Ruger American Predator 6.5 COAL too short?

[easydoesit]

Forgive me if this is a stupid question, but I am relatively new to reloading and want to make sure I'm doing this correctly. Using the Hornady OAL gauge and comparator kit I measured to the lands 15 times and came out with an average CBTO (cartridge base to ogive) length of 2.0248. I backed it off 0.020 and ended up with CBTO length of 2.0048 and decided on seating to 2.0050. However, when I seat to this CBTO length, I end up with a COAL of 2.6395 and the book recommends 2.800. (this is for the Hornady 140gr ELDM). I am gently applying pressure until resistance is felt on the OAL gauge, then locking it down tightly and backing the case out and measuring. Am I missing something here, or will this work for my rifle? Thanks for your time.

Also, I have been using Hornady 140gr ELDM factory ammo thus far, and haven't seen any signs of pressure even though there are at or slightly past the 2.800 COAL.

 

[jsthntn247]

Seat a bullet in a empty case to the max coal you found. Shine the bullet with steel wool and chamber the bullet. Look at it under the light and see if you see land marks. 2.6395 is too short.

 

[easydoesit]

Seat a bullet in a empty case to the max coal you found. Shine the bullet with steel wool and chamber the bullet. Look at it under the light and see if you see land marks. 2.6395 is too short.

I don't have any steel wool and every place is closed at this hour, so I used the sharpie colored bullet and dented case method and I did it twice and came back with 2.7735 and 2.6835 COAL. The sharpie and dented case method can be found here https://www.wideopenspaces.com/reloading-finding-lands-pics/

 

[txguero]

I had a similar issue with a Criterion 6.5 Creed barrel. I was reaching the lands around 2.680 with the 140 ELD-M. Thought I was going crazy but I measured again and again and that's where I was at. Barrel still shot lights out but that spec definitely seemed shorter than SAAMI.

 

[spife7980]

What do you get until you press and feel solid resistance? You’re pushing the case all the way forward in the chamber until it bottoms out first and then the bullet?

I’m guessing the bullet is dragging on a tight freebore or there is some runout and that’s pishing the bullet off to one side more where it’s dragging etc.

 

[easydoesit]

What do you get until you press and feel solid resistance? You’re pushing the case all the way forward in the chamber until it bottoms out first and then the bullet?

I’m guessing the bullet is dragging on a tight freebore or there is some runout and that’s pishing the bullet off to one side more where it’s dragging etc.

Correct, I'm pushing the bullet all the way forward in the chamber, then the bullet. I'm going to load a couple at 2.7 and a minimum load and see how it does.

 

[txguero]

Depending on how that goes you might try some 120s and 130s if you do have a short throat.

 

[Brux]

Clean the barrel real good and remeasure. If it still comes up that short send it back to Ruger.
If the freebore is that short I am surprised you could close the bolt on the factory ammo.

 

[allaue]

I am having the same issue as the OP. I posted this over at RugerForum.net and had some insightful responses, but wanted to put here as well.

I have a 22" Ruger American Predator 6.5 Creedmoor that I purchased April 2020. When I use the Hornady O.A.L. gauge and bullet comparator, I come in around 2.055 for CBTO to the lands for the 140gr ELD-M bullet. I got similar results with using a Sharpie felt-tip black marker (around 2.040). First, I seated the bullet in a dummy round at 2.80 COAL and then I started using the comparator until I had no land mark scrapes all the way until the 2.04 CBTO length. . This would give me a COAL of around 2.660 for that bullet.

I looked around for other general resources for short throat or freebore, but couldn't really understand how to apply the .199 standard for this caliber in my situation.

My first 70 rounds shot were factory Winchester 125gr target rounds, then 20 rounds of federal 140gr non typical. I don't have the lengths of those, but I did not have problems chambering either one.

I took those fired cases and reloaded with Hornady 140gr SST at the published 2.690” COAL. I deprimed / Neck size, trimmed to 1.915”, did various charges of Winchester 760 and seated all at 2.690” This was before I bought the comparator and O.A.L. length gauge. There were no problems with closing the bolt with any of these rounds or ejecting after shooting or bad primer signs.

Now that I’m doing my second round of reloads, I wanted to get more into the hobby and pick up the extra tools for these 140gr ELD-M.

I contacted Ruger and asked if they have heard of this issue and said that it is made to SAAMI specification. Am I looking at this the right way? Should I still ask to send it in for repair?

Thank you in advance for your responses!

