I have 5 loaded with 95.5gr Retumbo and seated to 3.225" OGL. This is the load I've already tested.
I have an additional 5 loaded with 95.5gr Retumbo and seated to 3.105" OGL. This load will be to compare accuracy against the original as well as velocity.
3.105" OGL
As you can see, I seated the bullet so the base is at the shoulder and right on top of the powder and the case neck has full bearing on the surface of the bullet.
Here are the two depth compared.
I will settle on the one that gives me the best accuracy. If they are equal in that regard. I'll go for the fastest.
"To Hell with efficiency, it's performance we want!" - Elmer Keith
Disclaimer: You are free to belive or disbelieve the following if you so choose. I didn't believe it myself. You are free to think me a liar and full of crap. All I can do is relay what was in front of me.
Took "The Sister" to the range today to test loads again. As mentioned above, I wanted to verify the 95.5gr load that I shot on Friday as well as test the same load with the bullet seated deeper.
Well, I was thinking that the barrel was heating up beyond the rifles ability to maintain accuracy for the third shot as most all groups had the third shot spreading out the other day. So, today I planned to wait and let the barrel cool between shots. I fired a fouling round and waited for the barrel to cool. Then, I waited 10 minutes between shots at 70 degrees for the 3 shot group. At that temp, the barrel cooled down enough, I think.
What I saw when finished defied everything I've ever believed and had it not just happened in front of me, I would probably call you a liar.
Holy CRAP!!!!!
A sporter weight factory barrel is NOT supposed to do that!!! I even got off my rifle between shots!!! You're NOT supposed to do that! Granted, I went back to as exactly the same mount as possible, but.........I came off the rifle.
That hole is .324" in diameter. Basically, it looks like a .308 cal hole. I know that. But, it's three .284 cal bullets holes. Even though it doesn't look like it. I appologize that I didn't shoot a more realistic looking group. That's all I got.
Folks, I'll never be able to do that again. I know that it was a blind fluke and NOT repeatable. But..........I'll take it once in my life, if that's all I get.
Anyway, I then shot that load for velocity and those 162gr A-Max bullets are trucking along at 3,374 fps and a SD of 7. I'm not a velocity fiend, but I'll take that in a heartbeat!
Next, I wanted to test the same powder charge with bullets seated .120" deeper (see pics in earlier post).
Yeah.........THAT didn't work!!!!!
Same powder charge. Just seated deeper. The whole thing came unglued!!!
Folks, those bullets are keyholing into the target!! Figure THAT one out! Only thing I can think of is that the excessive freebore in the chamber is allowing the bullets to hit the lands off kilter and zinging them out the barrel in an unstable manner. Even the recoil was drastically increased. I mean.......it felt like I was shooting a different rifle!
Even though I was technically D-U-N with that particular load, I wanted to see the velocity.
3,439 fps
Seating the bullet just .120" deeper in the case increased the velocity 65 fps, w/ a SD of 31 fps, caused the bullets to keyhole in the target, and increased recoil noticeably!!
WOW!
It is cool to verify what I already suspected in that arena.
Anyway, take it or leave it. Believe it or not. That's all I got.
"To Hell with efficiency, it's performance we want!" - Elmer Keith
Amazing group. Sometimes guns can defy all logic on what they shoot well and shoot not so good.
It's only true if it's on this forum where opinions are facts and facts are opinions
Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
I'd rather have my sister work in a whorehouse than own another Taurus!
Zedrick, just ran the numbers through quick target (QL's ballistic software ) I know you like impact speeds above 1800 fps. QT says your bullets will still be doing 1925 fps @ 1k :worthy:
Since he is not a long-range hunter it doesn't really make any difference.
The second group leaves me with a whole lot of pondering. My first thought about the keyhole is that the extra velocity overstablized the bullet, and it's yawing off course. Too fast?
Second thought, what about magazine length ammo?
Third thought, maybe you got a bad bullet?
Anyway, pretty iteresting, thanks for taking the time to do the experiment.
Zedrick, just ran the numbers through quick target (QL's ballistic software ) I know you like impact speeds above 1800 fps. QT says your bullets will still be doing 1925 fps @ 1k :worthy:
That'll work. Thanks!
"To Hell with efficiency, it's performance we want!" - Elmer Keith
The second group leaves me with a whole lot of pondering. My first thought about the keyhole is that the extra velocity overstablized the bullet, and it's yawing off course. Too fast?
