Trouble chambering in bolt action rifle.

[RobertTheBruce]

I suspect a consentricity issue as blkwolf pointed out.
Neck sizing can cause a variety of problems.
Jim
You could roll a loaded round on a mirror to check consentricity

SPJ - I think you are correct. Especially since the scratches on the bullet are in the same location reguardless of orientation. (Bullets that are rotated and rechambered do not scratch in a different location) can you explain the process for checking concentricity on a mirror? That would be a big help.

 

[gambleone]

Is this a new barrel? If not,
how many rounds through the barrel? What is your cleaning regimen? Do you use bronze brush?

You could possibly have a carbon buildup. I also agree with the ejector tilting the round during extraction can cause a rub mark.

Agree, possible carbon ring, that's why i asked about cleaning regimen.

 

[Uncle Ed]

SPJ - I think you are correct. Especially since the scratches on the bullet are in the same location reguardless of orientation. (Bullets that are rotated and rechambered do not scratch in a different location) can you explain the process for checking concentricity on a mirror? That would be a big help.

You roll the cartridge on a flat surface and look for bullet wobble at its tip. If you can "see" the tip of the bullet wobble you have considerable neck runout. I remember we did this at work one day and then took the bullets to the machine shop and they had as much as .021 runout.

A neck sizing die does not hold the body of the case in aliment with the neck of the die. Meaning a full length resized case is more concentric with the case body and neck.

One of the biggest causes of neck runout happens if the expander is locked down off center.

FYI, the Forster full length benchrest dies with their high mounted floating expander produce very concentric cases. The expander enters the case neck when the neck of the case is held and centered in the neck of the die.

Below a Forster full length benchrest die with its high mounted floating expander.

Below a Forster benchrest die seating die, and the die chamber holds and centers the case and bullet in perfect alignment. Meaning the bullet can not tip during seating and induce neck runout.

If you want to make ammunition better than factory loaded ammunition a runout gauge will tell you if the case, resizing die or seating die is causing problems.

Military match grade ammunition must have .003 or less bullet runout. And you will not see this .003 rolling the case on a mirror or flat surface.

A full length resized cartridge has more wiggle room to be self aligning in the throat of the chamber. The cartridge is held in the rear by the bolt face and by the bullet in the throat. And the only part of the case that touches the chamber walls is the case shoulder.

If the case is thinner on one side the thin side of the case expands more and the case can warp. And a warped neck sized case body can cause the bullet to be out of alignment with the axis of the bore.

Last night I was full length resizing some Lake City 7.62 cases. After sizing I checked the case necks with a Redding neck thickness gauge. Then I checked the case neck on a concentricity gauge and subtract the neck thickness variations from the reading. When done I had less than .002 neck runout with the majority having less than .001 runout.

Bottom line, without a concentricity gauge you will have no idea where the runout is coming from. And right now you have a big alignment problem and do not know where it starts and how to fix it.

 

[Steve Ladino]

View attachment 1067140

I have been reloading ..308 for other rifles for about 10 years, and never experienced this problem. I am starting to reload for my Remington 700, using once fired brass (through the same rifle) that I neck sized. I am using 175 grain SMK bullets, and seating them with an RCBS Gold Medal Seater die.

I made a batch of 10, and chambered them to function test. All of the rounds had trouble chambering, and when ejected, I noticed heavy scratches on the bullet head. I colored one with sharpie (see photo) to try and locate the problem.

Note: empty neck sized brass chambers with no issue. And completed cartridges fit into a Wilson headspace gauge with no issue. Only issue is chambering into my rifle.

I called RCBS, they feel I need to have a custom Seater plug built for the particular bullets I’m using (at a cost of $17)

Seems a little crazy, plus I don’t want to spend $17 every time I change bullet heads.

Has anyone experienced this problem? I really don’t want to get into buying concentricity gauges and driving myself crazy.

slightly lose tube

 

[SSL]

You might try only seating the bullet about half way and then rotating the case 180 degrees to complete the seating process. This might lessen and/or prove any crooked seating and help eliminate a possible issue.

 

[Ggmac]

SPJ - I think you are correct. Especially since the scratches on the bullet are in the same location reguardless of orientation. (Bullets that are rotated and rechambered do not scratch in a different location) can you explain the process for checking concentricity on a mirror? That would be a big help.

Have you measured the bullets . Sometimes they aren't as advertised . Could be larger than normal . Especially if a factory round chambers .

 

[gambleone]

ok, so assuming you're using the same rcbs seating die & say you've been reloading for other rifles for 10 yrs, then my question would be, why all of a sudden with another rifle you are finding the bullet is seating crooked, using the same die??? Maybe get a factory cartridge and marker it up and see how it chambers.

 

[carlsbad]

Original R700 barrel has enough freebore for a 300 grain bullet so it isn't too long. But it may be longer than factory ammo so maybe you're hitting a carbon ring or other debris. Inspect/clean the freebore area.

Otherwise, bullet may be crooked. Even top quality dies can have a problem. Have you disassembled and cleaned the seating die?

 

[JFrank]

SPJ - I think you are correct. Especially since the scratches on the bullet are in the same location reguardless of orientation. (Bullets that are rotated and rechambered do not scratch in a different location) can you explain the process for checking concentricity on a mirror? That would be a big help.

SPJ - I think you are correct. Especially since the scratches on the bullet are in the same location reguardless of orientation. (Bullets that are rotated and rechambered do not scratch in a different location) can you explain the process for checking concentricity on a mirror? That would be a big help.

youll figure it out"

 

[Uncle Ed]

The first read the following expression was at German Salazar's "The Rifleman's Journal" By the late Jim Hull of the Sierra ballistic test lab and competitive shooter.. Jim Hull full length resized his cases and jokingly said "The cartridge should fit the chamber like a rat turd in a violin case". Meaning give the cartridge a little wiggle room and let the bullet be self aligning with the bore. And a neck sized case does not give you any wiggle room.

