Tuning the load for TRG 42 win 300 HELP!!

[Biomechanic]

Hi,

I have just purchased a SAKO TRG 42 Win 300 26inch stainless barrel. Mark 4 8.5-25 leopold scope. Its very nice but its the first long range rifle I have owned so Im heading into way new territory and would love some advice about reloading.

I have redding comp die, chrono graph, wind meter, horus ballistic software, Leica range finders and in 15mins I can be shooting 1 km, so I have, I think, "all the gear but no idea" so to speak. The more I read the less I find out I don’t know.

This is what I have done so far.

reloading winchester supreme ammo for the cases and resizing them. Running a hornady 208 A max bullet with winchester primers, 209 power. 62 g

first I worked out the the best overall length was 85mm, 90mm) being the max length of the bullet when touching the lands. This length shot about on average ½ inch MOA @100 yards. Once this load shot 3 shots in the same hole @ 200 yards but I havent done that again. They are coming out at 2620 feet sec, varying about 20-40 feet per sec.
I cant believe that the gun likes being off the lands by 5 mm!!!!. All my other guns are 5 to 10 thous of an inch. Anyway….

At 400 yards Im getting 3 inch groups with wind and hitting within a 2 inches of the target, ½ inch dot) This is after putting the all the data into the horus software.

At 600 yards im getting 6 inch groups right on target. This software is fantastic, I just put in the distance after calibrating and I don’t need any test shoots, I can just shoot and pretty well right spot.

At 950 yrds first 3 shots shot, a 15-18 inch group at the right height but 18 inches to the right. Just wind I think as it was hard to judge. I took a while between shots but had a spotter on the wind and he told me when to shoot.

Now im pretty happy with how far I have come but what can I do to improve the grouping as I read that I should keep reloading to get down to 0.25 inch at 100 yards or 1 inch @ 300 yards.

Should I change primers? Fine tune length of bullet, or fine tune power load. Change my neck tension. Try different brass? Im at a real loss!!

Or is that pretty well the potential of this gun. I’m hoping its not as I can become a lot better at shooting as well.

Any help appreciated

 

[tx_shooter]

I'm going to advise running a couple of tests with seating depth at 200 yds. Maybe load up a handful of rounds in 5 mil seating depth increaments and see if it opens up or tightens up with depth. Also - how are you doing your brass prep? Look around and see if there are any other tips/ tricks you can do to add to the quality of your brass.

 

[Biomechanic]

thanks for the reply

Ive tried 200m as 100m the groups were pretty well the same, but at 200m i could tell that 85mm length was the best, 3 shots one hole) but it didnt/ couldnt do that again the next week??

I tried half mm variations before. should I try .2mm variations from the 85mm bench mark?

cases are from the winchester supreme ammo I brought. cases prep Im not sure about. Ive check the runout and they are about 1 thousandth inch runout. I have a trim pro rcbs, which trims etc etc. case thickness I dont know much about.

are their any good links about this on th net?

should I get new cases, Ive heard that the Nosler comp brass is very good?


Thanks again

 

[tx_shooter]

If your looking to go with premium cases, step up to Lapua cases. They take about 99% of the prep work out of new cases. I would still uniform the flash holes and keep an eye on the interior of the neck though. What angle reamer are you using now to clean up the case mouth after trimming? I used a standard reamer for a while - but found better results with a 22* VLD reamer.

 

[tx_shooter]

Bimechanic
I don't think your driving them fast enough.The 300 Win Mag standard load for years was a 190 Sierra between 2930 and 2950 fps.Naturaly with a 26 ionch barrel and 208's you'll get less velocity but 300 fps.
I don't convert metric to well either so I don't know what your seating depth is but if you start fully jammed into the lands and work your way out in 0.005 inch increments you will find a point were it all starts to work very well.
On the powder charge you can go to www.benchrest.com then click on the 1,000 yard forum and look at the post about incremental load development.It ha what your after plus pictures to show.
Lynn

While he might not be pushing them hard enough; the 208gr AMax can do +3000 fps out of a 26" barrel. I've seen enough chronograph reports on other forums at 2900 fps; and still not showing pressure signs. I'm currently having good results loading 75 grains of IMR 7828SSC in Winchester brass, with CCI 250 Magnum primers. I just have to find a friend that has a chronograph now to get my fps.

 

[tsiero]

I am curious with the mixing of meteric and english measurements. Isn't 1 MM = 0.040"? If so you should refine the seating depth changes to .1mm or .004".

 

[Biomechanic]

thanks for the reply,
around where I shoot there are not many shooters that are interested in the accuracy that I would ike to achieve with this gun so its hard to get advice.

is it unusual that this gun shoots best with the bullet 5mm or .2 of an inch off the lands??. this seems way too far, as all my other sakos are about 10 thousanths of an inch.


Im not experience with reloading but if I start again with the bulet 5 thousanths of the lands and work back. do I start with the lowest load of powder??, find the best group then hot them up?

Im very lost to which order to start or change to, especially with regard to seating depth and powder load.

thankyou in advance.

at the moment I can hit a 1 x 1 yard cardboard target at 1000 yards., no sighters ) with about 12 inch group with the winchester brass and with the lapua brass to my surprise they shoot exactly the same at 700 yards but 24 inches lower at 1000 yards.??? , Is this just me and my shooting style???) The group of 3 were amazing, about 4 -6 inches. the was no wind.
im using horus software and lecia binos

 

[Biomechanic]

thanks,

just a clarification,

do I seat the bullet on the lands or .005 off them to start, find the best accuracy, then start moving back off the lands?

If so what kind I accuracy should I be expecting off the trg bipod, ie not true bench rest shooting? .5 inch MOA at 200 yards.?

or it just a process of getting the best possible then backing the bullet off the lands until the groups refine?

 

[alf]

Here's what I'd do.
Use a good solid bench along with a good front rest and rear bag. Use of wind flags are a must also. We're looking for the most accurate load, not testing your abilities, although good bench techniques are a requirement too.
Start with your bullets hard in the lands. I start with a seating depth to give me square marks on the bullet. As Lynn says, there's only one direction to go from there.
I generally will use one grain increments in the bigger cases.
When you find something promising, you can work on either side of that charge. After that you can playing with seating depth.
I'll usually try those in 10 thou increments.
You need to define what accuracy you'd be happy with. Your search for the "holy grail" may just end with a wore out barrel.
An honest 1 moa gun in the hands of a good shooter will kick the snot out of a 1/2 MOA gun in the hands the inexperienced.

AL

 

[Biomechanic]

thank you very much,

all points very much noted.