeling that these loads are just not going to work out. I have tried 260 accubonds as well. Accuracy is so-so, but I did not push them as hard as I could. I just got to my target velocity and then stopped.

The most consistently accurate loads I have tried so far are cheap(er) Fed Powershocks in 300 grain round noses. I have a feeling that maybe my rifle wants heavier bullets, but that's not exactly what I have had planned!

Thanks!

Why not just pick a slightly wider range which includes 75.5 and 76 and maybe another .5 one one side or the other or both. Split that range up by about .1's orso depending on the number you load at a time.

I am about to begin load devolopment on my first rifle and that is my plan. Pick the best string of 3 groups and split them down. The range about your question charges fills the same role.

A thouht occurs, if one end or the other beyond those 2 weights is markedly less accurate than the other end, the better group is probably not the closer of the pair. Just a theory.

15fps is a very small difference i suppose speed increase can be a little irregular even then everything is ok. Try 0.5gr down , 0,5up and 75,5.

For years, I have followed the reloading books' advice about checking for signs of pressure before just jumping in so I load a round from the starting load and move up to the max load in 1 grain increments to check. If the max load doesn't indicate any pressure signs to give me pause, I go back and look for my target velocity and load 10 different loads, 5 groups on both sides of my target velocity and load 5 rounds in .1 gr increments. after shooting all 10 groups, there will usually be anywhere from 2 to as many as 4 that exhibit more accuracy than the rest and then I just choose from there which loads to test for repeatability. Usually, one will prove itself out more than the rest.
That's just the way I do it.

I've found that my 375 likes 300 gr bullets in the 2400 fps range. Regardless of what bullet I load, and the powder used, it seems to like that range. What I've also learned is my barrel seems to be 150-200 fps slower than published book speeds. Fine with me as long as I can count on the bullet to end up where I want it.

Here are a couple of examples with 3 different bullets, but all in the same general speed range.

10 to 20 fps SD with over 75 grs of powder then only a half gr different.

One can get that much SD or more out of many loads with out changing a thing

I seen where one has to add a lot powder then half gr to get a vel change.

All depends on the gun casings ect.

Some guns so changes rather quickly others don't

Pull a bullet weigh the powder and start from there. roger

Bartshce,

Wish I could but I shot them all! Ha!

But seriously, to all, another problem has risen. A friend of mine checked on quickload and it indicates my loads are over max.

Problem is, I got these from talking on the phone with Barnes, and they actually sent me the info from two manuals and gave me instructions on how to proceed. I followed them, and my velocities match what they say I should be getting (I have a little longer barrel and a tiny bit lower velocity, but close enough).

So now I am a bit concerned and not sure how to proceed. Think maybe another call into Barnes is in order...

I'd believe the folks at Barnes. As long as your rifle isn't showing signs for pressure, I wouldn't care what QL says. I have a few loads that are over QL limits, but they work well in my rifles.

Graybird,

I just got off the phone with Barnes again...talked with Ty, who I had worked with in the past. He tells me that unless my gun is showing pressure signs, this is a safe load that they have actually tested. He said he gets calls like this about QL fairly often. He says its a good place to start, but from there, stick to their data and your gun signs.

So we went through checking for the signs...ejector marks, flattened primers, bolt throw stiffening...none were present. He told me that they find accuracy with this bullet often right around max load. That's not really what I had in mind, was really looking for something a little milder, but I think it's worth pursuing anyway.

So my plan is to load up a bunch at the velocity I wanted (74 grains), and then also some at the one that showed the best promise so far (76 grains), and give it a try again.

Thanks for all the help from everyone btw!

Chad

On my reload notes (Excel spreadsheet), I like to plot (graph) velocity increase per grain of powder. I have found, with few exceptions, that at some point, my graph shows a 'plateau' before rising steeply again. In some cases, this plateau is so marked as to give lower velocities at higher charges. Interesting that I generally get my smallest extreme spreads and best accuracy right on this plateau.

So, in my experience, I'd guess you're right around a load that your rifle likes. That would mean more to me than a couple of feet per second velocity.

We do well to remember that five shots over a chronograph produce results that are rarely if ever reliable. You need a larger sample size and the larger the SD the larger sample size you need. 20 shots would would produce a more useful average velocity number.

quote:

Originally posted by Rikkie:
Chad

On my reload notes (Excel spreadsheet), I like to plot (graph) velocity increase per grain of powder. I have found, with few exceptions, that at some point, my graph shows a 'plateau' before rising steeply again. In some cases, this plateau is so marked as to give lower velocities at higher charges. Interesting that I generally get my smallest extreme spreads and best accuracy right on this plateau.

So, in my experience, I'd guess you're right around a load that your rifle likes. That would mean more to me than a couple of feet per second velocity.

This is kinda funny in that it is exactly right on with what I saw.

