Thread: Light Primer Strikes

Originally Posted by Cigar

Also a possibility that despite all being the same thickness, there may be differences in hardness.

Same applies to primers

Originally Posted by grandpamac

Greetings All,
As mentioned previously in this thread light firing pin strike and missfires can be different to a lot of different things but it can be due to a combination of things. One thing that was mentioned by @Moa Hunter was excess head space, This can be present in the rifle or it can be created in the FL sizing die. The OP mentioned the .280 AI as the problem chambering. The .280 AI chamber is shorter from the neck shoulder junction than the parent .280 Rem case. This is done so factory .280 ammo can be fire formed in the AI chamber. To convert a .280 Rem chamber to .280 AI the barrel needs to be set back a thread so that his junction supports the case properly. This takes extra work and I don't know how often this step might be ommitted. All of the other 06 based cartridges have shorter headspace than the .280 so other cases need a false shoulder created to support the case close to the bolt face when firing.
Recently I bought myself a Hornady Head Space Comparator. Measurements revealed that my old Lyman 6.5x55 dies were setting back the shoulder more than 0.010" from the fired position in my T3 and more like 0.015" in my M38 and a friends Ruger 77. New Lapua cases measured close to fired cases in the T3 so the problem was the dies. A new set of Redding dies and a Competition Shellholder were purchased but I found the Redding dies still needed the +0.010 shellholder to get the right amount of shoulder bump. The US standard dimensions for the 6.5x55 clearly differ from the original. There is a level of arogance in the US about things not invented there and the same situation may apply to other continental cartridge dies so be warned.
Regards Grandpamac.

Very interesting that the dies are out of spec and not the rifle chamber. Also interesting that there are +0.010 shell holders. What is the reason to use this shell holder instead of just backing the die off and setting locking ring ?

Greetings @Moa Hunter,
The dies are likely cut to US SAAMI spec but this is out of line with the spec being used in Finland. Unfired and fired Lapua cases from the T3 measure almost the same, both made in Finland, so I am assuming that the cases are max and the chamber is min. The Ruger factory rifle is longer by 0.005' so this would be a max chamber on the Finnish spec. Only the US dies are out of step.
Regarding the Redding Competition shellholders I find that these give a more precise sizing than backing of the die based on my measurements. I also have more than one rifle in .308 and 6.5x55 so the shellholders are a better way of setting the case headspace instead of having to adjust the die. My VSSF .223 is spot on with the standard shell holder and my T3 .223 needs the +0.002" so I borrow a shell holder from my son for any sizing for it. For My SAUM which I don't use mutch I will probably just set the die as you suggest.
Regards Grandpamac.

5 thou = a fly shit...literally, if your round is carried in pocket/pouch/packet for anylength of time it could pick up that much crap n crud.... 2 thou is even less..how in blue blases are you measureing this infintisimal error in brass size and why in blue blazes are you even bothering??? it will chamber and fire....
if Im wrong....make 3 of each measurement...3 with die set hard down onto std base and 3 with your fancy pants adjustment...go shoot them and see if there is a measuable difference in group size.....50 quid to a knob of goat shit there will be NOTHING IN IT.....
if your dies are out of spec EG too big...you will not be able to chamber loaded round.....if they are too small,the round will fit easily ,and as MH has said if you back die out a flyshit,1/4 turn...you have corrected any possible error.

Originally Posted by Micky Duck

5 thou = a fly shit...literally, if your round is carried in pocket/pouch/packet for anylength of time it could pick up that much crap n crud.... 2 thou is even less..how in blue blases are you measureing this infintisimal error in brass size and why in blue blazes are you even bothering??? it will chamber and fire....
if Im wrong....make 3 of each measurement...3 with die set hard down onto std base and 3 with your fancy pants adjustment...go shoot them and see if there is a measuable difference in group size.....50 quid to a knob of goat shit there will be NOTHING IN IT.....
if your dies are out of spec EG too big...you will not be able to chamber loaded round.....if they are too small,the round will fit easily ,and as MH has said if you back die out a flyshit,1/4 turn...you have corrected any possible error.

My understanding of what GPM is doing is that he has several rifles to load for that all have their own dies and he wants to leave the die 'set' for each rifle rather than resetting. The dies are all wound down the same to kiss the shell holder for consistent repeatability but because some dies dont match the chambers different shell holders are used to get the sizing perfect.
This sort of stuff is a foreign language to you and I MD because we are not target shooters and dont understand the hidden intricacies of getting perfect groups at 1000 yards.
I think GPM should sell us his Saum

Greetings to you both @Moa Hunter and @Micky Duck,
Thank you both for your kind words and advice. I suspect that you both handload out of neccesity and for you the handloading is the prelude to the main event. I also suspect that I am a lot closer to the crematorium than either of you. For me "hunting" is limited in duration and my main event is the handloading. Having retired some years ago I have now settled into the endless rabbit warren that is handloading. In my long departed youth I reloaded .303 cartridges and encountered endless problems with neck cracking and incipient head separations. I solved this by buying a .308 and neck sizing to extend case life. Handloading kept me supplied with ammo for hunting and low level target shooting. Later as funds allowed more rifles appeared in the safe and some new kit appeared on my loading bench. In early 1980 I discovered Handloader Magazine, subscribed and still do. This has changed my life. Since retirement more time and adequate funds have allowed me to experiment with the handloading rather more. I still tend toward low tech solutions and don't have much of the kit that some handloaders regard as essential. Difficult cartridges interest me such as tha 6.5x55, .303 Brit and .30-40 Krag. For these there is varaible data and some research is needed for decent results. For me handloading has become the main event. I realise that some of my methods are way over the top to some and stone age to others and all are free to pick the eyes out of my how I do things or ignore them altogether. I am not much of a target shooter but am hoping to do some more medium range bench rest target shooting later in the year. I participate in target shooting rather than compete. Lastly the Sendero seems quite happy in my safe but if it does get itchy feet you will be the first to know.
Regards Grandpamac.