3000fps with 100gr

[sgt_murf]

What about the 5.56? It was the original and runs at 62K psi?

Please do not quote me for sure but I think 62k is proof loads but I do not remember if the pressure are quoted as CUP or PSI two differant animals.
Let me do some checking in some of the old ammo tms I have

[sgt_murf]

Found it
M193 5.56mm Ball=52,000 psi 55gr pill at 3250
M855 5.56mm ball = 55,000psi 62gr pill at 3025
proof loads are usually at 125% of the established working load ---- thus Proof Load is at 68K psi for the M16A2
65K psi for the M16/A1
per TM 42-0001-27 dated april 1994

What was in my head was the normal operating pressure for the AR15 .223 Remington which is 50K to 53/4K psi.

[sneaky one]

Hornady- maybe,,,, the old ones, from the 60-70's-- they are so tiny, less resistance, bearing surface. - I found some at a gun show here 6-mo. ago. Or,,, I may not even bother. I could probably get a 92-3 gmx, that side by side is a close ringer to a 100-TTSX barny, to maybe get close to 3k....,...... let's wait till after next wknd., to see how close I got with all the units. I'll post the results, and hopefully have a witness or 4.

Mseric, I'll call soon. The grr., and 7.62, 6ppc., and all the rounds that use the .220 russian case- base will use up more of the bolt face-- from a 5.56. -opened up====less pressure upon it, it has to be de-tuned a bit to hold up long term. I'm sure it can handle the occasional 51-52k hit,,, I;m sure I went over the top here and there,, but then I back off- .5 grn., or more . Think. , study,,,, then load it. All the info is out there for all to see. Check out LUtz Moeller- the german bullet designer- researcher dude. OMG. He has a .338 bullet that he shoots long range- looks like a canoe with 4 rubber bands around it-- the bands are the only bearing surfaces....= wow.

[LRRPF52]

Proof loads for 5.56 NATO are the 62k. I've seen most historical figures for 5.56 55gr M193 at 55k if I remember correctly. I'm seeing figures up to 58,000 psi doing a search, but The Black Rifle Volumes are probably one of the best references for this. Either way, 5.56 NATO is a very hot load in both M193 and M855, to get the velocity. They were originally trying for 3300+ fps with the prototype .222 Special

From The Gun Zone--A 5.56x45mm Timeline:

"The new projectile is also produced by Sierra. Robert Hutton uses Speer's Ballistic Calculator to estimate the muzzle velocity need to provide the desired performance at 500 yards. The results indicate a muzzle velocity of 3300fps with the 55 grain bullet will be required. Hutton begins load development with IMR 4198, IMR 3031, and an unnamed Olin ball powder. Using a Remington Model 722 with a 22" Apex bull barrel and a Lyman 25x scope, Hutton successfully perforates US helmets at 500 yards during a public demonstration. However, testing also indicates that the .222 Remington cannot achieve the required velocity without excessive chamber pressure. Stoner contacts Winchester and Remington about increasing the case capacity; Remington accepts the request. (This refusal is hardly surprising since Winchester had their own SCHV rifle and cartridge in the works.) The resulting cartridge is designated the .222 Special."

If you have some time, it's an informative read about the development and adoption of 5.56x45. http://www.thegunzone.com/556dw.html

[sgt_murf]

Proof loads for 5.56 NATO are the 62k. I've seen most historical figures for 5.56 55gr M193 at 55k if I remember correctly. I'm seeing figures up to 58,000 psi doing a search, but The Black Rifle Volumes are probably one of the best references for this. Either way, 5.56 NATO is a very hot load in both M193 and M855, to get the velocity. They were originally trying for 3300+ fps with the prototype .222 Special

From The Gun Zone--A 5.56x45mm Timeline:

"The new projectile is also produced by Sierra. Robert Hutton uses Speer's Ballistic Calculator to estimate the muzzle velocity need to provide the desired performance at 500 yards. The results indicate a muzzle velocity of 3300fps with the 55 grain bullet will be required. Hutton begins load development with IMR 4198, IMR 3031, and an unnamed Olin ball powder. Using a Remington Model 722 with a 22" Apex bull barrel and a Lyman 25x scope, Hutton successfully perforates US helmets at 500 yards during a public demonstration. However, testing also indicates that the .222 Remington cannot achieve the required velocity without excessive chamber pressure. Stoner contacts Winchester and Remington about increasing the case capacity; Remington accepts the request. (This refusal is hardly surprising since Winchester had their own SCHV rifle and cartridge in the works.) The resulting cartridge is designated the .222 Special."

