Short chamber on .308 F/TR

I own a Savage .308 F/TR which has had the barrel replaced with a Pacnor. I've had a few problems with closing the bolt when feeding some handloads, factory is fine but necksizing will jam about a third of the sized cases. I recently checked the COL with a Hornady COL gauge and found that with several bullets, notably Sierra Match King 168 grain and 155 grain, the COL is only 2.7" which is a tad short. The rifle performs adequately, three quarter minute groups with factory GGG match and better than that with handloads. Anyone have any thoughts on the COL?

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Originally Posted by UK-Shootist

I own a Savage .308 F/TR which has had the barrel replaced with a Pacnor. I've had a few problems with closing the bolt when feeding some handloads, factory is fine but necksizing will jam about a third of the sized cases. I recently checked the COL with a Hornady COL gauge and found that with several bullets, notably Sierra Match King 168 grain and 155 grain, the COL is only 2.7" which is a tad short. The rifle performs adequately, three quarter minute groups with factory GGG match and better than that with handloads. Anyone have any thoughts on the COL?

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Are you saying bolt won't close with the shorter loads?

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Originally Posted by UK-Shootist

I own a Savage .308 F/TR which has had the barrel replaced with a Pacnor. I've had a few problems with closing the bolt when feeding some handloads, factory is fine but necksizing will jam about a third of the sized cases. I recently checked the COL with a Hornady COL gauge and found that with several bullets, notably Sierra Match King 168 grain and 155 grain, the COL is only 2.7" which is a tad short. The rifle performs adequately, three quarter minute groups with factory GGG match and better than that with handloads. Anyone have any thoughts on the COL?

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Case length can be a minimum (saami standard... different guns vary) of 2.005 and max of 2.015 and OAL bullet and all 2.800

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Originally Posted by Ted_Feasel

Case length can be a minimum (saami standard... different guns vary) of 2.005 and max of 2.015 and OAL bullet and all 2.800

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Sorry max of 2.015 - .020 for minimum

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Originally Posted by Ted_Feasel

Are you saying bolt won't close with the shorter loads?

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No. Forgive me for not being clearer. The bolt jamming happens only on about 30% of any batch of neck sized cases. There is no bolt jamming on factory ammunition or handloads loaded to 2.7". Most factory ammo fells tight on closing the bolt but not overly so. I initially had problems with loaded neck sized rounds, which was a bit tricky to sort out with the bolt half way down. Then I started chambering all the neck sized cases to see what would work. Much safer!! I've now given up on neck sizing and full length resize all cases and no further jams have occurred. (Interestingly I have the same neck size jamming problem on my Savage BVSS .223 but COL is on spec.) There is only slight marking on the jammed cases which shows up on the rear third of the case. On both rifles I am assuming tight chambers.

The interesting part is the short .308 COL. If I understand it correctly, there would be no point in unscrewing the barrel as this would not change the difference between case shoulder and bullet tip. I am assuming that the Pacnor barrel was deliberately short chambered by the previous owner for some reason or other, possibly to use 7.62 ammunition. The only downside of this seems to be a reduced COL and consequential reduced muzzle velocity.

I understand now all I do know for sure is all my Savages and I have several of them all have very very tight chamber specifications on them maybe that has something to do with it the fact that Savage builds their tolerance is so tight on their Chambers. Are you bumping the shoulder back when you next size only if not that maybe the problem you may just need to bump the shoulder back two or three thousand

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Originally Posted by Ted_Feasel

I understand now all I do know for sure is all my Savages and I have several of them all have very very tight chamber specifications on them maybe that has something to do with it the fact that Savage builds their tolerance is so tight on their Chambers.

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That's really useful, and reassuring, to know. Thanks.

