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Posted: 8/5/2016 10:10:29 AM EDT
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I just started loading 7.62x54R. To make a long story short, I've been using plated bullets with light charges to fire-form the new cases to my chamber then neck-sizing. I've shot a few full power loads with some cheap pulled bullets but for the most part haven't really tried to put together a really good load yet...until yesterday.
A friend called and invited me to his club to do some shooting. I mostly go to one of two farms where I have ranges set up. The 100yrd farm/range has been unusable for the last 2 years due to farm equipment being in the way, the other, I can only get back to 50yrds. So, that's where I've been shooting from. I had just made up a bunch of test rounds and was getting ready to go shoot them @ 50yrds when that call came for a chance to shoot them @ 100yrds. 
The loads I made up were 8 different charges of 2 rounds each in .5gr increments from 39.0gr of H-4895 to 42.5gr. with 150gr bullets. My intention was to do sort of a ladder test since these bullets ain't cheap. Shoot the same target with both rounds of two consecutive charge weights. I set up my video camera to record where each round hit. Anyways, the 1st few charges hit just below the paper and made pretty good groups, they climbed with each higher charge. Then I got this:  " />
I finished the rest of the testing, watched the video and discussed the results with my friend. He didn't know what to do and neither did I. I still don't know where to go with further testing because they both shot so well. 9 & 10 are 41.0gr and 11 & 12 are 41.5gr. They are both nearly identical distances apart at 1/2'' center to center and the whole group is not much bigger. Since these charges are half a grain different I was really surprised to have them hit so close together. The ones before and after were spread out about 1''. Where should I start the next round of charges ? Go up in .2gr increments from low to high or go high to low ? Or just say screw it and make 5 of each, 41.0gr and 41.5 and see if they hold up ? The problem is that I don't know when I'll get another chance to go back there to shoot at 100 yards again. What to do ? |
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I think your increment of powder weight change is too small to tell a difference.
A good load in a good rifle will shoot nearly the same size group +/- 1 full grain in cartridges with 40 or so grain capacity which your 54R obviously is. I usually load in 1 full grain increments for cartridges this size so I can see without a doubt where the accuracy nod is. Then I work to find the middle ground. If a rifle will stay within 75% of its best group going +/- 1 grain you can count on it staying accurate in all normal conditions. BTW: What rifle and optic are you using? Motor |
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Quoted:
shoot more groups of the same charges and see if something changes first. too small of a test with just 4 rounds. It could be you, the wind, not enough fouling in the barrel? I shot 3 foulers first, they were lighter charges and hit the cardboard backing below the paper, dead center windage-wise but low. I knew they would. And I'm shooting these in a Lead Sled Plus so once the riflebutt is wedged in the pocket, rear sight leveled, sights on target, I can stand next to it and pull the trigger, it's not going to move. So, it takes me completely out of the picture except for getting the sights aligned. This rifle is a known fantastic shooter which is why I chose it instead of ''other'' rifles I have in this caliber. It shoots 1'', and less sometimes, groups @ 50yrds with surplus ammo. I agree that 4 shots doesn't tell you much but having those hit so close together when the others were making crap groups has to say something. I think it's saying I found the accuracy node but with which charge ? I know further testing has to be done. |
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Quoted:
I think your increment of powder weight change is too small to tell a difference. A good load in a good rifle will shoot nearly the same size group +/- 1 full grain in cartridges with 40 or so grain capacity which your 54R obviously is. I usually load in 1 full grain increments for cartridges this size so I can see without a doubt where the accuracy nod is. Then I work to find the middle ground. If a rifle will stay within 75% of its best group going +/- 1 grain you can count on it staying accurate in all normal conditions. BTW: What rifle and optic are you using? Motor You're saying you would've expected these to hit close ? A half grain isn't a big enough difference in this size cartridge ? I thought it would have been. I didn't see this developing a load for 30-06 but again, I can only shoot at 50 yards right now. What I did there is get it as good as I could @ 50 then I'll test them again when I can get out to 100 yards. I did the same thing with my