Question on dialling in on a load

[WWGunslinger]

I have a Tikka T3 Lite in .223 which is a really nice accurate rifle. With Hornady vmax 55 gr and Fiocchi Vmax 40 gr at 100 yards I am able to get .5" 3 shot groups with it quite often. Sometimes they open up a bit but I think that is probably me, but pretty much with good ammo it is always within 1" at 100 yards.

I've been messing with reloading for it and with a 55 gr vmax bullet and 24.1 and 25.1 gr of Winchester 748 (of the 3 powders I test, this has been the best) I have been able to get .5" 3 shot groups. In my last outing, I shot two 3 round groups of each. on the 1st 3 shots for each one, it was .5" but the 2nd 3 shot groups opened up to just under an inch. it could be me, could be not letting the rifle cool enough, dirty barrel, etc.

Trying to figure out next steps to get more consistent and accurate loads.

I've tried to measure my OAL by putting a bullet in a prepped case (fire formed to this rifle) and chambering it, then pulling it out and measuring it. I know this isn't the most accurate way to do it but I know it can help get it close. I did this about 15 times, threw out the lowest and highest numbers, and the averaged the rest and came out to .243 OAL. I've set my die to seat at .241 oal. I guess I could play with the OAL a bit.

I clean the primer pockets and I debur and chamfer.

I forget what my case lengths are off hand, but I believe they are within .02 of each other. I could try to separate the cases by length and only use the same lengths or try to trim them more consistently.

When you are adjusting how much powder to use, is there a best method? Like should I change by .1 gr, .2 gr, .5 gr etc?

[DaveM55]

I have a Bravo Company precision AR15 in 223/556 and it has a 1:8 twist. I use 77gr Federal Gold Medal Match and it shoots more accurate than I can.

Depending on your twist rate I would go with heavier bullets.

[BobGun]

Be careful about barrel temp. Winchester powders are VERY temp sensitive. I put together a load for my 22-250 that clocked at bout 3600 FPS during 60 degree temp. I tried to shoot a groundhog at 200 yrds with that load and missed twice. This load was shooting 1/4 inch 5 shot groups at 100 yrds. The temp on that day was around 95 degrees. When I got home I ran the load through my chrono an it clocked at 3900 fps. I was using Win 760, but I have noticed the same thing with Win 748.

[ianb1116]

1) We need to know the twist rate of your barrel. Based on my internet search, it turned up a 1:8? If this is the case 55 grain should be fine. However, I would be using 62-69 grain for that twist rate.

2) Winchester powders are, IMHO, best for plinking. If you're trying to squeeze accuracy out of a gun, go with something time-tested and proven, like Varget or 8208 XBR. Metering is more difficult but it sounds like you've got the patience for it.

3) The Lite profile barrels, are, well...light. "Rapid" fire is no bueno here ESPECIALLY in Win powders. I typically wait between 15-30 seconds between shots on a heavy barrel. Minutes between groups.

4) I always use a powder throw to about 0.5 shy of my goal weight. Then I trickle the last 0.5 grain in. When developing a load, I typically start with 0.3 grain increments and refine from there only after range feedback. My preferred accuracy load is 23.1 grain varget under a 77 grain Sierra HPBT set to magazine length. I've gotten under 0.5" 5 round groups in my AR with this.

5) As for barrel fouling, most subscribe to the belief the gun will shoot, not only more consistently, but more precisely with a fouled barrel. This is not your problem.

The fact that you're achieving about 1/2 MOA with your first group should tell you the load is fine. Unfortunately, as with most situations, the shooter is the problem .



Also, who shoots 3-round groups? Come on, man! Gotta be at least 5 WITH pictures

[frankski]

The Tikka t3 is a nice rifle. My t3 Lite Stainless .223 shoots a number of loads well under 1". Initial guidance came from accurateshooter.com http://www.accurateshooter.com/cartridge-guides/223rem/

Maybe it's just the gun but I find .223 to be less finicky than .308. All my brass is either Lake City (mixed years) or Federal (new and once fired). I do not sort cases by weight. I trim after every firing to 1.750", and size to push back the shoulder about .001" to .002". This works in both my ARs, so I don't have to load specifically for the Tikka.

A variety of powders work well. For consistent metering, it's hard to beat h335 (or w748). Varget is preferred for some heavier bullets. The 60g vmax is amazingly accurate with h4895.

To get to your question, I start with a recommended load (see the table labeled Load Map in the article, or Sierra's recommended loads online), back off a grain or so to start, and increase by .2 to .3 grain intervals. I let the barrel cool between strings. It helps to bring two rifles to the range so you can shoot another rifle while the test rifle cools. Chrony the results.

