Ppu 223 69 grain match ammo

[User00053]

Question all, have some of these which came with a rifle with 1:12 twist, 223, read it’s not ideal and maybe will not suit with poor stability but anyone had any joy.
Don’t want to go to target to zero to find waste of time, just curious if it’s been done with fox accuracy so to speak, if not will start from scratch with other factory flavours. Thanks.

 

[bowji john]

I'm playing with what I believe to be PPU 62 grain FMG in .223 win at the mo

I say 'believe' because it was a bag of 300 bullets of unknown origin given to me for free - they weigh in at a smidge under 62 grain

Anyway - 1 in 10 twist

I get just under half an inch at 150m with 55 grain commercial ammo but greater than 4 inches at all the powder loads I've tried to date with these freebys

Today we played with 40 grain Vmax and 77 grain bt tailed sierra - all at 150m and a variety of powder charges

Groups from 1.5 inches to 5 inches

Appalling ES - worst was 150; best was about 40

Surprisingly I got stability for the 77 grain from my 1 in 10 - perhaps you will too with your 1 in 12 and 69 grain

Not too sure where this rambling is going - other than to suggest that it is worth giving your 69 grains a try

 

[Smellydog]

I'm playing with what I believe to be PPU 62 grain FMG in .223 win at the mo

I say 'believe' because it was a bag of 300 bullets of unknown origin given to me for free - they weigh in at a smidge under 62 grain

Anyway - 1 in 10 twist

I get just under half an inch at 150m with 55 grain commercial ammo but greater than 4 inches at all the powder loads I've tried to date with these freebys

Today we played with 40 grain Vmax and 77 grain bt tailed sierra - all at 150m and a variety of powder charges

Groups from 1.5 inches to 5 inches

Surprisingly I got stability for the 77 grain from my 1 in 10 - perhaps you will too with your 1 in 12 and 69 grain

Not too sure where this rambling is going - other than to suggest that it is worth giving your 69 grains a try

223 win, is that the wssm cartridge?
How fast does it shoot the 77gn bullets?
Thanks

 

[bowji john]

It is the standard .223 lapua

I made these up about 4 years ago but sold the Southern Gun Company rifle ages ago (wylde chambering for which they were made) so they have sat on my shelf until I recently purchased a .223 barrel for my Blaser

Got 2600 ft per out of them but referring back to my notes I failed to write up the charge weight in Varget !!

I shot them rather than pull them in the hope of learning something about what weight would stabilise in my barrel

 

[Miki]

69gr maybe a bit long to stabilise in a 1:12.
I can't imagine that 77gr would ba any good at all in a 1:12

Pull a bullet and measure it's length then put the figures in here Twist Rate Stability Calculator

 

[User00053]

69gr maybe a bit long to stabilise in a 1:12.
I can't imagine that 77gr would ba any good at all in a 1:12

Pull a bullet and measure it's length then put the figures in here Twist Rate Stability Calculator

Ok thanks for info

 

[User00053]

I'm playing with what I believe to be PPU 62 grain FMG in .223 win at the mo

I say 'believe' because it was a bag of 300 bullets of unknown origin given to me for free - they weigh in at a smidge under 62 grain

Anyway - 1 in 10 twist

I get just under half an inch at 150m with 55 grain commercial ammo but greater than 4 inches at all the powder loads I've tried to date with these freebys

Today we played with 40 grain Vmax and 77 grain bt tailed sierra - all at 150m and a variety of powder charges

Groups from 1.5 inches to 5 inches

Appalling ES - worst was 150; best was about 40

Surprisingly I got stability for the 77 grain from my 1 in 10 - perhaps you will too with your 1 in 12 and 69 grain

Not too sure where this rambling is going - other than to suggest that it is worth giving your 69 grains a try

Very interesting thanks, will get some factory 50- 55 grain and go to target in near future with plan to zero with them and if 69 grains shoot will put them to use.

 

[ashray]

good afternoon,i have two 223rem one has a 1in9 twist and the other is a1in12. my rifles shoot THE 1 IN 9. 40gr up to 75gr <not the 75gr a-max though> all accurate and no issues. the 1 in 12, 40 upto 53 gr ,some 55gr but wont group anything 60gr or over. the ppu 69gr and 75gr group very well in my 1 in 9 . if you intend to try the 69gr in a 1 in 12 twist make you remove your moderator if you use one,at least for the first few to make sure they dont tumble.

 

[Miki]

good afternoon,i have two 223rem one has a 1in9 twist and the other is a1in12. my rifles shoot THE 1 IN 9. 40gr up to 75gr <not the 75gr a-max though> all accurate and no issues. the 1 in 12, 40 upto 53 gr ,some 55gr but wont group anything 60gr or over. the ppu 69gr and 75gr group very well in my 1 in 9 . if you intend to try the 69gr in a 1 in 12 twist make you remove your moderator if you use one,at least for the first few to make sure they dont tumble.

