Author Topic: Powder measuring (Read 879 times)

mrfishnhunt · « **on:** June 12, 2005, 02:41:02 PM »

Ok guy's I'm new at this. I have a Savage 243 that I am handloading for.I started with 2 boxes of Rem 80 gr. Corlokt. I shot these and the groups looked pretty good so I know the rifle will shoot . I found my bullet and powder that I wanted to use and used the once fired cases. I am using Sierra 85 gr. HPBT gameking bullets with H-Varget powder and CCI 200 primers. I talked with Sierra and they told me to use 35-38 gr. of powder, and an OAL of 2.650". I loaded up 10 each of 35, 35.5, 36, 36.5,37,37.5,38gr loads. The tightest group was at 37.5 gr. I figured this is where I want to be. I loaded up 50 rounds with this combo. They did pretty good but not all that consistant in group size. Do you guys weigh each powder charge and trickle to get each one exact or do you trust the powder measure to stay true. I loaded up 10 today and I had to add to all but 3. Could this cause my problems? I didn't have to add much average of about 3 actual pellets of Varget. Any other ideas would help. I am getting aound 1"-1 1/4" groups at 100 yrds. I know this is ok for hunting but I think that the rifle can do better. It only has about 120 rounds through it.

ricciardelli · « **Reply #1 on:** June 12, 2005, 05:10:34 PM »

MY powder measures are set to throw just under my desired weight, then I trickle the rest in.

HOWEVER, I do not do this with any of my straighwalled pistol cases (.30 carbine, 9mm, .38 Super, .38 Special, .357 Magnum, .44 Magnum, .44 Special or .45ACP). I take whatever the powder measure dishes out...after setting it up properly.

Flash · « **Reply #2 on:** June 13, 2005, 12:50:51 AM »

Rob162, in addition to weighing each charge, increase your OAL by .005 in groups of ten rounds. The SAAMI specification for the 243 is 2.71. Also, trim your cases or group them by length if you don't trim yet.

victorcharlie · « **Reply #3 on:** June 13, 2005, 04:35:08 AM »

I've loaded the 85 grain BTHP for years. There are several things you can try. I would think the savage would shoot a little better than that. Make sure the action is all the way back in the stock. Loosen the screws and lightly bounce the butt. The idea is to get the recoil lug to contact the stock squarely. This is where glass bedding the action can help improve accuracy. Also make sure the barrel is free floated and not touching the stock's forearm. A trigger job should help a little. Make sure your shooting off a steady rest.

First, haven't tried H Varget powder, but have had very good results using IMR4831. When you fire a rifle, the barrel vibrates like a tuning fork. The powder type and charge changes the rate the barrel vibrates. The idea is here is to find a powder and charge that make the barrel resonate, or cancels the vibrations.

Second, for a bolt action rifle, after the cases are fire formed, neck sizing instead of full length resizing should help. Cases, when fired, are very close to the true size of the chamber. By neck sizing, the case fits the chamber with the neck more aligned to the bore. When full length resizing, the case lays on the bottom of the chamber with the bullet out of alignment with the bore.

Third, OAL. Neck size a case with no powder or primer, just enough to hold the bullet. Seat the bullet way out. Smoke the bullet with a candle or such and chamber the round. You will see a mark on the bullet where the bullet contacts the lands. This will give the OAL of where the bullet touches the lands of the rife. Write this down and play with the seating depth using this number. While some say this increases pressure, I have found on my rifle, that the best accuracy comes when the bullet is just touching the lands of the rifle. Try adjusting the bullet depth just off the lands first. The idea is if the bullet enters the bore straight, when the seating depth is right, the "jump" before entering the bore won't create a "yaw" on the bullet.

Fourth, try a wilson bullet seating die. This is a hand die, but the bullet is seated with very little run out when using the wilson die. Again, the idea is to the have the case fitting properly in the chamber, the case neck aligned with the bore, and the bullet seated straight in the case with the depth adjusted so that everything is in as close to perfect alignment as possible to the bore.

There are lots of other hand loading technics such as inside neck reaming, outside neck turning, which again, affects the way the case fits in the chamber and the bullet in the case..........case head squaring, primer pocket uniformity etc........For hunting and varmit accuracy, as well as the time involved, the gains by doing these things are relatively small.

My rifle shoot terrible with factory loads........my hand loads makes it a totally different beast!

Questor · « **Reply #4 on:** June 13, 2005, 05:24:26 AM »

Just using the RCBS powder measure to dispense by volume works great for me. I never weigh charges because my groups are always good without it. Maybe there's a problem with the consistency of your measure. Weigh the charges it's dispensing. If they're inconsistent, then it's time for a new measure.

victorcharlie · « **Reply #5 on:** June 13, 2005, 11:05:41 AM »

I don't think I answered your question in my previous post.

Quote

Do you guys weigh each powder charge and trickle to get each one exact or do you trust the powder measure to stay true. I loaded up 10 today and I had to add to all but 3. Could this cause my problems?