[SteveWag]

Buy a Chronograph!!! Make a bunch of 5-round loads, about 0.2 gr. apart, maybe 15 say 60 t0 70 rounds total. Target set at 100 yds. shoot 5 rounds at a time. Record Average Velocity, Standard Deviation and Extreme Spread. Load all into a spreadsheet and graph Load vs these three and pick the best. .223/5.56 is very easy to load, much less sensitive than larger calibers, especially 30 cal. Don't worry about trimming cases. Uniform the primer pocket, debur it flash hole (inside) once. Use a good powder, don't forget about IMR (especially 4895!) powders. use Federal match or CCI benchrest primers. Use as heavy a bullet that the twist of the rifle will support. DON'T GO FOR MAXIMUM VELOCITY. Once powder charge is narrowed down, adjust OAL (Seating depth). Very often this might result in a AOL that will not fit into the magazine, resulting in single loading.
Here is a link showing some steps I used for a 6.5 x 55 chambered rifle:

http://www.gswagner.com/6.5matchrifl...tchrifle6.html

Looks like 44 5-round (220 total) just to select the best powder and load.
Steve

[Hawk]

Many powders are temperature sensitive. Varget is a very popular power because it's pretty stable at all temperatures.

[theunrulychef]

I wouldn't use 3 shot groups as a real accuracy test. I've shot too many 1 hole 3 shot groups, only to have 4 & 5 have me in fits of rage back at the shooting bench.

To dial in for reloading, I highly recommend the Optimal Charge Weight method: http://optimalchargeweight.embarqspace.com/

Here's an overview:
You pick a bullet, case, powder & primer that you want to use. Unless you know a particular bullet likes to be close to the lands, I would start with SAAMI COAL. You look up the loading data & find the min / max charges for your powder / bullet combination. You then load up 3-5 shots every .2 or .3 grains (they recommend 2% of the max as an increment). Keep them in order of course. I mark the tips with different color sharpies & have everything labelled really well so that I know what charge is what.

Go to the range. Optional - set up your chronograph. Put out a target for each charge weight. Start at the lowest & shoot one round of each charge at it's corresponding target, then the 2nd round, 3rd etc in a round robin until you have a group for each load. You then triangulate the center of your groups, and compare all the targets to see where the sweet spots / "nodes" are. Groups that are located in the same proximity next to each other indicate a flat node for your barrel & you should focus your attention there. If you've got your chronograph going, you will hopefully be seeing low SD with these loads as well. This should get you in a .5 grain window that you can start really working on.

From there, I load up 5-10 of each load, in .1 increments. Once I find the best grouping / lowest SD, I know my charge. You can fine tune further by testing other primers, seating depth (try jamming .010 in the lands, back off .30 etc until you get to SAAMI COAL - one should jump out as the best depth).

As for sorting your cases by LENGTH, no need. If you want to really dial in your brass, sort them by WEIGHT, not length (people also sort the bullets by weight too sometimes). Find the shortest one in your group & trim them all to the exact same length. Chamfer, deburr, clean primer pockets of course. Deburr your flash holes if you have the tool. If you start to really get crazy, you turn down your necks to a uniform wall thickness, check runout on every round & get into annealing the brass.

Good luck!

[WWGunslinger]

thanks for all the advice.

the barrel is 1 in 8 twist.

i shoot 3 shot groups because of a few reasons:
1) it's how Tikka garrantees their rifles (3 shot groups within an inch)
2) i figure that should be good enough to show accuracy
3) the more shots I fire the more chance there is of ME screwing up

why stop at 5? why not 8, 10, 15 shots? haha

I've been loading up 6 rounds and making 2 3 shot groups.

One thing that I am kind of stumped on is making the OAL the same. Some of you are saying not to measure case length or trim or sort by case length. Heck, even with same case lengths the OAL ends up being different. would that be due to bullet variances? either that or something wrong with my press or seating die. I have to keep adjusting the die to get everything the same OAL.

I did try Varget and H335. Varget with 25.5 grains which I think is the starting load in my manual, basically fills the case. My 2 groups with that were .75" for the 1st and just under 1.5" for 2nd.
The loads with H335 weren't great. Best group was .75" and rest about an inch or more. 3 different loads with h335.

I should say I'm not doing this for anything but myself for groundhog hunting and target shooting. not in any competitions, not trying to brag about my rifle or anything like that. Honestly the 3 shot .5" groups make me happy, but I like to tinker with stuff and it gives me something to do and more excuses to go shooting.

I should also say I don't want to get too complicated/involved in doing all kinds of different things.

[frankski]

Assuming your seating die is capable of repeat consistency, differences in bullet shape may well be the cause of OAL variation.

I've found that inexpensive bulk bullets will vary not only in weight but shape. That makes the seating die contact then at different points, leading to differences in seating depth.

Of course, different bullets need to be seated to specific OAL. You're not seating all types to the same length, are you?