twist rates

[mattmillerrx]

I was reading some of the old post tonight.  Found one on twist rates, it had a nice formula with it but could not use it because can not find published date on the lengths of the bullets.

I have a 1903a3 with a 1:10 twist rate, by my understanding this is ideal for heavier bullets but according to the formula bullet wt has nothing to do with it only velocity, length of bullet and diameter of bullet.  So based on this here is my thinking:  A lighter bullet slowed to the speed of a heavier bullet should perform ok.

My reason for asking is I am gather as much info before I start reloading as possible and am looking for a light load for a 30-06 to shoot bench rest matches at 100yds with open sites.  Was thinking of using h4895 and a 125-130 gr bullet and maybe use the 60% rule I have seen posted on here with that powder.

[LaOtto222]

You are correct a shorter bullet does not have to spin as fast to stabilize as a longer bullet - thus you do not have to push it very fast to stabilize. However I would not drop below reliable published data. Some powders do not react well when the case is not full or nearly full. Pressure spikes can result. Worst case is rifle damage, over pressuring your case and can at the least give you erratic results. Speer reloading manual #14 gives a limited number of reduced loads. I do not have mine handy to give you any data with.

[Catfish]

If your going to shoot competition forget the velocity, what you need is accuracy. I lightest bullet I have ever found that shoot well in an 06 is the 130 gn. Speer HP.

[mattmillerrx]

Accuracy is what I am looking for.  My question, to clarify, was that shooting a lighter bullet slower should be more accurate at that twist rate designed for a heavier bullet than a lighter bullet at a fast speed.  I do not plan to go outside of published data.  I will check out speer's manual dad has one I can look at.  The loads I was looking at Hodgdon is putting out calling them youth deer loads with 125, 130 and 135 gr bullets at velocities between 2500-2650 ft/sec using h4895.  The other load am looking at and reading up on is also from there data that states you can reduce the max load with that powder by 60% and use it for a reduced load.  It states anywhere the powder is listed on there data this can be done.  I could do this with a heavier bullet if necessary but am still reading up on this and that was one of my concerns was the case not being near full.  The 130 speer hp, I will give those a try.  I was going to post a link to the rule mentioned above but there website is having some trouble it appears.  Has anyone heard of doing this or done it.  It is not in my manuals but only on there site.  I first read of it on this forum.

[LaOtto222]

I am not sure if you are talking about Hodgdon web site or not. I would not trust any load data unless it is from a major bullet or powder manufacturer. Speer #14 manual has a reduced load for their 130 grain HP as follows AA 5744 Starting at 25.0 for 1814 fps and going up to 27.0 for 1941 fps. Their starting load for the same bullet and with H4895 is 45.0 for 2624 fps up to 49.0 for 2730 fps. If your target is 2650 fps then I would try 45 grains of H4895 for 2624. This will get you pretty close to what you want. As far as accuracy is concerned, all I can tell you is try it. You may find that the "reduced" loads give your best accuracy, but you may also find that full power or some where in between give you best accuracy. You may find you can not get decent accuracy no matter what you try with that bullet. It depends on your gun. No two are alike, even from the same manufacturer and model. Good Luck and good shooting.

[Grumulkin]

As far as accuracy is concerned, all I can tell you is try it. You may find that the "reduced" loads give your best accuracy, but you may also find that full power or some where in between give you best accuracy. You may find you can not get decent accuracy no matter what you try with that bullet. It depends on your gun.

Actually, I can't remember a single instance where a reduced load gave me optimal accuracy in any of the many cartridges I've loaded for.

For a 30/06, I've gotten my best accuracy with 165 and 168 grain bullets loaded with Varget.  My bullets of choice are Sierra Matchkings, Nosler BTHP match bullets, Barnes TSX bullets and Barnes banded solids.

[Catfish]

   A rifle with a very fast twist is far more forgiving with lite bullet, as far as accuracy goes, than a rifle with a slow twist is with heavy bullets. You`ll never really know untill you try afew things.

[mattmillerrx]

Thanks guys.  I am going to give it a try.  I am hoping to get something that will out shoot factory loads.  I am going to be shooting a military bolt action match with the 03a3 at 100yds with open sites.  I am guessing the best I can do at that range with that set up will be 1 1/2 - 2 inches.  The winning groups have been between 1/2 and 1 inch 10 shot groups then they shoot 40 more and score all 50 shots.  I want the lighter loads because I will shoot better despite what the gun will do.
Should I test these loads at say 50 or 75 yrds to take my poor eye sight out of the picture, I will still test at 100 of course but thought that might give me a better chance of seeing what the loads are really doing.