M1a seating depth

[splotch]

Is it possible to seat the primers too deep - I read a bit about keeping the primers on the deep side so I bought a sinclair pocket reamer and reamed the primer pockets, according to instructions, and seated the primers by hand with a lee hand primer, I just used the pressure I normally used. And none of them will fire there is just a small dent on the primer. How do you control the depth?

[country gent]

I have a sinclair uniformer and the collar has a small set screw in it to set the depth it can cut. All you want to do is clean up the primer pocket to "flat" this is ussually around .002-.003 removed. How far below the case are the new primers sitting? They should be around .005 below case head if I remeber corectly. There is a very narrow band as the firing pin only has so much forward movement (protrusion) allowed. Measure the depth below the case head these primers are sitting and let us know that. The depth rod on calipers should measure this easiy. other wise use a small primer, measire case length then over case with small primer on primer of case, subtract case length and primers thickness from reading sould leave you with primer depth. If you didnt reset the tool to depth you may have cut them 2 deep. On my tool .003-.005 pretty much fills the tool to where it cant cut any more till removed to clear chips and start over.

[splotch]

the sinclair uniformer that I have has no adjustment just a ledge the controls the depth it will cut. So I assumed that you cut to the stop. I will have to check the depth with a caliper.

[country gent]

I have the carbide model and it is adjustable. If yous is not adjustable and cutting to deep contact sinclairs with the depth it is over cutting and actual measurements. They are a great company and easy to work with. Ill bet they stand behind it. How many cases did you do before checking it ?

[Gtek]

I think I would first be checking and confirming firing pin protrusion before adjusting anymore brass, Min. .044" - Max. .060". Second would be hammer spring followed by inspection of freedom of movement (Hammer) in trigger group. IIRC the SAAMI spec. for primer seating depth is 0.002"-0.005" below flush and most handloaders do not measure it. I would assume you have a vernier and micrometer? What was the country of origin, who made it? One should be careful and educated with this design weapon when tinkering, an out of battery is not good for anyone.

[Doc Highwall]

This is the Sinclair primer pocket uniformer that I use with a power adapter for use in a cordless drill, and they are non adjustable.

http://www.sinclairintl.com/reloadin...prod34720.aspx

[splotch]

Problem solved. Turns out that the new bullet I was playing with had enough different profile that it was out to far a little deeper seating fixed the problem

[country gent]

Glad to hear that.