2400 in 223

[steve4102]

You can also look at it terms of actual numbers.
Slugging the bore gives the handloader a fairly accurate account of actual bore size. Agreed or no?

Lets say you slug the bore of your 1911 45 acp and as with most pistols it measures .451. Jacketed bullet also measure .451. If the bore diameter is identical to the bullet diameter , would not a reasonable conclusion be that the bullet-to-bore fit is a tight fit and gas "Blow-by" is more of a theory then a fact.

Maybe it's just my thick head, but I can't grasp this.
A properly sized cast boolit will seal the bore and contain the pressure til the boolit leaves the barrel. Now a Jacketed bullet will not conform to the rifling enough to seal it, hence allowing gases to pass by it and not allow for complete potential pressure buildup.

If the jacketed bullet is already the same diameter as the bore, there is nothing to "Conform" to. It's already a tight fit. If anything the pressures on the base of a jacketed bullet should cause a somewhat tighter fit similar to the lead bullet, although not as much.

IMO, no way there is Gas-by-pass when using jacketed bullets. They are tight before the round is fired and they will get tighter after the round is fired.

[JonB_in_Glencoe]

Looks like skate marks to me...not much conforming to rifle grooves on these. If they aren't conforming to the rifle grooves, don't tell me that tens O thousands of PSI of burning gases aren't going to leak around it.

[Harter66]

My actual head to head test. 21' .277x.284 bbl hooked to a Carcano action chambered in 7x6.8 Rem SPCII.
22.0 RL10x
Rem LRP 6.8 Rem direct neck up brass
CCI lrg rifle standard primer
Serria 120 SP (old stock 1974?)
27-130 FP RCBS paper patched 134gr as loaded.

I selected the load as it is a prefered of several shooters of 6.8 Rem and safe w/the 120gr weight in the 6.8 (277)cartridge.

The Serria 120 clocked 2230 average for 8 rounds (all the jackets this rifle will likely ever see) . The PP'd RCBS at 134gr clocked 2250 average for 10rd. That says to me something changed. Heavier bullets simply can't go faster w/o being slicker all else being the same.

Example number 2 (This 1 is slightly flawed but holds true)
32 Remington (Data for 32 Win special is excepted as direct interchange per Ben Amonte @ ATK)
The load is
Win brass (both correct and turned 32 Win)
CCI LRP standard
IMR 4350
170 gr FP (Book)
323-170 actually chrono'd at 175 gr

170 FP, 34.4 for 1800fps 37.7 2000 fps from 12/1975 Hornady Handbook
323-170, 31.0gr 2100 fps (best group w/Plain based boolit.

Less powder, same boolit weight goes 100 fps faster, 6gr+ less than max going 100fps faster than than max says lower pressures to me.

From approved data, look at the 748 you will see .6 gr difference in the maximum charge and 200fps loss on the boolit vs jacked but also a reduction of 5000 CUP. Taken from the 47th Lyman reloading handbook for 223 in the universal reciever 24'' bbl
Attachment 93526
Attachment 93527

[steve4102]

Looks like skate marks to me...not much conforming to rifle grooves on these. If they aren't conforming to the rifle grooves, don't tell me that tens O thousands of PSI of burning gases aren't going to leak around it.

I'm not telling you anything. I'm telling you I don't "Think" "gas by pass" is possible in a jacketed bullet. At least not enough to alter/reduce pressures.

If it were, then the Hard A$$ Barnes Solid would have developed less pressure than a softer Cup-n-core bullet before the "Rings" were introduced, not more. As the all copper bullet will "Conform" less to the bore it should have resulted in more "Gas-by-Pass, resulting in less pressure, Not More.

[Harter66]

This 5 second video at an advertised 1million frames per second would tend to disagree . It looks like even a powder flake escaped before the bullet and certainly high pressure gas.

https://www.youtube.com/watch?v=otpF...e_gdata_player

[Certaindeaf]

It was always my impression that given everything the same, save one slug being jacketed and the other being lead, the lead bullet goes a fair bit faster.

[JonB_in_Glencoe]

This 5 second video at an advertised 1million frames per second would tend to disagree . It looks like even a powder flake escaped before the bullet and certainly high pressure gas.

https://www.youtube.com/watch?v=otpF...e_gdata_player

A great video. I had to look at it many times.
It's clear to me that Gas is bypassing that bullet.
Easiest to see on top of the bore, the gases exiting in front of the bullet are clearly going faster than the bullet.

[GabbyM]

It’s a known fact cast lead bullets have less friction in the bore. Jacketed bullets will always yield higher pressure and lower velocity unless you are doing something funky.

Jacketed bullets can stick in a bore when using cast data.

