Bolt Won't Close

[zedsdead]

I finally got all the parts I needed and the time to put my Shilen 6BR barrel on my Savage. I put it on an older 110 single shot action that was originally chambered in 223 so naturally I had to get a new bolt head with a 308 bolt face.

Now for my problem. I can't get the bolt to close with a piece of new Lapua brass that has been through a f/l size die in the chamber. Without a round in the bolt closes fine. I checked the headspace repeatedly using a new PTG gauge and everything is on the money. I finally got the bolt to close by slamming the bolt forward a few times. When I opened the bolt the brass had a big ding on the edge of the rim, caused by the extractor. It looks like something is not allowing the extractor to slide over the case rim. I took the barrel off and inspected the action with the bolt closed. I can't see any obstruction and I can push a round onto the bolt face and it clicks over the extractor without much force at all.

This is my first barrel install so I am sure I am making some stupid rookie mistake but I'm stumped. Any ideas?

Thanks
Jason

 

[SteveNash]

Jason,

Try a piece of brass that hasn't been F/L sized....you may have bumped the shoulder back to far and the case is too far into the chamber for the extractor to clip over the rim and let the bolt close all the way

Cheers
Steve

 

[fdshuster]

Jason: Did you measure the chamber over-all length? Is there a chance it could be less than your case length/ 1.5?? chamber for 1.560" brass? I take actual chamber length's using the Sinclair gages. Or, without the gage, you could try trimming the case: .005" shorter & try to chamber, and maybe another .005" and try again. Just a thought.

 

[zedsdead]

Try a piece of brass that hasn't been F/L sized....

At this time I only have 100 pieces of brass and all of them have gone through the f/l sizer.

you may have bumped the shoulder back to far and the case is too far into the chamber for the extractor to clip over the rim and let the bolt close all the way

I checked the headspace length on the gauge and the brass and the brass is .003 shorter than the gauge so everything should be good to go?

Did you measure the chamber over-all length? Is there a chance it could be less than your case length/ 1.5??

I did not think of that but will definitely give it a try.

After looking at the drawings on the 6BR info page I did some measuring and this is what I found. The drawing shows the measurement from the case head to the neck/shoulder junction to be 1.237. My go-gauge measures 1.233. The best measurement I could get on the brass in this area looks like the brass may be a few thousandths longer in this area. I do not have a bushing the correct size to get an exact measurement on the brass so that is ballpark but it looked a little long.

I even unscrewed the barrel a little at a time and kept trying to close the bolt as I went. When I had finally lengthened the headspace enough for the bolt to close without slamming it the extractor was not going over the rim and the case had to be pushed out with a cleaning rod. There was little/no resistance when pushing it out so I don't think the brass is binding up.

The way the rim is chewed up by the extractor looks like the extractor is not sliding over to get over the top of the rim but pushing the brass against the bolt head with the barrel removed from the action does not confirm this. This afternoon I'll try to take a picture of the brass and post it.

Thanks again for any help.

Jason

 

[rayjay]

You should always remove the extractor and the ejector when setting the headspace. Then if there is an issue when you reinstall the extractor and ejector you know it's one of them and not an improperly installed bbl.

Sounds like the bolt head could have been machined wrong when they drilled the hole for the extractor spring. If you are using an ejector can you push the plunger below the surface of the bolt face ?

You did put the extractor spring in first and then the ball on top and the slide in the extractor ??

SSS makes a longer extractor for pulling a PPC case with a 308 bolt head. If you got the parts from them maybe one of the longer extractors got thrown in the order by mistake.

Are there any burrs on the surfaces where the extractor fits ? I have seen extractors that had the 'ball recess' drilled too deeply which practically locked up the extractor.

 

[zedsdead]

Sounds like the bolt head could have been machined wrong when they drilled the hole for the extractor spring. If you are using an ejector can you push the plunger below the surface of the bolt face ?

That was the problem. I put the extractor in a vise and filed off .030. Now everything works like a champ.

One more question and I'll try to leave you guys alone for awhile. When the barrel is on and headspaced only about .670 of the barrel is inside the action. Once the barrel nut is tightened there are about three threads showing. Is this enough thread/barrel in the action? Again, I'm probably overthinking things but this being my first barrel swap I don't want to blow myself up.

Jason

 

[rayjay]

Ideally there should be about .005" of clearance between the rear face of the bbl and the front face of the bolt head. The max should be no more than .015". You can measure the depth of the bolt head recess and measure how much the go gauge sticks out of the back of the chamber. Subtract the smaller number from the larger and this is how much clearance your combination should have.

A picture is worth a 1000 words. Show us some

 

[zedsdead]

Rayjay

I took the measurements you told me to and got .007 so I guess I'm good to go. I guess I was just worried that only about 5/8 of an inch of barrel was threaded into the action. The fact that threads are showing outside of the barrel nut had me worried. Thank to everyone for all the help.

Regarding pictures, I've yet to figure out how to download them. Maybe when I get finished spending all my free time getting this gun ready to go I'll try to figure it out.

Jason

 

[rayjay]

Having threads showing beyond the bbl nut doesn't sound right. Do you have the recoil lug in place ?


With the bbl removed you can measure from the front face of the receiver back to the bolt face and the bolt recess and then compare this to the bbl threads.

Another good 'piece of mind' thing you can do is place the go gauge in the dismounted bbl and then sit the bolt head or complete bolt onto the go gauge this will give you a visual and measurable confirmation of the space between the back of the bbl and the bolt face.

 

[pdog06]

For some reason different barrel makers will put more threading on the barrel than others. Yours probably has a couple more threads than others. I have a McGowen like that, but also had a Douglas that needed more threads. Musta been Friday afternoon when they made those barrels :. Having the threads showing isnt gonna hurt anything as long as it is installed properly, just a little eyesore though.

I know SSS threads it a little longer incase you will be using an aftermarket(thicker) recoil lug. Better to have a thread or two too much than not enough.

 

[zedsdead]

I got it figured out. Through this whole ordeal I have probably taken the barrel off 20+ times. Somehow I forgot to put the recoil lug back on. : I have finally got everything together and will hopefully get to go out for a few hours in the morning to test it. If you don't hear back from me within a few days I did something VERY wrong. Thanks again for the help guys. I greatly appreciate it.

Jason

 

[olddog]

rayjay,
From the response to your suggestions, it sounds like you have been around the barn a couple of time, bless you.

Thanks for sharing your insight.

Roger

 

[rayjay]

I am definitely an expert on:

Having a wrench under a shop towel.

Having a part under a shop towel.

Trying to do 3 things at once to save time [ takes 4 times as long when you have to do it all over ].

Trying to carry 1.5 arms full to save a trip [ clank goes an expensive item ].

False economy is my passion