If you have some time, it's an informative read about the development and adoption of 5.56x45. http://www.thegunzone.com/556dw.html

WE are so close it isn't funny on the 5.56mm/ .223 (and yes the Adult world will develop a powder /receipe to produce mo' velocity with lower pressure, the Military woohoo is stuck with manual and the Powder called out at set pressure)
and what I am recalling is the published data from the Army and the Military loads.
LRRPF sir I believe your research is correct from what you are seeing.
Back thrust is another issue on the bolt which on the Grendel is eat out (enlarged). A LBC/Grendel with a rebated rim of the 5.56mm???
works for the 6.5x.284? thoughts? anybody ever heard of before?
Maybe we could get wolf to produce them hehe

[JASmith]

...Back thrust is another issue on the bolt which on the Grendel is eat out (enlarged). A LBC/Grendel with a rebated rim of the 5.56mm???
works for the 6.5x.284? thoughts? anybody ever heard of before?...

I've thought about that too, but discovered that the back-thrust is developed by multiplying the pressure times the area of the inside of the case head.

All that rebating does is let you use a standard bolt face, but does not reduce the force put on the bolt lugs.

[sgt_murf]

Ohhh well just a thought
maybe I need to buy a lathe and turn some of my own Boolits.
Or simply use a Bolt gun with the LBC / Grendel 6.5 and easily get the 3K speed without pressure limits

[LRRPF52]

A rebated rim will also be less mass, meaning faster plasticity times for the brass, meaning less pressure/heat tolerance from the brass. I think you would have no problem getting 3000fps with 100gr in a bolt gun with a long pipe. A buddy of mine built a CZ527 micro action and runs 139gr Scenars at 2650-2700fps. That is .260 Rem territory. The 100gr projectiles at those velocities will only increase your lead shower within 500 yards, wherever the 2600fps threshold is at that velocity.

[bwaites]

I get 2900+ from 100 grain Bergers without pressure signs, running out of my 28" Grendel.

[LRRPF52]

Been waiting for you to say that...

[bwaites]

Been waiting for you to say that...

LOL!! It was a great load in my 20 inch, and didn't seem to be a problem, but the velocity was much higher than I expected out of that long tube!

[mseric]

Remington 30 AR, .492 Rim dia, 55,000psi

http://en.wikipedia.org/wiki/.30_Remington_AR

223 Remington, .378 Rim dia, 55,000psi

http://en.wikipedia.org/wiki/.223_Remington

5.56 Nato, .378 Rim dia, 62,366psi

http://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO

[mseric]

LOL!! It was a great load in my 20 inch, and didn't seem to be a problem, but the velocity was much higher than I expected out of that long tube!

What powder are you using? Longdayjake is getting 2800fps out of his 20 inch barrel with AA 2230 and 100gr bullets.

[sgt_murf]

Remington 30 AR, .492 Rim dia, 55,000psi

http://en.wikipedia.org/wiki/.30_Remington_AR

223 Remington, .378 Rim dia, 55,000psi

http://en.wikipedia.org/wiki/.223_Remington

5.56 Nato, .378 Rim dia, 62,366psi
http://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO

Yep that supports what I said from the TM (technical Manual for ammuntions http://www.kmike.com/Ammo/tm%2043-0001-27.pdf ) Proof loads (62K) not standard working loads (55k) in the 5.56mm that is what the rifle manufacting must meet before shipping the rifle. I must fire a proof load at 62K with no damage (that is 125% of the accepted normal working load of 55k). Also the rifle must fire a 20 shot group for accuracy using either M193 or M855 for military acceptance.
HOWEVER Lake City in MO (ATK- aka Speer, CCI, Sierria, etc, etc,- a private contractor) must produce ammuntion within the guidelines of the TM. Glad to see we all agree

P.S.
also note that the TM will advise the Grs of powder and type (commercial /manufact type) within a given loads although what You buy off the shelf is actually better than what is used. If the powder that LC is mandated to use was better then the National Guard Marksmanship Unit located here in Arkansas and the Army Marksmanship Unit in Georgia would use the Gov't contracted powder vs off the shelf such as RL15, AA2520.

[JASmith]

Remington 30 AR, .492 Rim dia, 55,000psi

http://en.wikipedia.org/wiki/.30_Remington_AR

223 Remington, .378 Rim dia, 55,000psi

http://en.wikipedia.org/wiki/.223_Remington

5.56 Nato, .378 Rim dia, 62,366psi
http://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO

Have you checked the default pressure values in the QuickLoad database?

The Hodgdon website shows one load of 52,900 for the 30 RAR and has loads upwards of 62,000 psi for the WSSM. This, coupled with those big case diameters, explains why the 30RAR and the WSSM implementations have different and larger bolts.