New load development on .223

[Blacknsilver]

I may go back to the drawing board. All are 5 shot groups. I thought I would start off as close to the lands with the development. First mistake possibility. Second maybe to have jumped up in .5 where .2 would have been the way to go.

I shot the 5 and let the barrel cool etc..

the 24gr was a non starter as I had put new scope mounts on so needed to sight in. So the 24.5gr was the start of it.

I plan on working around the 24.5gr to 25.5gr in .2gr increments.

The powder is H4895 and bullet is 69gr TMK

Any thoughts?

[JSC]

What rifle/chamber/barrel is this?

 

Do you have a chrono or can you borrow one?

 

In any case, what's wrong with that 25gn group? Elevation looks pretty good to me.

[Blacknsilver]

Remington 700 1-8 twist. 26in barrel .223

Looking to buy a chrono.

[Andrew]

Most of your dispersion is horizontal which usually spells bedding or operator's 'minute of wiggle'. What size optic for those tiny dots you were shooting at??~Andrew

[Blacknsilver]

I have a 12-42-56 optic. I will load a few loads tonight and try again on Thursday night all being well.

[chaz]

I start with 10 thou off the lands and shoot groups of 4, going up mainly in .2 increments.

Usually I work up 4 or 5 different loads.

No idea if this is the correct way, but rather than shooting a group and waiting for the barrel to cool down. I was told to shoot 1 of each load weight from lowest to highest, then start again at the lowest until all groups are done. Obviously depending on how hot your barrel gets...I presume it's along the lines of consistent barrel warm up for each weight???

As stated you could do with a chrono to see if the bullet speeds are close for each group of rounds so you know the powder weights are accurate.

Chaz.

[gbal]

Chaz,you are correct-the shot sequencing you describe is a 'round robin' method-the logic is that the barrel warming effects will be there,but pretty nearly equally for each of the groups.It also similarly controls for getting gradually better or worse (practice and fatigue) -minimises differntial effects on the groups.

Groups of four shots and .2g apart seems reasonable to establish likely best spots..ditto seating depth,maube .05 steps.

 

Howevewr,the only way to check powder is by an accurate consistent weighing scale-a good beam is better than .1,often way better.

Good electronics will be OK-the best will hold a kernel-.025g approx (kernels vary!),but some cost a fair bit.

But there are other factors that affect MV-especialy neck tension,which is hard to measure directly-so is usually varying a little.No reason not to get powder effects on velocity minimised,of course-by very good weighing.

Magnetospeed (and much more expensive Lab Radar) is the current chrono of choice-immune from light fluctuations that can affect sight screen technology.It does no harm at all to know MV accurately-but poor measurement is mischievious....as is any inconsistent/inaccurate measurement.

 

For most shooters,holes in paper are pretty definitive-one reason accuracy fanatics like 100y BR shooters often don't weigh or chrono-if its goind through the same whole-who cares how fast? :-).Long range competitors can't be so cavalier,as effects start to show,especially in vertical dispersion.

 

Blacksilver,JSC's point is good-the 25.5 group looks good-maybe shoot a few more-anything consistently sub .5 for 5 shots at 100y is very decent indeed for a factory rifle (note 'consistently'). An aggregate of .3 would be exceptional-and hard to see why uoy'd need any better...satisfaction of course,when consistent! Sometimes a bullet change (Berger are best bet) may do it (or powder,but if it's not really broke,you could spend a lot of time fiddling...),but may not suit the shooting application (eg poor expansion,whatever...). Seems OK though.

 

gbal

[VarmLR]

To start:

 

Your jumps are too much at .5 intervals really. I would start somewhere around 15 thou off, and work up in .2 to 0.3 intervals. Before that though I'd load a ladder test in 0.5 jumps up to about a grain under max recommended, then switch to 0.2 grain and go on up until pressure signs were noted. Forget velocities at this juncture. At that point, I'd back off a complete grain to allow some wriggle room for temperature (unless loading in today's heat!).

 

Then starting from perhaps mid way between min and max loads, work up in .2 to .3 jumps and shoot a ladder test, discarding any loads that fall off the vertical. Keep those that all lay within a similar vertical spread and discard any that group horizontally or fall to one side or other of the main vertical group. Select the tightest of the vertical groups and load some more in say 0.1 to 0.2gr intervals each side of that to fined the sweet spot.

 

Next, try altering seating depth. My attempts with the 69TMK required considerable jump (100 thou in my case) to get the best barrel time node. My two nodes happened at 15 thou off and 100 thou off using the same load. You could see the groups opening up and then tightening again. Pick one of these two nodes (you should get at least 2) and there's your load for the TMKs. Some people just find that their barrel doesn't like these and return to using the 77 SMKs instead (which themselves are a very good accurate bullet).

 

Once you have (hopefully) found your load, then is the time to dig out the chrono and test a suitable sample size for velocity, make a note of temperature and this can be used for your ballistic apps. I usually chrono at least 10 degrees apart in temps to get an approximation for temperature sensitivity to calibrate my app.

[Blacknsilver]

The rifle is a semi custom. Fully blue printed 700. Archer stainless barrel. Sweet trigger. Unsure of the model. AI mag conversion and bedded stock.

I bought it more for target shooting.

I was going to do the round robin style but with the wind the way it was I thought shoot the 5 and the wind wouldn't have played much part in accuracy.

I may keep the COAL the same and try a few rounds around the 25gr mark with .2 either way.

I'm using Laupu match brass TMK 69gr and H4895 powder although I have Ramshot Tac powder which. Could swap to if needed.

