.223 Load Development Issues

[KidsClay&Cartridges]

I'm after some ideas around possible causes of a really poor load development session I had this week. I'm a fairly experienced reloader across both rifle and pistol calibres so I don't think it's anything I've done but I want to explore potential issues.

I bought a used .223 Schmeisser straight pull and I'm trying to work up a target load for CSR / general target shooting. The guy I bought it from told me the barrel had been threaded by a reputable gunsmith and a flash hider / brake fitted. It all looks like it was done OK.

I loaded up a series of rounds in 0.2gn increments using new Lapua brass, CCI small rifle primers, N140 and Lapua Scenars in 69gn. COAL was standard for .223.

I then fired 3 shot groups at 100 yards off a bench with a bipod and rear bag. I also gave time for the barrel to cool between groups.

The target looked like a shotgun pattern with only one load giving anything close to a sub MOA size group. Previous load development I've done has not seen such a wild scattering of rounds so I'm wondering if there might be a problem with the rifle (or me?).

 

[Foxyboy43]

I'm after some ideas around possible causes of a really poor load development session I had this week. I'm a fairly experienced reloader across both rifle and pistol calibres so I don't think it's anything I've done but I want to explore potential issues.

I bought a used .223 Schmeisser straight pull and I'm trying to work up a target load for CSR / general target shooting. The guy I bought it from told me the barrel had been threaded by a reputable gunsmith and a flash hider / brake fitted. It all looks like it was done OK.

I loaded up a series of rounds in 0.2gn increments using new Lapua brass, CCI small rifle primers, N140 and Lapua Scenars in 69gn. COAL was standard for .223.

I then fired 3 shot groups at 100 yards off a bench with a bipod and rear bag. I also gave time for the barrel to cool between groups.

The target looked like a shotgun pattern with only one load giving anything close to a sub MOA size group. Previous load development I've done has not seen such a wild scattering of rounds so I'm wondering if there might be a problem with the rifle (or me?).

Hmm. Cheapest option is to get someone else with proven ability to shoot it - 2 groups of five at least then compare. If no improvement back to the seller you go…….

 

[Muir]

How accustomed to an AR platform are you? And what were the actual group sizes? ~Muir

 

[Lancaster]

I'm after some ideas around possible causes of a really poor load development session I had this week. I'm a fairly experienced reloader across both rifle and pistol calibres so I don't think it's anything I've done but I want to explore potential issues.

I bought a used .223 Schmeisser straight pull and I'm trying to work up a target load for CSR / general target shooting. The guy I bought it from told me the barrel had been threaded by a reputable gunsmith and a flash hider / brake fitted. It all looks like it was done OK.

I loaded up a series of rounds in 0.2gn increments using new Lapua brass, CCI small rifle primers, N140 and Lapua Scenars in 69gn. COAL was standard for .223.

I then fired 3 shot groups at 100 yards off a bench with a bipod and rear bag. I also gave time for the barrel to cool between groups.

The target looked like a shotgun pattern with only one load giving anything close to a sub MOA size group. Previous load development I've done has not seen such a wild scattering of rounds so I'm wondering if there might be a problem with the rifle (or me?).

How does it shoot with factory?

 

[Andyquadra]

Couple if things
How does it shoot without the muzzle break, and what does the crown look like?

I assume the barrel has a twist rate that can stabilise 69grain?

What's the powder weight and coal you have loaded to so far?

 

[DavyG]

I’ll assume it’s a 1:9 twist, so should be fine with 69’ers.
You’ve bought a used rifle…was it “try before you buy” or was it bore scoped…?
I’d start by giving a deep clean…
Regards,
DG

 

[sidesy]

Is it a .223 wylde chamber ?

You given barrel a good clean

I'd shoot some standard ammo and see how it performs. If no better I'd be returning it to previous owner.

 

[KidsClay&Cartridges]

Thanks for the responses.

To answer the comments in order from the first response:

My only experience with an AR platform is my M&P 15-22, so none with centre fire but I tried to as I would with any other rifle off a bipod and rear bag. Best group size was about 0.75MOA the rest were all in the 1 to 2 MOA area.

I used some cheap Remington factory ammo to zero it and it wasn't good, but I put that down to cheap ammo.

Haven't tried without the brake as its just threaded without a cap. Everything looks OK on the crown. Pretty sure it's a 1:9 twist so ok for 69gn bullets. I used N140 in increments from 23.1gn to 24.7gn. The one acceptable group was 23.5gn. COAL was 2.260 which is a bit longer than standard but fed OK. I guess I could try seating them deeper.

I didn't try before buying but I have given it a good clean before I started with the load development. It only had some carbon fouling with very little copper residue showing on the patches. Haven't bore scoped it.

 

[Muir]

Thanks for the responses.



