Load Tuning

[Lou Tenant]

I'm working up a load on a new 22-250 factory rifle. The top pic is 31.7 of Varget , 53 gr Vmax, CCI BR primer in Win brass fully prepped and sorted loaded twenty thousand off of the lands.
The second pic is a 60 gr Vmax with 32gr Varget and a Win primer. They are almost identical. I was told the 53 gr would be a better bullet weight for the caliber so I didn't explore the 60 gr any further.

Should I go .3 gr on each side, adjust seating depth, or...

Any input would be appreciated.

 

[mongo chicago]

You didn't state what yardage you shot at. To me, twenty thousandths is a lot. You are two hundredths off the lands. I'd try for around three thousandths. See how that goes. Just my opinion, I am sure others disagree.

 

[Lou Tenant]

This was shot at 100 yards. I was trying to stay within the mag length , but it's not a deal killer. I guess in hindsight I could have shot it at two hundred. That's the max distance at our range. I did shoot the 60 gr. at 500 on steel and it held under a minute.

Thanks for the reply.

 

[MagnumManiac]

You need to try seating depth, then charge weight, not the other way around.
I load 5 @ .005" intervals and shoot groups. Start at max mag length and work BACKWARDS from there. You should find the sweet spot from .010" away to about .040" away.

.020" off the rifling is not a lot, in fact, my 22-250 likes this length with 50gr BT's.

Cheers.

 

[T-shooter]

You need to try seating depth, then charge weight, not the other way around.
I load 5 @ .005" intervals and shoot groups. Start at max mag length and work BACKWARDS from there. You should find the sweet spot from .010" away to about .040" away.

.020" off the rifling is not a lot, in fact, my 22-250 likes this length with 50gr BT's.

Cheers.

I shot 30 rounds at 6 targets dialing in the jump. My Savage .308 seems to like .025" These are 168 grain Hornady BTHP Match bullets in Lapua brass. These targets were fired with 1 shot each from #1 through #6 in 5 series. I let the barrel cool a little in between shots. This is at 100 yards off a rest. The target dots are .985" diameter. This is just a cheap rifle with a factory barrel.

 

[Richard Coody]

I shot 30 rounds at 6 targets dialing in the jump. My Savage .308 seems to like .025" These are 168 grain Hornady BTHP Match bullets in Lapua brass. These targets were fired with 1 shot each from #1 through #6 in 5 series. I let the barrel cool a little in between shots. This is at 100 yards off a rest. The target dots are .985" diameter. This is just a cheap rifle with a factory barrel.

That explains why you need to do the seating depth test and what you are looking for graphically

Need to run a OCW or better yet a ladder test to find the real best charge weight

After charge weight and seating depth test the you can fine tune both

 

[Lou Tenant]

Since these loads were developed on a latter test which produced the least amount of vertical stringing, I will do a seat test .

Thanks

 

[T-shooter]

Since these loads were developed on a latter test which produced the least amount of vertical stringing, I will do a seat test .

Thanks

Sometimes I've found more vertical stringing with a lighter load and as they got hotter, the stringing closed up sometimes into almost a flat line. Then increasing the load more made them start stringing vertically again. Finding the tightest group is a starting point to fine tune the load, maybe going in .2 grain increments and at least 5 shots each. Then play with the seating depth, maybe in .005" increments. Have some extra ammo ready and if you pull a shot or have a flier, disregard it and take the shot over. Try to keep the barrel temperature constant as possible. I've tried measuring but the easiest way is to let it cool until you can grip the barrel without it burning you.

 

[hogan]

You are dialed-in... Pretty damn good for a "factory rifle". What do you expect?

Want to get tighter groups? Prolly need to tune the rifle, trigger, action screws, free float the barrel, bed the stock...

Want tighter groups? better scope and mount system maybe. have the barrel pulled and set back enough for short oal chamber.
Want tighter groups? get a custom barrel once it dawns on you barrel is likely cheapest element in your rifle equation.

 

[Webster]

I'm working up a load on a new 22-250 factory rifle. The top pic is 31.7 of Varget , 53 gr Vmax, CCI BR primer in Win brass fully prepped and sorted loaded twenty thousand off of the lands.
The second pic is a 60 gr Vmax with 32gr Varget and a Win primer. They are almost identical. I was told the 53 gr would be a better bullet weight for the caliber so I didn't explore the 60 gr any further.

