Ok I haven't posted for a while (been busy). I have loaded for my Ruger 22-250 m 77 with a 1 in 14 twist with 55 grain Hornady soft points, the brass was a mixture of Remington and Frontier once shot (in this rifle) and full length resized with hornady dies. The powder was Varget at 35.5 grains (weighed, not just thrown). The groups were five shot and they were just over 1 inch at 100 yards, barring my fault. Winchester primers. No sign of over pressure that I could see. Here is my question--About 20% of the time I had a "heavy" bolt lift, which I understand is a sign of over pressure, but the load was well under the max by half to one grain, depending on which book you go by. If it was over pressure it should be fairly consistent or more than 20%? The rifle has always had a "snug" bolt lift, even with factory ammo. Is this something normal that I can blame on the brass that I was using or is it more serious? Thanks for any and all opinions!
Just a question about possible overpressure
- Thread starter Nube
- Start date
You can't always go by cratered primers. I have a Remington M700 that will crater a primer shooting a 110 gr. bullet over 5.0 gr. of Unique. 
A close look at the firing pin hole in the face of the bolt shows it came chamfered from the factory. I know this because I bought that rifle brand new back in 1981. Anyway, primers aren't the best way of checking for high pressure.
Paul B.
A close look at the firing pin hole in the face of the bolt shows it came chamfered from the factory. I know this because I bought that rifle brand new back in 1981. Anyway, primers aren't the best way of checking for high pressure.Paul B.
I did check the length of the cases and they were fine. The brass was random between the two brands and I didn’t have any more of a problem with it at 1/2 grain more, just a little less accurate. This brass is quite old if that has any thing to do with it being a little more of a heavy bolt lift as it was just a few cases? Thanks for the replies!
Hard bolt lift , and snug even with factory ammo . Let's go one step at a time . When moving the action without anything is it smooth . Then chamber a sized and trimmed case, try not to oversize your cases .002 is good , then if all goes well seat a bullet to the OAL your seating . You could have a dirty chamber , I don't know how you clean your rifle , you could be oversizing your cases or you could be seating long . It's hard to say without going over all the steps. I found if sizing with too much headspace you can get a harder bolt lift , also in jamming your bullets you will feel resistance when closing the bolt .
Isn't that backwards? Do you mean head clearance?
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Bart B
For some reason I found when I sized my case ( only a test ) with the standard shellholder full contact was .004 clearance between bolt face and case base , my fired cases had a harder bolt lift then normal , with a mild load . I wanted to see if it made a difference with group size but the hard lift I wasn't expecting . Went back to .001 - 2 and it disappeared .
Chris
For some reason I found when I sized my case ( only a test ) with the standard shellholder full contact was .004 clearance between bolt face and case base , my fired cases had a harder bolt lift then normal , with a mild load . I wanted to see if it made a difference with group size but the hard lift I wasn't expecting . Went back to .001 - 2 and it disappeared .
Chris
Something is being measured wrong.
Bolts start binding and get harder to open as case head clearance to bolt face reaches zero.
Have you ever measured mild loaded case headspace before and after firing? Was the case shoulder ever set back any amount from firing pin impact?
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Bart B
My cases get shorter when fired , when I sized them to that length almost like neck sizing . The case chambered fine but on bolt lift the locking lugs felt rough with a click at bolt lift . Doesn't make sense to me , may be a over expansion thing , but when I size the case to a .001 clearance it's fine .004 not so good . Has to do with the OD of the case body , my chamber is good , clean and smooth . It's not a problem for me because I size to .001 , it was just a test at .004 fired size to see how it shot , the rough bolt lift puzzled me .
Chris
My cases get shorter when fired , when I sized them to that length almost like neck sizing . The case chambered fine but on bolt lift the locking lugs felt rough with a click at bolt lift . Doesn't make sense to me , may be a over expansion thing , but when I size the case to a .001 clearance it's fine .004 not so good . Has to do with the OD of the case body , my chamber is good , clean and smooth . It's not a problem for me because I size to .001 , it was just a test at .004 fired size to see how it shot , the rough bolt lift puzzled me .
Chris
What's the chamber length difference from case length? Closed bolt face to chamber mouth.
Do you know how to measure that?
I ask because the more case shoulders are set back the more case length gets longer. Even .001" longer than chamber length will cause the bolt to bind up when closed on such cases.
Has the bolt face been squared up with the chamber axis?
Do you know how to measure that?
I ask because the more case shoulders are set back the more case length gets longer. Even .001" longer than chamber length will cause the bolt to bind up when closed on such cases.
Has the bolt face been squared up with the chamber axis?
