Reply With QuoteAre you full length resizing your brass each time?
Hi new guy here. I have a Savage 12 LPV DBM, 26" fluted barrel, Accu-stock/Accutrigger in 204. Lately I have been having problems opening the bolt. Sometimes it opens easily and others I can raise the handle but have to bump it open with my hand.. Shooting hand loads, and have tried using minimum loads, but it still does it at times.. Haven't found any answers yet, so I am asking here.. Really no rhyme or reason to this but I'd like to eliminate the issue.
Are you full length resizing your brass each time?
Primary extraction?
The Dunning-Kruger effect is alive and well.
FL or NS die makes no difference though I prefer a FL die sets. You need to bump your shoulders back a bit and check your brass length, bottleneck cases (most calibers) grow with each firing. With some dies, bumping shoulder back can be an issue, some are not. It all depends on the die maker and if you are using a bushing die or a fixed bore die, but any die can be 'made' to bump by modifying the base (the closer the base is to the sizing bore, the more 'bump' you can obtain). Myself, I like to bump my shoulder back 0.002 (measured with a Hornady Headspace gauge and calipers. No amount or degree of bumping will overcome a case that is too long. Cases must be between the nominal and maximum COAL (Case overall length, not Cartridge overall length to function properly.
That is your issue btw. The shoulder datum is to tight a fit in the chamber causing heavy bolt lift. Take a look at your bolt face as well. Telltale brass streaks on the bolt face is indicative of an headspace issue that bumping will eliminate in 99% of all cases.
My rule of thumb is I always use premium cases (Lapua or Norma) and anneal after the third loading with no exceptions and discard when the pockets feel 'loose'.
Because I use only bushing dies (and I machine my own bushings), I remove the expander balls from my dies entirely. No need to work the brass twice. An expended case had already expanded the case mouth so why run it through an expander ball, only to have the neck section of the die close it up again. Brass hardens each time you work it. I prefer to only work it once.
Thanx for the replies.. I full length size every time and trim to length. I'll check the face for brass.. To clarify: It's not that the bolt is hard to lift. It isn't. The problem is after the handle is raised the bolt will not slide back.. I thump it a few times with my hand and it opens.. I loaded some new brass and had issues still. Note, it's not every round.. Sometimes it doesn't occur for 15-20 rounds..
I read elsewhere that one fella had this problem and cured it by replacing the bolt handle.. On a whim I swapped bolts with my son's Savage 12 in 223. I fired close to 200 rounds today P-dawging and not one issue.. One box of reloads was on it's fourth reloading.. Now I am wondering if the issue isn't just the bolt handle.. FWIW there are a lot of people with this issue it seems, as I was googling ..
FWIW I am using a Redding competition die set. I am familiar with bushing dies, just do not own any
gets my vote.Originally Posted by Robinhood
Can you guys expound on this?? Please/
Ok just googled primary extraction.. Found a video on this site explaining it.. So now I need to replicate the problem and look for primary extraction. So if this is the issue what's to be done about it?
http://www.savageshooters.com/conten...ary-Extraction
In the Article Bill PA mentions his fix and many have used it.
Do you understand the primary extraction consisting of the bolt handle and the rear baffle relationship?
The Dunning-Kruger effect is alive and well.
Redding is a good die, I have a few in pistol calibers. However the base on a Redding, just like an RCBS is long to the point where, even with an interference fit between the shellholder and the die base, it's impossible to bump a shoulder. There are 2 solutions, you can purchase (from Sinclair) a reduced height shellholder. The machined distance from the top face of the shellholder is less that an off the shelf (standard one and you can buy them in 2 thousands increments or, you can grind off the base of the die a bit, you can even do that with a grinding wheel if you are careful. I chuck mine upside down on a surface grinder in the shop. You need to check the bolt face for brass transfer that will be the giveaway as to a headspace issue.
Typically, when I build a load for any rifle (I just happen to build loads for a lot of clients), I always start with a no bump situation on new sized brass and work up from there ascertaining bolt lift, drawback and brass transfer and then start bumping the shoulder to where the symptoms disappear and no more. That is typically 0.002-0.003 (measured with the appropriate headspace gauge).
I have no idea how hot (or mild) you load and don't care really, but, 4 reloads is pushing a case, especially if you are resizing with an expander ball on the die stem. That neck is getting brittle.
All my long range rifles and medium range ones as well have dedicated custom made die sets, made by John Whidden expressly for that rifle. I send John 4 fired cases and he machines the die to match the fired case dimensions or to a reamer print. I'm of the understanding that RCBS will do the same with their Gold Medal dies. That way, you size with a die that has internal dimensions exactly that of the fireformed case because every chamber is different, just like fingerprints and stock dies are made to SAMMI dimensions which probably aren't the dimensions of your actual chamber.
