head space
#11
Nontypical Buck
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Yes, i believe you do understand. When the action is put into battery, there is a fixed space for the primer to fit into. If this 'space' is larger than the primer, there usually will be blow by. If this space is 0.003" or so, smaller than the primer, the primer makes a seal, and there is no blow by. What i do is close the action on my primer of choice after i measure them. When they are measured after removing them from the rifle unfired, i want them to be some less than they were out of the box.
Making each rifle fit a certain primer is what i do. STS primer are a favorite of mine because they seem to be more uniform in size, compared to others.
Making each rifle fit a certain primer is what i do. STS primer are a favorite of mine because they seem to be more uniform in size, compared to others.
#12
Spike
Join Date: Oct 2011
Posts: 14
Ron, do you put the shims around the breechplug by this i mean do you unscrew it and slide the shim around the plug and then tighten it back up.I would like to see a picture if possible also what is the inner and outer dia. of your shims.THANKS
#13
Nontypical Buck
Join Date: Aug 2006
Location: Rivesville, WV
Posts: 3,192
I got you now. But wouldn't it just be easier to try different primers to see which one gives the best fit??
I tried different ones in my Knight rifle. Then I believe the bolt also applies a slight crush fit to the primer. So I get absolutely zero blowback without doing any shimming or such.
Does this make the crush fit a slightly better system?? I did notice that when the primer fit better I had less crushing of the primer. Still a slight crush, but not nearly as noticable as other primers.
I have Sabot Loader to thank for that little bit of information. He showed me exactly how to get my primer to fit perfectly. I was actually suprised that after 25 shots of Black Horn I had absolutely zero residue of any type anywhere on the bolt or any other part rear of the inside of the breech plug. I was very happy with that. Tom.
I tried different ones in my Knight rifle. Then I believe the bolt also applies a slight crush fit to the primer. So I get absolutely zero blowback without doing any shimming or such.
Does this make the crush fit a slightly better system?? I did notice that when the primer fit better I had less crushing of the primer. Still a slight crush, but not nearly as noticable as other primers.
I have Sabot Loader to thank for that little bit of information. He showed me exactly how to get my primer to fit perfectly. I was actually suprised that after 25 shots of Black Horn I had absolutely zero residue of any type anywhere on the bolt or any other part rear of the inside of the breech plug. I was very happy with that. Tom.
Last edited by HEAD0001; 10-23-2011 at 06:13 AM.
#14
Nontypical Buck
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Pictured is the firing pin bushing from my Accura, with a shim along side. The shim need to fit over the threads which measure 0.306", and has to be smaller than the rim, which measure 0.384"
#15
Nontypical Buck
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
However this doesn't always work. One of my Knight makes a perfect fit using W209, and as you describe has zero blow by, what i mean is zero blow by. The other Knight won't fit any primer made perfectly, and so far it is quite clean using the W209, but it isn't what one would say is zero blow by. Two of my Omega use W209 with a perfect fit; the other doesn't. For the odd Omega, i am using a modified breech plug that gives a nice crush to STS primer, but it cannot use W209 primer.
CVA rifle are made looser than Knight or TC, and to get a perfect fit with any primer, one needs to adjust the headspace by backing out the firing pin bushing, and shimming it.
#16
Nontypical Buck
Join Date: Aug 2006
Location: Rivesville, WV
Posts: 3,192
At first my Knight was also smashing or force fitting(with a little too much force) the 209's I was using. That is when SabotLoader taught me a trick about cleaning the rifle that completely changed the way the primers fit. Without any shims, just a drill and a good bore brush with some Butch's. Tom.
#17
Spike
Join Date: Oct 2011
Posts: 14
Ron i meant to say firing bushing i want to thank you for all the info. you have given us also i will e-mail max to see if he has the shims.Sabotloader thank you for the link but i do not think they have the size i need.Head0001 thanks for this thread i apolize for minor hijacking but one can learn alot from these fellas.THANKS
#19
Spike
Join Date: Oct 2011
Posts: 14
MD54 l'm not trying to be a smarta$$ but if you or anyone else have the shims i would like to buy some to try out.I have the optima and i will say again i really like this rifle.THANKS
#20
Fork Horn
Join Date: Jan 2007
Location: Arizona
Posts: 202
O-rings
Not trying to go off topic, but wouldn't the little rubber o-rings that were mentioned in a recent discussion (fitted around a primer) be easier and also work with BH-209? The pictures showed a very clean primer - I assume that that would keep enough gasses from escaping to make BH-209 work fine - right? I'm just saying that rather than take your firing pin assembly apart to adjust/shim it for every type of primer you want to use, just add a reusable o-ring around your primer and not risk losing parts or messing something up.
Pictures at bottom of page:
http://www.huntingnet.com/forum/blac...ader-help.html
Pictures at bottom of page:
http://www.huntingnet.com/forum/blac...ader-help.html
Last edited by donw; 10-23-2011 at 01:14 PM.