Bart B
My chamber length from base to shoulder datum is 1.632 I use that measurement in the Precision Mic to size my cases to 1.631 . When I had the stock barrel replaced by Accurate Ordanance , I wanted it completely blueprinted , they trued the bolt face , lug and barrel , bedded the action . The new barrel is a Rock Creek M24 5R worked out well and like I posted before , I'm getting close to 4000 through the barrel , I saw on Brownells sight how to measure from base to case mouth but I trim every firing , in most cases more of a cleanup . My cases when I size to my .001 size with very little resistance. The cases I sized to the .004 that caused a hard lift , when sized to the .001 on the next firing worked fine . My trimmer is setup to the same adjustment all the time because I only shoot this rifle . I know it doesn't make sense a oversized case should have plenty of room . Once was enough I'll stick with my F/L sized cases to .001
Chris
My chamber length from base to shoulder datum is 1.632 I use that measurement in the Precision Mic to size my cases to 1.631 . When I had the stock barrel replaced by Accurate Ordanance , I wanted it completely blueprinted , they trued the bolt face , lug and barrel , bedded the action . The new barrel is a Rock Creek M24 5R worked out well and like I posted before , I'm getting close to 4000 through the barrel , I saw on Brownells sight how to measure from base to case mouth but I trim every firing , in most cases more of a cleanup . My cases when I size to my .001 size with very little resistance. The cases I sized to the .004 that caused a hard lift , when sized to the .001 on the next firing worked fine . My trimmer is setup to the same adjustment all the time because I only shoot this rifle . I know it doesn't make sense a oversized case should have plenty of room . Once was enough I'll stick with my F/L sized cases to .001
Chris
I never measured the chamber length to the neck area limit , being I'm trimming to the mid range of the scale every firing , I didn't think it mattered . On the .004 sized cases all were placed in the trimmer after sizing and tested with stripped bolt to test , bolt dropped with no resistance . It is the third reload with these cases when this happened , the two times before sized to .001 and trimmed everything went fine , on the third sizing I wanted to see if left to the fired length how it would shoot . That's when I noticed the issue with the bolt lift . Sizing and trimming those cases back to the .001 everything went back to normal. What are your thoughts. The shorter cases .004 are getting the rough lift not the longer .001 cases
Chris
Chris
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I'm betting mixed brass is the problem. Not all brands of brass has the same internal volume. My load manual says 36.5 is a max load using Winchester brass. In my experience Winchester and Remington is close enough to not cause problems. But Federal brass tends to have less case capacity. That means it takes less powder to achieve the same pressures and velocity. Frontier brass is made by Federal.
I reload Federal brass, but keep it separate and work up loads separately. I wouldn't be surprised if you start paying attention that the hard bolt lifts are all with the Frontier brass.
I reload Federal brass, but keep it separate and work up loads separately. I wouldn't be surprised if you start paying attention that the hard bolt lifts are all with the Frontier brass.
Bart B
Maybe I'm not explaining myself properly because everything I do is repeatable , the only problem and it wasn't a problem because I'm not oversizing my cases , I just didn't think you could get a rough bolt lift not a hard lift like when the case is too long but more of a click when bolt is lifted up . I normally size with a minimum of case space .001 . So for the sake of wasting everyones time in straying off topic I'll just end it here . Thanks for the time
Chris
Maybe I'm not explaining myself properly because everything I do is repeatable , the only problem and it wasn't a problem because I'm not oversizing my cases , I just didn't think you could get a rough bolt lift not a hard lift like when the case is too long but more of a click when bolt is lifted up . I normally size with a minimum of case space .001 . So for the sake of wasting everyones time in straying off topic I'll just end it here . Thanks for the time
Chris
jmr
I don't mix my brands , I do shoot 3 different brass brands , all on the thick side . FC , HMR & ADI , 3 set of 30 each that I rotate each week . They all fire and size the same , my only question is when I sized one lot once to .004 instead of .001 the .004 the bolt lift wasn't smooth . Going back to the norm of .001 everything worked well . I just felt it was odd . No scratches on the brass , no flattened or cratering on the primers . What I should of done was take measurements of those fired cases , I just popped the primers , cleaned and resized to .001 . My cases get shorter when fired .004
I don't mix my brands , I do shoot 3 different brass brands , all on the thick side . FC , HMR & ADI , 3 set of 30 each that I rotate each week . They all fire and size the same , my only question is when I sized one lot once to .004 instead of .001 the .004 the bolt lift wasn't smooth . Going back to the norm of .001 everything worked well . I just felt it was odd . No scratches on the brass , no flattened or cratering on the primers . What I should of done was take measurements of those fired cases , I just popped the primers , cleaned and resized to .001 . My cases get shorter when fired .004
Head to shoulder or head to mouth?
Virtually all cases get shorter a few thousandths head to mouth when fired.
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