I'm interested in the deviation of an 'overly long' bullet as it leaves the rifle. I can't determine when the deviation occurs however.
Millers formula indicate that a bullet with a Gyroscopic Stability factor of 1.0 tumbles 'right out the barrel' but I don't know what the deviation is.
A .224 69gr bullet, 0.88" in length, travelling at 3300 = 1.11SG
Between 1.0 and 1.5 (marginal stability) short range accuracy 'isn't an issue' although the resultant pitch and yaw does reduce the BC and increases the drag. To get the BC maximised you need a higher spin rate, ie for long range.
Interstingly you can have to much spin, if the SG is above 2.0 (relatively short/light bullets going too fast) then you need to reduce the barrels twist.

Although the above statements are loaded with generalities (short and long rage for example) I don't think your 69gr bullet will clout the moderator as this is typically less than 250mm in front of the muzzle.
If you were showing an extreme 6MOA POI v POA @ 100M the deviation from the muzzle is less than 0.4mm @ 250mm (0,2mm radial) - if everthing was linear, which I am pretty sure it isn't....

REF: http://accurateshooter.net/Blog/millerformula.xls

 

[Dr. Strangelove]

Interstingly you can have to much spin, if the SG is above 2.0 (relatively short/light bullets going too fast) then you need to reduce the barrels twist.

I’m not sure that’s correct. The below is from Bryan Litz’s FB page. I’m absolutely not an expert but he is, so I’ll defer to him!




To me that reads as a faster twist only making bullets more accurate!

 

[Miki]

I read an article once where too much spin creates instability, can't find it now (typical) I seem to reall it was in the short range 6PPC dicipline.
Obviously too fast and fangible bullets will disintegrate but that is extreme ....

You're not wrong - Bryan Litz, Don Miller and Michael Courtney are far better at this than I am .... god like, IMO


Found it

It is generally believed that, for match bullets, best accuracy is achieved at the minimal spin rates that will fully stabilize the particular bullet at the distances where the bullet must perform. That’s why short-range 6PPC benchrest shooters use relatively slow twist rates, such as 1:14″, to stabilize their short, flatbase bullets. They could use “fast” twist rates such as 1:8″, but this delivers more bullet RPM than necessary. Match results have demonstrated conclusively that the slower twist rates produce better accuracy with these bullets.

linky

 

[Heym SR20]

My 223 Rem 700 with 1 in 12 Twist shoots PPU 50 (might be 55gn) soft point and target ammo very well. I have not tried the longer bullets yet.

 

[nun_hunter]

I bought a load of these hoping they would be good for practicing in a 1:9 Howa 1500 and they just were no where near a s good s i hoped. Id get maybe a 1.5moa group on average but then there would be at least 1 or 2 round that would be another inch or more away. A friend shot a group with his CZ527 and had the same result. Maybe a bad batch or just not suited to our rifles.

 

[MarinePMI]

I read an article once where too much spin creates instability, can't find it now (typical) I seem to reall it was in the short range 6PPC dicipline.
Obviously too fast and fangible bullets will disintegrate but that is extreme ....

You're not wrong - Bryan Litz, Don Miller and Michael Courtney are far better at this than I am .... god like, IMO


Found it

It is generally believed that, for match bullets, best accuracy is achieved at the minimal spin rates that will fully stabilize the particular bullet at the distances where the bullet must perform. That’s why short-range 6PPC benchrest shooters use relatively slow twist rates, such as 1:14″, to stabilize their short, flatbase bullets. They could use “fast” twist rates such as 1:8″, but this delivers more bullet RPM than necessary. Match results have demonstrated conclusively that the slower twist rates produce better accuracy with these bullets.

linky

Over spinning implies a fast twist. While bullets can disintegrate from extreme RPMs/centrifugal force, usually the problem is bullet deformation. This is clearly demonstrable in fast twist, heavy for diameter (long) bullets. It is one of the reasons that Gain Twist barrels are making a come back (along with modern machining advances). The trend of late has been heavy for caliber bullets, and doppler radars are exposing this bullet deformation as it occurs. Voids are created and jackets get torn during the rapid increase in rotational spin when a long bullet's nose engages the rifling, as the rear of the bullet tries to remain in rotational stasis. Again, this can be seen as the BC of the bullet changes from these deformations (hence the comment of a doppler radar), because the bullets begin to show erratic BC's, and thus loss of accuracy on paper. It's not so much a loss of accuracy, so much as it is you are now shooting bullets, that once they leave the barrel, have different BC's. This is also demonstrated through unexplained vertical stringing...because the BC's are changing (ever so slightly) the time of flight. If the deformations were consistent, the bullets would appear just as accurate as non-deformed bullets. It's the inconsistency of the deformation that leads people to think that a bullet isn't accurate (in the case of long for caliber bullets). IIRC, Jim Boatwright wrote an interesting white paper on this...

