light primer strikes 45-70 X lever

[bsumoba]

Shot the X lever for the first time. Had a dismal amount of FTF due to light primer strikes using handloads and TulAmmo LR primers. Out of 20, maybe half failed to go and of the 1/2, maybe 1/4 of them fired on the second strike.

Primers look completely depressed, although I will check it again, but they are well recessed into the primer pocket.

I was thinking hard primers, but I've used this lot of primers in other firearms with zero issues.

Lastly, it could be gun related, light hammer spring, junk in the firing pin hole, or the safety block thing is doing something funky.

Anyone had experience with FTFs in their Henry and what the solution was, other than sending it to Henry?

[MongooseV8]

Pics? Set deep in the primer pocket it could be your brass or primers are off spec.

[splithoof]

I’ve used a ton of Wolf primers of various sizes, and never have had a single primer-caused issue.
Does that ammunition you have loaded function properly in another firearm?
Does the problem continue with factory-fresh ammunition?
I might also look at the firing pin channel for leftover debris, and clean any parts associated.

[bsumoba]

Attached.

Picture with the double stuck primer are rounds that never touched off.

The other are two that fired no problem

The picture of the primer shows how set into the pocket it is. These are new, never fired starline 45-70 brass

[MongooseV8]

Not as much as I was expecting. IME they need to be in like 0.020 or more to cause light strikes.

My guess is firing pin (protrusion out of spec or debris inside the bolt) or maybe headspace?

[MongooseV8]

Second thoughts if the 1 strike rounds look normal its most likely something preventing the firing pin from striking consistently. Debris in the bolt try that first.

[slamfire1]

Primer hits should be in the middle of the primer. The further offset the hit from the tip of the anvil, the greater the chance of a misfire.

Send the rifle back to Henry and get them to fix that. Do not accept anything but a perfectly centered firing pin hit on the primer. Give or take a couple of thousandths. This ignition problem will not solve itself, will not get better, it will get worse as the mainspring weakens, the firing pin wears, and in cold weather. And, given weak ignition, you may have squibs.

I had a similar problem with a Ruger #1 in 35 Whelen. The offset was 25-30 thousandths and it misfired frequently until Ruger Customer service fixed it. Ask Henry about the depth the firing pin makes on coppers, and the offset. And make sure the Technician understands that it misfires with your primers.

For the education of those who are interested in firing pin offset, the following is copied from a paper copy of this report:

Report No. R-462 Primer Sensitivity vs. Firing Pin eccentricity
Frankford Arsenal Dec 1943

Object: To determine the effect of firing pin eccentricity on the sensitivity of small arms primers

Summary: Retaining firing pin plates were constructed for the drop test machine that have blows eccentric by .00”, .02” and 0.04”. Drop tests were made on cal.30, .30 carbine, cal 0.45, and cal .50 primed cases (in cases) with sharp anvils, and on cal .30 primers (H-4 in cases) with flat cups.

Very little, if any, changes in sensitivity occurs with blows of 0.02” eccentricity; large differences occur with blows of 0.04”.

“H bar” H̅ is the mean critical firing height. (approximately the 50% ignition point)

The 1943 report shows for the Cal 0.45ACP, H̅ with a four ounce weight is 3.70” for 0.0” eccentricity, 3.70” for 0.02” eccentricity, and 5.11” for 0.04” eccentricity. The further the offset of the firing pin strike, the more energy it takes to get ignition, until, the offset is so bad nothing makes the primer go bang, except perhaps, a sledge hammer or a flame.

From Percussion Primers, Design Requirements, McDonnell Douglas 1970:

“Primer manufacturers in their data sheets customarily provide the 100% “all fire” level of their products. This is essentially the same as the mean firing height plus five standard deviations.”

You will find some who think a primer will ignite no matter where the firing pin hits, and this shows how little they know about primers. So, contrary to the delusions held by many, the further from the center of the primer, and the tip of the anvil, the more likely is the probability of a misfire. Maybe this cross section of primer construction will help in understanding this:



Something else that does contribute to misfires is a high primer. CCI, in the article
Mysteries And Misconceptions Of The All-Important Primer claimed that the most common cause of misfires is high primers.

If the anvil is not firmly seated and the cup pushed down to set the gap between cup and primer, then the primer will misfire. If the anvil is dangling in the air, often a firing pin strike will seat the primer in the primer pocket, and a second hit usually ignites the primer. Sometimes the primer cake is broken with the first strike and then there is nothing for the anvil to pinch.

[ar15barrels]

Attached.

Picture with the double stuck primer are rounds that never touched off.

The other are two that fired no problem

The picture of the primer shows how set into the pocket it is. These are new, never fired starline 45-70 brass

Those firing pin strikes are really off-center.
It becomes very obvious when you see the double strike and the hits are not even in the same spot.
Look at the cross section of a boxer primer and the problem will be obvious.
Fix the bolt so the firing pin is striking centered and the ignition will get much better.

[bsumoba]

I had a feeling it was due to firing pin not striking consistently center once I took pictures of it. I didn't really analyze things until I did that.

I'll report back once I get this taken care of.

[MongooseV8]

That wouldnt be a light primer strike then. I thought you were getting light strikes and solid strikes inconsistently.

[Fjold]

Here's an easy check, to see where the off center lies

Take a sharpie and mark the top of the cartridge head when you manually load it in the chamber.

Fire the cartridge and when you eject it you can see if the firing pin strike is left, right, up or down.

If you can disassemble the gun, pull the bolt out and look at the bolt face to see if you see an obvious issue with that like an oversized firing pin hole. Some guns have a thick bolt face and the front of the firing pin actually rest in the firing pin hole. If the hole is oversized the pin rests on the bottom of the hole and will strike low.

[bsumoba]

That wouldnt be a light primer strike then. I thought you were getting light strikes and solid strikes inconsistently.

My immediate thought was light primer strikes because of the FTF. But it could be off center strikes too. I called Henry today and am expecting a call with a tech guy tomorrow.

Here's an easy check, to see where the off center lies

Take a sharpie and mark the top of the cartridge head when you manually load it in the chamber.

Fire the cartridge and when you eject it you can see if the firing pin strike is left, right, up or down.

If you can disassemble the gun, pull the bolt out and look at the bolt face to see if you see an obvious issue with that like an oversized firing pin hole. Some guns have a thick bolt face and the front of the firing pin actually rest in the firing pin hole. If the hole is oversized the pin rests on the bottom of the hole and will strike low.
Remove the case

This is exactly what I am thinking of doing.