My wife's 270 is hard to eject even with factory loads. Looking at the casings I noted what appear as light rings just behind the shoulder. I think they are tooling marks in the chamber that is causing sticky ejection. Do you think a chamber polish would fix this or could I end up with an over size chamber. Thinking I will have to take it to a gunsmith for this work. I tried to take a picture but the ring hardly show up.
Thanks
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have you switched ammo brands?
Remington pumps can have hard ejection with hot ammo. that's why Rem. doesn't load their ammo that the pumps are chambered in to high pressure. I have a 760 in .30/06 and reload for it. some of maximum book loads can be hard to eject. (especially with the 220 gr bullets)
the Rem. 760 has been out of production for years. I doubt an old used chamber would have tool marks that suddenly started causing problems. maybe some grit or something scratched the chamber. try cleaning it good. if that doesn't help, bring it to a gunsmith. (if you can find one now days that will work on anything other than an AR 15 or a Glock.) :'(
Yes she uses Remington 150 Grain core locks we tried federals and Winchester with the same results. We got this rifle three years ago and I doubt it has had 200 rounds through it. I know the guy we bought it from used it one season and bought it new. No signs of pressure with any loads primers all look good. We have three other 760s and have had 0 issues with them. Also this was the first year she used it.
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As you're probably aware the Remington 760, 742, 1100, 870 are of the same family of guns designed by Remington after WWII. The rifle action uses a free float barrel that is held in place with just one bolt under the barrel. The gun is subject to barrel droop, kinda like the Ruger 10/22's with a full bull barrel. It doesn't take much to get the barrel and action out of alignment. I have a 742 with that exact problem. If you need to unload a round you'll almost have to beat it open. It's far easier to just pull the trigger and let it unload itself. Don't be surprised if accuracy falls out and you start chasing bullet impact. I'm not sure I could hit my truck at 100 yds with mine now........and it has less than 100 rounds thru it. The 742 and the 760 were known as the Jam-o-matics. There's a reason they quit making them, now you know.
Cleaning is a must even the gas system...I found that I needed faster burning powder for my 742 30'06 to keep from ripping case heads off. I went with IMR 3031 and that allowed th pressure to drop a bit for easier extractions.
I'd agree with giving it a good cleaning. The 760 bolt uses a crazy amount of small locking lugs that rotate, like an interrupted thread, to lock in place. The semi autos, like the 742, used the same type bolt that was changed when the 7400s came out. It's really easy to get a build up of carbon and tiny brass shavings in the small recesses all those locking lugs are trying to move in. It's also hard to see without disassembly and a light.
I spent 2 hours cleaning my wife's grandfather's 742 to get the bolt to move freely because of this buildup of crud. His gun, being an auto, would eject fine, but not always go fully into battery. Yours, being a pump, might be struggling to open because you are the power source rotating the bolt to unlock. A good cleaning is never a bad thing and the cheapest of all possible solutions.
Good luck with it. Please let us know the outcome.
the 742 has a well earned the reputation of "jam-o-matic" but the 760 that I have owned since 1968 has yet to jam. (neither has any of the 760s owned by any of my friends) yes the bolt will stick with high pressure loads but it has none of the problems associated with the 742. even though they share the same bolt with the failure prone extractor ring, I have yet to hear of the extractor ring giving problems in the 760. but I have replaced extractor rings on a couple of 742 bolts. although they share many common parts, they are two entirely different animals.
back to the O.P. - I think your problem might be a scoured chamber. in the past, someone might have tried to force chamber a dirty round with some hard substance like silica sand or metal filings. I would try to polish the chamber and if that didn't work, look for a gunsmith with a finish chamber reamer.
Quote from: blaster on December 24 2019 08:12:36 AM MST
the 742 has a well earned the reputation of "jam-o-matic" but the 760 that I have owned since 1968 has yet to jam. (neither has any of the 760s owned by any of my friends) yes the bolt will stick with high pressure loads but it has none of the problems associated with the 742. even though they share the same bolt with the failure prone extractor ring, I have yet to hear of the extractor ring giving problems in the 760. but I have replaced extractor rings on a couple of 742 bolts. although they share many common parts, they are two entirely different animals.
back to the O.P. - I think your problem might be a scoured chamber. in the past, someone might have tried to force chamber a dirty round with some hard substance like silica sand or metal filings. I would try to polish the chamber and if that didn't work, look for a gunsmith with a finish chamber reamer.
A good cleaning of the locking lugs and their corresponding recesses would be a bad idea, why? The OP mentions a "ring" not scratches lengthwise on his empties. The slight ring he mentions, that doesn't show up in pictures, could have been from there from the chamber reamer the day it was made.
If you want to know if the problem is the chamber, stick a fired empty case fully in the chamber, with the action open, then see how hard it is to tap out with a cleaning rod.
Quote from: Graybeard on December 24 2019 08:54:23 AM MST
Quote from: blaster on December 24 2019 08:12:36 AM MST
the 742 has a well earned the reputation of "jam-o-matic" but the 760 that I have owned since 1968 has yet to jam. (neither has any of the 760s owned by any of my friends) yes the bolt will stick with high pressure loads but it has none of the problems associated with the 742. even though they share the same bolt with the failure prone extractor ring, I have yet to hear of the extractor ring giving problems in the 760. but I have replaced extractor rings on a couple of 742 bolts. although they share many common parts, they are two entirely different animals.
back to the O.P. - I think your problem might be a scoured chamber. in the past, someone might have tried to force chamber a dirty round with some hard substance like silica sand or metal filings. I would try to polish the chamber and if that didn't work, look for a gunsmith with a finish chamber reamer.
A good cleaning of the locking lugs and their corresponding recesses would be a bad idea, why? The OP mentions a "ring" not scratches lengthwise on his empties. The slight ring he mentions, that doesn't show up in pictures, could have been from there from the chamber reamer the day it was made.
If you want to know if the problem is the chamber, stick a fired empty case fully in the chamber, with the action open, then see how hard it is to tap out with a cleaning rod.
I have given it a good cleaning and the action cycles easy. The issue only is with fired cases. There are three rings that look like tooling marks on the fired cases. My plan was to polish the chamber. My concern is will polishing cause over size chamber or excessive pressure on the bolt from a slick chamber. Having said that I think I will see if a local gunsmith has a finish teamed for it.
Thanks for the input
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Quote from: blaster on December 24 2019 08:12:36 AM MST
the 742 has a well earned the reputation of "jam-o-matic" but the 760 that I have owned since 1968 has yet to jam. (neither has any of the 760s owned by any of my friends) yes the bolt will stick with high pressure loads but it has none of the problems associated with the 742. even though they share the same bolt with the failure prone extractor ring, I have yet to hear of the extractor ring giving problems in the 760. but I have replaced extractor rings on a couple of 742 bolts. although they share many common parts, they are two entirely different animals.
back to the O.P. - I think your problem might be a scoured chamber. in the past, someone might have tried to force chamber a dirty round with some hard substance like silica sand or metal filings. I would try to polish the chamber and if that didn't work, look for a gunsmith with a finish chamber reamer.
The 760 is a pump action and we have 4 of them this is the only one we have ever had trouble with.
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