Chamber too short??

[Paddyd]

Hi,
If anyone here can help I sure would appreciate it.
Several weeks ago I ordered a Criterion Savage prefit barrel in 223R. It finally arrived and I installed it on the rifle. Today I finally had some time to check some measurements and to be frank, I'm confused.
First, I tried my Hornady modified case tool with some Nosler 55gn FBHP Nosler load data says to load to an overall length of 2.260" Well the ogive hits a dead stop right at .100" short of that placing more than half the bullet into the case touching.
Next I tried some Hornady 68gn match bullets. Seated out to the lands, the base of the bullet is about at the base or below the shoulder. I've been loading all these bullets in a M70HV and to kiss the lands I always worried about not having enough shank inside the neck. It's just the opposite with this barrel. To seat just .015" off the lands puts way too much bullet inside the case. Is this normal?? I know I'm not crazy because virtually every bullet style and weight I have tried (except Hornady 55gn FMJ) has been impossible to seat to any recommended overall length listed in my Lyman manual or the Hodgdon data page online.
PLEASE give me your opinions as to what might be going on here.

 

[338 dude]

Hi,
If anyone here can help I sure would appreciate it.
Several weeks ago I ordered a Criterion Savage prefit barrel in 223R. It finally arrived and I installed it on the rifle. Today I finally had some time to check some measurements and to be frank, I'm confused.
First, I tried my Hornady modified case tool with some Nosler 55gn FBHP Nosler load data says to load to an overall length of 2.260" Well the ogive hits a dead stop right at .100" short of that placing more than half the bullet into the case touching.
Next I tried some Hornady 68gn match bullets. Seated out to the lands, the base of the bullet is about at the base or below the shoulder. I've been loading all these bullets in a M70HV and to kiss the lands I always worried about not having enough shank inside the neck. It's just the opposite with this barrel. To seat just .015" off the lands puts way too much bullet inside the case. Is this normal?? I know I'm not crazy because virtually every bullet style and weight I have tried (except Hornady 55gn FMJ) has been impossible to seat to any recommended overall length listed in my Lyman manual or the Hodgdon data page online.
PLEASE give me your opinions as to what might be going on here.

You didn’t say but if you’ve installed a barrel before I’m sure you used a go no go gauge if that is correct it sounds like the throat is too short and needs to be throated for longer bullet or more free bore

 

[Paddyd]

Yes, I used the head space tools, but regardless, headspace isn't an issue here. My issue is from the case shoulder to the lands. The bolt isn't even in the receiver when testing seating lengths. I'm thinking the free bore is basically non existent in this chamber. With a bullet literally jammed, the cartridge overall length is between .050 and .125" shorter than the SAMI spec recommended length which normally includes somewhat of a jump. What I'm looking for is whether possibly CBI didn't chamber it correctly and what can be done to remedy it. Or am I not doing something right? I've been measuring with this Stoney Point tool for about 10 yrs now with several different rifles and projectiles so I think I am doing it correctly. Has anyone here experienced this before?

 

[searcher]

Very strong possibility you have slight burrs left from machining where the bullet makes contact. This is a very common in new barrels and can be seen with a borescope if you have access to one. Wrap a bit of 400 grit emery cloth around the end of a dowel rod which has been put into a pencil sharpener. I do this to touch up all new barrels as it is rare that a new barrel doesn't exhibit even the smallest of machine "fuzz". Given the extraordinary variation you have - it will be readily apparent if you have one.

 

[NorCalMikie]

Short throat chamber? Consider yourself VERY LUCKY! Most bullets are ready to fall out of the case neck if you get close to the lands.
I PREFER as much bullet in the neck as I can get. Base at or down a bit in the case neck/shoulder junction. All loads "jammed" .010 INTO the lands.
Won't be too long and the throat WILL wear. Probably faster than you want/expect.
I order all my chambers cut with ZERO freebore so I can start off with the lightest bullets I can get my hands on and go heavier as the throat wears and still be able to touch/jam the lands.
If you must, there's a thing called a "throating reamer" so you extend the freebore and can load heavier bullets BUT, you do that and the next thing you know, the throat is too long. Again, consider yourself lucky to have a short throat chamber.