My old Hornady book list there 55gr fmj-bt with reduced velocity loads using SR4759 powder. Slowest load they list is 2100 fps. Hornady doesn’t explain why the start load is 2100 fps. I’d assume two things. Test barrel was 24 inch 12 twist. Slower and bullets are probably not accurate due to low stability. Then you have the bullet sticking in the bore issue. Start load of SR5759 is 11.3gr for 2100fps. Max is 15.2gr for 2600fps. 2400 powder is just a tad faster than SR4759. Hornady doesn’t list pressures but I’d imagine that 15.2 grains is getting up to the top plus it probably about fills a 223 case. Your idea to start at 12.0 grains IIRC looks about right to me for a start point. I’d get it bumped up in pressure to at least get a good case to chamber seal. My Lyman 3rd edition list 11.5 grains under the 225646 at 2206fps and 27,100 CUP. It’s never a great idea to extrapolate load data. But between the SR4759 data and the cast data on 2400 I’d be confident with the 12gr start charge. If it was me I’d load three up with 14.0 grains for a start.

[Digital Dan]

You fellas are debating this based on a lot of assumptions and not too many facts.

Best of luck!

[steve4102]

This 5 second video at an advertised 1million frames per second would tend to disagree . It looks like even a powder flake escaped before the bullet and certainly high pressure gas.

https://www.youtube.com/watch?v=otpF...e_gdata_player

Great video Thanks. Hard to tell, but it looks to me as though that is a lead or plated bullet?

Do you have any info on what the round,bullet caliber, cartridge was?

Would be nice to see the same type of video with different types of bullets, lead vs Jacketed vs plated vs solid copper. Then we could compare how much "Gas-blow-buy" each type of bullet generates.

[Silvercreek Farmer]

What's different is the seating depth, not the COAL, but how deep the boolit is in the case. Given the same COAL, the lead displaced by the lube grooves ends up in the case, reducing case capacity and increasing pressures when compared to a jacketed bullet of the same weight, but only minimally based on the data posted. Loaded to the same pressure, the boolit will have a higher velocity because of the reduced bore friction of lead vs copper.

[jackmanuk]

Jackmanuk, are you wanting to load for a bolt or gas rifle?

its for my ar 15 but since over here we cant have the gas system so no worry of cycling issues

[jackmanuk]

i went to work this morning hoping for an answer to my question, instead iv started a big debate on jack v lead

[JonB_in_Glencoe]

Sorry for the thread drift.

[Harter66]

Great video Thanks. Hard to tell, but it looks to me as though that is a lead or plated bullet?

Do you have any info on what the round,bullet caliber, cartridge was?

Would be nice to see the same type of video with different types of bullets, lead vs Jacketed vs plated vs solid copper. Then we could compare how much "Gas-blow-buy" each type of bullet generates.

I don't have anything except what is seen .There are 100s of like video clips from U-tube .

I didn't intent to push the drift either.

[steve4102]

since i have tons of 2400 and ...well....nothing else i need a load for my 223 , i only see one instance of 2400 in the lyman load book using 11.5 max with 55 grn alloy, so im thinking on using 12 grains wit ha 55 grn fmj , should it be ok?

atm iv loaded one scoop of a .7cc lee dipper which is 9. something grns

I too apologize for hijacking your thread.

To answer your original question, I found this.

Shows a Max load of 15.9gr 2400 with a 55gr jacketed bullet for Silhouette loads.
Also shows a max charge of 14.0gr for standard loads with 55gr bullet in the 223.


Reduce by 10% for Start charge.

http://www.castpics.net/LoadData/Fre.../Alliant96.pdf

More data here.

http://www.castpics.net/LoadData/Fre...M/Alliant.html

[jackmanuk]

thanks for the info steve , i was planning 12 grains but im starting with 10


btw whats a silhouette load ?

[steve4102]

thanks for the info steve , i was planning 12 grains but im starting with 10


btw whats a silhouette load ?

Duno.

I know what shooting Silhouettes is/are, but I don't know how that applied to handloads.

http://en.wikipedia.org/wiki/Metalli...uette_shooting

I think you should follow the Alliant data and Start 10% below Max not 25% below max. 10% below max would give you a start charge of 12.6gr. Your original plan of starting with 12gr is a good plan, dropping to 10gr not so much.

[steve4102]

Now, back to the hijack and the speculation.

The video showed gases and even powder escaping the muzzle prior to the bullet.

Speculation says that the gases escaped past the bullet due to a poor bullet-to-bore fit.

..but what about the powder? How did powder flakes get past the bullet-to-bore fit? IMO, it can't there is no way that flakes of powder can fit between the bore and the bullet and escape in tact. It's physically not possible.

So how did the powder get itself in front of the bullet? My speculation is that it escaped around the bullet before the bullet entered the lands and sealed the bore. If this is possible, it is also probable that all of the gases we see in the video entered the bore at the same time and did not pass up the bullet as it traveled down the bore, but entered the bore first.

Or, what we see in the video is not "Powder flakes" but rather powder fouling and **** left in the bore from previous rounds.

[Certaindeaf]

Sorry for the thread drift..

I don't know that it's thread drift.. *shudder* lol.. I think "it's" cogent and germane to the subject at hand.