Ar-10 358 Winchester

ruger357w · December 13, 2023, 10:12 AM

I recently put together an ar-10 upper in 358 Winchester. It will cycle and run smooth with no issues using 308 brass necked up. My problem is when I try to use Jamison 358 Winchester brass the upper will stick the case in the extractor groove and not eject the case. It will lock the bolt back every time. I'm measured 308 case head and there 0.049 thick the Jamison case head is 0.053 thick. I'm thinking this is my issue but I've never run into this before. Any thoughts. I'd try other 358 brass if I could find it. I also don't mind running 308 case if that's all it will like. Just nice having correct head stamp considering I'm running a 308 upper as well.

MarkCO · December 13, 2023, 11:36 AM

I'd just modify the extractor. I've done it for several wildcats in the AR15 and AR10 patterns.

stagpanther · December 13, 2023, 11:46 AM

In other words the rifle cycles but the extractor "holds on" to the case? Like Mark says--sometimes the extractor edges can be a bit sharp and can use some stoning down. I built my 358 win AR with a KAK barrel and used one of the their heavy duty bolts which features double ejectors--never once had an issue with it. Some bolts these days sometimes come with "overzealous" extractors; stiffer springs and rubber donut bushings.

stagpanther · December 14, 2023, 02:58 AM

On second thought...

If your bolt carrier locks back but still holds on to the case--you could also possibly have the bolt clocked the wrong way in the carrier (ejector would be pushing the case in instead of out) or the ejector itself simply isn't pushing with enough force--it's fairly common for the the ejector assembly in the bolt to get gummed up or the spring compressed enough that it fails to push with enough force. More guesses.

ruger357w · December 14, 2023, 05:35 AM

I did some polishing on the extractor last night and it seems to have helped. I have not fired it sence yet but it will now eject the rounds cycling by hand. Thank for a the help. And I'm very impressed with how accurate this kak barrel is.

stagpanther · December 14, 2023, 06:39 AM

I bought my barrel from Kurt years ago--when I asked him what a good load that could also be used for hunting might be he said "Just use 225 gamekings with AA 2520 and you'll be happy"--he was right, it's a great load, at least in the AR barrels he makes.

tangolima · December 14, 2023, 09:55 AM

Check rim diameter too. The bolt face may be cut just a bit too small.

Bolt can't be clocked wrong. The bolt doesn't go in.

-TL

Sent from my SM-N960U using Tapatalk

stagpanther · December 14, 2023, 11:58 AM

Quote:

Bolt can't be clocked wrong. The bolt doesn't go in.

The only reason I mention it is that I managed to do it once--but it was a long time ago, maybe was a different type of bolt.

tangolima · December 14, 2023, 12:15 PM

Quote:

Originally Posted by stagpanther

The only reason I mention it is that I managed to do it once--but it was a long time ago, maybe was a different type of bolt.

Right. The pins I have come with slight taper. They can't go in if the bolt is timed wrong. I caught it before I took out the big hammer

-TL

Sent from my SM-N960U using Tapatalk

stagpanther · December 14, 2023, 12:30 PM

Pins and pin holes in the carrier can wear pretty easily over time.

**44 AMP** · December 14, 2023, 01:09 PM

Quote:

I'm measured 308 case head and there 0.049 thick the Jamison case head is 0.053 thick.

You're measuring the rim thickness, right??

Case drawings in my manuals show the same for .308 and .358 (no surprise there). Max spec given is 0.054" so your brass is "in spec" for rim thickness.

Tuning the extractor is the next step (assuming the ejector is working ok). While you're at it, buy a couple of spare extractors. Put one in your spare parts stash, and the other in the butt trap or pistolgrip if your rifle has them. Tape it in, so it won't rattle or fall out. That way, you will have a spare with you in the field if you ever need it.

Spare pins and springs for the bolt aren't a bad idea, either. Not that they easily break, but they are easy to lose....

ruger357w · December 14, 2023, 06:38 PM

Yes rim thickness. I worked on extractor last night and cycling manual it seems to be working. I have not had time to test fire it yet. I tried to post picture of what it's doing but I couldn't get it to upload. Not computer smart I guess. But I could before working on extractor put a case in bolt with the bolt removed from the upper and it would hold the case at an angle without wanting to release it. Now they pop out instanly.

ruger357w · December 14, 2023, 06:48 PM

Trying to post picture

stagpanther · December 15, 2023, 02:22 AM

Sometimes extractors go out that have sharp points on the ends of the radius of the claw, that can dig in and hang on to the rim.

December 13, 2023, 10:12 AM	#1
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	Ar-10 358 Winchester I recently put together an ar-10 upper in 358 Winchester. It will cycle and run smooth with no issues using 308 brass necked up. My problem is when I try to use Jamison 358 Winchester brass the upper will stick the case in the extractor groove and not eject the case. It will lock the bolt back every time. I'm measured 308 case head and there 0.049 thick the Jamison case head is 0.053 thick. I'm thinking this is my issue but I've never run into this before. Any thoughts. I'd try other 358 brass if I could find it. I also don't mind running 308 case if that's all it will like. Just nice having correct head stamp considering I'm running a 308 upper as well.

December 13, 2023, 11:36 AM	#2
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 4,309	I'd just modify the extractor. I've done it for several wildcats in the AR15 and AR10 patterns. __________________ Good Shooting, MarkCO www.CarbonArms.us

December 13, 2023, 11:46 AM	#3
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,893	In other words the rifle cycles but the extractor "holds on" to the case? Like Mark says--sometimes the extractor edges can be a bit sharp and can use some stoning down. I built my 358 win AR with a KAK barrel and used one of the their heavy duty bolts which features double ejectors--never once had an issue with it. Some bolts these days sometimes come with "overzealous" extractors; stiffer springs and rubber donut bushings. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

December 14, 2023, 02:58 AM	#4
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,893	On second thought... If your bolt carrier locks back but still holds on to the case--you could also possibly have the bolt clocked the wrong way in the carrier (ejector would be pushing the case in instead of out) or the ejector itself simply isn't pushing with enough force--it's fairly common for the the ejector assembly in the bolt to get gummed up or the spring compressed enough that it fails to push with enough force. More guesses. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

December 14, 2023, 06:39 AM	#6
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,893	I bought my barrel from Kurt years ago--when I asked him what a good load that could also be used for hunting might be he said "Just use 225 gamekings with AA 2520 and you'll be happy"--he was right, it's a great load, at least in the AR barrels he makes. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

December 14, 2023, 05:35 AM	#5
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	I did some polishing on the extractor last night and it seems to have helped. I have not fired it sence yet but it will now eject the rounds cycling by hand. Thank for a the help. And I'm very impressed with how accurate this kak barrel is.

December 14, 2023, 09:55 AM	#7
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,878	Check rim diameter too. The bolt face may be cut just a bit too small. Bolt can't be clocked wrong. The bolt doesn't go in. -TL Sent from my SM-N960U using Tapatalk

December 14, 2023, 12:30 PM	#10
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,893	Pins and pin holes in the carrier can wear pretty easily over time. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

December 14, 2023, 06:38 PM	#12
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	Yes rim thickness. I worked on extractor last night and cycling manual it seems to be working. I have not had time to test fire it yet. I tried to post picture of what it's doing but I couldn't get it to upload. Not computer smart I guess. But I could before working on extractor put a case in bolt with the bolt removed from the upper and it would hold the case at an angle without wanting to release it. Now they pop out instanly.