 

[243winxb]

The ogive should not be seated below the case neck. This is where the .224" diameter gets smaller.

What is the twist rate of the new barrel?

 

[Paddyd]

It is a 26" Full Bull Criterion 223R 9 twist.

 

[243winxb]

A 9 twist should be good for up to 68, 69 gr bullets. The plastic tip bullets are longer then the hollow points. There is a lot of bullet shank into the case.

 

[Paddyd]

Yes the 9 twist and bullets isn't the issue. The issue is seating length. If I seat ANY bullet .020"off the lands, it will be FAR to far inside the case. Hell it's far to far inside when jammed. So far in fact that a Sierra 69G when against the lands the base of the bullet is at the base of the shoulder where the shoulder meets the case body. To me that is a serious issue and I'm at a loss as to why unless they screwed up the chambering. I can't see a smith worth his salt chambering a 9 twist that will only shoot a 53 gn Varnageddon unjammed.

 

[Walt Krafft]

There are lots of different 223 chambers. Before you modify it in any way, ask what reamer they used. They will fix it if it is not right.

 

[243winxb]

Sierra 69 gr tipped & Hormady 68 gr match bullets @ 2.260 COL. At this COL, both should chamber.

The ogive is in front of the black line, towards the tip.

Normal if loading for an AR15 to fit the magazine.

 

[243winxb]

Freebore length.

 

[Paddyd]

Sierra 69 gr tipped & Hormady 68 gr match bullets @ 2.260 COL. At this COL, both should chamber.

The ogive is in front of the black line, towards the tip.

Normal if loading for an AR15 to fit the magazine. View attachment 1131563

If I load them to that length, when I close the bolt I have to almost force it closed and it pushes the bullet back into the case. It's as if there isn't nearly enough room for the bullet. As for the hard bolt closure, the case is full length sized and unloaded, the case will easily chamber with zero effort so it is the freebore lacking. These bullets load in my M70 with lots of freebore to spare.
Monday AM I will be on the phone to Criterion to see what they have to say about my situation.

 

[K22]

Comments:

1. I would not jam bullets into the lands - creates too much pressure.

2. Try a bullet with a more forgiving ogive. For example, I have a custom Hart barrel 243 that has very little free bore such that I can't shoot my favorite bullet, i.e. the Sierra 85 BTHP because the ogive is such that I have to seat it too far into the case to avoid jamming into the lands. However the 80 grain Nosler seats just fine with about the optimum bullet depth in the case (one bullet diameter) and optimum length (for me) .010" off the lands.

3. My guess is that the barrel is set up for shorter length bullets such as 50 or 55 grain bullets.

 

[Paddyd]

Comments:

1. I would not jam bullets into the lands - creates too much pressure.

2. Try a bullet with a more forgiving ogive. For example, I have a custom Hart barrel 243 that has very little free bore such that I can't shoot my favorite bullet, i.e. the Sierra 85 BTHP because the ogive is such that I have to seat it too far into the case to avoid jamming into the lands. However the 80 grain Nosler seats just fine with about the optimum bullet depth in the case (one bullet diameter) and optimum length (for me) .010" off the lands.

3. My guess is that the barrel is set up for shorter length bullets such as 50 or 55 grain bullets.

The first bullet I tried was a 55g Nosler FBHP ( Midway Dogtown) loaded out to 2.260 per the Nosler book. When chambered, it pushed that bullet back into the case till the ogive was actually below the case mouth.. Something aint right with this one and I'm not shooting it till I get it inspected by a good smith. I ordered this barrel with the 9 twist with the explicit instruction to be able to shoot up to a 70 gn bullet. If I only wanted to shoot a 50 to 55 I'd have ordered a 12 twist.