Then there's the whole "center of rotation" aspect of ballistics, but that's another discussion.

 

[25 Sharps]

I read an article once where too much spin creates instability, can't find it now (typical) I seem to reall it was in the short range 6PPC dicipline.
Obviously too fast and fangible bullets will disintegrate but that is extreme ....

You're not wrong - Bryan Litz, Don Miller and Michael Courtney are far better at this than I am .... god like, IMO


Found it

It is generally believed that, for match bullets, best accuracy is achieved at the minimal spin rates that will fully stabilize the particular bullet at the distances where the bullet must perform. That’s why short-range 6PPC benchrest shooters use relatively slow twist rates, such as 1:14″, to stabilize their short, flatbase bullets. They could use “fast” twist rates such as 1:8″, but this delivers more bullet RPM than necessary. Match results have demonstrated conclusively that the slower twist rates produce better accuracy with these bullets.

linky

But that is talking about short, flat based bullets, at short range - it does not necessarily follow that longer and / or boat tailed bullets will follow the same trend.

 

[25 Sharps]

I bought a load of these hoping they would be good for practicing in a 1:9 Howa 1500 and they just were no where near a s good s i hoped. Id get maybe a 1.5moa group on average but then there would be at least 1 or 2 round that would be another inch or more away. A friend shot a group with his CZ527 and had the same result. Maybe a bad batch or just not suited to our rifles.

I found the same in a 6.5 rifle that is reliably Sub moa, they wouldn't group for toffee

 

[Miki]

But that is talking about short, flat based bullets, at short range - it does not necessarily follow that longer and / or boat tailed bullets will follow the same trend.

Correct and 'yes I agree'.
But, I think, you are twisting the point (sic).
Bullets do have an 'optimal' spin rate, in the same way your barrel has an optimal harmonic deflection. Get all those ducks in a row, align them to a distance, be repeatable and you will be a champ.
Too much for me to be honest.

As long as there is an impaired rotation (spin), my understanding is that FB bullets are more accurate as they have less angles to complicate matters.
In comparison they FB bullets have a lower BC so will lose ground over the higher BC of a BT bullet (which becomes the dominant factor) however, the rate of spin has little to no bearing on that or indeed my point in post #11, but you do like an argument.

The OP asked - will PPU 69gr, HPBT match bullets be OK in my 1:12 .223 - and the answer is 'probably not' bordering on a definite math derived 'No'.
Will they be so unstable as to clout the moderator ? was also a 'No' however over a greater distance they (69gr .223 bullets) will likely be innacurate'.

@boltgun is going to 'try' them and get back to us.

 

[25 Sharps]

Correct and 'yes I agree'.
But, I think, you are twisting the point (sic).
Bullets do have an 'optimal' spin rate, in the same way your barrel has an optimal harmonic deflection. Get all those ducks in a row, align them to a distance, be repeatable and you will be a champ.
Too much for me to be honest.

As long as there is an impaired rotation (spin), my understanding is that FB bullets are more accurate as they have less angles to complicate matters.
In comparison they FB bullets have a lower BC so will lose ground over the higher BC of a BT bullet (which becomes the dominant factor) however, the rate of spin has little to no bearing on that or indeed my point in post #11, but you do like an argument.

The OP asked - will PPU 69gr, HPBT match bullets be OK in my 1:12 .223 - and the answer is 'probably not' bordering on a definite math derived 'No'.
Will they be so unstable as to clout the moderator ? was also a 'No' however over a greater distance they (69gr .223 bullets) will likely be innacurate'.

@boltgun is going to 'try' them and get back to us.

My understanding, with no particular science, is that flat base bullets stabilise quicker whilst boat tail bullets take longer to stabilise to the optimal spin around their axis, this makes sense as BT are generally longer for any given weight. The net result is you may get better accuracy with boat tail bullets further out once they've 'settled' than you will with the same bullet close in, this is why flat based bullets are used for short range competition (and often better at stalking ranges).

As for 69 gr bullets through a .223 with a 1:12 barrel, a waste of time, powder and primers as its a foregone conclusion . . . .

 

[Rewulf]

As for 69 gr bullets through a .223 with a 1:12 barrel, a waste of time, powder and primers as its a foregone conclusion . . . .

Got to agree, they might well group OK at 100 yards , but after that, in my experience, it all starts falling apart.
I did much experimentation with a 1:12 .223 once , there was even a clear difference between 50 and 55g of the same bullet make.

 

[25 Sharps]

Question all, have some of these which came with a rifle with 1:12 twist, 223, read it’s not ideal and maybe will not suit with poor stability but anyone had any joy.
Don’t want to go to target to zero to find waste of time, just curious if it’s been done with fox accuracy so to speak, if not will start from scratch with other factory flavours. Thanks.

I would choose a suitable fox/vermin bullet over these, they may well not expand