Should I go .3 gr on each side, adjust seating depth, or...

Any input would be appreciated. View attachment 1009837 View attachment 1009838

Top photo. Did you pull the two shots out on the left? Do you use wind flags. Was there a wind change to account for the two shots to the left. I would shoot the top group again. A 10 mph cross wind a 100 yds is about an inch. I can tell if a shot is going to be in the group without looking at the target based on good sight picture when the rifle goes off and smooth trigger pull. It should be a surprise when the rifle goes off. No flinching allowed. I shoot a Rem 700 with a heavy Krieger 6BR barrel for varmints. Any group over .400" is my fault. After 45 years I still don't always have a good trigger pull. I cannot hold the rifle still due to the way I squeeze the bag. The bag and bipod have to be repositioned after every shot which doesn't help. It's a right hand bolt and I shoot it left handed. You have to be fanatic at analyzing your gun handling and wind reading to consistently shoot small groups. Every time I go to the range I shoot a few groups where 3 or 4 go into one hole then I pull a couple out. I know what I am doing wrong but I don't know how to fix it. My bag may not be filled properly.

 

[T-shooter]

Top photo. Did you pull the two shots out on the left? Do you use wind flags. Was there a wind change to account for the two shots to the left. I would shoot the top group again. A 10 mph cross wind a 100 yds is about an inch. I can tell if a shot is going to be in the group without looking at the target based on good sight picture when the rifle goes off and smooth trigger pull. It should be a surprise when the rifle goes off. No flinching allowed. I shoot a Rem 700 with a heavy Krieger 6BR barrel for varmints. Any group over .400" is my fault. After 45 years I still don't always have a good trigger pull. I cannot hold the rifle still due to the way I squeeze the bag. The bag and bipod have to be repositioned after every shot which doesn't help. It's a right hand bolt and I shoot it left handed. You have to be fanatic at analyzing your gun handling and wind reading to consistently shoot small groups. Every time I go to the range I shoot a few groups where 3 or 4 go into one hole then I pull a couple out. I know what I am doing wrong but I don't know how to fix it. My bag may not be filled properly.

I wonder about the same things. I expect that if I do exactly the same things, the results will be the same. It doesn't work out that way. I usually shoot off a bench using a Caudwell front rest and rear bag. The .308 is more stable with a muzzle brake. But I've noticed that if I have a bit of pressure on my cheek, the rifle recoil jumps the muzzle to one side, if I compensate with my trigger hand, it does it the other way, especially when I shoot off a bipod. I've tried holding the stock tight against my shoulder, and also just lightly touching letting it jump back. That seems to work better and keeping my cheek off the stock (maybe lightly touching) and using a very light grip/hold with the trigger hand, plus to put a slight rearward pressure on the trigger guard helps with my other hand's index finger seems to do better not putting any side loading into the rifle. You should be able to let go of it and the point of aim not change. I always use a level and end up wiggling around trying to get everything perfect before firing. I also monitor the barrel temperature. I have a 1-3/4 lb trigger pull. Also I have to be aware of the reticle on the target the instant it fires. Still there is the occasional flier I can't account for.

 

[Webster]

I wonder about the same things. I expect that if I do exactly the same things, the results will be the same. It doesn't work out that way. I usually shoot off a bench using a Caudwell front rest and rear bag. The .308 is more stable with a muzzle brake. But I've noticed that if I have a bit of pressure on my cheek, the rifle recoil jumps the muzzle to one side, if I compensate with my trigger hand, it does it the other way, especially when I shoot off a bipod. I've tried holding the stock tight against my shoulder, and also just lightly touching letting it jump back. That seems to work better and keeping my cheek off the stock (maybe lightly touching) and using a very light grip/hold with the trigger hand, plus to put a slight rearward pressure on the trigger guard helps with my other hand's index finger seems to do better not putting any side loading into the rifle. You should be able to let go of it and the point of aim not change. I always use a level and end up wiggling around trying to get everything perfect before firing. I also monitor the barrel temperature. I have a 1-3/4 lb trigger pull. Also I have to be aware of the reticle on the target the instant it fires. Still there is the occasional flier I can't account for.