 

[Texas10]

I'm thinking what you need right now is a borescope or endoscope camera that will allow you to look directly into the throat and see for yourself what's going on.

This thread contains some information on a very good camera that will do the job, and it's not expensive. This would answer some of your questions immediately.

https://forum.accurateshooter.com/t...ry-agony-of-defeat-teslong-endoscope.3989042/

On possibility is that the reamer used on your new barrel was a bit undersized, and your bullets are stopping somewhat short of the lands during measurement.

 

[chuckshooter]

I'm thinking what you need right now is a borescope or endoscope camera that will allow you to look directly into the throat and see for yourself what's going on.


On possibility is that the reamer used on your new barrel was a bit undersized, and your bullets are stopping somewhat short of the lands during measurement.

this is good advice, defective or damaged reamer is a good possibility.

but the only way to know is look with a bore scope , as well as a gunsmith with a grizzly rod or indicator rod with bushings to measure barrel bore diameter and then maybe a chamber casting.

I would be willing to bet CBI will ask you to sent it back for this type of evaluation.

 

[243winxb]

Load a long COL bullet, nose first, no powder and jam it into the rifling.

Doing this may result in a stuck dummy round or broke bolt. I took 2 sized scrap brass, placed a Sierra 53 gr flat base bullet just lightly into the case neck. Locked the bolt down, pushed the bullet into the case. Taking a measurement from case head to bullet face is 1.965" Rifle Savage Axis 223.

 

[Paddyd]

Load a long COL bullet, nose first, no powder and jam it into the rifling.

Doing this may result in a stuck dummy round or broke bolt. I took 2 sized scrap brass, placed a Sierra 53 gr flat base bullet just lightly into the case neck. Locked the bolt down, pushed the bullet into the case. Taking a measurement from case head to bullet face is 1.965" Rifle Savage Axis 223.

View attachment 1131868

That's a great idea. What is the normal freebore in a "standard" 223R chamber or is there even one? I suppose I could just shoot a few thousand V'Maxes until I get enough erosion to be able to shoot a 69g Sierra, but I'd much rather start shooting them now. LOL

 

[coldboreshot]

Hi,
If anyone here can help I sure would appreciate it.
Several weeks ago I ordered a Criterion Savage prefit barrel in 223R. It finally arrived and I installed it on the rifle. Today I finally had some time to check some measurements and to be frank, I'm confused.
First, I tried my Hornady modified case tool with some Nosler 55gn FBHP Nosler load data says to load to an overall length of 2.260" Well the ogive hits a dead stop right at .100" short of that placing more than half the bullet into the case touching.
Next I tried some Hornady 68gn match bullets. Seated out to the lands, the base of the bullet is about at the base or below the shoulder. I've been loading all these bullets in a M70HV and to kiss the lands I always worried about not having enough shank inside the neck. It's just the opposite with this barrel. To seat just .015" off the lands puts way too much bullet inside the case. Is this normal?? I know I'm not crazy because virtually every bullet style and weight I have tried (except Hornady 55gn FMJ) has been impossible to seat to any recommended overall length listed in my Lyman manual or the Hodgdon data page online.
PLEASE give me your opinions as to what might be going on here.

On RARE occasions (personal experience), a reamer can be overly used beyond the point where the reamer dimensions get smaller. Its "possible", the bullet is getting hung up in the throat not allowing complete free passage to the leading edge of the lands. Seat one of your bullets in an inert case but use a heavier neck tension. This may "help" the bullet thru the throat to the lands. Close the bolt and extract the sample round. Measure it and check if it is any longer than the current measurement you are getting now. I suggest seating the bullet to your original specs before this new barrel. If you get the same result as previous, then I concur with the other suggestions to send it back or have a smith run a throating reamer. I believe throat diameter may be causing you issues. Even 1/2 of a thousandths can clog the bullet in the throat. But a heavily neck tensioned bullet should be able to pass with the bolt closure. Maybe take a look at mic'ing your bullets as well. Hope this helps.