 

[Jordanwickham]

That seems like you are coming up with an incredibly short freebore, as in no freebore. My Ruger barrel brand new was able to seat 140 ELDMs at 2.800 with .037" jump. The only round I had to load short was 140 SMKs because of the secant ogive. Even those were 2.72 with .010" jump. When youre running the Hornady tool are the bullets getting stuck in the rifling ( not coming back out with the case )? I've feathered that tool and only had a couple not lodge in the lands. If youre measurement is correct then general 140g 6.5 ammo would be jammed by .150" minimum and that's not how they send barrels out.

 

[Jordanwickham]

Also it doesnt hurt to put a little umph on it to make sure it's in the lands. I've found that tool gets bound up sometimes on the push rod. But regardless if you don't have the bullet getting lodged atleast 50% of the times you try to measure you aren't into the lands.

 

[allaue]

Yes, I even used a cleaning rod on the other end of the barrel to 'play' with the seating. I can feel it enter the lands and I typically have to remove the bullet by pushing it out, as in it comes out of the modified case. When I touch the lands, it's 2.055 and if I 'push' into the lands, its about 2.07-2.100 max.

 

[Jordanwickham]

Yes, I even used a cleaning rod on the other end of the barrel to 'play' with the seating. I can feel it enter the lands and I typically have to remove the bullet by pushing it out, as in it comes out of the modified case. When I touch the lands, it's 2.055 and if I 'push' into the lands, its about 2.07-2.100 max.

You have shot 140g factory ammo in the rifle?

 

[allaue]

Yes, I shot 20 rounds Federal 140g Non-Typical. I don't recall it being hard to chamber though.

 

[Jordanwickham]

I'd check the measurements of some of that ammo

 

[allaue]

Thank you, I am going to send it out to get looked at.

 

[allaue]

Just an update, I sent it to Ruger and they are sending it back with a new bolt. I don’t see how that change the original issue of the short throat though.

 

[918v]

Why don’t you load a dummy round to 2.900” and try to chamber it. The bolt will prolly not close. Then keep seating the bullet deeper in small increments until the bolt closes. That will give you a general idea where the lands are.
I think you’re feeling a rough freebore and confusing it with the rifling.

 

[allaue]

Here's what happened with a round loaded to 2.800". Any thoughts?

 

[918v]

You’re not hitting the lands in the sense that you’re pressing against the leade. Maybe the chamber reamer was worn and cut the throat too tight in the sense it did not cut off all of the rifling down to the walls. But what you have will wear in after a few hundred rounds.

 

[allaue]

You’re not hitting the lands in the sense that you’re pressing against the leade. Maybe the chamber reamer was worn and cut the throat too tight in the sense it did not cut off all of the rifling down to the walls. But what you have will wear in after a few hundred rounds.

Can you elaborate more? Am I jamming into the lands at this length? Should I seat at 2.800 and just go to the range or should I try to seat deeper according to what the OAL gauge says, which is more like 2.550 - 2.650" ?

 

[918v]

Your pics shows that you have a quarter inch of rifling marks on the bullet. I can tell you with absolute certainty that there is no way in hell you can jam a bullet that much into the lands.

When they cut your chamber the reamer failed to remove all of the rifling from the throat. It left a faint remnant of the rifling to scratch your bullet. A throat is normally .0005” to .0020” bigger in diameter than the bullet and this causes all of the rifling lands to be removed. In your case it wasn’t, but it’s not like there is no throat at all. You do have a throat, but it’s too tight. But it will also wear in as you’re shooting the gun. After a few hundred rounds you won’t see those marks anymore. The powder will smooth them out.

I’m not going to tell you what COAL to use until you find the COAL where you are making hard contact with the rifling, hard as when you can’t close the bolt.

Start with something like 2.950” and seat that bullet deeper in small increments until you can close the bolt. That will be your max COAL. Then get back to us.

 

[918v]

Look, this is the relationship between your bullet and the chamber:

 

[allaue]

Thank you for the thorough response. So, I took your advice about seating a round starting at 2.90"

At 2.90" absolutely could not close the bolt.
Went to 2.875" could close bolt if I did it hard/quickly, but was definitely hard to pull the bolt back. I noticed dark black rifling markings (not just a scrape) on the bullet.
Went to 2.85" could close bolt a little easier and remove, but still had to do it quickly to chamber.
Around the 2.80-2.82" mark, I was able to close the bolt slowly and extract it alright.

So, based on this, the 2.80" neighborhood seems to be okay, but I was still getting those long markings that I posted before.