I didn't try before buying but I have given it a good clean before I started with the load development. It only had some carbon fouling with very little copper residue showing on the patches. Haven't bore scoped it.

That was your first mistake. Seat deeper. Stop cleaning. Keep shooting. Screw the bore scope. (totally worthless in diagnosing your issue)
New Fl sized brass?~Muir

 

[Mud Stuffin]

Have you checked the scope rings, mounts/rail? I only say this as I had something similar happen to me and was going nuts trying to work out why I couldn’t zero a rifle. After far too many shots I worked out the scope rings had come lose - tightened them up and it zeroed fine after that.

 

[Andyquadra]

Seat deeper.

2.260 is Vits info

 

[KidsClay&Cartridges]

Actually, on double checking the 2.260 COAL is the standard length so not too long. I guess I could try a few thousands lower though.

 

[KidsClay&Cartridges]

Have you checked the scope rings, mounts/rail? I only say this as I had something similar happen to me and was going nuts trying to work out why I couldn’t zero a rifle. After far too many shots I worked out the scope rings had come lose - tightened them up and it zeroed fine after that.

Thanks, yeah, I had already done that as the reticle did look slightly off to me. All undone and then torqued back up in line with mount manufacture's recommendation.

 

[Lancaster]

Thanks, yeah, I had already done that as the reticle did look slightly off to me. All undone and then torqued back up in line with mount manufacture's recommendation.

Is it a known good scope, and what did the Remmy ammunition look like in terms of group size?
Personal thought is that, if this a new to you rifle, you need to eliminate all other possible issues before questioning your loads, otherwise you will spend a lot of time, effort and consumables trying to improve something that isn't load related.

 

[KidsClay&Cartridges]

Is it a known good scope, and what did the Remmy ammunition look like in terms of group size?
Personal thought is that, if this a new to you rifle, you need to eliminate all other possible issues before questioning your loads, otherwise you will spend a lot of time, effort and consumables trying to improve something that isn't load related.

Thanks, that sounds like good advice. It's a good scope, Sightron SIII in American Defense one piece mount. Rummy ammo was about 1.5 MOA but with the 10 rounds I used there were 3 or 4 random flyers.

 

[Sharpie]

I'm after some ideas around possible causes of a really poor load development session I had this week. I'm a fairly experienced reloader across both rifle and pistol calibres so I don't think it's anything I've done but I want to explore potential issues.

I bought a used .223 Schmeisser straight pull and I'm trying to work up a target load for CSR / general target shooting. The guy I bought it from told me the barrel had been threaded by a reputable gunsmith and a flash hider / brake fitted. It all looks like it was done OK.

I loaded up a series of rounds in 0.2gn increments using new Lapua brass, CCI small rifle primers, N140 and Lapua Scenars in 69gn. COAL was standard for .223.

I then fired 3 shot groups at 100 yards off a bench with a bipod and rear bag. I also gave time for the barrel to cool between groups.

The target looked like a shotgun pattern with only one load giving anything close to a sub MOA size group. Previous load development I've done has not seen such a wild scattering of rounds so I'm wondering if there might be a problem with the rifle (or me?).

How long is the barrel ?

Bullet stability is not as simple as just "an x" per 12" twist will stabilize up to y grain bullets". Far from it.

A bullet has to be spun up to at least a certain rotational spin rate, which is a function of muzzle velocity and twist. Then the bullet length is critical too. I don't know how your Lapua Scenars compare in length with other similar weight bullets.

If you want to get scientific, online calculators are available, the Berger one is fairly well respected. You will need to know your muzzle velocity (chrono), or you could estimate it using e.g. a P-Max simulation. As well as bullet length, and BC.

Twist Rate Stability Calculator

Yours is obviously a very early model, since it did not come threaded, as they all do nowadays.

AFAIK they do them in 14.5" 16" and 18". Plus the "Ultramatch" 20" Which also has an 8" twist, heavy match chambered SS barrel. I doubt that yours is one of those.

Finally, bear in mind that Vhitavuori use a 25" test barrel for their load data. So do not pay any attention to their published muzzle velocities if you are using one much shorter than that. They will be far lower.

OK, I'm feeling bored, so, here is a quick and dirty estimate.

Lapua Scenar 69gr .224 bullet length 0.910". Source JBM - Bullet Length List

Ballistic coefficient G1 = 0.341. Source 4,5 g / 69 gr Scenar-L OTM GB544

Lets go for worst case, a 14.5" barrel. Using the Vhit max. load of 24.7 gr N140.

P-,Max suggests you might achieve an MV of 2566 fps.



I am confident that it is pretty close, actually perfect, since when I put in the 25" barrel length Vhit. states 2,884 fps. P-Max says 2,883 fps. !!!