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Originally Posted by Ted_Feasel

Are you bumping the shoulder back when you next size only if not that maybe the problem you may just need to bump the shoulder back two or three thousand

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No. I have purchased a Forster shoulder bumping die I've yet to use as it took so long to arrive that I just went on to full length resizing. Interestingly, after very many years of using Lee case lube I switched to Hornady sizing wax and am a lifetime convert. It F/L sizes like the case isn't there and is easy to wipe off of completed rounds. As far as case life is concerned I'm having more issues with the primer pockets expanding too much than any other case wear. My usual load is 46 grains of Vihtavouri N140 behind SMK 155 grain which is a bit beefy. I was measuring COL because I found that 168 grains were measurably more accurate at closer range and thought I should check the COL.

I've just Googled 7.62 specs and the COL is 2.750" as opposed to the .308's 2.8". As the barrel was used (lightly) before I got it, I can only assume that the previous owner was a target rifle shooter using 7.62 issue ammunition and wanted the bullet into the lands.

But still if you're able to run factory 308 through it there's got to be something else going on

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I'm not a betting man but if I was I would lay money if you're able to chamber Factory ammo just fine but not next size only that it's only a matter of bumping your neck back a few thousands

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Sorry not your neck the shoulder

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Originally Posted by Ted_Feasel

But still if you're able to run factory 308 through it there's got to be something else going on

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True, but using factory .308 closing the bolt seems 'snug'. More like I would expect if a bullet was seating into the rifling and thinking back those factory rounds seemed quite frisky. By contrast, F/L sized rounds of 2.680" drop in as smooth as silk. The PITA trying to think about this is the jamming that also occurs. Your remarks about tight chambers in savage rifles may have answered that part, and thoughts on a barrel chambered for a 7.62 target rifle shooter has also helped. It would be tempting to try some F/L sized cases with the bullet seated further out but it's a real hairy, not to mention brutal, job opening a bolt that is half closed on a live round. Your input has been a great help to me. Thanks again.

Your welcome... just be careful... if your primer pockets are prematurely getting loose, that's a sign of to much pressure

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Originally Posted by Ted_Feasel

I'm not a betting man but if I was I would lay money if you're able to chamber Factory ammo just fine but not next size only that it's only a matter of bumping your neck back a few thousands

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I'm sure your right. I'll start dusting off that shoulder bumping die and let you know. I know about the primer pocket issue. One of the penalties of loading hot for 1,000 yards. I believe that's why Lapua have started making .308 'Palma' brass that uses small rifle primers. I'm doing to ease off quite a bit as I don't shoot that distance too often so there's no point in straining things.

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Originally Posted by UK-Shootist

I'm sure your right. I'll start dusting off that shoulder bumping die and let you know. I know about the primer pocket issue. One of the penalties of loading hot for 1,000 yards. I believe that's why Lapua have started making .308 'Palma' brass that uses small rifle primers. I'm doing to ease off quite a bit as I don't shoot that distance too often so there's no point in straining things.

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I bought one of those RCBS headspace gauges for checking your cases it's well worth the $12 I paid for it
To give you an idea of how tight Savage Chambers are you know that too. 800 is about the maximum length with bullet and all well when I did my ogive measurement it let me run out my bullet 2.896 so that's $96,000 of space which is not much at all so there can't be much shoulder space in there either

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Have you measured your Headspace DL of your fired cases? If so what is the measured difference between your fired cases and your ammo that will not chamber?

If the headspace DL of the ammo that won't fire is larger than the measured fired rounds then you are not bumping the shoulder sufficiently.Properly sized Headspace DL for bolt rifles should be .001" to .003" smaller than chamber.

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Originally Posted by rbp75503

Have you measured your Headspace DL of your fired cases? If so what is the measured difference between your fired cases and your ammo that will not chamber?

If the headspace DL of the ammo that won't fire is larger than the measured fired rounds then you are not bumping the shoulder sufficiently.Properly sized Headspace DL for bolt rifles should be .001" to .003" smaller than chamber.

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Yes I don't have to bump my shoulders every time about every third firing there expanded enough where I have to bump them back typically if I were to take a new case and a fire case and measure the difference I'll have about 3000 s of difference

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