The 75.5 load was 2887, the 76 load was 2872, the 76.5 load was 2901. The SD and ES on the middle load was the best of all the loads I tested that day. The 2901 load was by far the worst.

So yeah, I have the exact trend you see, and have had this actually happen on some other loads I worked up for other bullets etc...just did not understand why.

Tim,

with you on the need for a much larger sample to tell, but I was just starting development to see what was safe and get basic groups.

I plan on further testing two loads that look promising in one way or another.

My problem is, accuracy wise, I am not up to the task with this rifle. So I am looking into getting a lead sled to take as many of my errors out of the equation as possible until I can determine a baseline for the load and rifle. Any of you guys use this method, and if you do, would you use the LS plus, or the solo? The solo seems cool in that it allows the rifle to recoil upwards so not so much pressure is sent to the wrist of the (wood) stock. But I don't know....thoughts?

There's no magic to a lead sled. Nor any other device if the person using them doesn't know how to shoot to begin with. I have a firm belief in dry firing as a means to improve your shooting. You can practice on the kitchen table or on a bench in the basement. You don't have to make a special trip to the range; you don't have to contend with the recoil. And you can see exactly what happens to the cross hairs when you pull the trigger.

Definitely need to work on the technique with dry firing. I was just talking to an Army Sniper trainer about that the other day, but I have an additional problem, and it's due to the level of recoil and keeping consistency under those conditions. He and I were talking about that too, he mentioned that to test groups, consistency is key and I need to make sure the components of hold, recoil movement, head position etc. are all exactly the same shot to shot.

I can shoot pretty accurately with my .22 out to 100 yards, I also practice at home with my Beeman R7, and am able to hit my own pellet holes. Do pretty well with the 270 as well.

But with the 375, everything goes flying when I shoot. The gun rarely comes straight back. I noticed it will sometimes slide off my shoulder when on the bench, so I think during the recoil impulse, it's very inconsistent. A big part of that is me, I am not a benchrest shooter, so my form is not so good. Add to that the high level of recoil, and consistency is out the window.

So most shots its resetting the gun, resetting the bags, realigning the front etc. I try to get everything back the exact same way, but I can feel the difference in how I am effected by the recoil as well, which means I am inconsistent in my hold. This does not seem to effect me as much with the lower recoil cartidges, but that level of recoil uncovers all my mistakes.

It does not help that the benches at my range don't fit me well and are not adjustable. That and I am trying to get the rifle up as high as I can so I can sit up straighter and not get pounded as much.

Hence my consideration of a lead sled. I know it's not going to help me be a better shooter. I feel that way, to a degree, about shooting off the bench in general as well. But for load testing, I need it just to get some consistency into the equation only for load development, but some have told me they are no good for precision, but have not told me why that would be.

I have to think it will be more consistent than I am able to be shooting off the bench right now. Funny thing is, they were on sale at Cabelas for like 80 bucks after Christmas, but I refused to buy one because I don't like shooting off the bench, I do it as a necessary evil, and this seemed even more useless to me. So I did not want to waste the money. But I probably have wasted the cost of the sled in components at this point! Ah well, live and learn!

Anyway, I think this has probably strayed from the original question I posed. That one appears solved, thanks for everyone's input!

I should probably start a new thread re the lead sled. Think I'll do that as I am curious about people's experience and solutions in this area.

Chad, I read with interest your posts and experience with your 375. I shoot a lot of 375 and 416 both off the bench so I understand your recoil issues. I suspect you will as I have develop a tolerance for it to the point where it bothers you little.

One comment on the benches at your range not fitting you well. Most of the time this is a height issue. I use a portable bench all the time on my range, but for a seat I use an adjustable drummers seat. It has worked wonders for my positioning because I can raise and lower it to get exactly the position that I want for the best shooting comfort. I bought a good one so it's really solid.

Re: your velocity question. Barrel harmonics play a huge part in your precision equation. As you work up a load you will go through various nodes where the rifle and the various combinations will shoot well often times you can't get to that next node safely so you have to back down. Velocity isn't the endgame. Safety is! Also, when you get towards max load, adding more powder will not increase your velocity, it just plateaus. This is when it's time to stop.

There is so much in the loading equation that there is no simple answer. In order for recoil to be comfortable, if that's the right answer, you have to have a comfortable shooting mass, i.e., rifle set up weight and it has to fit you well. You did not mention what you're shooting.

I'm not a Barnes fan but that's just my personal preference, I also don't use or like Led Sleds, but again that's personal and if it helps you develop loads better then go for it.

Let me know if I can help...Eric

Kambaku,

Thanks for your response!

I am shooting a Win Alaskan. It weighs 9lbs with scope. As for bullets, I started with 260 Accubonds, but ran out and could not find more, so I have switched to TTSX's as they are available. Ultimately, I guess I'll have two loads that will work, giving me flexibility in these component uncertain times.

