Load coming out of tune?

[gunsandgunsmithing]

I may have missed it but is this my tuner or a different one? If it's one of mine, I'm very happy to walk you through it but regardless, it might be worthwhile just to give the maker a call to discuss what increments to move in and what those increments should look like on the target. All tuners work on the same principle but there are substantial differences in small details regarding how they are best used.

Again, I'm very happy to help if I can. Just give me a call is all it takes. Pictures would help as well. I look for very distinct and predictable group shapes mostly but there's more to it than that. Every detail should support one another to come to a setting that I'd be confident in. Shooting small is great but knowing what to look for as it starts to go away and how to fix it, is what tuning is all about, on the fly.

 

[Ajwilly96]

I may have missed it but is this my tuner or a different one? If it's one of mine, I'm very happy to walk you through it but regardless, it might be worthwhile just to give the maker a call to discuss what increments to move in and what those increments should look like on the target. All tuners work on the same principle but there are substantial differences in small details regarding how they are best used.

Again, I'm very happy to help if I can. Just give me a call is all it takes. Pictures would help as well. I look for very distinct and predictable group shapes mostly but there's more to it than that. Every detail should support one another to come to a setting that I'd be confident in. Shooting small is great but knowing what to look for as it starts to go away and how to fix it, is what tuning is all about, on the fly.

It’s an EC tuner.

I just got a chance to measure my jam point again, the last time I measured it was 2.0880, it is now 2.1275. I’m going to load some rounds at the longer length and see what happens

 

[Murray Brook]

It’s an EC tuner.

I just got a chance to measure my jam point again, the last time I measured it was 2.0880, it is now 2.1275. I’m going to load some rounds at the longer length and see what happens

I would do this also, but get your velocity as well. If it is down due to the new OAL then you may have to add .1gr of powder as well to get it back to where it was. JMO

 

[Ajwilly96]

Got a chance to go shoot this morning. I loaded them much longer, my original load was 2.098 this load is 2.1375. The group tightened right back up and I did not lose any velocity

 

[Bill Norris]

Got a chance to go shoot this morning. I loaded them much longer, my original load was 2.098 this load is 2.1375. The group tightened right back up and I did not lose any velocity
View attachment 1566451

In this situation turning the tuner may not have brought it back into tune but since it was a vertical change as opposed to the green dot group I believe it could have.

 

[Ajwilly96]

In this situation turning the tuner may not have brought it back into tune but since it was vertical as opposed to the green dot group I believe it could have.

The green dot group is just fire form loads to warm/foul the barrel. The groups it was shooting before I loaded them long we’re just a much larger circle about double size

 

[Bill Norris]

The green dot group is just fire form loads to warm/foul the barrel. The groups it was shooting before I loaded them long we’re just a much larger circle about double size

I see. I thought you were showing a before and after bullet seating depth change.

 

[Kracken McGraw]

The green dot group is just fire form loads to warm/foul the barrel. The groups it was shooting before I loaded them long we’re just a much larger circle about double size

On your new length now, where are you from the touch point?( just curious).

 

[Ajwilly96]

On your new length now, where are you from the touch point?( just curious).

I’m Back to .010 jam

 

[spike-55]

It’s an EC tuner.

I just got a chance to measure my jam point again, the last time I measured it was 2.0880, it is now 2.1275. I’m going to load some rounds at the longer length and see what happens

In 600 rounds that seems to be an extreme amount of throat erosion???
stan

 

[Ajwilly96]

In 600 rounds that seems to be an extreme amount of throat erosion???
stan

I thought so as well, with a bore scope I am seeing zero fire cracking. Comparing to another shooters comparator measurement I am closer to theirs now using the same reamer design but different reamers.

I will take a measurement without the comparator later, I’m wondering if my throat area smoothed out from being chambered finally allowing me to get the proper use of the FB

 

[Ajwilly96]

So my new COAL measurement is 2.7370 to touch. The person I was comparing with was sitting at 2.701.

Either this is a fast wearing barrel, or thoroclean is causing some wear.

 

[6BRA]

How are you measuring?

 

[searcher]

See Mr Frank example above. It is not possible to have over a 50deg increase with no change in velocity and therefore barrel time as well.

I have never seen a 50 degree temp change not affect velocity in a .223, regardless of powder used. Your group falling apart at increased temperature verifies that is likely what is going on with your load.

In 600 rounds that seems to be an extreme amount of throat erosion???
stan

It is quite common to get a "significant" difference in jam measurement after only a short number of rounds on a new barrel. It is likely very little to do with throat erosion - but rather the ironing out of the sharp edges from when your throating was cut - at the juncture where the lands start.

 

[Murray Brook]

Maybe I missed it but what powder are you using.

 

[Ajwilly96]

Maybe I missed it but what powder are you using.

N140

 

[Ajwilly96]

How are you measuring?

I took three fired cases that have had their shoulder bumped, barely seat the bullet into them and then chamber them and quickly open the bolt

 

[Murray Brook]

N140

Not known to be a hard powder on the throat. I believe @searcher is right about the rough edges in the new throat.

 

[Owens85]

I took three fired cases that have had their shoulder bumped, barely seat the bullet into them and then chamber them and quickly open the bolt

If neck tension is normal while doing this that's your jam point and not your touch point. If your familiar with the stripped bolt method try that to find touch.

 

[6BRA]

I took three fired cases that have had their shoulder bumped, barely seat the bullet into them and then chamber them and quickly open the bolt

what ejector? Firing pin removed? Wheeler method will give you exact touch point. If TG ejector you wont need to mess with. Firing pin must be removed. The free bolt drop will tell you. Still not sure of your bolt configuration.
edit
a hornady/stoney point will not give you exact. If you want to mark you touch point for repeatable and future reference for throat erosion. Unless you pull the bbl, there is really no other way to do this. This method measures to the thousandth. jmo. My Bra with 700 hot rounds has .007 erosion. It must be known.
Mike