Second thought, what about magazine length ammo?
Third thought, maybe you got a bad bullet?
Anyway, pretty iteresting, thanks for taking the time to do the experiment.
You still gonna try the other experiment?
I think the bullets were hitting the lands too fast and too off kilter. Can't prove that, though. But, all three bullets were slightly keyholed through the backer. Not just one.
I'll eventually get around to the other test.
"To Hell with efficiency, it's performance we want!" - Elmer Keith
Out of curiosity, what's the COL on those rounds? I see that book COL is 3.650" for a 162SMK, I'd assume that's magazine length. The max COL for all of the other RUMs is 3.600"
I'm just wondering how much closer to the lands you are.
(my thinking is that there's way more jump in mag length ammo, and it shoots ok. Maybe there's a not so good jump length?)
Out of curiosity, what's the COL on those rounds? I see that book COL is 3.650" for a 162SMK, I'd assume that's magazine length. The max COL for all of the other RUMs is 3.600"
I'm just wondering how much closer to the lands you are.
(my thinking is that there's way more jump in mag length ammo, and it shoots ok. Maybe there's a not so good jump length?)
I'm not sure what the COAL was for the deep seated bullets. But, there were still longer than the handloads Jerm sent me. So, I'm not saying they were too short. Just think that particular bullet didn't like whatever combination of speed and distance to lands. I guess. Obviously? Heck, something wasn't working.
I won't be loading anymore rounds seated to that depth. So, I won't know the COAL.
Edit: Once I load the long seated bullets again, I'll measure the COAL and subtract .120" from them.
"To Hell with efficiency, it's performance we want!" - Elmer Keith
I'm not sure what the COAL was for the deep seated bullets. But, there were still longer than the handloads Jerm sent me. So, I'm not saying they were too short. Just think that particular bullet didn't like whatever combination of speed and distance to lands. I guess. Obviously? Heck, something wasn't working.
I won't be loading anymore rounds seated to that depth. So, I won't know the COAL.
Edit: Once I load the long seated bullets again, I'll measure the COAL and subtract .120" from them.
Cool.
It's all speculaton, but, might be one of those tidbits to keep under ones hat, for future reference.
Interesting to me, at least.
Serious question and I know it's really impossible to truly know the answer. But, I'm puzzled.
I am over 150 feet per second faster than the Hodgdon Book Max velocity and only .5 grain over their Max load. I am 100 feet per second faster than other accounts I've been able to find.
I have zero external pressure signs. I could probably even go higher! Not going to, though. But, what could be causing these numbers? Granted, I've found no data with the powder/charge/bullet/seat depth that I'm using. It shouldn't be that much different than what I'm finding.
Could be the chronograph, but it's on par with other rifles when used. Fast barrel? Sure, but 150 fps fast?
Anyway, just curious.
"To Hell with efficiency, it's performance we want!" - Elmer Keith
I've spent no small amount of time on the Berger site recently and they are big fans of seating long and describe how that allows lower pressures. So i think that would reinforce kp's post.
Or you could use that extra space but I can't image why would want to change a thing.
Teach your children to love guns, they'll never be able to afford drugs
Replies
"The Un-Tactical"
Probably.
I have 5 loaded with 95.5gr Retumbo and seated to 3.225" OGL. This is the load I've already tested.
I have an additional 5 loaded with 95.5gr Retumbo and seated to 3.105" OGL. This load will be to compare accuracy against the original as well as velocity.
3.105" OGL
As you can see, I seated the bullet so the base is at the shoulder and right on top of the powder and the case neck has full bearing on the surface of the bullet.
Here are the two depth compared.
I will settle on the one that gives me the best accuracy. If they are equal in that regard. I'll go for the fastest.
Yes.
Took "The Sister" to the range today to test loads again. As mentioned above, I wanted to verify the 95.5gr load that I shot on Friday as well as test the same load with the bullet seated deeper.
Well, I was thinking that the barrel was heating up beyond the rifles ability to maintain accuracy for the third shot as most all groups had the third shot spreading out the other day. So, today I planned to wait and let the barrel cool between shots. I fired a fouling round and waited for the barrel to cool. Then, I waited 10 minutes between shots at 70 degrees for the 3 shot group. At that temp, the barrel cooled down enough, I think.
What I saw when finished defied everything I've ever believed and had it not just happened in front of me, I would probably call you a liar.
Holy CRAP!!!!!