As to lead sleds, yeah, I don't care for the idea generally. This rig if for hunting, and I believe in training like you will play. I actually bought a rock combo instead in January. I thought I would be able to let my boys use it as a front rest as they start to learn to shoot, when I was done with load dev and get onto field positions, which is how I do all my shooting. I am looking for real world use. But turns out, a sled probably would have been a better choice for my situation. Yeah, it would eventually gather dust, but I have probably wasted the price in components due to my inability to shoot the gun well off the bench. Coulda saved time and probably money at this point, but I was a little too cavalier in my assessment of how I would do off the bench at this point.

I usto shoot lots of 375 and 458 from the bench many years ago, and I thought nothing of the recoil. But I stopped shooting for something like 11 years (busy with my son). Just got back started again, and yeah...my feeling about the recoil is definitely different! Losing 60 lbs probably does not help there either, but I read on one post, the guy said it took him something like 300 rounds to get back into the recoil groove, so I hope it grows on me. The recoil already does not bother me when standing up, so I think I'll get there.

Your idea on the bench seat is spot on, something I have considered as well...that is getting an adjustable height stool as the benches are too low for me. I'm going to look around and see what I can find, but that would probably help immensely!

On the load, it sounds like I might have some headroom to keep going up in velocity, but I don't want that. My goal was 100fps lower than my max load already. I don't see the need for more than 2800 with a 250, or 2750 with a 260. Those numbers will fill my needs as far as the turret I have and expansion capability at the ranges I will eventually hope to be proficient at. Though I may need to switch to 300's, which would change everything. I don't need that weight, but it appears, from the little shooting I have done so far, that my gun seems to like the heavier bullets.

Anyway, thanks for the advice, gonna see if I can find myself a portable adjustable seat that's not too expensive.

Chad, see my PM.

Chad's remarks about the rifle flying through the air when shot off a bench and not flying the same way twice mirror my concerns and questions when shooting big rifles off the bench. One thing to think about, conservation of momentum requires MV forward = MV rearwards. Integrating both sides, MS forward = MS rearwards where S = displacement. A quick calculation shows a 260 grain bullet moving forward to the muzzle by 24 inches requires the 8 pound rifle to move rearwards about 1/10 inch. For this example I am neglecting the powder gasses which should be considered. My point is after the first 1/10 inch of movement of the rifle it does not matter how the rifle flies through the air because the bullet is gone. But it does seem to matter in practice. This is in my mind the $64 question, how do you shoot a big bore rifle off the bench without being beat up and achieving consistent results. I personally do not know but I would like to.

Tim, your question is an excellent one and one that I've pondered and experimented with a lot of times.

I'm not particularly bothered by recoil and have my Jewel triggers on my 375 and 416 set at about 3.5 pounds.

When developing loads I shoot these off the bench w/o any problems. Most of the time I simply let the rifle stock sit on my front rest with the rear of the stock sitting in a bunny bag of sorts. Shooting right handed, I simply do whats required to fire the rifle with a light trigger squeeze and use my left arm tucked in under the aft end of the stock to adjust elevation if necessary and send it. In this manner, the forearm of the stock jumps around after firing, but I seem to get a decent shot group, i.e., most of the time if I'm doing my part with trigger control and follow though. At other times I use my left hand to hold down the forearm of the stock pulling it down and back into the front rest and shoulder. To be honest, I don't see much difference between the two techniques. The latter may be a bit more comfortable, however, having said that, without a hand on the forearm, there's a lot of muzzle jump and things go flying a bit, but what I'm after, i.e., doing load development is precision. I simply do not know which way is better or correct and I too would like to learn more about this. It's never an issue on my smaller bores, I'm just talking about the big stuff.

Tim,

I was reading an article somewhere the other night about this. It was probably on a long range or precision rifle forum. It was not specifically about big recoil cartridges, but the importance of that movement right after the trigger is pulled, including what your hand does etc. And how all of that makes a difference because just fractions of an inch make a huge difference at 300 yards or whatever.

Long and short, and what the army sniper told me, consistency is key so that the gun is moving in the same way, the same direction, same speed etc. every time.

Now, how you achieve that is a totally different conversation, and an answer I don't have yet. But people do it, so it's just a matter of getting some help. I'm going to get some training, personally. Just need to find the right guys and verify they know what they are talking about. I have a few I am looking into locally here, once I have it all worked out, well, hopefully they will work me out!

Chad, you hit the nail on the head, "consistency". There may or may not be a "right way".

I've been through a number of long range shooting schools and with my personal experience not a whole lot matters out to 300 yards. Don't take this to mean you can be sloppy, however, beyond that everything matters.

You also can't diagnose a problem if you're changing a whole bunch of variables at one time. Stick to one at a time, do that consistently and you may have a clue.