[VarmLR]

...

[VarmLR]

H4895 and TAC I think have similar burn rates so there may be little point in swapping. tbh, I'd be tempted to try a slightly slower powder with the 69's, especially as you have a 26 inch barrel. N140 is a very good match, RS50 also very good for this combo. H380 or Varget would also be a good. I'd be surprised though if you couldn't find a decent node using 4895. I use N140 at 23.6grains for 2800 fps in mine.

[Blacknsilver]

The Tac powder came with the rifle. Only using the H4895 as I good results on the .204 with it. That's now gone out of the window now the head space has been sorted. The load that was shooting bug holes at 100 is not no more.

[bradders]

I'd try Rl15, Varget or N140

Any of those and around 24.5 should shoot well under 1 minute (I didn't use the term 'sub' as it really grates on me) but those bullets are designed to be primarily shot from at AR15 mag OAL of around .2.50, and can achieve excellent accuracy with those numbers, so I think you're way overthinking this.

 

If you can't get a decent group using those stats, then perhaps you need you look elsewhere

[Blacknsilver]

I've just loaded up 5x

24.8

25

25.2

25.4

 

H4895 powder. Gold medal match primers

 

Will see what happens. Hope to test tomorrow.

[snakeman]

I'd try Rl15, Varget or N140

Any of those and around 24.5 should shoot well under 1 minute (I didn't use the term 'sub' as it really grates on me) but those bullets are designed to be primarily shot from at AR15 mag OAL of around .2.50, and can achieve excellent accuracy with those numbers, so I think you're way overthinking this.

 

If you can't get a decent group using those stats, then perhaps you need you look elsewhere

 

+ 1

 

Test what you've already loaded but make that your final test with that recipe; if it doesn't work - change it

 

24.5g or thereabout of N140 is a given in .223....it's shootings' worst kept secret

[Blacknsilver]

Thanks guys.

[gunner]

4895 is a good powder for that bullet weight and heavier , i wouldn't bother trying the tac with heavier bullet as i found it much faster burning and pressure spikey came on very quick with little +grain increment . Go for it with lighter bullet id say with tac its well suited.

I haven't personnely tried 224 TMKs yet but may on Saturday . From memory some on here were talking about this 69 TMK specifically and from memory si snip had them best at 30thou off but could be wrong , ill have a look tomorrow now see if i can find post . As im wondering where to seat them lol . Cheers

[Blacknsilver]

Cheers. That may help. Didn't manage to get out last night. Maybe Monday now.

[VarmLR]

Seating seems to be critical with the 69's. I couldn't get them to work initially, and played with the seating, eventually loading to 2.26 at 23.6gr. That produced very tight groups in my rifle. I also had success at loading to 2.35 OAL with 24.5gr N140 albeit with a compressed load which was starting to show slight signs of pressure.

[Blacknsilver]

Any believe how lucky I was with the .204 load. Got it shooting bug holes at 100 and I know you can't go off a 3 shot group but at 300 yards shot a very tight group. Within an inch.

The rifle has had some work done lately to have head space sorted. Now the loads that shot great are not anymore. So need to start again with that. Gutted.

[VarmLR]

Simple enough to do. Like all reloading, change one variable, you'll alter something else, so you may need to tweak something like seating (that's where I'd start in your shoes) or simply pick a fixed seating close to lands and tweak load itself.

[Blacknsilver]

Having trouble uploading a picture.

Best I have got is still 25gr of H4895. 69gr bullet.

Centre to centre is 10mm of a 5 shot group.

I have a guy selling a 1kg tub of V140 for £50. May try that or would you play with seating depth? Not put these over chrono yet.

[gbal]

Blacksilver- 10mm is just under .4 inch. If consistent,that is as good as many factory rifles will get....look at the 100y BR factory class at say,Diggle...it would be a podium aggregate

 

You could tweak seating depth-the easiest option.

 

You could see what another known good shooter can do...

 

You could try V140 (a good all roundpowder).....but the combinations start to get out of hand....powder/bullets interact....

 

What would 7.5 mm do for you...I can appreciate 5mm (.2") would encourage smiles....Many serious BR rigs don't manage that every time out (wind,mainly)...

...of course it's a fun hobby trying to replicate that....good shooting. :-)

gbal

[Blacknsilver]

The rifle is semi custom. Blue printed 700. Bedded action. Archer stainless barrel etc. Was hoping for a ragged hole at 100. That's what I was getting with the .204 until the rifle had work done and now getting nowhere near that.

I will knock up a few more and see what some one else can do with it and possibility seat the bullet at factory spec as it's sat of the lands by 20 thousands at the mo.

[gbal]

Sorry,specs are better than factory barrel,so reasonable to expect -do we know what the factory barrel did?...204...until work done-does this mean a (factory ?) 204 was donor,rebarreled etc to 223 and now doesn't shoot as well as it did as 204? That would be a little surprising,if no other changes....

A ragged hole can easily be two+ calibres,though...better to shoot into card and get clean clear hole(s) edges...that can be measured-I mean 'ragged hole' is too vague..and variable....3 isn't (nor is .4,nor .5....)

 

Not clear what you mean by fsctory specs-unless you mean the COAL of factory rounds with that bullet....

...but maybe better to try 10 thou off ,then 15 off....maybe 20...should see some kind of pattern-group increasing/shrinking-though sometimes best is a fair bit off-or touching lands....just like powder weight,best to steadily (.05) increase and see...

g