 

[918v]

OK so 2.8” is a good start. Now find your max powder charge and you’re ready for accuracy testing.

You will get those marks for a while but they will go away eventually. The crude picture I drew is exaggerated. Notice the throat is much bigger than the bullet. Now imagine the throat being a lot tighter and some remnants of the rifling still there. These 6.5’s have long bullets. Half the bullet is in the throat and half in the neck. It’s bound to get scraped if everything isn’t perfectly aligned.

 

[allaue]

Thank you again, what you said in all the replies is the missing piece of the puzzle and the best explanation for what is happening. It puts together what I read in other threads across multiple forums about the chamber/throat not being "finished" correctly.

Now that I understand it based on what you said, I took the Hornady OAL gauge and really seated the bullet in the chamber with confidence (some "umph") and got a measurement that was consistent and repeatable with any bullet I tried from the box. So, I think I am now correctly pushing it past the rifling that isn't cut all the way and hitting the actual rifling after the leade based on your diagram? I was getting around 2.200" CBTO with this method. This was about 2.820 - 2.830" COAL roughly. So with that, I took it down to 2.180" CBTO on my actual bullet seating for my reloads which puts it at 2.800". I'll experiment with seating .01 and .02" off this 2.220" CBTO I was getting on the gauge.

 

[918v]

I concur. Except I would change the COAL in .005” increments rather than .010”. So starting with 2.800” I would also try 2.795”, 2.805”, etc. What brass and powder are you using?

 

[allaue]

I concur. Except I would change the COAL in .005” increments rather than .010”. So starting with 2.800” I would also try 2.795”, 2.805”, etc. What brass and powder are you using?

Oh okay I will do that! I am using Winchester brass and IMR 4451.

 

[Jordanwickham]

Oh okay I will do that! I am using Winchester brass and IMR 4451.

Never messed with Winchester brass but I have messed with IMR 4451. You'll find it to produce pretty low velocity. IDK if you have manuals but what I'm seeing as published data is 41.1-41.3 as max. Can't believe it but Hornady is showing the highest charge of 41.3. They are notorious for being low on charge weights.
Definitely want to go in .005" increments as 918 said. You can completely miss (best) nodes going in .010". I ran a depth test the other day that had alot of .4-.5 groups but could have missed the .2-.3 groups.
I also don't know what the general consensus is but I run a fairly wide range of total seating depth. The test I ran the other day covered .090".

Before I run seating tests I find a stable powder charge. I don't know what your process is but just in the context your last long post makes it sound like you were going straight into a seating test? I may have missed something though.

The 4451 did produce good groups, was just too slow for what I was looking for.

 

[allaue]

Never messed with Winchester brass but I have messed with IMR 4451. You'll find it to produce pretty low velocity. IDK if you have manuals but what I'm seeing as published data is 41.1-41.3 as max. Can't believe it but Hornady is showing the highest charge of 41.3. They are notorious for being low on charge weights.
Definitely want to go in .005" increments as 918 said. You can completely miss (best) nodes going in .010". I ran a depth test the other day that had alot of .4-.5 groups but could have missed the .2-.3 groups.
I also don't know what the general consensus is but I run a fairly wide range of total seating depth. The test I ran the other day covered .090".

Before I run seating tests I find a stable powder charge. I don't know what your process is but just in the context your last long post makes it sound like you were going straight into a seating test? I may have missed something though.

The 4451 did produce good groups, was just too slow for what I was looking for.

I’m new to reloading and the caliber, so I was just trying to figure out the seating depth and working off the lands. I will try the increments as you said. I haven’t really gotten into velocities and what charge is best. I just make 10 rounds or so at the different charges in the Hornady manual app I have.

Also, I called a gunsmith who was very thorough at explaining how to break the barrel in and also concurred with what was said here. He offered a service to “hone” the barrel if I chose to do so.

 

[918v]

You can hone it yourself using JB Bore Paste. It’s a mild abrasive cleaning paste, kinda like dust suspended in tan colored toothpaste, that you embed in a cleaning patch and run up and down on a jag. It will polish the rough areas of the throat and lands.

 

[allaue]

Just an update to this.. I sent it in to Ruger again with the pictures I posted above. They honed the chamber/throat and cleaned the gun. They even sent back 3 pictures of their results of a Hornady Precision Hunter 143gr ELD-X Cartridge colored with a sharpie with no land marks. I'm pleased to report that I am now getting consistent measurements of 2.198-2.200 CBTO with Hornady 140gr ELD-M bullets.