Defiance classic issue

[Dmagna]

Anyone else have issues using defiance prefits on a classic? I just put together a dasher and I don't believe it's a headspace or chamber issue. The reason why is because I have tried two barrels on the rifle. One proof research and one snowy mountain, both are producing heavy ejector marks on the cases.

I am using 32 gr varget with alpha brass in an alpha chamber. 105 bergers are at 2860 fps with a 26" barrel.

Has anyone seen this issue with a defiance action and if so how do I fix it? No other pressure signs but ejector swipes.

 

[Rodbolt]

Pics don't do much for diagnosis but micrometer (not dial calipers) brass measurements before and after would help. Did you do a cerrosafe chamber cast for headspace and throat? Just a big guess but looks to be the result of a stiff fire forming load with excessive headspace.

 

[Dmagna]

Pics don't do much for diagnosis but micrometer (not dial calipers) brass measurements before and after would help. Did you do a cerrosafe chamber cast for headspace and throat? Just a big guess but looks to be the result of a stiff fire forming load with excessive headspace.

Unfired alpha brass is 2.254 fired brass is 2.260, that's using the hornady 350 comparitor

 

[dustbag]

Assuming.030 off with 105s that's where mine likes them. For my rifles 32 grain is getting up there. I run 31.4 in a Bart 28" at 2900.
Also did u check with go/no gauge just to be sure.

 

[Dmagna]

Assuming.030 off with 105s that's where mine likes them. For my rifles 32 grain is getting up there. I run 31.4 in a Bart 28" at 2900.
Also did u check with go/no gauge just to be sure.

I don't have any for the dasher

 

[dustbag]

If it was mine I would check that. Could back off half grain and see if it still does it too. If you want I could borrow you a go gauge to check it. PM me if you want to try it.
Dustin

 

[Dmagna]

Returning the action for inspection. Swipes continued all the way down to 30.5 grains. Something definitely not right

 

[Justice1327]

I have ~15 defiance actions…I think they are great at the price I paid. However, they are known to have a bur or rough edge around the plunger hole

 

[Rodbolt]

I only have 4 Defiance actions but they are stellar. Have Stolle, Bat, Nesika, Kelbley, Shilen actions too and never a problem. Will never do pre-fit, shouldered barrels though so I'd save my shipping fee on sending the action back and take the barreled action to a benchrest gunsmith for a diagnosis and fix. Sorry for your issues, sucks.

 

[Dmagna]

I only have 4 Defiance actions but they are stellar. Have Stolle, Bat, Nesika, Kelbley, Shilen actions too and never a problem. Will never do pre-fit, shouldered barrels though so I'd save my shipping fee on sending the action back and take the barreled action to a benchrest gunsmith for a diagnosis and fix. Sorry for your issues, sucks.

They paid for the shipping. I guess this is part of the headspace guarantee. Both barrels can't have issues, especially with such a low charge weight. The ejector marks we so bad I don't think I can reuse the brass. Has to be something wrong with the bolt

 

[highdrum]

Virgin brass? Your primers are still round. You say you're getting near 0.006 growth on shoulder? That's deeper than should be but oh well. What's likely going on here the firing pin/ejector are pushing the case forward, upon ignition it shoves the case head back against the bolt, known as bolt slap. Alpha gives ejector marks pretty regularly upon first firing.
Check the spring psi on your ejector, you should be able to depress it with you thumb nail, if not pull the ejector and trim half a coil at a time till it's compressable with your thumb nail.

Alpha dasher doesn't hold the powder volume nor grip the chamber as well as lapua. You won't be able to run the 2910-2950 that some guys do with lapua. Lots of guys run alpha dasher around 2820-2850 w/ 105s, usually 31.Xgr varget.

 

[huntinfool18]

I've got 7 of the classic actions, no issues as of yet. They are just as good as any other the other defiance actions I've messed with.
Havent used any prefits, all barrels have been fitted for that specific action.

 

[Dmagna]

Virgin brass? Your primers are still round. You say you're getting near 0.006 growth on shoulder? That's deeper than should be but oh well. What's likely going on here the firing pin/ejector are pushing the case forward, upon ignition it shoves the case head back against the bolt, known as bolt slap. Alpha gives ejector marks pretty regularly upon first firing.
Check the spring psi on your ejector, you should be able to depress it with you thumb nail, if not pull the ejector and trim half a coil at a time till it's compressable with your thumb nail.

Alpha dasher doesn't hold the powder volume nor grip the chamber as well as lapua. You won't be able to run the 2910-2950 that some guys do with lapua. Lots of guys run alpha dasher around 2820-2850 w/ 105s, usually 31.Xgr varget.

I was running it at around 2750 and the ejector marks were still very bad. Very large burrs on brass on every firing

 

[Rodbolt]

Virgin brass? Your primers are still round. You say you're getting near 0.006 growth on shoulder? That's deeper than should be but oh well. What's likely going on here the firing pin/ejector are pushing the case forward, upon ignition it shoves the case head back against the bolt, known as bolt slap. Alpha gives ejector marks pretty regularly upon first firing.
Check the spring psi on your ejector, you should be able to depress it with you thumb nail, if not pull the ejector and trim half a coil at a time till it's compressable with your thumb nail.

Alpha dasher doesn't hold the powder volume nor grip the chamber as well as lapua. You won't be able to run the 2910-2950 that some guys do with lapua. Lots of guys run alpha dasher around 2820-2850 w/ 105s, usually 31.Xgr varget.

I agree with your entire post. Only thing I might add is that fps - speed is barrel dependent and there are plenty of 28 and 30" barrels used to get speeds pasted.