A sporter weight factory barrel is NOT supposed to do that!!! I even got off my rifle between shots!!! You're NOT supposed to do that! Granted, I went back to as exactly the same mount as possible, but.........I came off the rifle.
That hole is .324" in diameter. Basically, it looks like a .308 cal hole. I know that. But, it's three .284 cal bullets holes. Even though it doesn't look like it. I appologize that I didn't shoot a more realistic looking group. That's all I got.
Folks, I'll never be able to do that again. I know that it was a blind fluke and NOT repeatable. But..........I'll take it once in my life, if that's all I get.
Anyway, I then shot that load for velocity and those 162gr A-Max bullets are trucking along at 3,374 fps and a SD of 7. I'm not a velocity fiend, but I'll take that in a heartbeat!
Next, I wanted to test the same powder charge with bullets seated .120" deeper (see pics in earlier post).
Yeah.........THAT didn't work!!!!!
Same powder charge. Just seated deeper. The whole thing came unglued!!!
Folks, those bullets are keyholing into the target!! Figure THAT one out! Only thing I can think of is that the excessive freebore in the chamber is allowing the bullets to hit the lands off kilter and zinging them out the barrel in an unstable manner. Even the recoil was drastically increased. I mean.......it felt like I was shooting a different rifle!
Even though I was technically D-U-N with that particular load, I wanted to see the velocity.
3,439 fps
Seating the bullet just .120" deeper in the case increased the velocity 65 fps, w/ a SD of 31 fps, caused the bullets to keyhole in the target, and increased recoil noticeably!!
WOW!
It is cool to verify what I already suspected in that arena.
Anyway, take it or leave it. Believe it or not. That's all I got.
See my sig........Elmer is 'da MAN!!!!!!
So is Sam.
Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
I'd rather have my sister work in a whorehouse than own another Taurus!
Good shooting!
"The Un-Tactical"
Since he is not a long-range hunter it doesn't really make any difference.
"The Un-Tactical"
On both accounts. Awesome group.
The second group leaves me with a whole lot of pondering. My first thought about the keyhole is that the extra velocity overstablized the bullet, and it's yawing off course. Too fast?
Second thought, what about magazine length ammo?
Third thought, maybe you got a bad bullet?
Anyway, pretty iteresting, thanks for taking the time to do the experiment.
You still gonna try the other experiment?
There's an honest man.
:cool2:
That'll work. Thanks!
It's the thought that counts.
I think the bullets were hitting the lands too fast and too off kilter. Can't prove that, though. But, all three bullets were slightly keyholed through the backer. Not just one.
I'll eventually get around to the other test.
Out of curiosity, what's the COL on those rounds? I see that book COL is 3.650" for a 162SMK, I'd assume that's magazine length. The max COL for all of the other RUMs is 3.600"
I'm just wondering how much closer to the lands you are.
(my thinking is that there's way more jump in mag length ammo, and it shoots ok. Maybe there's a not so good jump length?)
I'm not sure what the COAL was for the deep seated bullets. But, there were still longer than the handloads Jerm sent me. So, I'm not saying they were too short. Just think that particular bullet didn't like whatever combination of speed and distance to lands. I guess. Obviously? Heck, something wasn't working.
I won't be loading anymore rounds seated to that depth. So, I won't know the COAL.
Edit: Once I load the long seated bullets again, I'll measure the COAL and subtract .120" from them.
Dad 5-31-13
I couldn't do it again. Fluke. But, I'll take a fluke.
There used to be a guy on the forum that could do that pulling the trigger with his big toe, nicely done, that one needs to be hung on the 'fridge.
Cool.
It's all speculaton, but, might be one of those tidbits to keep under ones hat, for future reference.
Interesting to me, at least.
By all means!!!! I never go shooting that I don't learn something. Ballistics are amazing to study.
"The Un-Tactical"
I am over 150 feet per second faster than the Hodgdon Book Max velocity and only .5 grain over their Max load. I am 100 feet per second faster than other accounts I've been able to find.
I have zero external pressure signs. I could probably even go higher! Not going to, though. But, what could be causing these numbers? Granted, I've found no data with the powder/charge/bullet/seat depth that I'm using. It shouldn't be that much different than what I'm finding.
Could be the chronograph, but it's on par with other rifles when used. Fast barrel? Sure, but 150 fps fast?
Anyway, just curious.
Or you could use that extra space but I can't image why would want to change a thing.