Delayed response from my .338 lapua reloads

[BillyGoatMachine]

Sorry guys for yet another question. I've been taking up a lot of forum space lately. Being new to reloading and the fact that I live out in the sticks, Calguns is my greatest asset for my lack of knowledge. OK, so right after I pull the trigger, I can hear the firing pin connect with the primer and there is maybe 1/5 of a second delay until the bullet is fired. This happened maybe four times out of 50 reloads. Could primer seating depth have something to do with it? I spilled a few primers on the floor while reloading and picked them up??? Could this be part of the reason?
I loaded up .338 lapua magnum

Vit N560 started with 75 grns
CCI large magnum rifle primers
Lapua brass
Sierra 250 matchking hpbt

Thanks again. I wouldn't have been able to reload these at all without previous help from you guys.

[bigmike82]

How dirty is your floor?

[tteng]

Yes, the primer might not be all the way in. The firing pin is seating then firing the primer, thus the delay.

[BillyGoatMachine]

Yes, the primer might not be all the way in. The firing pin is seating then firing the primer, thus the delay.

My reloading manual says to seat them between .003" and .005". Most were seated to the correct depth with the exception of a few of them being to deep, .007-.008". The primers were either seated correctly, or to deep.

[Beelzy]

Hint: Always keep some factory ammo on hand to verify load or equip. malfunctions.

Primer depth, or contaminated(dust?) primers. OR, you set back the necks
on a couple of cases and they "shrank". I would check the case lengths on
the fired cases for Shorties.

[rksimple]

How old are the primers? Although rare, could just be a bad batch.

[BillyGoatMachine]

How old are the primers? Although rare, could just be a bad batch.

I bought them last week at my local gun shop. I suppose they could be up to six months old.

[6079Winston]

If you are shooting a TRG it might be a broken roll pin in the firing pin / striker assembly. A friend of mine had that happen to his. I have no idea how much powder a .338 LM uses, but 75 gr seems light to me. If you are below the minimum recommended starting loads you may be having hangfires due to a too light charge of slow burning powder, which is very dangerous. Check your data and make sure that load is at or above the minimum recommended starting load.

[Bolt2Bounce]

I agree light loads in magnum case with slow burning powder can BLOW Up your gun... Do not go below recommended starting charges in the manual..... My guess is a bad batch of primers... if it is your primer seating depth (primers seated too High) usually they misfire altogether... and you have to drop the hammer a second time to get ignition...B2B

[mrkubota]

http://www.lapua.com/fileadmin/user_upload/esitteet/VihtavuoriInternationalReloguideJuly2008.pdf

Though the load is at the minimum recommended by VV, I agree that you probably should start a little hotter than that:
Here are some examples of popular loads for the TRG .338LM from another site:

http://www.thefiringline.com/forums/showthread.php?p=2771987

Too, I've had issues with the CCI primer cups being a little too hard for some rifles. I've had better reliability with the FED 215 primers.

[BillyGoatMachine]

If you are shooting a TRG it might be a broken roll pin in the firing pin / striker assembly. A friend of mine had that happen to his. I have no idea how much powder a .338 LM uses, but 75 gr seems light to me. If you are below the minimum recommended starting loads you may be having hangfires due to a too light charge of slow burning powder, which is very dangerous. Check your data and make sure that load is at or above the minimum recommended starting load.

Im shooting through an Armalite AR-30. I did start my loads with the minimum powder load. Maybe I'll bump it up a few grains(2 to start). Again, only 3 out of 50 had the delay. Because I was using the minimum load, could the powder have bunched up to the front of the bullet, causing the delay because there wasn't enough powder right next to the primer? I picked up some federal 215 primers this afternoon so hopefully it will fix the problem. I'm still really curious as to what would cause the delay. I'm sure I'll get rid of the problem, but would still like to know.

[r08ert209cali]

do the case necks look ok ? sounds like a possible pressure problem. Is there unusual recoil?

[BillyGoatMachine]

do the case necks look ok ? sounds like a possible pressure problem. Is there unusual recoil?

case necks look fine. nothing different about them. The recoil was the same as the factory remington rounds that I started with that day. That gun has very minor recoil with the huge muzzle break.

[tteng]

Beelzy mentioned another possible issue: the shoulder/or mouth of the case might be too short for the chamber (one thing you can do is to compare ejected case's shoulder/and case length w/ your load's)

I don't know AR30/338LM operation (I'm assuming the headspace is at the cartridge shoulder), could it be the cartridge shoulder was not touching the chamber surface when chambered, thus the push-forward/delay-firing.

For my bolt gun,
I usually do the standard full-sizing (w/ both new and used brass) setup: raise shell-holder all the way up, screw down the die until it touches the shell-holder, lower the shell-holder, screw down 1/4-turn more and lock the die.

For my rim-less dummy-round (& to find exact headspace w/o a gauge), I will full-size w/ die set high, chamber the case(no bullet) by hand and gently rotate the bolt, if (usually) the bolt won't lock, remove and re-size the case w/ die set a bit lower. Repeat until the bolt will lock w/o effort. I do the same w/ bullet seater die for my dummy-round OAL (minus 0.005-0.01" for actual round OAL).

[rksimple]

Beelzy mentioned another possible issue: the shoulder/or mouth of the case might be too short for the chamber (one thing you can do is to compare ejected case's shoulder/and case length w/ your load's)

I don't know AR30/338LM operation (I'm assuming the headspace is at the cartridge shoulder), could it be the cartridge shoulder was not touching the chamber surface when chambered, thus the push-forward/delay-firing.

This isn't really a problem with a rifle that has an ejector (other than the firing pin not touching the primer). With an oversized case, the ejector just pushes the round forward, leaving more space at the boltface. This is how case stretching occurs at the web.