This week end the weather cleared enough to test out some loads I had for my 1885 Browning in 30-30. I loaded up 10 each of the following using True Shot 170gr. RNFP .309 bullets without gas checks:

10-22.5 grains 3031 for 1599fps & 18,300cup

10-19 grains RL7 for 1635fps & 20,200cup

10-25 grains 748 for 1613fps & 22,500cup

10-18 grains H4198 for 1606fps & 25,200cup

10-16.5 grains IMR4227 for 1575fps & 26,500cup

These loads were taken from the Lyman 48th Edition Loading Manual. All 10 shots were fired from the bench at 50 yards on different targets. I will list these from worst to best. The worst group was using the 3031 which was a 17"
group. Next was the RL7 for a 13" group. Next was the 748 for a 9" group. Next was the H4198 for a 4" group. And finally the 4227 for a 2" group. I also need to add that each of these 10 shots groups, for some reason, had 1 flyer which was almost off the target. My question is - since these are almost all the same velocity, same bullet, same primer & same case why did the 4227, which offered only more cup, tighten my groups so much? Was the extra pressure what I needed. It seems to me IMR 4227 will be the ticket if I just play with it a little more. Any suggestions appreciated. Thanks-



Jim

Just a guess, but maybe the extra pressure helped the CB "slug up" to ~.310" If you slug your bore, you may find that it needs a .310" or even .311" CB for optimum accuracy. ...Maven

1. There's almost always one bullet out of the group.
2. Some powders work better than others, even at the same velocity.
3. Try 14.5 IMR4227, this is a tried and proven load.
4. 12-12.5 AA#9 generally works better than the IMR4227 load.(See 2 above)
5. Large pistol primers frequently improve accuracy.
6. Bullets measuring .311 or .312 frequently improve accuracy.
joe b.

In general, it's how you make the velocity rather than the explicit velocity made. Your typical measuring devices cannot show the mechanical transients which determine the final happenings. So, given a specific system, man with gun, we must experiment boolits, powders and primers. A good rule to remember is that lower pressure loads use faster burning powders to make for a smoother characteristic pressure curve, and higher pressure loads use slower burning powders for the same. Primer choice is used for fine tuning a good load once found. These statements are in support of what Maven and Joe said. ... felix

One more thing, try to up the velocity to circa 1800, or lower it to circa 1500. I have observed an accuracy improvement when the average velocity for most expansion ratios is mostly divisible by 3 evenly. This is not a hard fact, but a super cool observation only. ... felix

Felix-

That is a very interesting comment you made re: velocity relationship for most expansion ratios. (i.e. Traditional cartridges that aren't significantly overbore?)

*IF* I'm understanding correctly - that would mean sweet spots at 900, 1200, 1500, 1800, 2100, 2400 the 1200-1800 being most useful for CB's.

Am I following your comment correctly? Anything you could add to this to explain why that might be true would be interesting.

Thanks-

Sky C.

Yeah, SkyC, you got it right. When a 1500 fps load does not shoot, like over four inch groups, etc., then don't didly, dadly around with 1/2 grain increments. Jump way up or drop way down to the next incremental segment, i.e., 1800 or 1200. Be careful, though, of keeping the boolit above or below the sound barrier all the way to the target. The short and fat boolits don't get bothered as much when going through the barrier, it seems, but this is a lie in itself. We just don't see it as much because these are typically plinking loads anyway. ... felix

SkyC, I can attempt to explain it via intuition only. It's like tuning HI-FI systems to sound right. You go to a bar and you hear a live band with the same instruments they have on a record you have at home. In other words, the exact same group of musicians. You get excited with the sound and you go home and adjust the fully equalized system at home to match the sound. Now you call in the sound engineer to scope the system with his white and pink noise apperatus. He tells you that the system at home now has over 20 percent distortion at the equalization point. He set it up with no more than 1 percent. But you ask him why it sounds better with all that distortion. He will tell you that the distortion delivered is mostly even harmonic. Now, you tell him to re-adjust the system to provide the same total frequency spectrum (approximate) for delivering odd harmonics. Guess what. After about 3 percent of that racket, you'd put on your shootin' ears. Rough as a cob, and bending over if I might add. So, to sum up this little antidote, the even harmonics are not necessairly destructive to accuracy, but beware of any odd harmonic distortion. We just can't allow the gun system (gun plus shooter with rest, shoulder or not) to realize odd harmonics. Quite simply, they are too wild to tame. It appears by observation the 300 fps intervals produce mostly even harmonics. If the metal compositions, chemical compositions change significantly in the next 20 years or so, then the increment would obviously change somewhat. Gun metals, including cases, just haven't changed that much over the last 30-50 years. Bring in plastics, and then expect a completely different system response. ... felix

JRM....The nexus of your problem is you are shooting your bullets without gas checks. Gas check those bullets, size them .309 or .310 and watch those goups shrink. I won't take the time, telling you why, just do it and you will be pleased.

I have one of these Browning Traditional Hunter's SS rifles in 30-30 and at 50 yards it will put five rounds in 1/2 with a charge of 16/4795/ plus 1 cc of PSB/Remington 9.5 primer. Any good bullet that fits the barrel in the 150-190 grain range will shoot under 1", I get my best groups with Lyman 411467 and RCBS 165 SIL.

Make certain your barrel is free from lead and metal fouling.

felix,
Wonderfull stuff!
Many thanks for sharing intuition; harmonics and ratios are I believe at the core of 'sweet spot' loads. Difficult to prove perhaps, but there is so much of the operator in that experiment every time I pull the trigger. As my understanding and manipulation of the mechanics of reloading, casting, and firearm get better, you are a guide to the next level.
Thank you for the education,
Richard

felix,
Your music analogy got me thinking. A good friend is 'front of house' for one of the big sound reinforcement companies, currently workin' with Cher. It's definitely an art form juggling a huge range of variables that are constantly changing from venue to venue, and number to number. Watching him work from behind the desk is really something.
As in piano, or much simpler, guitar tuning; if you do it 'by the numbers', you can't get a full dynamic range that balances. You need to 'compromise' the harmonics of each string to blend into a whole that sounds good.
The music of the spheres applies IMHO to the energy and vibrations created by same as that trigger is squeezed. The nodes are guides, yet Your Mileage Will Vary as to precisely where the individual on the day, with the load, the rifle and the boolit all mesh. Fine tuning indeed.
/{), a tip of the hat sir.
R*2