Yes, I do weigh each load for rifle cartridges. No, I don't think that using a powder measure is your problem. Measuring out each load is trying to eek out the last little bit of accuracy, via constancy. This alone will probably not improve your accuracy. There has been much debate on the need to weigh each load on large capacity cases where percentage wise, there is little error introduced by using the measure. Example, if you loaded 50 grains of powder, and were off by 1/2 grain, that would only be 1% margin of error. If your nearing max recommended loads, and are seeing signs of pressure, i.e. slightly flattened primers and craters, you may want to weigh each load, not for accuracy, but for safety. Again, the smaller the case, the more the potential for error increases.

If your gun, and your shooting are not the problem, then I think the biggest source of your accuracy problem is first the powder, (try a different one) and then OAL. Just my guess.........that said, your rifle may shoot better with a different bullet. But don't give up on the 85 grain BTHP yet. My .243 Ruger shoots almost the same hole at 100 yards with this bullet, and has killed near 50 deer, vaporizes crows, and turns ground hogs inside out. The bullet is a stellar performer.......

mrfishnhunt · « **Reply #6 on:** June 13, 2005, 12:50:58 PM »

I will loosen the action screws and make sure that the action is seated all the way to the rear of the stock. Next time that I go to the range I will pick up a box of the Winchester Supreme ballistic tips to try out, this should tell me if its the rifle.I have heard that these are very accurate cartridges. If the rifle is good than I know its something that I am doing in my reloads. I will probably try a differant powder next.VictorCharlie what powder did you recommend and whats the starting and max charges with the 85 BTHP? I called Sierra today and they told me to find the maximum OAL of the chamber and back down in .010 steps to see if it will help any. I will go out to the shop shortly and work on this.I would like to get the H-Varget to work so that I don't have to keep several kinds of powder around for the differant catridges that I plan to load for.Thanks for all the help.I will keep you updated.

mrfishnhunt · « **Reply #7 on:** June 13, 2005, 02:30:52 PM »

I think that I found one problem. I did the over all length. I started it at 2.710" (SAMMI Standard), I colored the bullet black with a magic marker.The rifleing made markes on the oglive of the bullet. I kept droping back .010" at a time. I got to 2.650"(my normal length) and still had marks. When I talked to Sierra today Robert told me to drop it back to 2.625" ,well this is .020 from the lands. I loaded up 10 rounds, I will test these on Sat. I think some of my problem was the bullet setting on the lands. I will find out if this is better next time out.Sierra recommends .010" from land, so I can go back out .010" max. This gives me lots of room when the throat erodes out. I can slowly lengthen as this happens.

victorcharlie · « **Reply #8 on:** June 13, 2005, 06:24:26 PM »

My rifle likes IMR4831. Are you full length resizing or neck sizing? Try neck sizing once fired brass.......

mrfishnhunt · « **Reply #9 on:** June 18, 2005, 07:26:05 AM »

Went to the range today with a varierty length of cartridges. I backed down .030" form the throat and went down from 2.630" to 2.610" in .005 increments. With the 2.630" I was able to cover the group with a nickel (except the one flyer).As the length went down the group spead out up to 2.5". Next trip I will increase the length by .005 incr. from 2.630 out to about 2.640" I want to see if I can get a tighter group, I am pleased with my results today. Thanks for the help guys and I will keep you posted on my results.

beemanbeme · « **Reply #10 on:** June 18, 2005, 05:10:40 PM »

Uuuhhhh, I don't want to be a spoil sport but adjusting the "jump" of the bullet is one way to FINE TUNE a load but it has to be a good load to begin with. Adjusting the bullet jump ain't gonna make a good load out of a bad one. A different col certainly isn't gonna pull a 1.5" group down to a one holer. I'd suggest you look for other reasons before you start messing with the col.
Varget should meter quite well. If your metering technique is up to it. That is to say, your metering motions are constant. When I am seeking a accurate load for the first time, I weight all of my charges. Try seating your bullets half way and then rotate the case 180degs and then complete seating the bullet. Are you lightly lubing the inside of the case mouth before you resize? A bedding job should be in order. Also, is the barrel not toughing at any point. Do the dollar bill trick.
Last but not least is bench technique. Are you capable of consistantly shooting a .5 group with good equipment? I don't know you nor do I know your capabilities but many of us lesser mortals can shoot same rifle, same load, same conditions and still have .5 or more variance from day to day. You know, earth tremors, gremlins and such.

Carphunter · « **Reply #11 on:** June 26, 2005, 05:05:06 PM »

You've done one piece of work to find that measurement to where the rifling touches the ogive of your bullet.

If you intend to play a lot with loads and alternate bullet types, do yourself a favor and order yourself a bullet comparator. This will give you the ability to measure your cartridge length to the full caliber diameter of the bullet.

Once you've done that, any time you want to try a new bullet, you don't have to play with your Sharpie...you can just set up the press, and measure away with your comparator until you have the exact measurement you need. (FYI, I use a sinclair comparator...simple as snot to use).

I didn't do this until I had to start loading for my Swiss K31. They have relatively short throats, and OAL measurements don't really mean squat. It's helped me avoid loading up test loads only to find out they're too tight and I'm getting overpressure halfway through a published charge range.