Is THIS Sticky Bolt Lift or just more issues with burs

300magman · September 16, 2011, 10:36 PM

I'm working up some loads for a Rem 700 in 300 win mag, but the bolt is chewing big chunks out of the brass, just ahead of the rim (where the normal expansion crease forms on every fired brass) and also the bolt head is filling with brass shavings

Anyway, I think the gun just has some burs that are catching the brass at this point when the case expands, but it definetly get much much worse as pressure increases.

The issue arrises when you try to extract a round. The bolt lifts up easily, but then is nearly impossible to pull back. . . . this is not what is normally refered to as "a stuck bolt" from excessive pressure...is it?

mehavey · September 16, 2011, 10:49 PM

Can you post a pic?

Although the 700 appears to use a shrouded/push feed design, I can't visualize how the bolt extends much past the extractor groove.

Q1: Can you feel ANY burr on the inside of the shroud?
Q2: How about the edges of the ejector cutout in the shroud? smooth or sharp?
Q3: And does the base of the case show a round imprint/smear where brass might be flowing into the ejector slot(hole)?

steve4102 · September 17, 2011, 03:18 AM

Pictures would be good, as would the details of your handloads.

Jimro · September 17, 2011, 03:21 AM

Quote:

I'm working up some loads for a Rem 700 in 300 win mag, but the bolt is chewing big chunks out of the brass, just ahead of the rim (where the normal expansion crease forms on every fired brass) and also the bolt head is filling with brass shavings

Anyway, I think the gun just has some burs that are catching the brass at this point when the case expands, but it definetly get much much worse as pressure increases.

The issue arrises when you try to extract a round. The bolt lifts up easily, but then is nearly impossible to pull back. . . . this is not what is normally refered to as "a stuck bolt" from excessive pressure...is it?

If it is ahead of the rim but behind the belt then likely your extractor claw is doing the gouging. If it doesn't do this on commercial ammo then it is a good sign that your loads are a bit too hot. What do the primers look like?

Jimro

300magman · September 17, 2011, 10:06 AM

I should have mentioned that the rifle eats brass quite badly with factory ammo as well. Though it preferes to take bigger bites out of some brands than others.

As for my loads, I don't remember the details off by heart, but I have 3 manuals and all indicate that I am well within the mid range for this bullet/powder combination. Primers look good, factory loads are actually flatter in some cases, and there are no other pressure signs.

And yes, I think I misworded my original post slightly. The bolt head is filling with brass from around the cartridge rim. But the brass eating farther out on the cartridge (just ahead of the belt) would appear to be more in line the end of the chamber, not the bolt.

mehavey · September 17, 2011, 06:10 PM

Examine here:

From your description it sounds like this area may be the culprit.

300magman · September 18, 2011, 10:54 AM

mehavey You are probably right about where the bolt head is chewing the brass.

As far as the forward problem area, a little gun smithing yesterday afternoon, seems to have fixed the problem. The chamber was lightly polished and now the bolt opens very smoothly and the area ahead of the belt shows no brass being scraped/removed.

September 16, 2011, 10:36 PM	#1
300magman Senior Member Join Date: September 12, 2008 Posts: 714	Is THIS Sticky Bolt Lift or just more issues with burs I'm working up some loads for a Rem 700 in 300 win mag, but the bolt is chewing big chunks out of the brass, just ahead of the rim (where the normal expansion crease forms on every fired brass) and also the bolt head is filling with brass shavings Anyway, I think the gun just has some burs that are catching the brass at this point when the case expands, but it definetly get much much worse as pressure increases. The issue arrises when you try to extract a round. The bolt lifts up easily, but then is nearly impossible to pull back. . . . this is not what is normally refered to as "a stuck bolt" from excessive pressure...is it?

September 16, 2011, 10:49 PM	#2
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,882	Can you post a pic? Although the 700 appears to use a shrouded/push feed design, I can't visualize how the bolt extends much past the extractor groove. Q1: Can you feel ANY burr on the inside of the shroud? Q2: How about the edges of the ejector cutout in the shroud? smooth or sharp? Q3: And does the base of the case show a round imprint/smear where brass might be flowing into the ejector slot(hole)? Last edited by mehavey; September 16, 2011 at 10:56 PM.

September 17, 2011, 10:06 AM	#5
300magman Senior Member Join Date: September 12, 2008 Posts: 714	I should have mentioned that the rifle eats brass quite badly with factory ammo as well. Though it preferes to take bigger bites out of some brands than others. As for my loads, I don't remember the details off by heart, but I have 3 manuals and all indicate that I am well within the mid range for this bullet/powder combination. Primers look good, factory loads are actually flatter in some cases, and there are no other pressure signs. And yes, I think I misworded my original post slightly. The bolt head is filling with brass from around the cartridge rim. But the brass eating farther out on the cartridge (just ahead of the belt) would appear to be more in line the end of the chamber, not the bolt. Last edited by 300magman; September 18, 2011 at 10:48 AM.

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September 17, 2011, 03:18 AM	#3
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,951	Pictures would be good, as would the details of your handloads.

September 17, 2011, 06:10 PM	#6
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,882	Examine here: From your description it sounds like this area may be the culprit.

September 18, 2011, 10:54 AM	#7
300magman Senior Member Join Date: September 12, 2008 Posts: 714	mehavey You are probably right about where the bolt head is chewing the brass. As far as the forward problem area, a little gun smithing yesterday afternoon, seems to have fixed the problem. The chamber was lightly polished and now the bolt opens very smoothly and the area ahead of the belt shows no brass being scraped/removed.