SmallCaliberCentral

I own a Savage 12FVC with a 26” barrel (1:12 twist). I have been working on fine tuning a load with the same bullet and powder and adjusting the amount of free bore (length to the lands from the ogive). As you will see from the chart, I have been able to get group sizes at just below 0.40” (0.38”) with a free bore of 0.090”. See graph at http://s1109.photobucket.com/albums/h43 ... eebore.jpg

My objective to all this testing is to I find the sweet spot (optimum distance to the lands) for this rifle and then I can start working up different combinations of powders, bullets and primers for this rifle.

My question to this group is; What is the best accuracy that I should expect to get from this rifle? Am I already there?

I look forward to hearing from you.

Bill

Bill: You're going about this in a different fashion than the rest of us. Optimum seating distance from the lands can and will vary with every different load in a particular rifle.

First, find THE load the rifle likes, THEN start dinking about with seating depth. Just because one load shoots well with say a jump to the lands of .080", another different powder/bullet combo may like more or less jump in the same rifle. You'll never know until you find the "right" load, then tweak the seating depth for that particular load to see results at the target.

I have four 204's and a 20 Vartarg. Every one of those .20 cal rifles likes a different seating depth with their respective Pet Load. Doing it the way you're doing it now will result in the powder and bullet manufacturers really taking a shine to you.

Just a thought......

By the way, "freebore" referrs to the amount of non-rifled portion of the chamber ahdead of the neck, and has nothing to do with seating depth. What you're referring to is "bullet jump", or ojive distance from the lands.

Good luck....I'd say you're not there yet, but when you are, you're going to be a very happy guy. Many Savage owners here have gotten screamer groups from their rifles (as in the "ones"). Your groups now are very decent, but will more than likely get better with load tweaking as mentioned above.

Thanks Rick:

I appreciate your advice.

Bill

Rick:

I thought about what you said about "First, fine The load the rifle likes, Then start dinking about with the seating depth".

So, where do I start with the seating depth? I was always under the impression that you should start seating the bullet about 0.010" off the rifling. The problem I have here is that this rifle has a ogive of 2.068" for the Sierra 32 and 39 grain bullets. Seating the bullet so that it is 0.010" off the lands give you only about 0.098" of grip on the bullet (inside the case) for the Sierra 32 grain bullet and 0.114" for for the 39 grain bullet, which is not much. I was also taught that you should have about the same amount of grip on the bullet as it diam. or 0.20" in this case.

Of course I could seat the bullet at what the manual states which is OAL of 2.260".

Any help will be appreciated.

Bill

Bill: In the 204R, it's seldom possible to get close to the lands (.010") as you mention, because of the factory chamber design with the long freebore. As such, most 204R handloaders start off with the factory suggested (SAAMI spec) seating depth, then work from there, almost always seating out longer.

The old handloading rule of having one bullet diameter in the case also comes into play here, as when you start seating the bullet out as is necessary in the 204R, that rule flies out the window. My Sako 204R shoots the 39SBK in the "twos" with a bullet jump of .080", but only about .100" of bullet gripped by the case mouth. I use bushing dies, so my neck tension must be spot-on loading like this, but that's one of the caveats of loading longer. You also cannot just throw rounds in your pack or pocket when loaded like this, as then bullet runout could be affected by minor bumping. It's out of the box, into the rifle, shoot, back in the box.....all single shot of course, as when loaded longer, the rounds seldom fit the magazine...no big deal for us, as we use our 204's for bench shooting colony rodents. My Kimber 204R is used as a repeater, and for that rifle I just load to SAAMI spec to keep things simple and use the magazine. It shoots in the .3's loaded that way.

Anyway, I'd start with the factory OAL, then work from there. The determining factor will be if you want to use your rifle as a repeater or not. Good luck, sounds like you're not far from some screamer groups.

Rick:

I took your advise and reloaded a series of new loads using multiple increments of powder. See the following image of the 8 targets and their results. I do hope you can see the text below each target which give the data for each group.

Can you give me your assessment of these loads and where you would go from here?

Thanks,

Bill

If you have access to a chronograph, I'd suggest you get it set up and start shooting your test loads over it and recording your velocities. Set the chronograph so the first screen is a minimum of 10 feet from the muzzle of your rifle and 12 feet away would be even better. Your loads are pretty tame compared to the maximum load listed by Hodgdon, but the 26.4 gr. load is pretty close to Sierra's max load of 26.5 gr. of H4895. Hodgdon list 27.8 gr. as the max load for the 40 gr. V-Max. A few of my hunting buddies use 28.0 gr. of H4895 with the 39 gr. Sierra and get excellent accuracy and pretty decent velocity. The 28.0 gr. load of H4895 is what I'm using for the 39 gr. Sierra in my old Savage 12VLP in .204 Ruger. Muzzle velocity with this load out of my rifle has varied between 3,860 and 3,890 fps. Here's a target with a better than average size group. I can't do this all day long, but once in awhile I get a hummer group on paper.



If you feel safe in doing so, I would suggest increasing your powder charge about .2 of a grain at a time from the 26.4 gr. load and work up to 27.8 or 28.0 gr. Remember: The loads I am suggesting worked flawlessly and safely in my rifles, but your mileage may vary. Stay safe.

25.6-26grs is a good placce to go .1gr like Silverfox mentioned. Now it's time to go to 5 shot groups as well.

+ One - Re: SF and Glen.

Not BR accuracy by any means, but here's a ten shot group from my Cooper M21 MTV in 204 using only 27.0grs of H4895 and the 39gr SBK for 3,780 fps. This load is under max, and kills dogs or squirrels way out there all day without overworking the brass, rifle, or me.



This particular rifle will do this all day (actually better)....your groups shown above are not far from this, in fact you may already "be there" so to speak. Take your best load and work both ways (+/-) in .1gr increments as mentioned. Once you see things tightening up, stop there and start tweaking your seating depth making the same observations.

And as mentioned, now it's time for five shot groups. When you think you have it all together, see what ten shots looks like under field conditons....that will tell the real story.

Rick, Glen and Silverfox:

Thanks for all your help. I have some new loads made up and will head for the range in the morning.

Thanks again!

Bill

Just remember, alot of accuracy issues depends on the indian - not the arrow.

Hi Guys:

Well I got to the range and shoot some targets, then put all the data into my computer and came up with the following charts. I look to you guys as mentors or coaches, so any advice or comments you can give me is appreciated. The next time I get to the range I think I would would like to work on the area between 27.5 to 28.0 grains of H4895.

Bill

It appears to me that 25.7 grains is the best group in that bunch. I'd retest it again and shoot FIVE shot groups to see if it's a fluke. If you had a chronograph, looking at the Standard Deviation and Extreme Spread would give you an indication of the loads potential at long range.

Tom

After reviewing the responses to my question, I did an extensive set of tests and the following gave me an accuracy of 0.020" center to center. (See the chart below)
I started this set of test with the factory recommended bullet seating of C.O.L. = 2.260" which worked out to be a 0.165" jump to the lands. From there, I adjusted the bullet depth until the "Average to Center" started to increase.

Thanks to everyone who posted suggestions and I hope this bit of information might help others.

Bill