switch barrel trouble

[686ppp]

Started life as a new Model Seven action had a local builder fit a 300 BO worked great and soon got bored with that. I picked up a lightly used factory 223 barrel and I changed it myself with no issues. I went back to the 300 BO and get 50% light primer strikes with several different brands of primers same lug, stock and trigger. Ive taken the bolt apart several times replaced the spring and did find a piece of brass inside, still having the same issue. Reinstalled the 223 out of frustration and it works fine. Any ideas?

 

[ELR LVR]

Started life as a new Model Seven action had a local builder fit a 300 BO worked great and soon got bored with that. I picked up a lightly used factory 223 barrel and I changed it myself with no issues. I went back to the 300 BO and get 50% light primer strikes with several different brands of primers same lug, stock and trigger. Ive taken the bolt apart several times replaced the spring and did find a piece of brass inside, still having the same issue. Reinstalled the 223 out of frustration and it works fine. Any ideas?

Off the top of my head, the primer is limited in its travel legth (has a built in stop inside the bolt)
The 300BO barrel may not be screwing on all the way as tight as it did before
(Burr, ding on the edge etc???)
preventing the firing pin from hitting the primer hard enough
--------------
Translation, maybe the headspace changed slightly since it was removed

 

[SSeal]

Has your gun has fired any of the 300 bo rounds since you reinstalled it? If so measure and compare the brass fired from the original installation.
My guess is you have some trash between the shoulder area.

 

[ELR LVR]

Has your gun has fired any of the 300 bo rounds since you reinstalled it? If so measure and compare the brass fired from the original installation.
My guess is you have some trash between the shoulder area.

Yes, this ^^^

 

[ShtrRdy]

Are you reloading for the 300 BO?

 

[686ppp]

reloading for the 300. the brass started as new and has only been in that chamber. In that time i have trimmed case length. Ill remove the barrel and check for trash and torque a bit more. I think i stopped at 45lb.

 

[Sniperhandle]

Has your gun has fired any of the 300 bo rounds since you reinstalled it? If so measure and compare the brass fired from the original installation.
My guess is you have some trash between the shoulder area.

Trash in the shoulder area would reduce headspace, Not increase it, Thereby making a long headspace problem not likely due to debris.

As mentioned before, The 300 BO barrel not screwing in all the way could cause the issue. I would disassemble the bolt and check real good inside and blow it out with compressed air and solvent, The OP mentioned finding brass inside the bolt, Which would indicate possible blanked primers from when he was shooting 223 that may be stuck inside the bolt body limiting firing pin travel.

 

[ELR LVR]

Trash in the shoulder area would reduce headspace, Not increase it, Thereby making a long headspace problem not likely due to debris.

As mentioned before, The 300 BO barrel not screwing in all the way could cause the issue. I would disassemble the bolt and check real good inside and blow it out with compressed air and solvent, The OP mentioned finding brass inside the bolt, Which would indicate possible blanked primers from when he was shooting 223 that may be stuck inside the bolt body limiting firing pin travel.

(Shoulder on the Tenon my friend) not the chamber
taking the barrel on and off would increase the likelihood of this you see

 

[Sniperhandle]

(Shoulder on the Tenon my friend) not the chamber
taking the barrel on and off would increase the likelihood of this you see

If he meant the shoulder of the tenon, Then you are right, I read it as the shoulder area of the chamber. But brass in the bolt body is probably the issue. Remington firing pin holes are too large and it's been an issue discussed on here many times.

 

[686ppp]

I've disassembled the bolt several times blasted the bolt body with carb cleaner and compressed air. I don't see how anything else can be in there. Back down the rabbit hole.

 

[ELR LVR]

If he meant the shoulder of the tenon, Then you are right, I read it as the shoulder area of the chamber. But brass in the bolt body is probably the issue. Remington firing pin holes are too large and it's been an issue discussed on here many times.

Good point there, he should disassemble his bolt and check/ clean/ lube internally.
(Edit: he already done that)
Check if your firing pin is rubbing against the hole it protrudes through
(witness marks on the pin)
this will slow it down

 

[Sniperhandle]

I've disassembled the bolt several times blasted the bolt body with carb cleaner and compressed air. I don't see how anything else can be in there. Back down the rabbit hole.

Have you ever had a blanked primer? (A primer with a hole in it) On this rifle?

 

[ShtrRdy]

reloading for the 300. the brass started as new and has only been in that chamber. In that time i have trimmed case length. Ill remove the barrel and check for trash and torque a bit more. I think i stopped at 45lb.

When you resize the 300 BO case is it possible that you're pushing the shoulder too far forward? This would create a space/gap between the base of the cartridge and the breach face on the bolt.

When the gunsmith installed the barrel he likely torqued to 100+ ft-lb.

 

[Sniperhandle]

It can only be a few things:

: Firing pin protrusion

: Firing pin travel

: Headspace

Shouldn't be that hard to diagnose.

 

[jelenko]

When you resize the 300 BO case is it possible that you're pushing the shoulder too far forward? This would create a space/gap between the base of the cartridge and the breach face on the bolt.

When the gunsmith installed the barrel he likely torqued to 100+ ft-lb.

Just to confirm. What would be the difference in headspace between 45 ft-lb and 100 ft-lb? [I'm thinking << than .001]

 

[ELR LVR]

Also your spring may simply be worn out (weak)
you could upgrade your firing pin spring, check its spring weight etc

 

[tobnpr]

Punch a witness mark across the bottom of the receiver/barrel breech. I've done this on every rifle I've ever built...

A quick glance will confirm whether the barrel has been torqued back to original headspace.

 

[686ppp]

The first thing i did was replace the spring. Blanked primer not that i know of but one could have slipped through easily. ill pick up some factory 300BO ammo and see if those work. I dont remember adjusting the die after i set it the first time. All my cases have 3 or 4 firings on them.

 

[DShortt]

Same primers being used when you reload the 300BO and the .223?
Some primer cups are thicker/harder than others. Then you're back to firing pin protrusion.

 

[686ppp]

Ive disassembled and cleaned. Only thing i see is the coating on the lug. Where the barrel and receiver contact the lug are not the same width. One way the coating would be between the metal surfaces. i reassembled hand tight and have fired several primers. Ill try a few different brands of primers before final torque and hit the range tomorrow.