AK, which I took along with me on that trip. It shot two 20 round groups, one was 3 1/4'' the other was 3 1/2''. I'm leaving that one alone, that's good enough for an AK. I don't think it could get better. What rifle and optic am I using ? Check back a while where I posted that I was having issues with failure to fires in x54R. It was BLC-2 that I was using to fire-form the cases. Don't laugh, it's a Chinese T-53, no optic just iron sights. It shot real good when I bought it a few years ago but I did a lot of work to get it better. I figured I could do that to this gun and not ruin any collector value because it doesn't have any. LOL The stock is all beat to hell but the metal looks like it's brand new. I bedded the action, got rid of pressure points along the barrel, changed front sight posts with a taller one, polished all the camming surfaces on the bolt and did a nice trigger job. I know, that's a lot of work on a junky rifle but it shoots great, better than any of the 7 or 8 other Mosins I have. Back to the problem...I took a better look at the other targets. I put the second over the third and drew a circle inside the bullet holes onto the third target and the same with the 4th. Here's what those look like:  " />
1 thru 4 didn't even hit paper, neither did 5 & 7. Then vertical stringing with 13 thru 16 but 15 and 16 look good. I just can't help but think 9 thru 12 is where ''it's'' at. Right now I think I have to make more of those 2 loads and bug my friend into going out to his range again or get the farmer to move the equipment that's in my way so I can re-test these. |
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Yes. You need to shoot at a farther distance so the group has a chance to open up to something more readable.
A type 53 with a good barrel (which is kinda rare) is one of the best shooting com block 54R carbines. The Polish made ones are right there with them. Again with good barrels. So you groups really don't surprise me. The fact that you are shooting them with the iron sights does. You must still have very good eye sight. Considering that you are shooting a carbine with iron sights though you had better be an expert shot to tell the difference between 1/2 grain loads. Shooting at 100 yards instead of 50 will help a lot as long as you can maintain a good sight picture. Motor |
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I was expecting a large roar of laughter about my choice of rifle. For some reason every T-53 I've seen has a stock that's beat to hell and people think a rifle like that will shoot as good as it looks. My stock looks like it was dragged over every inch of The Great Wall of China then had a brand new receiver/barrel assembly installed. My brother's is the same way. We bought them at the same time for $150 each. Why are they like that ? I'm serious, I'd really like to know why.
I was 3 months old when Pres. Kennedy was killed. That should tell my age and I'm fortunate not to need glasses yet. Still can see pretty good. Concerning being able to tell the difference between half grain increments...that's what the video camera was for. Later, I watched as each shot hit, that's how I know what did what and where. The target I made has LARGE black lines on it to help me align the sights in the vertical and horizontal planes. Plus, the front sight post is custom made by a machinist friend. It's 2 pieces. The bottom is normal except the post is threaded so a wider, taller post screws down over it. That leaves just a tiny sliver of the target on both sides. It really helps to get the windage aligned that's why that bright purple diamond is taped to the paper. It's easy to see on either side of the post. I usually use orange and they are just 3x3 inch sticky notes. Mosins have a U shaped rear sight notch. I used a small file to square off the bottom corners. That also helps with sight alignment. I've recovered bullets fired from this gun and they have very good, sharp rifling marks on them from the lands and the bore is mirror bright. If it was ever used before I bought it I can't tell. Anyways, what do you make of the other shots on the target ? I think 1 thru 8 suck and the same for 13 thru 16 except those aren't so bad. 9 to 12 is what I think I should re-test. But, in an effort to save bullets how do I go about doing that ? I've never been faced with 2 different loads half a grain apart that shot to the same place. |
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I would go right in the middle of 9-12 and shoot it at longer range.
I've seen what some would call large spreads of powder charges shoot good before. When I shot my 300 short mag for pressure testing I had 5 rounds loaded in one grain increments and the top 3 were only about an inch apart. This of course was just awesome to see because I new right away getting good accuracy was not going to be hard and the load would have a lot a tolerance for different atmospheric and weather conditions. Motor |
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