Berger calc., with these numbers says:





Even if I back off to Vhit. start load of 22.8 gr, P-Max says 2336 fps. At which point Berger still says



Conclusion: you ought to be able to shoot that bullet out of even the shortest Schmeisser, at a start load, and expect the bullet to be stable.

So some other factor(s) are happening, maybe just your load, seating depth etc. But there is a limit to how far out you can seat them if they are still to fit in the magazine.

As @Muir suggests, try seating deeper.

If that doesn't work, well then start suspecting a problem with the rifle itself.

But this is all just theory from me.

 

[Foxyboy43]

How long is the barrel ?

Bullet stability is not as simple as just "an x" per 12" twist will stabilize up to y grain bullets". Far from it.

A bullet has to be spun up to at least a certain rotational spin rate, which is a function of muzzle velocity and twist. Then the bullet length is critical too. I don't know how your Lapua Scenars compare in length with other similar weight bullets.

If you want to get scientific, online calculators are available, the Berger one is fairly well respected. You will need to know your muzzle velocity (chrono), or you could estimate it using e.g. a P-Max simulation. As well as bullet length, and BC.

Twist Rate Stability Calculator

Yours is obviously a very early model, since it did not come threaded, as they all do nowadays.

AFAIK they do them in 14.5" 16" and 18". Plus the "Ultramatch" 20" Which also has an 8" twist, heavy match chambered SS barrel. I doubt that yours is one of those.

Finally, bear in mind that Vhitavuori use a 25" test barrel for their load data. So do not pay any attention to their published muzzle velocities if you are using one much shorter than that. They will be far lower.

OK, I'm feeling bored, so, here is a quick and dirty estimate.

Lapua Scenar 69gr .224 bullet length 0.910". Source JBM - Bullet Length List

Ballistic coefficient G1 = 0.341. Source 4,5 g / 69 gr Scenar-L OTM GB544

Lets go for worst case, a 14.5" barrel. Using the Vhit max. load of 24.7 gr N140.

P-,Max suggests you might achieve an MV of 2566 fps.

View attachment 267816

I am confident that it is pretty close, actually perfect, since when I put in the 25" barrel length Vhit. states 2,884 fps. P-Max says 2,883 fps. !!!

Berger calc., with these numbers says:

View attachment 267812

View attachment 267815

Even if I back off to Vhit. start load of 22.8 gr, P-Max says 2336 fps. At which point Berger still says

View attachment 267818

Conclusion: you ought to be able to shoot that bullet out of even the shortest Schmeisser, at a start load, and expect the bullet to be stable.

So some other factor(s) are happening, maybe just your load, seating depth etc. But there is a limit to how far out you can seat them if they are still to fit in the magazine.

As @Muir suggests, try seating deeper.

If that doesn't work, well then start suspecting a problem with the rifle itself.

But this is all just theory from me.

If I may can I ask if the length of the bullet actually engaging with the rifle twist is a factor? I.e. will two bullets of the same length (in extremis perhaps) but different construction and which have different bearing/engagement on the rifling, spin at a different rate and will it impact (!) on velocity?
Just curious.

 

[Sandyb]

Thanks for the responses.

To answer the comments in order from the first response:

My only experience with an AR platform is my M&P 15-22, so none with centre fire but I tried to as I would with any other rifle off a bipod and rear bag. Best group size was about 0.75MOA the rest were all in the 1 to 2 MOA area.

I used some cheap Remington factory ammo to zero it and it wasn't good, but I put that down to cheap ammo.

Haven't tried without the brake as its just threaded without a cap. Everything looks OK on the crown. Pretty sure it's a 1:9 twist so ok for 69gn bullets. I used N140 in increments from 23.1gn to 24.7gn. The one acceptable group was 23.5gn. COAL was 2.260 which is a bit longer than standard but fed OK. I guess I could try seating them deeper.

I didn't try before buying but I have given it a good clean before I started with the load development. It only had some carbon fouling with very little copper residue showing on the patches. Haven't bore scoped it.

Did you ask about the rifles shooting accuracy or pictures of the sellersrevious shot groups?
Maybe the seller was cunning selling it on knowing there was a problem with it?

 

[Dalua]

The target looked like a shotgun pattern

You were counting the percentage of shots making it into a 30" circle at 40yds??

Seriously, though: would be interesting to know what the max size was of the thee-shot series for the various loads, to be able to compare to the one load that did about an inch.

The 'good' load wasn't the fastest - so presumably it's not about bullet stabilisation being inadequate: unless, of course, the good 'group' was a coincidence. It's worth keeping in mind that three shots do not really constitute a group.

Were all the bullet-holes round?

 

[Drum123]

Is 3/4 of an inch group so bad in a 2nd hand AR platform with an unknown shot count?