I do the same with my client's rifles. When I do a build I order a custom die and that dies goes with the rifle plus I do all the load workups using that one die.
Your bolt face will tell the story. Even faint brass transfer is a headspace issue. There should be none unless you are really running hot loads and then issues usually show up with the primer cratering.
People attribute all sorts of issues to everything other than inadequate headspace and headspacing is an easy fix. I know a guy who literally knocked his bolt handle off trying to get the rifle to come out of battery.
Iam sure I will flamed on this
but the last 3 that I had problems with , the bolt body was out of spec
the relief was not cut deep enought
Which can cause primary extraction issues also. Flame retardant is generously handed out.
"And you shall know the truth, and the truth shall make you free.” John 8:32 (New King James Version)
No this is all new to me.. Never had this issue with any fire arm before now..
Just looked at the bolt head. Using a jewelers loupe, no brass of any kind is present. As far as dies, what I have is what I use.. I'll look into the Sinclair shell holders..
Ordered the shell holder set. I'll give it a try..
Edit. Ordered the wrong thing and cancelled. I cannot find a reduced shell holder set at Sinclair. The one they have actually is thicker in .002" increments.
SidecarFlip, you have some good information in there. Johns dies are top shelf for sure. Definitely not the the expert on the matter but some things I have experienced in reloading. Annealing will solve spring back on hard brass. A case that has long head space prior to being fired will make it very difficult to close the bolt.
Drybean, What dimension/relief was out of spec?
zilla, To test the primary extraction you need a feeler gauge set. Otherwise you might try to anneal your brass. Sidecar is correct that the brass may be getting hard. If you are not experiencing a hard to close bolt, your case head space is probably not too long. Following sidecars advice and size for the .002-.003 clearance at the shoulder is always a good practice. Lots of tools to check that dimension.
The Dunning-Kruger effect is alive and well.
So how do you check it?? Primary extraction?
Robinhood posted this earlier, ck link
For a visual ck this out
http://youtu.be/x-1ddHYW6wA
I watched that. Now if someone can explain what is sgoing on. That is pretty much what happens with my bolt..
Update. took the rifle to the range to check my zero. Also took my son and his Savage 12 in 223 Rem. Decided to swap bolts to see what happened. His bolt works flawlessly in my Rifle. Mine in his is having the same issue.. Me thinks something about the bolt is FUBAR. Probly the primary extraction business. Not sure what to do about it..
The rear baffle has a cam at the bottom left hand corner, it acts in concert with the bolt handle to pull the expired case from the chamber. Converting rotational motion to lateral motion pulling the case rearward (freeing the case so the operator can pull the bolt back ejecting the spent round).
If the clearance between the bolt and baffle are too great the cam will not produce the needed rearward motion. You can shim the baffle (between the baffle and action) once you know how much is required (that's where the feeler gauges come into play).
Hopefully this makes some sense
Switch the bolt handles bolt to bolt then try both their actions.
Bill
Each morning eat a live green toad, it will be the worst thing you'll have face all day.
OK, will do.. Makes sense..
I may get flamed as well, but I have a different take on this.
I have two Savage rifles (3 now but have shot just the two, third this weekend). One is a long action, the other shot.
One is a year old, one is at least 6 years old, as much as 10 or so (used, shot little) .
Both exhibited the problem after some rounds down the tube.
I understand the primary extraction aspect, but to work fine then not with little wear is??????
I am now cleaning my chambers very specifically and carefully.
Since I did I have had little of it occur.
I do think that the bore guide keeps you from doing that so I go around it and do a chamber clean.
I do need to get the gauges with me and see what happens when if I occurs, but its turned into such a seldom problem and I have to find my gauges or bring them in from work. .
I think there is more to this than just a dirty chamber, but still puzzling over what the relationships are and causes, it may be marginal extraction pushed over the edge, but I don't think Primary extraction specifically is the issue. I am also looking at re-size new vs older brass etc.
I suspect Savage has pretty tight chambers contributing to this. Some and some (if true) , tighter chamber is a more accurate one as well.
Could be wrong, been there, done that, have boxes of T shirts. My spidey senses say there is more to this than sometimes is offered up as a flat covers all response and maybe more accurately, primary extraction issue is a symptom not a cause.
I just got back from the range.. Changed bolt handles. No problems with either rifle.. Gotta go back out tomorrow when the wind dies down and finish zero-ing.. We'll see how it goes.. I am waiting for the problem to occur again so I can look at the rear of the bolt now that I think I know what to look for..
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