How do I control primer depth?

[Slooshark1]

I'm having issues with misfires on my Winchester / Miroku 1886 45-70 and 45-90s. I tried a box of factory loads and had no issues with them, so it's my reloads. How do I consistently seat primers to the proper depth? I'm currently using an RCBS Rockchucker press.

Any advice would be appreciated.

Thanks,

Slooshark1

 

[762shooter]

I'm having issues with misfires on my Winchester / Miroku 1886 45-70 and 45-90s. I tried a box of factory loads and had no issues with them, so it's my reloads. How do I consistently seat primers to the proper depth? I'm currently using an RCBS Rockchucker press.

Any advice would be appreciated.

Thanks,

Slooshark1

I use a hand tool to seat primers. I try to feel when the primer bottoms in the primer pocket then I check that they are flush or a few thousand below flush. Low tech but it works for me.

 

[Nipigon Jack]

Check out 21st Century priming tool. Or K&M priming tool. They are a little over the top, but either one should be able to fix your problem.

 

[thump_rrr]

I wouldn't be so quick to blame primer seating depth.
I would check headspace and firing pin protrusion first.

 

[Slooshark1]

If it were a headspace issue, wouldn't the factory loads have misfired, too?

 

[thump_rrr]

If it were a headspace issue, wouldn't the factory loads have misfired, too?

Depends if you're pushing the shoulder back too far causing the headspace issue yourself.
Compare the factory rounds to your manufactured rounds using a Hornady or Sinclair headspace gauge.
Or a drop in gauge such as those made by L.E. Wilson.

 

[tjsudbury]

I wouldn't be so quick to blame primer seating depth.
I would check headspace and firing pin protrusion first.

This is happening with both of his new guns. Not likely to be a headspace issue

 

[tjsudbury]

Depends if you're pushing the shoulder back too far causing the headspace issue yourself.
Compare the factory rounds to your manufactured rounds using a Hornady or Sinclair headspace gauge.
Or a drop in gauge such as those made by L.E. Wilson.

45-70 and 45-90 = no shoulder

 

['Boo]

Depends if you're pushing the shoulder back too far causing the headspace issue yourself.
.

These cartridges head-space on the rim, NOT the shoulder.

 

['Boo]

For the primer seating depth issue I suggest a ram-primer from Lyman or RCBC if using the press to prime or a dedicated hand primer tool.

 

[rookie wildcat]

Depends if you're pushing the shoulder back too far causing the headspace issue yourself.
Compare the factory rounds to your manufactured rounds using a Hornady or Sinclair headspace gauge.
Or a drop in gauge such as those made by L.E. Wilson.

Really? Shoulder? Thanks for playing! And you are helping out?

 

[rookie wildcat]

These cartridges head-space on the rim, NOT the shoulder.

Whoops, sorry, slow Internet. What he said.^^

 

[thump_rrr]

Really? Shoulder? Thanks for playing! And you are helping out?

Missed the calibers.
Multi-tasking failure.

 

[Tex Critter]

For me, primer seating is done with a hand tool and by the "feel".

 

[Collint2005]

Maybe just try seating a few primers making sure they aren't recessed and maybe just slightly above and see how they work

 

[bigedp51]

rookie wildcat

I bought my Rockchucker press in 1973, after one attempt of priming 20 cases and not liking the results, I went out the next day and bought a hand priming tool and the priming arm was removed from the press.

Below shows seating a primer with a slight crush and seating the anvil. The face of the primer is seated below the rear of the case.

U.S. Military requirements for primer seating states the face of the primer must be .008 below the rear of the case.

 

[rookie wildcat]

rookie wildcat

I bought my Rockchucker press in 1973, after one attempt of priming 20 cases and not liking the results, I went out the next day and bought a hand priming tool and the priming arm was removed from the press.

Below shows seating a primer with a slight crush and seating the anvil. The face of the primer is seated below the rear of the case.

U.S. Military requirements for primer seating states the face of the primer must be .008 below the rear of the case.

Ummmm, thank you?

I am not the OP, and there hasn't been a priming arm on any ofmy presses for quite a few years. Only press-mounted one I would even remotely use would be a Ram Prime type.

I have both of Lee's hand priming tools and an RCBS one.

The nickname is older than some of the members here. LOL

 

[old enfields]

Try a Sinclair primer pocket uniformer followed by your choice of hand priming tool. If the pockets are not uniform no priming tool will make up for it.

 

[ciPeterF]

Do the misfire rounds fire on a second (or third) attempt? If so, your primers may not be fully seated. Personally I user a primer pocket reamer (Sinclair), and "firmly" seat the primer. Reamer ensures consistent depth, firmly seating ensures all the firing pin force is causing the anvil to do it's thing, not finish seating the primer first.. May \ May not be your issue.. (assuming you've cleaned any crud out of the firing pin channel..

 

[Boomer]

Years ago I had a '70s manufactured '95 Marlin that had ignition problems that turned out to be not enough hammer spring combined with thick cup CCI primers. This was remedied with a couple of shims behind the spring. If uniforming your primer pockets to ensure the primers are fully seated doesn't solve your problem, it might turn out to be a gun problem, and the firing pin energy might be the culprit.