For a factory rifle I would say your groups are very respectable. Sounds like we are trying the same variables as far as rifle handling. I always have a little wobble of the cross hairs on the target. I tried to find the major source of wobble (shaking). No hands at all on the gun or bag (no wobble). Trigger hand only various grips, no shoulder or face touch. Hand on sand bag only. Squeezing the sandbag is about the entire problem. Slam the sand bag down on the bench to make sure the bottom is flat. I slide the rifle forward and back a little to see if the cross hair moves vertical up and down, then rotate the bag to get the v groove properly aligned. With no hands on the bag or gun I position the cross hair about 1 inch below the bull. This allows minimum bag sqeezing to get centered on the bull’s eye.

 

[SheepDog]

While there is nothing inherently wrong with working multiple loads having different powders, primers, bullets and seating depths I like to work with a single powder, bullet, primer and the recommended seating depth (when it fits) until I find those loads that group well. The last bit of tuning is done with powder charges just 0.1 grain apart. When I find the most accurate load that shoots the same over a month or two of range sessions I can further dial it in using seating depths. If I want to experiment with a different powder I start over with the new powder. That way I am only dealing with one change at a time and it is easier for me to record the difference a single change makes.
Bear in mind that I am not a long range shooter - just a hunter - so your method may be different.

 

[T-shooter]

While there is nothing inherently wrong with working multiple loads having different powders, primers, bullets and seating depths I like to work with a single powder, bullet, primer and the recommended seating depth (when it fits) until I find those loads that group well. The last bit of tuning is done with powder charges just 0.1 grain apart. When I find the most accurate load that shoots the same over a month or two of range sessions I can further dial it in using seating depths. If I want to experiment with a different powder I start over with the new powder. That way I am only dealing with one change at a time and it is easier for me to record the difference a single change makes.
Bear in mind that I am not a long range shooter - just a hunter - so your method may be different.

Just like tuning a race car. One thing at a time. Change 4-5 and you have no idea which if any worked.

 

[Texas10]

It might be time to invest in a good chronograph if you're serious about load development and shooting small groups. Start your load development by shooting 5 shot groups in varying seating depth over a chronograph and note the correlation between vertical dispersion and SD and ES on your chrono. Find the best seating depth, and then work the charge weight. If you're not getting low ES and SD numbers, change powders or primers and start over.
As others have written, there are a thousand variables that all contribute to shooting accurately and consistently. A Chronograph will allow you to actually measure a few important variables and produce a load that will shoot constantly well in a particular barrel. Once you know you have a load that will shoot well, you have a starting point for further development of your skills and gun components.

Question for you: What rifle are you shooting, and what is the barrel length and twist?

 

[Lou Tenant]

Thanks for all the replies

Texas10,

it's a Savage model 12 fv 26" 1-12

 

[SheepDog]

It is my considered opinion that the chronograph is best left alone until you get good results on the target. You can chase velocity and standard deviation for weeks without getting a accurate load. Once you have an accurate load you can see if you can improve the standard deviation without ruining your accuracy.

 

[alb]

It is my considered opinion that the chronograph is best left alone until you get good results on the target. You can chase velocity and standard deviation for weeks without getting a accurate load. Once you have an accurate load you can see if you can improve the standard deviation without ruining your accuracy.

This. A low SD means....that you have a low SD, really. Bravo in terms of consistency, but it doesn't mean 'accurate', unfortunately.

 

[ranger3]

I. Have a load 36.5 gr. Varget w 52 Speers shoots .5 moa or better in a couple different rifles. These are seated close to the lands. If you're looking for more velocity. You could move up a few grains.

 

[SheepDog]

alb,
I agree. I have had very low SD with wildly inaccurate ammo and accuracy with double digit SD. With some loads you get both where you like to see them but sometimes you get either or.
Once I get an accurate load I pull the chronograph out to find out what the velocity is (for predictive ballistics) and to work on tuning the SD within the limits of accuracy. That is really all a chronograph is good for. It can't measure or even predict pressures and no matter what it says about how consistent your load is it cannot predict accuracy. I would like to get a Labradar for its ease of use and multiple velocity measurements of each shot but it is something I have to budget for. Living on a fixed income sucks.