Speer gr TNT speed limit

[gzig5]

I think I read where the 50gr has a "limit" from speer of 3400fps. Is the 55gr the same? Anyone have issues running them 3600-3800? they will be moly coated, new barrel. They are pretty cheap and the 50's always shoot great in my 222

 

[MQ1]

I think I read where the 50gr has a "limit" from speer of 3400fps. Is the 55gr the same? Anyone have issues running them 3600-3800? they will be moly coated, new barrel. They are pretty cheap and the 50's always shoot great in my 222

I think it more depends on the quality of your barrel. I have a Hart that I have no issues pushing TNTs past 3800...

MQ1

 

[grovey]

I was told the 55's were made because the 50's did come apart as you said. I was also told the 50's were more accurate. The 55's shot "ok" in my factory 223, but not well enough to make me change my go to bullet.

 

[gzig5]

I'm looking at using them in a 8 twist 22 BR, so there will be some additional centripetal stress over a standard 12" twist. Will be a brand new Krieger.

 

[284winner]

Buddy shot the 50s thru his Bushmaster AR at about 3300 and they came apart before even leaving the barrel. Unknowing he continued shooting and evidently fragments of the jackets remained in the rifling. After several shots, the gun basically blew up. His last shot blew the mag out the the well and blew the bottom out of the mag leaving the spring and follower on the bench. Literally rounded both sides of his lower receiver below the ejection port. Slightly but enough to ruin it. Still do not understand how it happened other than possible fragments in the barrel causing pressure with every round shot. These could have been a bad batch of bullets as well as I've never seen that before. It's a 9 twist 24" barrel and speeds we're not all that fast.

 

[jepp2]

I think I read where the 50gr has a "limit" from speer of 3400fps

Maybe I'm totally off base, but my understanding is the failure of the jacket is due to excessive RPM. The speed was an issue only if the twist caused excessive RPM of the bullet.

I was shooting the Speer 52 HP (4708) in an 8T AR15 and starting to have failures at 3300 fps, which was almost 300,000 RPM. I wrote Speer and they said that 300,000 RPM was about where the bullets would start failing. They would make it out the barrel and through the chrony (14 feet from the muzzle) but not make it to the target.

 

[John Russell]

I think I read where the 50gr has a "limit" from speer of 3400fps. Is the 55gr the same? Anyone have issues running them 3600-3800? they will be moly coated, new barrel. They are pretty cheap and the 50's always shoot great in my 222

The box for the Speer 55gr TNT's is marked "For the 22-250 and .220 Swift"... the jackets are thicker.

 

[RussellJ]

I think I read where the 50gr has a "limit" from speer of 3400fps. Is the 55gr the same? Anyone have issues running them 3600-3800? they will be moly coated, new barrel. They are pretty cheap and the 50's always shoot great in my 222

In the SPEER #14 Reloading Manual page 20 shows the TNT velocity limits on the 50grn TNT bullets as 3400fps with a note below the chart saying: These limits assume some degree of barrel wear or roughness. Some barrels may allow higher velocities. NOTE: Speer has yet to reach a velocity limit for the .224 55 HV TNT bullets in any commercial cartridge.