Below Kevin Thomas of Team Lapua USA who also worked in the Sierra ballistic test lab with Jim Hull.
Click on the image below to enlarge

 

[Sundown]

Bob, You're not seating the bullet deep enough. Take one of your reloads and keep seating it deeper until bolt closes with no force. tell us what that measurement is "OAL"

 

[Uncle Ed]

Bob, You're not seating the bullet deep enough. Take one of your reloads and keep seating it deeper until bolt closes with no force. tell us what that measurement is "OAL"

Go back and look at the OP photos, the rub marks are just above the mouth of the case. And the rub marks remain in the same spot even when the case is rotated.

Look at the image below, the OPs case neck and bullet are tilted and the bullet is rubbing the opening of the throat and not the rifling. In a SAAMI .308 chamber drawing the throat opening is .310 so the bullet has .001 clearance around its circumference. And the bullet is tilted and rubbing on the throat opening, meaning excessive bullet runout.

I could loan the OP my Hornady concentricity gauge to fix his cases but this would loosen the bullet in the case neck and squash the nylon tip of the adjustment screw. The force required to fix his cases would cause the threads on the adjustment screw to smoke and a gorilla would get a sore wrist trying to do it.

Now look at the image below and visualize where the rub marks are on the bullet.

 

[Lefty Trigger]

Man I had this happen on my .223 and it was hard carbon build up in the throat. Was leaving scratch marks on one side and before I found the cause it was starting to make chambering a round harder and scratching 3/4 way around. Got into better cleaning habits now.

 

[Intheshop]

My latest cast rig is a 223 ADL..... handloading to the umpteenth degree with very specific,specialized to this particular chamber and bullet,equipment... got all the bell N whistle loading "stuff".

None of which overcomes the factory ejector spring's rate being suitable as a valve spring for a racing small block. Not saying it's the problem in your rig. You need to check your runout with some kind of repeatability. There's lots of things in the loading process that can cause issues. A simple runout gauge is how you can start eliminating possible causes. Good luck with your rig.

 

[Liven The Dream]

Neck Sizing great article in the Bulletin as why NOT TO.

If factory Ammo goes in and Fires ???? Then it sounds to me your reloading is where to LOOK ?

I would FL Size and Trim some Brass and see if it fits.
I would Clean the Chamber well to start and the Bolt Face . Brass chips in the extractor ??

 

[JFrank]

Go back and look at the OP photos, the rub marks are just above the mouth of the case. And the rub marks remain in the same spot even when the case is rotated.

Look at the image below, the OPs case neck and bullet are tilted and the bullet is rubbing the opening of the throat and not the rifling. In a SAAMI .308 chamber drawing the throat opening is .310 so the bullet has .001 clearance around its circumference. And the bullet is tilted and rubbing on the throat opening, meaning excessive bullet runout.

I could loan the OP my Hornady concentricity gauge to fix his cases but this would loosen the bullet in the case neck and squash the nylon tip of the adjustment screw. The force required to fix his cases would cause the threads on the adjustment screw to smoke and a gorilla would get a sore wrist trying to do it.

Now look at the image below and visualize where the rub marks are on the bullet.

That's a lot of run out^^^

 

[243winxb]

Bullet that hit the feed ramp , on loading, may get a crocked bullet.

 

[1lnbrdg]

I have never ever has as much runout as I had trying to use the RCBS Gold Medal seating dies. On .223 and .308, sometimes as much as .015. I scrapped them and went with a Forster and was extremely pleased.

Neck Sizing, never had so many failure to feed problems in my life. Life is too short, full length resize for me.

 

[Peebles24]

OP are you neck sizing and depriming at the same time? As someone mentioned neck sizing does not support the case body. I had about .003 runout when i was depriming with a full length neck bump whidden die, i can only imagine neck sizing and depriming at same time would be much worse. When i started depriming before sizing my runout went to .001 or better.

 

[Uncle Ed]

The OPs RCBS competition seating die is "NOT" as good at controlling bullet runout as the Forster and Redding seating dies.

And after looking at the video below the RCBS die falls into the Swiss Army Knife of do everything type seating die.

The redding and Forster seating dies hold the bullet and case in perfect alignment in the die chamber. German Salazar did seating die testing of various seating dies and the Forster and Redding type seating dies could actually correct "case neck runout" during bullet seating at the link below. (in adobe pdf format)
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwiwi8PDz97dAhUEyFkKHahHDfwQFjAAegQICRAC&url=http://www.uniquetek.com/store/696296/uploaded/Reloading-Seating-Die-Runout.pdf&usg=AOvVaw0PTrUzbIFGXpTquMkz6CtT

I'm a cheap bastard and I buy bulk once fired Lake City 7.62 brass, and some very simple things can create neck runout during resizing. And if you add a less than perfect seating die your bullet runout can be made worse.

To the OP, buy a Sinclair Concentricity Gauge they are on sale at https://www.sinclairintl.com/reload...s/sinclair-concentricity-gauge-prod37479.aspx

With this simple runout gauge you can check your cases after sizing and your bullets after seating. Meaning finding the problem where it starts and then fix the problem. On my bench I also have a Redding Case Neck Concentricity Gauge and can check the case neck thickness variations.

With one turn of the wrist the Redding gauge will tell you a good deal about your neck thickness variations and the quality of the brass. I have had Remington .223 cases with over .009 neck thickness variations and only good enough for blasting ammo in a AR15.