I am a lead sled fan, plain and simple. I don't use it with a double, but for big bore load development, it's the bomb.
There is no way I am going to shoot several dozen 416 Rigby loads off the bench consistently enough to evaluate loads without it. It takes me out of the equation, and I suspect that I would be a bigger and bigger variable toward the end of a session without it.
Shooting with a lead sled is almost clinical.

Load evaluation is not practice. Get over it.

quote:

Originally posted by Marty:

There is no way I am going to shoot several dozen 416 Rigby loads off the bench consistently enough to evaluate loads without it.

Several dozen ... In one range session, really?

With a lead sled, yes. Let's say I have a half dozen each of five or six potential loads to fire. It adds up, and I can do it in a session. Practice from field positions? Six to 10 full tilt loads is all I will shoot in a session. Unless I am practicing with reduced velocity practice loads, which I also do.

Use the accurate load you have, its mild and you are getting excellent velocity. If you chronograph 10 rounds of any load you will have from 10 to 50 FPS difference with the same identical load, Your problem is only imagined and without substance. I will shoot 10 rounds of a specific load thru my chronograph, take out the high and the low reading and average the rest..

Velocity between two barrels can differ as much as 125 FPS..

When working up a load, don't sweat the small stuff, just be carefull with max pressures and deal with whats accurate. 100 FPS means little in the field.

For Dangerous game such as buffalo a 375 with 300 gr. bullets at 2400 to 2500 FPS is a better killer than the same bullet at the 375s max velocity of 2650 FPS.

The lead sled has broken more stocks than any bench rest in history, that's a fact. I have seen the results of lead sleds over the last few years on repaired more than a few riflestocks

I strongly recommend the Evo Shield shooting shirt. Google it. I do a lot of load development for larger stuff. The secret is a pad that hardens to fit your body. It spreads the recoil force over a wide area.

I would not worry about the last 100 fps in such a caliber.

Do you plan to hunt with the rifle? Where?

If you are planning on Africa, just learn to shoot off sticks out to say 250 meters. Also do off hand practice at 50 meters.

I got my 416 Rigby rifle about 14 months ago & I did my very first bench session on Saturday! I have sot almost 300 rounds off sticks or off hand. I found the faster loads were strong on recoil & I dropped the loads to more traditional 416 Rigby levels. My accuracy improved significantly and I stopped pulling shots.

The Lead Sled is not the best of designs, but if used correctly it would be a huge help in developing loads for a .375. But first, don't overload the Lead Sled. A few sandbags tossed onto the frame is fine, but DON'T use any 25-lb bags of lead shot. I won't go into all of the deficiencies in the Lead Sled design, the biggest of which is that it is not a sled at all, but rather has rubber feet which "dig in" to the bench surface and prevent the frame from recoiling freely, however, reducing the recoil of a big boomer when fired from the bench is critical to proper load development.

And in case you're wondering, no, the point of impact and grouping when using a recoil-absorbing bench device are no different than when the same rifle is fired offhand or from a non-recoil absorbing rest (loose sandbags). Despite my own doubts, I've been able to demonstrate this in numerous instances.

So go buy a friggin' Lead Sled (I'd recommend something else if there were a viable competitor on the market.) Put a few sandbags on it, and you'll effectively be shooting a 25-pound rifle instead of a 10-pounder. It will make a world of difference in your shooting.

Another piece of advice if you want your rifle to shoot where you point it and make a bigger hole in the animal than just the diameter of the bullet: Get the lead out of the Sled and put it in your bullets where it belongs. You can take the left over copper bullets and use them to weight down your sled if you want. They won't be heavy enough to damage the stock.

Guys, thanks for all the advice posted. After doing some more work, and getting a better shooter behind it, it appears that I have a bedding problem with my rifle. It's supposed to have been floated from the factory, but there is a high spot part way down the forearm, not a pressure point, but intermittently floated...you can cause contact with one finger and your thumb. When the rifle heats up, or if you set the bags a little forward, accuracy goes out the window. After talking with Barsness via 24 hour, and then finding a good smith, it's determined this must be sorted first, then back to it.

So kinda back to square one. First move get that fixed...next back to load dev...maybe with a sled.

quote:

Originally posted by Nakihunter:
I would not worry about the last 100 fps in such a caliber.

Do you plan to hunt with the rifle? Where?

Naki,

This particular 375 is being setup as a 'do everything everywhere' rifle. So shots from point blank to 500 yards....1k on steel. It's a little different than most 375's are used for I guess, but I am still not needing top velocities. In fact, the problem appeared to be that the accuracy was found at a higher velocity than I really want to run with. Now that I have figured out there is a bedding issue, however, I am back to the start.

So I guess we'll find out in a month or so what we have. It likes to put 2 accubonds into one hole, but it also likes to throw the third one well off. So I am hoping after the bedding work, that improves and gets me the accuracy I am needing.